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91447636 | 1 | /* |
2d21ac55 | 2 | * Copyright (c) 2000-2007 Apple Inc. All rights reserved. |
91447636 | 3 | * |
2d21ac55 | 4 | * @APPLE_OSREFERENCE_LICENSE_HEADER_START@ |
91447636 | 5 | * |
2d21ac55 A |
6 | * This file contains Original Code and/or Modifications of Original Code |
7 | * as defined in and that are subject to the Apple Public Source License | |
8 | * Version 2.0 (the 'License'). You may not use this file except in | |
9 | * compliance with the License. The rights granted to you under the License | |
10 | * may not be used to create, or enable the creation or redistribution of, | |
11 | * unlawful or unlicensed copies of an Apple operating system, or to | |
12 | * circumvent, violate, or enable the circumvention or violation of, any | |
13 | * terms of an Apple operating system software license agreement. | |
8f6c56a5 | 14 | * |
2d21ac55 A |
15 | * Please obtain a copy of the License at |
16 | * http://www.opensource.apple.com/apsl/ and read it before using this file. | |
17 | * | |
18 | * The Original Code and all software distributed under the License are | |
19 | * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER | |
8f6c56a5 A |
20 | * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, |
21 | * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, | |
2d21ac55 A |
22 | * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. |
23 | * Please see the License for the specific language governing rights and | |
24 | * limitations under the License. | |
8f6c56a5 | 25 | * |
2d21ac55 | 26 | * @APPLE_OSREFERENCE_LICENSE_HEADER_END@ |
91447636 A |
27 | */ |
28 | /* | |
29 | * @OSF_COPYRIGHT@ | |
30 | */ | |
31 | /* | |
32 | * Mach Operating System | |
33 | * Copyright (c) 1991,1990,1989,1988,1987 Carnegie Mellon University | |
34 | * All Rights Reserved. | |
35 | * | |
36 | * Permission to use, copy, modify and distribute this software and its | |
37 | * documentation is hereby granted, provided that both the copyright | |
38 | * notice and this permission notice appear in all copies of the | |
39 | * software, derivative works or modified versions, and any portions | |
40 | * thereof, and that both notices appear in supporting documentation. | |
41 | * | |
42 | * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" | |
43 | * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR | |
44 | * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. | |
45 | * | |
46 | * Carnegie Mellon requests users of this software to return to | |
47 | * | |
48 | * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU | |
49 | * School of Computer Science | |
50 | * Carnegie Mellon University | |
51 | * Pittsburgh PA 15213-3890 | |
52 | * | |
53 | * any improvements or extensions that they make and grant Carnegie Mellon | |
54 | * the rights to redistribute these changes. | |
55 | */ | |
56 | /* | |
57 | * File: kern/lock.c | |
58 | * Author: Avadis Tevanian, Jr., Michael Wayne Young | |
59 | * Date: 1985 | |
60 | * | |
61 | * Locking primitives implementation | |
62 | */ | |
63 | ||
64 | #include <mach_kdb.h> | |
65 | #include <mach_ldebug.h> | |
66 | ||
67 | #include <kern/kalloc.h> | |
68 | #include <kern/lock.h> | |
69 | #include <kern/locks.h> | |
70 | #include <kern/misc_protos.h> | |
71 | #include <kern/thread.h> | |
72 | #include <kern/processor.h> | |
73 | #include <kern/sched_prim.h> | |
74 | #include <kern/xpr.h> | |
75 | #include <kern/debug.h> | |
76 | #include <string.h> | |
77 | ||
78 | #if MACH_KDB | |
79 | #include <ddb/db_command.h> | |
80 | #include <ddb/db_output.h> | |
81 | #include <ddb/db_sym.h> | |
82 | #include <ddb/db_print.h> | |
83 | #endif /* MACH_KDB */ | |
84 | ||
85 | #ifdef __ppc__ | |
86 | #include <ppc/Firmware.h> | |
87 | #endif | |
88 | ||
89 | #include <sys/kdebug.h> | |
90 | ||
2d21ac55 A |
91 | /* |
92 | * We need only enough declarations from the BSD-side to be able to | |
93 | * test if our probe is active, and to call __dtrace_probe(). Setting | |
94 | * NEED_DTRACE_DEFS gets a local copy of those definitions pulled in. | |
95 | * | |
96 | * Note that if CONFIG_DTRACE is off, the include file below stubs out | |
97 | * the code hooks here. | |
98 | */ | |
99 | #if CONFIG_DTRACE | |
100 | #define NEED_DTRACE_DEFS | |
101 | #include <../bsd/sys/lockstat.h> | |
102 | #endif | |
103 | ||
91447636 A |
104 | #define LCK_RW_LCK_EXCLUSIVE_CODE 0x100 |
105 | #define LCK_RW_LCK_EXCLUSIVE1_CODE 0x101 | |
106 | #define LCK_RW_LCK_SHARED_CODE 0x102 | |
107 | #define LCK_RW_LCK_SH_TO_EX_CODE 0x103 | |
108 | #define LCK_RW_LCK_SH_TO_EX1_CODE 0x104 | |
109 | #define LCK_RW_LCK_EX_TO_SH_CODE 0x105 | |
110 | ||
111 | ||
112 | #define ANY_LOCK_DEBUG (USLOCK_DEBUG || LOCK_DEBUG || MUTEX_DEBUG) | |
113 | ||
114 | unsigned int lock_wait_time[2] = { (unsigned int)-1, 0 } ; | |
115 | ||
116 | /* Forwards */ | |
117 | ||
118 | ||
119 | #if USLOCK_DEBUG | |
120 | /* | |
121 | * Perform simple lock checks. | |
122 | */ | |
123 | int uslock_check = 1; | |
124 | int max_lock_loops = 100000000; | |
125 | decl_simple_lock_data(extern , printf_lock) | |
126 | decl_simple_lock_data(extern , panic_lock) | |
127 | #if MACH_KDB | |
128 | decl_simple_lock_data(extern , kdb_lock) | |
129 | #endif /* MACH_KDB */ | |
130 | #endif /* USLOCK_DEBUG */ | |
131 | ||
132 | ||
133 | /* | |
134 | * We often want to know the addresses of the callers | |
135 | * of the various lock routines. However, this information | |
136 | * is only used for debugging and statistics. | |
137 | */ | |
138 | typedef void *pc_t; | |
139 | #define INVALID_PC ((void *) VM_MAX_KERNEL_ADDRESS) | |
140 | #define INVALID_THREAD ((void *) VM_MAX_KERNEL_ADDRESS) | |
141 | #if ANY_LOCK_DEBUG | |
142 | #define OBTAIN_PC(pc,l) ((pc) = (void *) GET_RETURN_PC(&(l))) | |
143 | #else /* ANY_LOCK_DEBUG */ | |
144 | #ifdef lint | |
145 | /* | |
146 | * Eliminate lint complaints about unused local pc variables. | |
147 | */ | |
148 | #define OBTAIN_PC(pc,l) ++pc | |
149 | #else /* lint */ | |
150 | #define OBTAIN_PC(pc,l) | |
151 | #endif /* lint */ | |
152 | #endif /* USLOCK_DEBUG */ | |
153 | ||
154 | ||
155 | /* | |
156 | * Portable lock package implementation of usimple_locks. | |
157 | */ | |
158 | ||
159 | #if USLOCK_DEBUG | |
160 | #define USLDBG(stmt) stmt | |
161 | void usld_lock_init(usimple_lock_t, unsigned short); | |
162 | void usld_lock_pre(usimple_lock_t, pc_t); | |
163 | void usld_lock_post(usimple_lock_t, pc_t); | |
164 | void usld_unlock(usimple_lock_t, pc_t); | |
165 | void usld_lock_try_pre(usimple_lock_t, pc_t); | |
166 | void usld_lock_try_post(usimple_lock_t, pc_t); | |
2d21ac55 | 167 | int usld_lock_common_checks(usimple_lock_t, const char *); |
91447636 A |
168 | #else /* USLOCK_DEBUG */ |
169 | #define USLDBG(stmt) | |
170 | #endif /* USLOCK_DEBUG */ | |
171 | ||
172 | /* | |
173 | * Routine: lck_spin_alloc_init | |
174 | */ | |
175 | lck_spin_t * | |
176 | lck_spin_alloc_init( | |
177 | lck_grp_t *grp, | |
178 | lck_attr_t *attr) { | |
179 | lck_spin_t *lck; | |
180 | ||
181 | if ((lck = (lck_spin_t *)kalloc(sizeof(lck_spin_t))) != 0) | |
182 | lck_spin_init(lck, grp, attr); | |
183 | ||
184 | return(lck); | |
185 | } | |
186 | ||
187 | /* | |
188 | * Routine: lck_spin_free | |
189 | */ | |
190 | void | |
191 | lck_spin_free( | |
192 | lck_spin_t *lck, | |
193 | lck_grp_t *grp) { | |
194 | lck_spin_destroy(lck, grp); | |
195 | kfree((void *)lck, sizeof(lck_spin_t)); | |
196 | } | |
197 | ||
198 | /* | |
199 | * Routine: lck_spin_init | |
200 | */ | |
201 | void | |
202 | lck_spin_init( | |
203 | lck_spin_t *lck, | |
204 | lck_grp_t *grp, | |
205 | __unused lck_attr_t *attr) { | |
206 | ||
207 | lck->interlock = 0; | |
208 | lck_grp_reference(grp); | |
209 | lck_grp_lckcnt_incr(grp, LCK_TYPE_SPIN); | |
210 | } | |
211 | ||
212 | /* | |
213 | * Routine: lck_spin_destroy | |
214 | */ | |
215 | void | |
216 | lck_spin_destroy( | |
217 | lck_spin_t *lck, | |
218 | lck_grp_t *grp) { | |
219 | if (lck->interlock == LCK_SPIN_TAG_DESTROYED) | |
220 | return; | |
221 | lck->interlock = LCK_SPIN_TAG_DESTROYED; | |
222 | lck_grp_lckcnt_decr(grp, LCK_TYPE_SPIN); | |
223 | lck_grp_deallocate(grp); | |
224 | } | |
225 | ||
226 | /* | |
227 | * Initialize a usimple_lock. | |
228 | * | |
229 | * No change in preemption state. | |
230 | */ | |
231 | void | |
232 | usimple_lock_init( | |
233 | usimple_lock_t l, | |
234 | unsigned short tag) | |
235 | { | |
236 | #ifndef MACHINE_SIMPLE_LOCK | |
237 | USLDBG(usld_lock_init(l, tag)); | |
238 | hw_lock_init(&l->interlock); | |
239 | #else | |
240 | simple_lock_init((simple_lock_t)l,tag); | |
241 | #endif | |
242 | } | |
243 | ||
244 | ||
245 | /* | |
246 | * Acquire a usimple_lock. | |
247 | * | |
248 | * Returns with preemption disabled. Note | |
249 | * that the hw_lock routines are responsible for | |
250 | * maintaining preemption state. | |
251 | */ | |
252 | void | |
253 | usimple_lock( | |
254 | usimple_lock_t l) | |
255 | { | |
256 | #ifndef MACHINE_SIMPLE_LOCK | |
91447636 | 257 | pc_t pc; |
91447636 A |
258 | |
259 | OBTAIN_PC(pc, l); | |
260 | USLDBG(usld_lock_pre(l, pc)); | |
261 | ||
262 | if(!hw_lock_to(&l->interlock, LockTimeOut)) /* Try to get the lock with a timeout */ | |
2d21ac55 | 263 | panic("simple lock deadlock detection - l=%p, cpu=%d, ret=%p", l, cpu_number(), pc); |
91447636 A |
264 | |
265 | USLDBG(usld_lock_post(l, pc)); | |
266 | #else | |
267 | simple_lock((simple_lock_t)l); | |
268 | #endif | |
269 | } | |
270 | ||
271 | ||
272 | /* | |
273 | * Release a usimple_lock. | |
274 | * | |
275 | * Returns with preemption enabled. Note | |
276 | * that the hw_lock routines are responsible for | |
277 | * maintaining preemption state. | |
278 | */ | |
279 | void | |
280 | usimple_unlock( | |
281 | usimple_lock_t l) | |
282 | { | |
283 | #ifndef MACHINE_SIMPLE_LOCK | |
284 | pc_t pc; | |
285 | ||
286 | OBTAIN_PC(pc, l); | |
287 | USLDBG(usld_unlock(l, pc)); | |
288 | sync(); | |
289 | hw_lock_unlock(&l->interlock); | |
290 | #else | |
291 | simple_unlock_rwmb((simple_lock_t)l); | |
292 | #endif | |
293 | } | |
294 | ||
295 | ||
296 | /* | |
297 | * Conditionally acquire a usimple_lock. | |
298 | * | |
299 | * On success, returns with preemption disabled. | |
300 | * On failure, returns with preemption in the same state | |
301 | * as when first invoked. Note that the hw_lock routines | |
302 | * are responsible for maintaining preemption state. | |
303 | * | |
304 | * XXX No stats are gathered on a miss; I preserved this | |
305 | * behavior from the original assembly-language code, but | |
306 | * doesn't it make sense to log misses? XXX | |
307 | */ | |
308 | unsigned int | |
309 | usimple_lock_try( | |
310 | usimple_lock_t l) | |
311 | { | |
312 | #ifndef MACHINE_SIMPLE_LOCK | |
313 | pc_t pc; | |
314 | unsigned int success; | |
315 | ||
316 | OBTAIN_PC(pc, l); | |
317 | USLDBG(usld_lock_try_pre(l, pc)); | |
2d21ac55 A |
318 | success = hw_lock_try(&l->interlock); |
319 | if (success) | |
91447636 | 320 | USLDBG(usld_lock_try_post(l, pc)); |
91447636 A |
321 | return success; |
322 | #else | |
323 | return(simple_lock_try((simple_lock_t)l)); | |
324 | #endif | |
325 | } | |
326 | ||
327 | #if USLOCK_DEBUG | |
328 | /* | |
329 | * States of a usimple_lock. The default when initializing | |
330 | * a usimple_lock is setting it up for debug checking. | |
331 | */ | |
332 | #define USLOCK_CHECKED 0x0001 /* lock is being checked */ | |
333 | #define USLOCK_TAKEN 0x0002 /* lock has been taken */ | |
334 | #define USLOCK_INIT 0xBAA0 /* lock has been initialized */ | |
335 | #define USLOCK_INITIALIZED (USLOCK_INIT|USLOCK_CHECKED) | |
336 | #define USLOCK_CHECKING(l) (uslock_check && \ | |
337 | ((l)->debug.state & USLOCK_CHECKED)) | |
338 | ||
339 | /* | |
340 | * Trace activities of a particularly interesting lock. | |
341 | */ | |
342 | void usl_trace(usimple_lock_t, int, pc_t, const char *); | |
343 | ||
344 | ||
345 | /* | |
346 | * Initialize the debugging information contained | |
347 | * in a usimple_lock. | |
348 | */ | |
349 | void | |
350 | usld_lock_init( | |
351 | usimple_lock_t l, | |
2d21ac55 | 352 | __unused unsigned short tag) |
91447636 A |
353 | { |
354 | if (l == USIMPLE_LOCK_NULL) | |
355 | panic("lock initialization: null lock pointer"); | |
356 | l->lock_type = USLOCK_TAG; | |
357 | l->debug.state = uslock_check ? USLOCK_INITIALIZED : 0; | |
358 | l->debug.lock_cpu = l->debug.unlock_cpu = 0; | |
359 | l->debug.lock_pc = l->debug.unlock_pc = INVALID_PC; | |
360 | l->debug.lock_thread = l->debug.unlock_thread = INVALID_THREAD; | |
361 | l->debug.duration[0] = l->debug.duration[1] = 0; | |
362 | l->debug.unlock_cpu = l->debug.unlock_cpu = 0; | |
363 | l->debug.unlock_pc = l->debug.unlock_pc = INVALID_PC; | |
364 | l->debug.unlock_thread = l->debug.unlock_thread = INVALID_THREAD; | |
365 | } | |
366 | ||
367 | ||
368 | /* | |
369 | * These checks apply to all usimple_locks, not just | |
370 | * those with USLOCK_CHECKED turned on. | |
371 | */ | |
372 | int | |
2d21ac55 | 373 | usld_lock_common_checks(usimple_lock_t l, const char *caller) |
91447636 A |
374 | { |
375 | if (l == USIMPLE_LOCK_NULL) | |
376 | panic("%s: null lock pointer", caller); | |
377 | if (l->lock_type != USLOCK_TAG) | |
378 | panic("%s: 0x%x is not a usimple lock", caller, (integer_t) l); | |
379 | if (!(l->debug.state & USLOCK_INIT)) | |
380 | panic("%s: 0x%x is not an initialized lock", | |
381 | caller, (integer_t) l); | |
382 | return USLOCK_CHECKING(l); | |
383 | } | |
384 | ||
385 | ||
386 | /* | |
387 | * Debug checks on a usimple_lock just before attempting | |
388 | * to acquire it. | |
389 | */ | |
390 | /* ARGSUSED */ | |
391 | void | |
392 | usld_lock_pre( | |
393 | usimple_lock_t l, | |
394 | pc_t pc) | |
395 | { | |
2d21ac55 | 396 | const char *caller = "usimple_lock"; |
91447636 A |
397 | |
398 | if (!usld_lock_common_checks(l, caller)) | |
399 | return; | |
400 | ||
401 | /* | |
402 | * Note that we have a weird case where we are getting a lock when we are] | |
403 | * in the process of putting the system to sleep. We are running with no | |
404 | * current threads, therefore we can't tell if we are trying to retake a lock | |
405 | * we have or someone on the other processor has it. Therefore we just | |
406 | * ignore this test if the locking thread is 0. | |
407 | */ | |
408 | ||
409 | if ((l->debug.state & USLOCK_TAKEN) && l->debug.lock_thread && | |
410 | l->debug.lock_thread == (void *) current_thread()) { | |
2d21ac55 | 411 | printf("%s: lock 0x%x already locked (at %p) by", |
91447636 | 412 | caller, (integer_t) l, l->debug.lock_pc); |
2d21ac55 | 413 | printf(" current thread %p (new attempt at pc %p)\n", |
91447636 | 414 | l->debug.lock_thread, pc); |
2d21ac55 | 415 | panic("%s", caller); |
91447636 A |
416 | } |
417 | mp_disable_preemption(); | |
418 | usl_trace(l, cpu_number(), pc, caller); | |
419 | mp_enable_preemption(); | |
420 | } | |
421 | ||
422 | ||
423 | /* | |
424 | * Debug checks on a usimple_lock just after acquiring it. | |
425 | * | |
426 | * Pre-emption has been disabled at this point, | |
427 | * so we are safe in using cpu_number. | |
428 | */ | |
429 | void | |
430 | usld_lock_post( | |
431 | usimple_lock_t l, | |
432 | pc_t pc) | |
433 | { | |
2d21ac55 A |
434 | int mycpu; |
435 | const char *caller = "successful usimple_lock"; | |
91447636 A |
436 | |
437 | ||
438 | if (!usld_lock_common_checks(l, caller)) | |
439 | return; | |
440 | ||
441 | if (!((l->debug.state & ~USLOCK_TAKEN) == USLOCK_INITIALIZED)) | |
442 | panic("%s: lock 0x%x became uninitialized", | |
443 | caller, (integer_t) l); | |
444 | if ((l->debug.state & USLOCK_TAKEN)) | |
445 | panic("%s: lock 0x%x became TAKEN by someone else", | |
446 | caller, (integer_t) l); | |
447 | ||
448 | mycpu = cpu_number(); | |
449 | l->debug.lock_thread = (void *)current_thread(); | |
450 | l->debug.state |= USLOCK_TAKEN; | |
451 | l->debug.lock_pc = pc; | |
452 | l->debug.lock_cpu = mycpu; | |
453 | ||
454 | usl_trace(l, mycpu, pc, caller); | |
455 | } | |
456 | ||
457 | ||
458 | /* | |
459 | * Debug checks on a usimple_lock just before | |
460 | * releasing it. Note that the caller has not | |
461 | * yet released the hardware lock. | |
462 | * | |
463 | * Preemption is still disabled, so there's | |
464 | * no problem using cpu_number. | |
465 | */ | |
466 | void | |
467 | usld_unlock( | |
468 | usimple_lock_t l, | |
469 | pc_t pc) | |
470 | { | |
2d21ac55 A |
471 | int mycpu; |
472 | const char *caller = "usimple_unlock"; | |
91447636 A |
473 | |
474 | ||
475 | if (!usld_lock_common_checks(l, caller)) | |
476 | return; | |
477 | ||
478 | mycpu = cpu_number(); | |
479 | ||
480 | if (!(l->debug.state & USLOCK_TAKEN)) | |
481 | panic("%s: lock 0x%x hasn't been taken", | |
482 | caller, (integer_t) l); | |
483 | if (l->debug.lock_thread != (void *) current_thread()) | |
2d21ac55 | 484 | panic("%s: unlocking lock 0x%x, owned by thread %p", |
91447636 A |
485 | caller, (integer_t) l, l->debug.lock_thread); |
486 | if (l->debug.lock_cpu != mycpu) { | |
487 | printf("%s: unlocking lock 0x%x on cpu 0x%x", | |
488 | caller, (integer_t) l, mycpu); | |
489 | printf(" (acquired on cpu 0x%x)\n", l->debug.lock_cpu); | |
2d21ac55 | 490 | panic("%s", caller); |
91447636 A |
491 | } |
492 | usl_trace(l, mycpu, pc, caller); | |
493 | ||
494 | l->debug.unlock_thread = l->debug.lock_thread; | |
495 | l->debug.lock_thread = INVALID_PC; | |
496 | l->debug.state &= ~USLOCK_TAKEN; | |
497 | l->debug.unlock_pc = pc; | |
498 | l->debug.unlock_cpu = mycpu; | |
499 | } | |
500 | ||
501 | ||
502 | /* | |
503 | * Debug checks on a usimple_lock just before | |
504 | * attempting to acquire it. | |
505 | * | |
506 | * Preemption isn't guaranteed to be disabled. | |
507 | */ | |
508 | void | |
509 | usld_lock_try_pre( | |
510 | usimple_lock_t l, | |
511 | pc_t pc) | |
512 | { | |
2d21ac55 | 513 | const char *caller = "usimple_lock_try"; |
91447636 A |
514 | |
515 | if (!usld_lock_common_checks(l, caller)) | |
516 | return; | |
517 | mp_disable_preemption(); | |
518 | usl_trace(l, cpu_number(), pc, caller); | |
519 | mp_enable_preemption(); | |
520 | } | |
521 | ||
522 | ||
523 | /* | |
524 | * Debug checks on a usimple_lock just after | |
525 | * successfully attempting to acquire it. | |
526 | * | |
527 | * Preemption has been disabled by the | |
528 | * lock acquisition attempt, so it's safe | |
529 | * to use cpu_number. | |
530 | */ | |
531 | void | |
532 | usld_lock_try_post( | |
533 | usimple_lock_t l, | |
534 | pc_t pc) | |
535 | { | |
2d21ac55 A |
536 | int mycpu; |
537 | const char *caller = "successful usimple_lock_try"; | |
91447636 A |
538 | |
539 | if (!usld_lock_common_checks(l, caller)) | |
540 | return; | |
541 | ||
542 | if (!((l->debug.state & ~USLOCK_TAKEN) == USLOCK_INITIALIZED)) | |
543 | panic("%s: lock 0x%x became uninitialized", | |
544 | caller, (integer_t) l); | |
545 | if ((l->debug.state & USLOCK_TAKEN)) | |
546 | panic("%s: lock 0x%x became TAKEN by someone else", | |
547 | caller, (integer_t) l); | |
548 | ||
549 | mycpu = cpu_number(); | |
550 | l->debug.lock_thread = (void *) current_thread(); | |
551 | l->debug.state |= USLOCK_TAKEN; | |
552 | l->debug.lock_pc = pc; | |
553 | l->debug.lock_cpu = mycpu; | |
554 | ||
555 | usl_trace(l, mycpu, pc, caller); | |
556 | } | |
557 | ||
558 | ||
559 | /* | |
560 | * For very special cases, set traced_lock to point to a | |
561 | * specific lock of interest. The result is a series of | |
562 | * XPRs showing lock operations on that lock. The lock_seq | |
563 | * value is used to show the order of those operations. | |
564 | */ | |
565 | usimple_lock_t traced_lock; | |
566 | unsigned int lock_seq; | |
567 | ||
568 | void | |
569 | usl_trace( | |
570 | usimple_lock_t l, | |
571 | int mycpu, | |
572 | pc_t pc, | |
573 | const char * op_name) | |
574 | { | |
575 | if (traced_lock == l) { | |
576 | XPR(XPR_SLOCK, | |
577 | "seq %d, cpu %d, %s @ %x\n", | |
578 | (integer_t) lock_seq, (integer_t) mycpu, | |
579 | (integer_t) op_name, (integer_t) pc, 0); | |
580 | lock_seq++; | |
581 | } | |
582 | } | |
583 | ||
584 | ||
585 | #endif /* USLOCK_DEBUG */ | |
586 | ||
587 | /* | |
588 | * The C portion of the shared/exclusive locks package. | |
589 | */ | |
590 | ||
591 | /* | |
592 | * Forward definition | |
593 | */ | |
594 | ||
595 | void lck_rw_lock_exclusive_gen( | |
596 | lck_rw_t *lck); | |
597 | ||
598 | lck_rw_type_t lck_rw_done_gen( | |
599 | lck_rw_t *lck); | |
600 | ||
601 | void | |
602 | lck_rw_lock_shared_gen( | |
603 | lck_rw_t *lck); | |
604 | ||
605 | boolean_t | |
606 | lck_rw_lock_shared_to_exclusive_gen( | |
607 | lck_rw_t *lck); | |
608 | ||
609 | void | |
610 | lck_rw_lock_exclusive_to_shared_gen( | |
611 | lck_rw_t *lck); | |
612 | ||
613 | boolean_t | |
614 | lck_rw_try_lock_exclusive_gen( | |
615 | lck_rw_t *lck); | |
616 | ||
617 | boolean_t | |
618 | lck_rw_try_lock_shared_gen( | |
619 | lck_rw_t *lck); | |
620 | ||
621 | void lck_rw_ext_init( | |
622 | lck_rw_ext_t *lck, | |
623 | lck_grp_t *grp, | |
624 | lck_attr_t *attr); | |
625 | ||
626 | void lck_rw_ext_backtrace( | |
627 | lck_rw_ext_t *lck); | |
628 | ||
629 | void lck_rw_lock_exclusive_ext( | |
630 | lck_rw_ext_t *lck, | |
631 | lck_rw_t *rlck); | |
632 | ||
633 | lck_rw_type_t lck_rw_done_ext( | |
634 | lck_rw_ext_t *lck, | |
635 | lck_rw_t *rlck); | |
636 | ||
637 | void | |
638 | lck_rw_lock_shared_ext( | |
639 | lck_rw_ext_t *lck, | |
640 | lck_rw_t *rlck); | |
641 | ||
642 | boolean_t | |
643 | lck_rw_lock_shared_to_exclusive_ext( | |
644 | lck_rw_ext_t *lck, | |
645 | lck_rw_t *rlck); | |
646 | ||
647 | void | |
648 | lck_rw_lock_exclusive_to_shared_ext( | |
649 | lck_rw_ext_t *lck, | |
650 | lck_rw_t *rlck); | |
651 | ||
652 | boolean_t | |
653 | lck_rw_try_lock_exclusive_ext( | |
654 | lck_rw_ext_t *lck, | |
655 | lck_rw_t *rlck); | |
656 | ||
657 | boolean_t | |
658 | lck_rw_try_lock_shared_ext( | |
659 | lck_rw_ext_t *lck, | |
660 | lck_rw_t *rlck); | |
661 | ||
662 | void | |
663 | lck_rw_ilk_lock( | |
664 | lck_rw_t *lck); | |
665 | ||
666 | void | |
667 | lck_rw_ilk_unlock( | |
668 | lck_rw_t *lck); | |
669 | ||
670 | void | |
671 | lck_rw_check_type( | |
672 | lck_rw_ext_t *lck, | |
673 | lck_rw_t *rlck); | |
674 | ||
2d21ac55 A |
675 | void |
676 | lck_rw_assert_ext( | |
677 | lck_rw_ext_t *lck, | |
678 | lck_rw_t *rlck, | |
679 | unsigned int type); | |
680 | ||
91447636 A |
681 | /* |
682 | * Routine: lock_alloc | |
683 | * Function: | |
684 | * Allocate a lock for external users who cannot | |
685 | * hard-code the structure definition into their | |
686 | * objects. | |
687 | * For now just use kalloc, but a zone is probably | |
688 | * warranted. | |
689 | */ | |
690 | lock_t * | |
691 | lock_alloc( | |
692 | boolean_t can_sleep, | |
693 | __unused unsigned short tag, | |
694 | __unused unsigned short tag1) | |
695 | { | |
696 | lock_t *lck; | |
697 | ||
698 | if ((lck = (lock_t *)kalloc(sizeof(lock_t))) != 0) | |
699 | lock_init(lck, can_sleep, tag, tag1); | |
700 | return(lck); | |
701 | } | |
702 | ||
703 | /* | |
704 | * Routine: lock_init | |
705 | * Function: | |
706 | * Initialize a lock; required before use. | |
707 | * Note that clients declare the "struct lock" | |
708 | * variables and then initialize them, rather | |
709 | * than getting a new one from this module. | |
710 | */ | |
711 | void | |
712 | lock_init( | |
713 | lock_t *lck, | |
714 | boolean_t can_sleep, | |
715 | __unused unsigned short tag, | |
716 | __unused unsigned short tag1) | |
717 | { | |
718 | if (!can_sleep) | |
719 | panic("lock_init: sleep mode must be set to TRUE\n"); | |
720 | ||
721 | (void) memset((void *) lck, 0, sizeof(lock_t)); | |
722 | #if MACH_LDEBUG | |
723 | lck->lck_rw_deb.type = RW_TAG; | |
724 | lck->lck_rw_attr |= (LCK_RW_ATTR_DEBUG|LCK_RW_ATTR_DIS_THREAD|LCK_RW_ATTR_DIS_MYLOCK); | |
0c530ab8 A |
725 | lck->lck_rw.lck_rw_priv_excl = TRUE; |
726 | #else | |
727 | lck->lck_rw_priv_excl = TRUE; | |
91447636 A |
728 | #endif |
729 | ||
730 | } | |
731 | ||
732 | ||
733 | /* | |
734 | * Routine: lock_free | |
735 | * Function: | |
736 | * Free a lock allocated for external users. | |
737 | * For now just use kfree, but a zone is probably | |
738 | * warranted. | |
739 | */ | |
740 | void | |
741 | lock_free( | |
742 | lock_t *lck) | |
743 | { | |
744 | kfree((void *)lck, sizeof(lock_t)); | |
745 | } | |
746 | ||
747 | #if MACH_LDEBUG | |
748 | void | |
749 | lock_write( | |
750 | lock_t *lck) | |
751 | { | |
752 | lck_rw_lock_exclusive_ext((lck_rw_ext_t *)lck, (lck_rw_t *)lck); | |
753 | } | |
754 | ||
755 | void | |
756 | lock_done( | |
757 | lock_t *lck) | |
758 | { | |
759 | (void)lck_rw_done_ext((lck_rw_ext_t *)lck, (lck_rw_t *)lck); | |
760 | } | |
761 | ||
762 | void | |
763 | lock_read( | |
764 | lock_t *lck) | |
765 | { | |
766 | lck_rw_lock_shared_ext((lck_rw_ext_t *)lck, (lck_rw_t *)lck); | |
767 | } | |
768 | ||
769 | boolean_t | |
770 | lock_read_to_write( | |
771 | lock_t *lck) | |
772 | { | |
773 | return(lck_rw_lock_shared_to_exclusive_ext((lck_rw_ext_t *)lck, (lck_rw_t *)lck)); | |
774 | } | |
775 | ||
776 | void | |
777 | lock_write_to_read( | |
778 | register lock_t *lck) | |
779 | { | |
780 | lck_rw_lock_exclusive_to_shared_ext((lck_rw_ext_t *)lck, (lck_rw_t *)lck); | |
781 | } | |
782 | #endif | |
783 | ||
784 | /* | |
785 | * Routine: lck_rw_alloc_init | |
786 | */ | |
787 | lck_rw_t * | |
788 | lck_rw_alloc_init( | |
789 | lck_grp_t *grp, | |
790 | lck_attr_t *attr) { | |
791 | lck_rw_t *lck; | |
792 | ||
793 | if ((lck = (lck_rw_t *)kalloc(sizeof(lck_rw_t))) != 0) | |
794 | lck_rw_init(lck, grp, attr); | |
795 | ||
796 | return(lck); | |
797 | } | |
798 | ||
799 | /* | |
800 | * Routine: lck_rw_free | |
801 | */ | |
802 | void | |
803 | lck_rw_free( | |
804 | lck_rw_t *lck, | |
805 | lck_grp_t *grp) { | |
806 | lck_rw_destroy(lck, grp); | |
807 | kfree((void *)lck, sizeof(lck_rw_t)); | |
808 | } | |
809 | ||
810 | /* | |
811 | * Routine: lck_rw_init | |
812 | */ | |
813 | void | |
814 | lck_rw_init( | |
815 | lck_rw_t *lck, | |
816 | lck_grp_t *grp, | |
817 | lck_attr_t *attr) { | |
818 | lck_rw_ext_t *lck_ext; | |
819 | lck_attr_t *lck_attr; | |
820 | ||
821 | if (attr != LCK_ATTR_NULL) | |
822 | lck_attr = attr; | |
823 | else | |
824 | lck_attr = &LockDefaultLckAttr; | |
825 | ||
826 | if ((lck_attr->lck_attr_val) & LCK_ATTR_DEBUG) { | |
827 | if ((lck_ext = (lck_rw_ext_t *)kalloc(sizeof(lck_rw_ext_t))) != 0) { | |
828 | lck_rw_ext_init(lck_ext, grp, lck_attr); | |
829 | lck->lck_rw_tag = LCK_RW_TAG_INDIRECT; | |
830 | lck->lck_rw_ptr = lck_ext; | |
831 | } | |
832 | } else { | |
833 | (void) memset((void *) lck, 0, sizeof(lck_rw_t)); | |
0c530ab8 A |
834 | if ((lck_attr->lck_attr_val) & LCK_ATTR_RW_SHARED_PRIORITY) |
835 | lck->lck_rw_priv_excl = FALSE; | |
836 | else | |
837 | lck->lck_rw_priv_excl = TRUE; | |
91447636 A |
838 | } |
839 | ||
840 | lck_grp_reference(grp); | |
841 | lck_grp_lckcnt_incr(grp, LCK_TYPE_RW); | |
842 | } | |
843 | ||
844 | /* | |
845 | * Routine: lck_rw_ext_init | |
846 | */ | |
847 | void | |
848 | lck_rw_ext_init( | |
849 | lck_rw_ext_t *lck, | |
850 | lck_grp_t *grp, | |
851 | lck_attr_t *attr) { | |
852 | ||
853 | bzero((void *)lck, sizeof(lck_rw_ext_t)); | |
0c530ab8 A |
854 | if ((attr->lck_attr_val) & LCK_ATTR_RW_SHARED_PRIORITY) |
855 | lck->lck_rw.lck_rw_priv_excl = FALSE; | |
856 | else | |
857 | lck->lck_rw.lck_rw_priv_excl = TRUE; | |
91447636 A |
858 | |
859 | if ((attr->lck_attr_val) & LCK_ATTR_DEBUG) { | |
860 | lck->lck_rw_deb.type = RW_TAG; | |
861 | lck->lck_rw_attr |= LCK_RW_ATTR_DEBUG; | |
862 | } | |
863 | ||
864 | lck->lck_rw_grp = grp; | |
865 | ||
866 | if (grp->lck_grp_attr & LCK_GRP_ATTR_STAT) | |
867 | lck->lck_rw_attr |= LCK_RW_ATTR_STAT; | |
868 | } | |
869 | ||
870 | /* | |
871 | * Routine: lck_rw_destroy | |
872 | */ | |
873 | void | |
874 | lck_rw_destroy( | |
875 | lck_rw_t *lck, | |
876 | lck_grp_t *grp) { | |
877 | boolean_t lck_is_indirect; | |
878 | ||
879 | if (lck->lck_rw_tag == LCK_RW_TAG_DESTROYED) | |
880 | return; | |
881 | lck_is_indirect = (lck->lck_rw_tag == LCK_RW_TAG_INDIRECT); | |
882 | lck->lck_rw_tag = LCK_RW_TAG_DESTROYED; | |
883 | if (lck_is_indirect) | |
884 | kfree((void *)lck->lck_rw_ptr, sizeof(lck_rw_ext_t)); | |
885 | ||
886 | lck_grp_lckcnt_decr(grp, LCK_TYPE_RW); | |
887 | lck_grp_deallocate(grp); | |
888 | return; | |
889 | } | |
890 | ||
891 | /* | |
892 | * Routine: lck_rw_lock | |
893 | */ | |
894 | void | |
895 | lck_rw_lock( | |
896 | lck_rw_t *lck, | |
897 | lck_rw_type_t lck_rw_type) | |
898 | { | |
899 | if (lck_rw_type == LCK_RW_TYPE_SHARED) | |
900 | lck_rw_lock_shared(lck); | |
901 | else if (lck_rw_type == LCK_RW_TYPE_EXCLUSIVE) | |
902 | lck_rw_lock_exclusive(lck); | |
903 | else | |
904 | panic("lck_rw_lock(): Invalid RW lock type: %d\n", lck_rw_type); | |
905 | } | |
906 | ||
907 | ||
908 | /* | |
909 | * Routine: lck_rw_unlock | |
910 | */ | |
911 | void | |
912 | lck_rw_unlock( | |
913 | lck_rw_t *lck, | |
914 | lck_rw_type_t lck_rw_type) | |
915 | { | |
916 | if (lck_rw_type == LCK_RW_TYPE_SHARED) | |
917 | lck_rw_unlock_shared(lck); | |
918 | else if (lck_rw_type == LCK_RW_TYPE_EXCLUSIVE) | |
919 | lck_rw_unlock_exclusive(lck); | |
920 | else | |
921 | panic("lck_rw_unlock(): Invalid RW lock type: %d\n", lck_rw_type); | |
922 | } | |
923 | ||
924 | ||
925 | /* | |
926 | * Routine: lck_rw_unlock_shared | |
927 | */ | |
928 | void | |
929 | lck_rw_unlock_shared( | |
930 | lck_rw_t *lck) | |
931 | { | |
932 | lck_rw_type_t ret; | |
933 | ||
934 | ret = lck_rw_done(lck); | |
935 | ||
936 | if (ret != LCK_RW_TYPE_SHARED) | |
937 | panic("lck_rw_unlock(): lock held in mode: %d\n", ret); | |
938 | } | |
939 | ||
940 | ||
941 | /* | |
942 | * Routine: lck_rw_unlock_exclusive | |
943 | */ | |
944 | void | |
945 | lck_rw_unlock_exclusive( | |
946 | lck_rw_t *lck) | |
947 | { | |
948 | lck_rw_type_t ret; | |
949 | ||
950 | ret = lck_rw_done(lck); | |
951 | ||
952 | if (ret != LCK_RW_TYPE_EXCLUSIVE) | |
953 | panic("lck_rw_unlock_exclusive(): lock held in mode: %d\n", ret); | |
954 | } | |
955 | ||
956 | ||
957 | /* | |
958 | * Routine: lck_rw_try_lock | |
959 | */ | |
960 | boolean_t | |
961 | lck_rw_try_lock( | |
962 | lck_rw_t *lck, | |
963 | lck_rw_type_t lck_rw_type) | |
964 | { | |
965 | if (lck_rw_type == LCK_RW_TYPE_SHARED) | |
966 | return(lck_rw_try_lock_shared(lck)); | |
967 | else if (lck_rw_type == LCK_RW_TYPE_EXCLUSIVE) | |
968 | return(lck_rw_try_lock_exclusive(lck)); | |
969 | else | |
970 | panic("lck_rw_try_lock(): Invalid rw lock type: %x\n", lck_rw_type); | |
971 | return(FALSE); | |
972 | } | |
973 | ||
974 | ||
975 | ||
976 | /* | |
977 | * Routine: lck_rw_lock_exclusive_gen | |
978 | */ | |
979 | void | |
980 | lck_rw_lock_exclusive_gen( | |
981 | lck_rw_t *lck) | |
982 | { | |
983 | int i; | |
91447636 | 984 | wait_result_t res; |
2d21ac55 A |
985 | #if CONFIG_DTRACE |
986 | uint64_t wait_interval = 0; | |
987 | int slept = 0; | |
988 | int readers_at_sleep; | |
989 | #endif | |
91447636 A |
990 | |
991 | lck_rw_ilk_lock(lck); | |
2d21ac55 A |
992 | #if CONFIG_DTRACE |
993 | readers_at_sleep = lck->lck_rw_shared_cnt; | |
994 | #endif | |
91447636 A |
995 | |
996 | /* | |
997 | * Try to acquire the lck_rw_want_excl bit. | |
998 | */ | |
999 | while (lck->lck_rw_want_excl) { | |
1000 | KERNEL_DEBUG(MACHDBG_CODE(DBG_MACH_LOCKS, LCK_RW_LCK_EXCLUSIVE_CODE) | DBG_FUNC_START, (int)lck, 0, 0, 0, 0); | |
1001 | ||
2d21ac55 A |
1002 | #if CONFIG_DTRACE |
1003 | if ((lockstat_probemap[LS_LCK_RW_LOCK_EXCL_SPIN] || lockstat_probemap[LS_LCK_RW_LOCK_EXCL_BLOCK]) && wait_interval == 0) { | |
1004 | wait_interval = mach_absolute_time(); | |
1005 | } else { | |
1006 | wait_interval = -1; | |
91447636 | 1007 | } |
2d21ac55 | 1008 | #endif |
91447636 A |
1009 | |
1010 | i = lock_wait_time[1]; | |
1011 | if (i != 0) { | |
1012 | lck_rw_ilk_unlock(lck); | |
1013 | while (--i != 0 && lck->lck_rw_want_excl) | |
1014 | continue; | |
1015 | lck_rw_ilk_lock(lck); | |
1016 | } | |
1017 | ||
1018 | if (lck->lck_rw_want_excl) { | |
1019 | lck->lck_rw_waiting = TRUE; | |
1020 | res = assert_wait((event_t)(((unsigned int*)lck)+((sizeof(lck_rw_t)-1)/sizeof(unsigned int))), THREAD_UNINT); | |
1021 | if (res == THREAD_WAITING) { | |
1022 | lck_rw_ilk_unlock(lck); | |
1023 | res = thread_block(THREAD_CONTINUE_NULL); | |
2d21ac55 A |
1024 | #if CONFIG_DTRACE |
1025 | slept = 1; | |
1026 | #endif | |
91447636 A |
1027 | lck_rw_ilk_lock(lck); |
1028 | } | |
1029 | } | |
1030 | KERNEL_DEBUG(MACHDBG_CODE(DBG_MACH_LOCKS, LCK_RW_LCK_EXCLUSIVE_CODE) | DBG_FUNC_END, (int)lck, res, 0, 0, 0); | |
1031 | } | |
1032 | lck->lck_rw_want_excl = TRUE; | |
1033 | ||
1034 | /* Wait for readers (and upgrades) to finish */ | |
1035 | ||
1036 | while ((lck->lck_rw_shared_cnt != 0) || lck->lck_rw_want_upgrade) { | |
91447636 A |
1037 | |
1038 | i = lock_wait_time[1]; | |
1039 | ||
1040 | KERNEL_DEBUG(MACHDBG_CODE(DBG_MACH_LOCKS, LCK_RW_LCK_EXCLUSIVE1_CODE) | DBG_FUNC_START, | |
1041 | (int)lck, lck->lck_rw_shared_cnt, lck->lck_rw_want_upgrade, i, 0); | |
2d21ac55 A |
1042 | #if CONFIG_DTRACE |
1043 | if ((lockstat_probemap[LS_LCK_RW_LOCK_EXCL_SPIN] || lockstat_probemap[LS_LCK_RW_LOCK_EXCL_BLOCK]) && wait_interval == 0) { | |
1044 | wait_interval = mach_absolute_time(); | |
1045 | } else { | |
1046 | wait_interval = (unsigned) -1; | |
1047 | } | |
1048 | #endif | |
91447636 A |
1049 | |
1050 | if (i != 0) { | |
1051 | lck_rw_ilk_unlock(lck); | |
1052 | while (--i != 0 && (lck->lck_rw_shared_cnt != 0 || | |
1053 | lck->lck_rw_want_upgrade)) | |
1054 | continue; | |
1055 | lck_rw_ilk_lock(lck); | |
1056 | } | |
1057 | ||
1058 | if (lck->lck_rw_shared_cnt != 0 || lck->lck_rw_want_upgrade) { | |
1059 | lck->lck_rw_waiting = TRUE; | |
1060 | res = assert_wait((event_t)(((unsigned int*)lck)+((sizeof(lck_rw_t)-1)/sizeof(unsigned int))), THREAD_UNINT); | |
1061 | if (res == THREAD_WAITING) { | |
1062 | lck_rw_ilk_unlock(lck); | |
1063 | res = thread_block(THREAD_CONTINUE_NULL); | |
2d21ac55 A |
1064 | #if CONFIG_DTRACE |
1065 | slept = 1; | |
1066 | #endif | |
91447636 A |
1067 | lck_rw_ilk_lock(lck); |
1068 | } | |
1069 | } | |
1070 | KERNEL_DEBUG(MACHDBG_CODE(DBG_MACH_LOCKS, LCK_RW_LCK_EXCLUSIVE1_CODE) | DBG_FUNC_END, | |
1071 | (int)lck, lck->lck_rw_shared_cnt, lck->lck_rw_want_upgrade, res, 0); | |
1072 | } | |
1073 | ||
1074 | lck_rw_ilk_unlock(lck); | |
2d21ac55 A |
1075 | #if CONFIG_DTRACE |
1076 | /* | |
1077 | * Decide what latencies we suffered that are Dtrace events. | |
1078 | * If we have set wait_interval, then we either spun or slept. | |
1079 | * At least we get out from under the interlock before we record | |
1080 | * which is the best we can do here to minimize the impact | |
1081 | * of the tracing. | |
1082 | */ | |
1083 | if (wait_interval != 0 && wait_interval != (unsigned) -1) { | |
1084 | if (slept == 0) { | |
1085 | LOCKSTAT_RECORD2(LS_LCK_RW_LOCK_EXCL_SPIN, lck, | |
1086 | mach_absolute_time() - wait_interval, 1); | |
1087 | } else { | |
1088 | /* | |
1089 | * For the blocking case, we also record if when we blocked | |
1090 | * it was held for read or write, and how many readers. | |
1091 | * Notice that above we recorded this before we dropped | |
1092 | * the interlock so the count is accurate. | |
1093 | */ | |
1094 | LOCKSTAT_RECORD4(LS_LCK_RW_LOCK_EXCL_BLOCK, lck, | |
1095 | mach_absolute_time() - wait_interval, 1, | |
1096 | (readers_at_sleep == 0 ? 1 : 0), readers_at_sleep); | |
1097 | } | |
1098 | } | |
1099 | LOCKSTAT_RECORD(LS_LCK_RW_LOCK_EXCL_ACQUIRE, lck, 1); | |
1100 | #endif | |
91447636 A |
1101 | } |
1102 | ||
1103 | ||
1104 | /* | |
1105 | * Routine: lck_rw_done_gen | |
1106 | */ | |
1107 | lck_rw_type_t | |
1108 | lck_rw_done_gen( | |
1109 | lck_rw_t *lck) | |
1110 | { | |
1111 | boolean_t do_wakeup = FALSE; | |
1112 | lck_rw_type_t lck_rw_type; | |
1113 | ||
1114 | ||
1115 | lck_rw_ilk_lock(lck); | |
1116 | ||
1117 | if (lck->lck_rw_shared_cnt != 0) { | |
1118 | lck_rw_type = LCK_RW_TYPE_SHARED; | |
1119 | lck->lck_rw_shared_cnt--; | |
1120 | } | |
1121 | else { | |
1122 | lck_rw_type = LCK_RW_TYPE_EXCLUSIVE; | |
1123 | if (lck->lck_rw_want_upgrade) | |
1124 | lck->lck_rw_want_upgrade = FALSE; | |
1125 | else | |
1126 | lck->lck_rw_want_excl = FALSE; | |
1127 | } | |
1128 | ||
1129 | /* | |
1130 | * There is no reason to wakeup a lck_rw_waiting thread | |
1131 | * if the read-count is non-zero. Consider: | |
1132 | * we must be dropping a read lock | |
1133 | * threads are waiting only if one wants a write lock | |
1134 | * if there are still readers, they can't proceed | |
1135 | */ | |
1136 | ||
1137 | if (lck->lck_rw_waiting && (lck->lck_rw_shared_cnt == 0)) { | |
1138 | lck->lck_rw_waiting = FALSE; | |
1139 | do_wakeup = TRUE; | |
1140 | } | |
1141 | ||
1142 | lck_rw_ilk_unlock(lck); | |
1143 | ||
1144 | if (do_wakeup) | |
1145 | thread_wakeup((event_t)(((unsigned int*)lck)+((sizeof(lck_rw_t)-1)/sizeof(unsigned int)))); | |
2d21ac55 | 1146 | LOCKSTAT_RECORD(LS_LCK_RW_DONE_RELEASE, lck, lck_rw_type); |
91447636 A |
1147 | return(lck_rw_type); |
1148 | } | |
1149 | ||
1150 | ||
1151 | /* | |
1152 | * Routine: lck_rw_lock_shared_gen | |
1153 | */ | |
1154 | void | |
1155 | lck_rw_lock_shared_gen( | |
1156 | lck_rw_t *lck) | |
1157 | { | |
1158 | int i; | |
1159 | wait_result_t res; | |
2d21ac55 A |
1160 | #if CONFIG_DTRACE |
1161 | uint64_t wait_interval = 0; | |
1162 | int slept = 0; | |
1163 | int readers_at_sleep; | |
1164 | #endif | |
91447636 A |
1165 | |
1166 | lck_rw_ilk_lock(lck); | |
2d21ac55 A |
1167 | #if CONFIG_DTRACE |
1168 | readers_at_sleep = lck->lck_rw_shared_cnt; | |
1169 | #endif | |
91447636 | 1170 | |
0c530ab8 A |
1171 | while ((lck->lck_rw_want_excl || lck->lck_rw_want_upgrade) && |
1172 | ((lck->lck_rw_shared_cnt == 0) || (lck->lck_rw_priv_excl))) { | |
91447636 A |
1173 | i = lock_wait_time[1]; |
1174 | ||
1175 | KERNEL_DEBUG(MACHDBG_CODE(DBG_MACH_LOCKS, LCK_RW_LCK_SHARED_CODE) | DBG_FUNC_START, | |
1176 | (int)lck, lck->lck_rw_want_excl, lck->lck_rw_want_upgrade, i, 0); | |
2d21ac55 A |
1177 | #if CONFIG_DTRACE |
1178 | if ((lockstat_probemap[LS_LCK_RW_LOCK_SHARED_SPIN] || lockstat_probemap[LS_LCK_RW_LOCK_SHARED_BLOCK]) && wait_interval == 0) { | |
1179 | wait_interval = mach_absolute_time(); | |
1180 | } else { | |
1181 | wait_interval = (unsigned) -1; | |
1182 | } | |
1183 | #endif | |
91447636 A |
1184 | |
1185 | if (i != 0) { | |
1186 | lck_rw_ilk_unlock(lck); | |
0c530ab8 A |
1187 | while (--i != 0 && |
1188 | (lck->lck_rw_want_excl || lck->lck_rw_want_upgrade) && | |
1189 | ((lck->lck_rw_shared_cnt == 0) || (lck->lck_rw_priv_excl))) | |
91447636 A |
1190 | continue; |
1191 | lck_rw_ilk_lock(lck); | |
1192 | } | |
1193 | ||
0c530ab8 A |
1194 | if ((lck->lck_rw_want_excl || lck->lck_rw_want_upgrade) && |
1195 | ((lck->lck_rw_shared_cnt == 0) || (lck->lck_rw_priv_excl))) { | |
91447636 A |
1196 | lck->lck_rw_waiting = TRUE; |
1197 | res = assert_wait((event_t)(((unsigned int*)lck)+((sizeof(lck_rw_t)-1)/sizeof(unsigned int))), THREAD_UNINT); | |
1198 | if (res == THREAD_WAITING) { | |
1199 | lck_rw_ilk_unlock(lck); | |
1200 | res = thread_block(THREAD_CONTINUE_NULL); | |
2d21ac55 A |
1201 | #if CONFIG_DTRACE |
1202 | slept = 1; | |
1203 | #endif | |
91447636 A |
1204 | lck_rw_ilk_lock(lck); |
1205 | } | |
1206 | } | |
1207 | KERNEL_DEBUG(MACHDBG_CODE(DBG_MACH_LOCKS, LCK_RW_LCK_SHARED_CODE) | DBG_FUNC_END, | |
1208 | (int)lck, lck->lck_rw_want_excl, lck->lck_rw_want_upgrade, res, 0); | |
1209 | } | |
1210 | ||
1211 | lck->lck_rw_shared_cnt++; | |
1212 | ||
1213 | lck_rw_ilk_unlock(lck); | |
2d21ac55 A |
1214 | #if CONFIG_DTRACE |
1215 | if (wait_interval != 0 && wait_interval != (unsigned) -1) { | |
1216 | if (slept == 0) { | |
1217 | LOCKSTAT_RECORD2(LS_LCK_RW_LOCK_SHARED_SPIN, lck, mach_absolute_time() - wait_interval, 0); | |
1218 | } else { | |
1219 | LOCKSTAT_RECORD4(LS_LCK_RW_LOCK_SHARED_BLOCK, lck, | |
1220 | mach_absolute_time() - wait_interval, 0, | |
1221 | (readers_at_sleep == 0 ? 1 : 0), readers_at_sleep); | |
1222 | } | |
1223 | } | |
1224 | LOCKSTAT_RECORD(LS_LCK_RW_LOCK_SHARED_ACQUIRE, lck, 0); | |
1225 | #endif | |
91447636 A |
1226 | } |
1227 | ||
1228 | ||
1229 | /* | |
1230 | * Routine: lck_rw_lock_shared_to_exclusive_gen | |
1231 | * Function: | |
1232 | * Improves a read-only lock to one with | |
1233 | * write permission. If another reader has | |
1234 | * already requested an upgrade to a write lock, | |
1235 | * no lock is held upon return. | |
1236 | * | |
2d21ac55 | 1237 | * Returns FALSE if the upgrade *failed*. |
91447636 A |
1238 | */ |
1239 | ||
1240 | boolean_t | |
1241 | lck_rw_lock_shared_to_exclusive_gen( | |
1242 | lck_rw_t *lck) | |
1243 | { | |
1244 | int i; | |
1245 | boolean_t do_wakeup = FALSE; | |
1246 | wait_result_t res; | |
2d21ac55 A |
1247 | #if CONFIG_DTRACE |
1248 | uint64_t wait_interval = 0; | |
1249 | int slept = 0; | |
1250 | int readers_at_sleep = 0; | |
1251 | #endif | |
91447636 A |
1252 | |
1253 | lck_rw_ilk_lock(lck); | |
1254 | ||
1255 | lck->lck_rw_shared_cnt--; | |
1256 | ||
1257 | if (lck->lck_rw_want_upgrade) { | |
1258 | KERNEL_DEBUG(MACHDBG_CODE(DBG_MACH_LOCKS, LCK_RW_LCK_SH_TO_EX_CODE) | DBG_FUNC_START, | |
1259 | (int)lck, lck->lck_rw_shared_cnt, lck->lck_rw_want_upgrade, 0, 0); | |
1260 | ||
1261 | /* | |
1262 | * Someone else has requested upgrade. | |
1263 | * Since we've released a read lock, wake | |
1264 | * him up. | |
1265 | */ | |
1266 | if (lck->lck_rw_waiting && (lck->lck_rw_shared_cnt == 0)) { | |
1267 | lck->lck_rw_waiting = FALSE; | |
1268 | do_wakeup = TRUE; | |
1269 | } | |
1270 | ||
1271 | lck_rw_ilk_unlock(lck); | |
1272 | ||
1273 | if (do_wakeup) | |
1274 | thread_wakeup((event_t)(((unsigned int*)lck)+((sizeof(lck_rw_t)-1)/sizeof(unsigned int)))); | |
1275 | ||
1276 | KERNEL_DEBUG(MACHDBG_CODE(DBG_MACH_LOCKS, LCK_RW_LCK_SH_TO_EX_CODE) | DBG_FUNC_END, | |
1277 | (int)lck, lck->lck_rw_shared_cnt, lck->lck_rw_want_upgrade, 0, 0); | |
1278 | ||
2d21ac55 | 1279 | return (FALSE); |
91447636 A |
1280 | } |
1281 | ||
1282 | lck->lck_rw_want_upgrade = TRUE; | |
1283 | ||
1284 | while (lck->lck_rw_shared_cnt != 0) { | |
1285 | i = lock_wait_time[1]; | |
1286 | ||
1287 | KERNEL_DEBUG(MACHDBG_CODE(DBG_MACH_LOCKS, LCK_RW_LCK_SH_TO_EX1_CODE) | DBG_FUNC_START, | |
1288 | (int)lck, lck->lck_rw_shared_cnt, i, 0, 0); | |
1289 | ||
2d21ac55 A |
1290 | #if CONFIG_DTRACE |
1291 | readers_at_sleep = lck->lck_rw_shared_cnt; | |
1292 | if ((lockstat_probemap[LS_LCK_RW_LOCK_SHARED_TO_EXCL_SPIN] || lockstat_probemap[LS_LCK_RW_LOCK_SHARED_TO_EXCL_BLOCK]) && wait_interval == 0) { | |
1293 | wait_interval = mach_absolute_time(); | |
1294 | } else { | |
1295 | wait_interval = (unsigned) -1; | |
1296 | } | |
1297 | #endif | |
91447636 A |
1298 | if (i != 0) { |
1299 | lck_rw_ilk_unlock(lck); | |
1300 | while (--i != 0 && lck->lck_rw_shared_cnt != 0) | |
1301 | continue; | |
1302 | lck_rw_ilk_lock(lck); | |
1303 | } | |
1304 | ||
1305 | if (lck->lck_rw_shared_cnt != 0) { | |
1306 | lck->lck_rw_waiting = TRUE; | |
1307 | res = assert_wait((event_t)(((unsigned int*)lck)+((sizeof(lck_rw_t)-1)/sizeof(unsigned int))), THREAD_UNINT); | |
1308 | if (res == THREAD_WAITING) { | |
1309 | lck_rw_ilk_unlock(lck); | |
1310 | res = thread_block(THREAD_CONTINUE_NULL); | |
2d21ac55 A |
1311 | #if CONFIG_DTRACE |
1312 | slept = 1; | |
1313 | #endif | |
91447636 A |
1314 | lck_rw_ilk_lock(lck); |
1315 | } | |
1316 | } | |
1317 | KERNEL_DEBUG(MACHDBG_CODE(DBG_MACH_LOCKS, LCK_RW_LCK_SH_TO_EX1_CODE) | DBG_FUNC_END, | |
1318 | (int)lck, lck->lck_rw_shared_cnt, 0, 0, 0); | |
1319 | } | |
1320 | ||
1321 | lck_rw_ilk_unlock(lck); | |
1322 | ||
2d21ac55 A |
1323 | #if CONFIG_DTRACE |
1324 | /* | |
1325 | * We infer if we took a sleep or spin path by whether readers_at_sleep | |
1326 | * was set. | |
1327 | */ | |
1328 | if (wait_interval != 0 && wait_interval != (unsigned) -1 && readers_at_sleep) { | |
1329 | if (slept == 0) { | |
1330 | LOCKSTAT_RECORD2(LS_LCK_RW_LOCK_SHARED_TO_EXCL_SPIN, lck, mach_absolute_time() - wait_interval, 0); | |
1331 | } else { | |
1332 | LOCKSTAT_RECORD4(LS_LCK_RW_LOCK_SHARED_TO_EXCL_BLOCK, lck, | |
1333 | mach_absolute_time() - wait_interval, 1, | |
1334 | (readers_at_sleep == 0 ? 1 : 0), readers_at_sleep); | |
1335 | } | |
1336 | } | |
1337 | #endif | |
1338 | ||
1339 | LOCKSTAT_RECORD(LS_LCK_RW_LOCK_SHARED_TO_EXCL_UPGRADE, lck, 1); | |
1340 | return (TRUE); | |
91447636 A |
1341 | } |
1342 | ||
1343 | /* | |
1344 | * Routine: lck_rw_lock_exclusive_to_shared_gen | |
1345 | */ | |
1346 | void | |
1347 | lck_rw_lock_exclusive_to_shared_gen( | |
1348 | lck_rw_t *lck) | |
1349 | { | |
1350 | boolean_t do_wakeup = FALSE; | |
1351 | ||
1352 | lck_rw_ilk_lock(lck); | |
1353 | ||
1354 | lck->lck_rw_shared_cnt++; | |
1355 | if (lck->lck_rw_want_upgrade) | |
1356 | lck->lck_rw_want_upgrade = FALSE; | |
1357 | else | |
1358 | lck->lck_rw_want_excl = FALSE; | |
1359 | ||
1360 | if (lck->lck_rw_waiting) { | |
1361 | lck->lck_rw_waiting = FALSE; | |
1362 | do_wakeup = TRUE; | |
1363 | } | |
1364 | ||
1365 | lck_rw_ilk_unlock(lck); | |
1366 | ||
1367 | if (do_wakeup) | |
1368 | thread_wakeup((event_t)(((unsigned int*)lck)+((sizeof(lck_rw_t)-1)/sizeof(unsigned int)))); | |
1369 | ||
2d21ac55 | 1370 | LOCKSTAT_RECORD(LS_LCK_RW_LOCK_EXCL_TO_SHARED_DOWNGRADE, lck, 0); |
91447636 A |
1371 | } |
1372 | ||
1373 | ||
1374 | /* | |
1375 | * Routine: lck_rw_try_lock_exclusive_gen | |
1376 | * Function: | |
1377 | * Tries to get a write lock. | |
1378 | * | |
1379 | * Returns FALSE if the lock is not held on return. | |
1380 | */ | |
1381 | ||
1382 | boolean_t | |
1383 | lck_rw_try_lock_exclusive_gen( | |
1384 | lck_rw_t *lck) | |
1385 | { | |
1386 | lck_rw_ilk_lock(lck); | |
1387 | ||
1388 | if (lck->lck_rw_want_excl || lck->lck_rw_want_upgrade || lck->lck_rw_shared_cnt) { | |
1389 | /* | |
1390 | * Can't get lock. | |
1391 | */ | |
1392 | lck_rw_ilk_unlock(lck); | |
1393 | return(FALSE); | |
1394 | } | |
1395 | ||
1396 | /* | |
1397 | * Have lock. | |
1398 | */ | |
1399 | ||
1400 | lck->lck_rw_want_excl = TRUE; | |
1401 | ||
1402 | lck_rw_ilk_unlock(lck); | |
1403 | ||
2d21ac55 | 1404 | LOCKSTAT_RECORD(LS_LCK_RW_TRY_LOCK_EXCL_ACQUIRE, lck, 1); |
91447636 A |
1405 | return(TRUE); |
1406 | } | |
1407 | ||
1408 | /* | |
1409 | * Routine: lck_rw_try_lock_shared_gen | |
1410 | * Function: | |
1411 | * Tries to get a read lock. | |
1412 | * | |
1413 | * Returns FALSE if the lock is not held on return. | |
1414 | */ | |
1415 | ||
1416 | boolean_t | |
1417 | lck_rw_try_lock_shared_gen( | |
1418 | lck_rw_t *lck) | |
1419 | { | |
1420 | lck_rw_ilk_lock(lck); | |
1421 | ||
0c530ab8 A |
1422 | if ((lck->lck_rw_want_excl || lck->lck_rw_want_upgrade) && |
1423 | ((lck->lck_rw_shared_cnt == 0) || (lck->lck_rw_priv_excl))) { | |
91447636 A |
1424 | lck_rw_ilk_unlock(lck); |
1425 | return(FALSE); | |
1426 | } | |
1427 | ||
1428 | lck->lck_rw_shared_cnt++; | |
1429 | ||
1430 | lck_rw_ilk_unlock(lck); | |
1431 | ||
2d21ac55 | 1432 | LOCKSTAT_RECORD(LS_LCK_RW_TRY_LOCK_SHARED_ACQUIRE, lck, 0); |
91447636 A |
1433 | return(TRUE); |
1434 | } | |
1435 | ||
1436 | ||
1437 | /* | |
1438 | * Routine: lck_rw_ext_backtrace | |
1439 | */ | |
1440 | void | |
1441 | lck_rw_ext_backtrace( | |
1442 | lck_rw_ext_t *lck) | |
1443 | { | |
1444 | unsigned int *stackptr, *stackptr_prev; | |
1445 | unsigned int frame; | |
1446 | ||
1447 | __asm__ volatile("mr %0,r1" : "=r" (stackptr)); | |
1448 | frame = 0; | |
1449 | while (frame < LCK_FRAMES_MAX) { | |
1450 | stackptr_prev = stackptr; | |
1451 | stackptr = ( unsigned int *)*stackptr; | |
1452 | if ( (((unsigned int)stackptr_prev) ^ ((unsigned int)stackptr)) > 8192) | |
1453 | break; | |
1454 | lck->lck_rw_deb.stack[frame] = *(stackptr+2); | |
1455 | frame++; | |
1456 | } | |
1457 | while (frame < LCK_FRAMES_MAX) { | |
1458 | lck->lck_rw_deb.stack[frame] = 0; | |
1459 | frame++; | |
1460 | } | |
1461 | } | |
1462 | ||
1463 | ||
1464 | /* | |
1465 | * Routine: lck_rw_lock_exclusive_ext | |
1466 | */ | |
1467 | void | |
1468 | lck_rw_lock_exclusive_ext( | |
1469 | lck_rw_ext_t *lck, | |
1470 | lck_rw_t *rlck) | |
1471 | { | |
1472 | int i; | |
1473 | wait_result_t res; | |
1474 | boolean_t lock_miss = FALSE; | |
1475 | boolean_t lock_wait = FALSE; | |
1476 | boolean_t lock_stat; | |
2d21ac55 A |
1477 | #if CONFIG_DTRACE |
1478 | uint64_t wait_interval = 0; | |
1479 | int slept = 0; | |
1480 | int readers_at_sleep; | |
1481 | #endif | |
91447636 A |
1482 | |
1483 | lck_rw_check_type(lck, rlck); | |
1484 | ||
1485 | if ( ((lck->lck_rw_attr & (LCK_RW_ATTR_DEBUG|LCK_RW_ATTR_DIS_MYLOCK)) == LCK_RW_ATTR_DEBUG) | |
1486 | && (lck->lck_rw_deb.thread == current_thread())) | |
2d21ac55 | 1487 | panic("rw lock (%p) recursive lock attempt\n", rlck); |
91447636 A |
1488 | |
1489 | lck_rw_ilk_lock(&lck->lck_rw); | |
2d21ac55 A |
1490 | #if CONFIG_DTRACE |
1491 | readers_at_sleep = lck->lck_rw.lck_rw_shared_cnt; | |
1492 | #endif | |
91447636 A |
1493 | |
1494 | lock_stat = (lck->lck_rw_attr & LCK_RW_ATTR_STAT) ? TRUE : FALSE; | |
1495 | ||
1496 | if (lock_stat) | |
1497 | lck->lck_rw_grp->lck_grp_stat.lck_grp_rw_stat.lck_grp_rw_util_cnt++; | |
1498 | ||
1499 | /* | |
1500 | * Try to acquire the lck_rw.lck_rw_want_excl bit. | |
1501 | */ | |
1502 | while (lck->lck_rw.lck_rw_want_excl) { | |
1503 | KERNEL_DEBUG(MACHDBG_CODE(DBG_MACH_LOCKS, LCK_RW_LCK_EXCLUSIVE_CODE) | DBG_FUNC_START, (int)rlck, 0, 0, 0, 0); | |
1504 | ||
1505 | if (lock_stat && !lock_miss) { | |
1506 | lock_miss = TRUE; | |
1507 | lck->lck_rw_grp->lck_grp_stat.lck_grp_rw_stat.lck_grp_rw_miss_cnt++; | |
1508 | } | |
2d21ac55 A |
1509 | #if CONFIG_DTRACE |
1510 | if ((lockstat_probemap[LS_LCK_RW_LOCK_EXCL_SPIN] || lockstat_probemap[LS_LCK_RW_LOCK_EXCL_BLOCK]) && wait_interval == 0) { | |
1511 | wait_interval = mach_absolute_time(); | |
1512 | } else { | |
1513 | wait_interval = (unsigned) -1; | |
1514 | } | |
1515 | #endif | |
91447636 A |
1516 | |
1517 | i = lock_wait_time[1]; | |
1518 | if (i != 0) { | |
1519 | lck_rw_ilk_unlock(&lck->lck_rw); | |
1520 | while (--i != 0 && lck->lck_rw.lck_rw_want_excl) | |
1521 | continue; | |
1522 | lck_rw_ilk_lock(&lck->lck_rw); | |
1523 | } | |
1524 | ||
1525 | if (lck->lck_rw.lck_rw_want_excl) { | |
1526 | lck->lck_rw.lck_rw_waiting = TRUE; | |
1527 | res = assert_wait((event_t)(((unsigned int*)rlck)+((sizeof(lck_rw_t)-1)/sizeof(unsigned int))), THREAD_UNINT); | |
1528 | if (res == THREAD_WAITING) { | |
1529 | if (lock_stat && !lock_wait) { | |
1530 | lock_wait = TRUE; | |
1531 | lck->lck_rw_grp->lck_grp_stat.lck_grp_rw_stat.lck_grp_rw_wait_cnt++; | |
1532 | } | |
1533 | lck_rw_ilk_unlock(&lck->lck_rw); | |
1534 | res = thread_block(THREAD_CONTINUE_NULL); | |
2d21ac55 A |
1535 | #if CONFIG_DTRACE |
1536 | slept = 1; | |
1537 | #endif | |
91447636 A |
1538 | lck_rw_ilk_lock(&lck->lck_rw); |
1539 | } | |
1540 | } | |
1541 | KERNEL_DEBUG(MACHDBG_CODE(DBG_MACH_LOCKS, LCK_RW_LCK_EXCLUSIVE_CODE) | DBG_FUNC_END, (int)rlck, res, 0, 0, 0); | |
1542 | } | |
1543 | lck->lck_rw.lck_rw_want_excl = TRUE; | |
1544 | ||
1545 | /* Wait for readers (and upgrades) to finish */ | |
1546 | ||
1547 | while ((lck->lck_rw.lck_rw_shared_cnt != 0) || lck->lck_rw.lck_rw_want_upgrade) { | |
1548 | i = lock_wait_time[1]; | |
1549 | ||
1550 | KERNEL_DEBUG(MACHDBG_CODE(DBG_MACH_LOCKS, LCK_RW_LCK_EXCLUSIVE1_CODE) | DBG_FUNC_START, | |
1551 | (int)rlck, lck->lck_rw.lck_rw_shared_cnt, lck->lck_rw.lck_rw_want_upgrade, i, 0); | |
2d21ac55 A |
1552 | #if CONFIG_DTRACE |
1553 | if ((lockstat_probemap[LS_LCK_RW_LOCK_EXCL_SPIN] || lockstat_probemap[LS_LCK_RW_LOCK_EXCL_BLOCK]) && wait_interval == 0) { | |
1554 | wait_interval = mach_absolute_time(); | |
1555 | } else { | |
1556 | wait_interval = (unsigned) -1; | |
1557 | } | |
1558 | #endif | |
91447636 A |
1559 | |
1560 | if (lock_stat && !lock_miss) { | |
1561 | lock_miss = TRUE; | |
1562 | lck->lck_rw_grp->lck_grp_stat.lck_grp_rw_stat.lck_grp_rw_miss_cnt++; | |
1563 | } | |
1564 | ||
1565 | if (i != 0) { | |
1566 | lck_rw_ilk_unlock(&lck->lck_rw); | |
1567 | while (--i != 0 && (lck->lck_rw.lck_rw_shared_cnt != 0 || | |
1568 | lck->lck_rw.lck_rw_want_upgrade)) | |
1569 | continue; | |
1570 | lck_rw_ilk_lock(&lck->lck_rw); | |
1571 | } | |
1572 | ||
1573 | if (lck->lck_rw.lck_rw_shared_cnt != 0 || lck->lck_rw.lck_rw_want_upgrade) { | |
1574 | lck->lck_rw.lck_rw_waiting = TRUE; | |
1575 | res = assert_wait((event_t)(((unsigned int*)rlck)+((sizeof(lck_rw_t)-1)/sizeof(unsigned int))), THREAD_UNINT); | |
1576 | if (res == THREAD_WAITING) { | |
1577 | if (lock_stat && !lock_wait) { | |
1578 | lock_wait = TRUE; | |
1579 | lck->lck_rw_grp->lck_grp_stat.lck_grp_rw_stat.lck_grp_rw_wait_cnt++; | |
1580 | } | |
1581 | lck_rw_ilk_unlock(&lck->lck_rw); | |
1582 | res = thread_block(THREAD_CONTINUE_NULL); | |
2d21ac55 A |
1583 | #if CONFIG_DTRACE |
1584 | slept = 1; | |
1585 | #endif | |
91447636 A |
1586 | lck_rw_ilk_lock(&lck->lck_rw); |
1587 | } | |
1588 | } | |
1589 | KERNEL_DEBUG(MACHDBG_CODE(DBG_MACH_LOCKS, LCK_RW_LCK_EXCLUSIVE1_CODE) | DBG_FUNC_END, | |
1590 | (int)rlck, lck->lck_rw.lck_rw_shared_cnt, lck->lck_rw.lck_rw_want_upgrade, res, 0); | |
1591 | } | |
1592 | ||
1593 | lck->lck_rw_deb.pc_excl = __builtin_return_address(0); | |
1594 | if (LcksOpts & enaLkExtStck) | |
1595 | lck_rw_ext_backtrace(lck); | |
1596 | lck->lck_rw_deb.thread = current_thread(); | |
1597 | ||
1598 | lck_rw_ilk_unlock(&lck->lck_rw); | |
2d21ac55 A |
1599 | #if CONFIG_DTRACE |
1600 | /* | |
1601 | * Decide what latencies we suffered that are Dtrace events. | |
1602 | * If we have set wait_interval, then we either spun or slept. | |
1603 | * At least we get out from under the interlock before we record | |
1604 | * which is the best we can do here to minimize the impact | |
1605 | * of the tracing. | |
1606 | */ | |
1607 | if (wait_interval != 0 && wait_interval != (unsigned) -1) { | |
1608 | if (slept == 0) { | |
1609 | LOCKSTAT_RECORD2(LS_LCK_RW_LOCK_EXCL_SPIN, lck, | |
1610 | mach_absolute_time() - wait_interval, 1); | |
1611 | } else { | |
1612 | /* | |
1613 | * For the blocking case, we also record if when we blocked | |
1614 | * it was held for read or write, and how many readers. | |
1615 | * Notice that above we recorded this before we dropped | |
1616 | * the interlock so the count is accurate. | |
1617 | */ | |
1618 | LOCKSTAT_RECORD4(LS_LCK_RW_LOCK_EXCL_BLOCK, lck, | |
1619 | mach_absolute_time() - wait_interval, 1, | |
1620 | (readers_at_sleep == 0 ? 1 : 0), readers_at_sleep); | |
1621 | } | |
1622 | } | |
1623 | LOCKSTAT_RECORD(LS_LCK_RW_LOCK_EXCL_ACQUIRE, lck, 1); | |
1624 | #endif | |
91447636 A |
1625 | } |
1626 | ||
1627 | ||
1628 | /* | |
1629 | * Routine: lck_rw_done_ext | |
1630 | */ | |
1631 | lck_rw_type_t | |
1632 | lck_rw_done_ext( | |
1633 | lck_rw_ext_t *lck, | |
1634 | lck_rw_t *rlck) | |
1635 | { | |
1636 | boolean_t do_wakeup = FALSE; | |
1637 | lck_rw_type_t lck_rw_type; | |
1638 | ||
1639 | ||
1640 | lck_rw_check_type(lck, rlck); | |
1641 | ||
1642 | lck_rw_ilk_lock(&lck->lck_rw); | |
1643 | ||
1644 | if (lck->lck_rw.lck_rw_shared_cnt != 0) { | |
1645 | lck_rw_type = LCK_RW_TYPE_SHARED; | |
1646 | lck->lck_rw.lck_rw_shared_cnt--; | |
1647 | } | |
1648 | else { | |
1649 | lck_rw_type = LCK_RW_TYPE_EXCLUSIVE; | |
1650 | if (lck->lck_rw.lck_rw_want_upgrade) | |
1651 | lck->lck_rw.lck_rw_want_upgrade = FALSE; | |
1652 | else if (lck->lck_rw.lck_rw_want_excl) | |
1653 | lck->lck_rw.lck_rw_want_excl = FALSE; | |
1654 | else | |
2d21ac55 A |
1655 | panic("rw lock (%p) bad state (0x%08X) on attempt to release a shared or exlusive right\n", |
1656 | rlck, lck->lck_rw.lck_rw_tag); | |
91447636 | 1657 | if (lck->lck_rw_deb.thread == THREAD_NULL) |
2d21ac55 | 1658 | panic("rw lock (%p) not held\n", |
91447636 A |
1659 | rlck); |
1660 | else if ( ((lck->lck_rw_attr & (LCK_RW_ATTR_DEBUG|LCK_RW_ATTR_DIS_THREAD)) == LCK_RW_ATTR_DEBUG) | |
1661 | && (lck->lck_rw_deb.thread != current_thread())) | |
2d21ac55 | 1662 | panic("rw lock (%p) unlocked by non-owner(%p), current owner(%p)\n", |
91447636 A |
1663 | rlck, current_thread(), lck->lck_rw_deb.thread); |
1664 | lck->lck_rw_deb.thread = THREAD_NULL; | |
1665 | } | |
1666 | ||
1667 | if (lck->lck_rw_attr & LCK_RW_ATTR_DEBUG) | |
1668 | lck->lck_rw_deb.pc_done = __builtin_return_address(0); | |
1669 | ||
1670 | /* | |
1671 | * There is no reason to wakeup a waiting thread | |
1672 | * if the read-count is non-zero. Consider: | |
1673 | * we must be dropping a read lock | |
1674 | * threads are waiting only if one wants a write lock | |
1675 | * if there are still readers, they can't proceed | |
1676 | */ | |
1677 | ||
1678 | if (lck->lck_rw.lck_rw_waiting && (lck->lck_rw.lck_rw_shared_cnt == 0)) { | |
1679 | lck->lck_rw.lck_rw_waiting = FALSE; | |
1680 | do_wakeup = TRUE; | |
1681 | } | |
1682 | ||
1683 | lck_rw_ilk_unlock(&lck->lck_rw); | |
1684 | ||
1685 | if (do_wakeup) | |
1686 | thread_wakeup((event_t)(((unsigned int*)rlck)+((sizeof(lck_rw_t)-1)/sizeof(unsigned int)))); | |
2d21ac55 | 1687 | LOCKSTAT_RECORD(LS_LCK_RW_DONE_RELEASE, lck, lck_rw_type); |
91447636 A |
1688 | return(lck_rw_type); |
1689 | } | |
1690 | ||
1691 | ||
1692 | /* | |
1693 | * Routine: lck_rw_lock_shared_ext | |
1694 | */ | |
1695 | void | |
1696 | lck_rw_lock_shared_ext( | |
1697 | lck_rw_ext_t *lck, | |
1698 | lck_rw_t *rlck) | |
1699 | { | |
1700 | int i; | |
1701 | wait_result_t res; | |
1702 | boolean_t lock_miss = FALSE; | |
1703 | boolean_t lock_wait = FALSE; | |
1704 | boolean_t lock_stat; | |
2d21ac55 A |
1705 | #if CONFIG_DTRACE |
1706 | uint64_t wait_interval = 0; | |
1707 | int slept = 0; | |
1708 | int readers_at_sleep; | |
1709 | #endif | |
91447636 A |
1710 | |
1711 | lck_rw_check_type(lck, rlck); | |
1712 | ||
1713 | lck_rw_ilk_lock(&lck->lck_rw); | |
2d21ac55 A |
1714 | #if CONFIG_DTRACE |
1715 | readers_at_sleep = lck->lck_rw.lck_rw_shared_cnt; | |
1716 | #endif | |
91447636 A |
1717 | |
1718 | lock_stat = (lck->lck_rw_attr & LCK_RW_ATTR_STAT) ? TRUE : FALSE; | |
1719 | ||
1720 | if (lock_stat) | |
1721 | lck->lck_rw_grp->lck_grp_stat.lck_grp_rw_stat.lck_grp_rw_util_cnt++; | |
1722 | ||
0c530ab8 A |
1723 | while ((lck->lck_rw.lck_rw_want_excl || lck->lck_rw.lck_rw_want_upgrade) && |
1724 | ((lck->lck_rw.lck_rw_shared_cnt == 0) || (lck->lck_rw.lck_rw_priv_excl))) { | |
91447636 A |
1725 | i = lock_wait_time[1]; |
1726 | ||
1727 | KERNEL_DEBUG(MACHDBG_CODE(DBG_MACH_LOCKS, LCK_RW_LCK_SHARED_CODE) | DBG_FUNC_START, | |
1728 | (int)rlck, lck->lck_rw.lck_rw_want_excl, lck->lck_rw.lck_rw_want_upgrade, i, 0); | |
2d21ac55 A |
1729 | #if CONFIG_DTRACE |
1730 | if ((lockstat_probemap[LS_LCK_RW_LOCK_SHARED_SPIN] || lockstat_probemap[LS_LCK_RW_LOCK_SHARED_BLOCK]) && wait_interval == 0) { | |
1731 | wait_interval = mach_absolute_time(); | |
1732 | } else { | |
1733 | wait_interval = (unsigned) -1; | |
1734 | } | |
1735 | #endif | |
91447636 A |
1736 | |
1737 | if (lock_stat && !lock_miss) { | |
1738 | lock_miss = TRUE; | |
1739 | lck->lck_rw_grp->lck_grp_stat.lck_grp_rw_stat.lck_grp_rw_miss_cnt++; | |
1740 | } | |
1741 | ||
1742 | if (i != 0) { | |
1743 | lck_rw_ilk_unlock(&lck->lck_rw); | |
0c530ab8 A |
1744 | while (--i != 0 && |
1745 | (lck->lck_rw.lck_rw_want_excl || lck->lck_rw.lck_rw_want_upgrade) && | |
1746 | ((lck->lck_rw.lck_rw_shared_cnt == 0) || (lck->lck_rw.lck_rw_priv_excl))) | |
91447636 A |
1747 | continue; |
1748 | lck_rw_ilk_lock(&lck->lck_rw); | |
1749 | } | |
1750 | ||
0c530ab8 A |
1751 | if ((lck->lck_rw.lck_rw_want_excl || lck->lck_rw.lck_rw_want_upgrade) && |
1752 | ((lck->lck_rw.lck_rw_shared_cnt == 0) || (lck->lck_rw.lck_rw_priv_excl))) { | |
91447636 A |
1753 | lck->lck_rw.lck_rw_waiting = TRUE; |
1754 | res = assert_wait((event_t)(((unsigned int*)rlck)+((sizeof(lck_rw_t)-1)/sizeof(unsigned int))), THREAD_UNINT); | |
1755 | if (res == THREAD_WAITING) { | |
1756 | if (lock_stat && !lock_wait) { | |
1757 | lock_wait = TRUE; | |
1758 | lck->lck_rw_grp->lck_grp_stat.lck_grp_rw_stat.lck_grp_rw_wait_cnt++; | |
1759 | } | |
1760 | lck_rw_ilk_unlock(&lck->lck_rw); | |
1761 | res = thread_block(THREAD_CONTINUE_NULL); | |
2d21ac55 A |
1762 | #if CONFIG_DTRACE |
1763 | slept = 1; | |
1764 | #endif | |
91447636 A |
1765 | lck_rw_ilk_lock(&lck->lck_rw); |
1766 | } | |
1767 | } | |
1768 | KERNEL_DEBUG(MACHDBG_CODE(DBG_MACH_LOCKS, LCK_RW_LCK_SHARED_CODE) | DBG_FUNC_END, | |
1769 | (int)rlck, lck->lck_rw.lck_rw_want_excl, lck->lck_rw.lck_rw_want_upgrade, res, 0); | |
1770 | } | |
1771 | ||
1772 | lck->lck_rw.lck_rw_shared_cnt++; | |
1773 | ||
1774 | lck_rw_ilk_unlock(&lck->lck_rw); | |
2d21ac55 A |
1775 | #if CONFIG_DTRACE |
1776 | if (wait_interval != 0 && wait_interval != (unsigned) -1) { | |
1777 | if (slept == 0) { | |
1778 | LOCKSTAT_RECORD2(LS_LCK_RW_LOCK_SHARED_SPIN, lck, mach_absolute_time() - wait_interval, 0); | |
1779 | } else { | |
1780 | LOCKSTAT_RECORD4(LS_LCK_RW_LOCK_SHARED_BLOCK, lck, | |
1781 | mach_absolute_time() - wait_interval, 0, | |
1782 | (readers_at_sleep == 0 ? 1 : 0), readers_at_sleep); | |
1783 | } | |
1784 | } | |
1785 | LOCKSTAT_RECORD(LS_LCK_RW_LOCK_SHARED_ACQUIRE, lck, 0); | |
1786 | #endif | |
91447636 A |
1787 | } |
1788 | ||
1789 | ||
1790 | /* | |
1791 | * Routine: lck_rw_lock_shared_to_exclusive_ext | |
1792 | * Function: | |
1793 | * Improves a read-only lock to one with | |
1794 | * write permission. If another reader has | |
1795 | * already requested an upgrade to a write lock, | |
1796 | * no lock is held upon return. | |
1797 | * | |
2d21ac55 | 1798 | * Returns FALSE if the upgrade *failed*. |
91447636 A |
1799 | */ |
1800 | ||
1801 | boolean_t | |
1802 | lck_rw_lock_shared_to_exclusive_ext( | |
1803 | lck_rw_ext_t *lck, | |
1804 | lck_rw_t *rlck) | |
1805 | { | |
1806 | int i; | |
1807 | boolean_t do_wakeup = FALSE; | |
1808 | wait_result_t res; | |
1809 | boolean_t lock_miss = FALSE; | |
1810 | boolean_t lock_wait = FALSE; | |
1811 | boolean_t lock_stat; | |
2d21ac55 A |
1812 | #if CONFIG_DTRACE |
1813 | uint64_t wait_interval = 0; | |
1814 | int slept = 0; | |
1815 | #endif | |
91447636 A |
1816 | |
1817 | lck_rw_check_type(lck, rlck); | |
1818 | ||
1819 | if (lck->lck_rw_deb.thread == current_thread()) | |
2d21ac55 | 1820 | panic("rw lock (%p) recursive lock attempt\n", rlck); |
91447636 A |
1821 | |
1822 | lck_rw_ilk_lock(&lck->lck_rw); | |
1823 | ||
1824 | lock_stat = (lck->lck_rw_attr & LCK_RW_ATTR_STAT) ? TRUE : FALSE; | |
1825 | ||
1826 | if (lock_stat) | |
1827 | lck->lck_rw_grp->lck_grp_stat.lck_grp_rw_stat.lck_grp_rw_util_cnt++; | |
1828 | ||
1829 | lck->lck_rw.lck_rw_shared_cnt--; | |
1830 | ||
1831 | if (lck->lck_rw.lck_rw_want_upgrade) { | |
1832 | KERNEL_DEBUG(MACHDBG_CODE(DBG_MACH_LOCKS, LCK_RW_LCK_SH_TO_EX_CODE) | DBG_FUNC_START, | |
1833 | (int)rlck, lck->lck_rw.lck_rw_shared_cnt, lck->lck_rw.lck_rw_want_upgrade, 0, 0); | |
1834 | ||
1835 | /* | |
1836 | * Someone else has requested upgrade. | |
1837 | * Since we've released a read lock, wake | |
1838 | * him up. | |
1839 | */ | |
1840 | if (lck->lck_rw.lck_rw_waiting && (lck->lck_rw.lck_rw_shared_cnt == 0)) { | |
1841 | lck->lck_rw.lck_rw_waiting = FALSE; | |
1842 | do_wakeup = TRUE; | |
1843 | } | |
1844 | ||
1845 | lck_rw_ilk_unlock(&lck->lck_rw); | |
1846 | ||
1847 | if (do_wakeup) | |
1848 | thread_wakeup((event_t)(((unsigned int*)rlck)+((sizeof(lck_rw_t)-1)/sizeof(unsigned int)))); | |
1849 | ||
1850 | KERNEL_DEBUG(MACHDBG_CODE(DBG_MACH_LOCKS, LCK_RW_LCK_SH_TO_EX_CODE) | DBG_FUNC_END, | |
1851 | (int)rlck, lck->lck_rw.lck_rw_shared_cnt, lck->lck_rw.lck_rw_want_upgrade, 0, 0); | |
1852 | ||
2d21ac55 | 1853 | return (FALSE); |
91447636 A |
1854 | } |
1855 | ||
1856 | lck->lck_rw.lck_rw_want_upgrade = TRUE; | |
1857 | ||
1858 | while (lck->lck_rw.lck_rw_shared_cnt != 0) { | |
1859 | i = lock_wait_time[1]; | |
1860 | ||
1861 | KERNEL_DEBUG(MACHDBG_CODE(DBG_MACH_LOCKS, LCK_RW_LCK_SH_TO_EX1_CODE) | DBG_FUNC_START, | |
1862 | (int)rlck, lck->lck_rw.lck_rw_shared_cnt, i, 0, 0); | |
1863 | ||
1864 | if (lock_stat && !lock_miss) { | |
1865 | lock_miss = TRUE; | |
1866 | lck->lck_rw_grp->lck_grp_stat.lck_grp_rw_stat.lck_grp_rw_miss_cnt++; | |
1867 | } | |
2d21ac55 A |
1868 | #if CONFIG_DTRACE |
1869 | if ((lockstat_probemap[LS_LCK_RW_LOCK_SHARED_TO_EXCL_SPIN] || lockstat_probemap[LS_LCK_RW_LOCK_SHARED_TO_EXCL_BLOCK]) && wait_interval == 0) { | |
1870 | wait_interval = mach_absolute_time(); | |
1871 | } else { | |
1872 | wait_interval = (unsigned) -1; | |
1873 | } | |
1874 | #endif | |
91447636 A |
1875 | |
1876 | if (i != 0) { | |
1877 | lck_rw_ilk_unlock(&lck->lck_rw); | |
1878 | while (--i != 0 && lck->lck_rw.lck_rw_shared_cnt != 0) | |
1879 | continue; | |
1880 | lck_rw_ilk_lock(&lck->lck_rw); | |
1881 | } | |
1882 | ||
1883 | if (lck->lck_rw.lck_rw_shared_cnt != 0) { | |
1884 | lck->lck_rw.lck_rw_waiting = TRUE; | |
1885 | res = assert_wait((event_t)(((unsigned int*)rlck)+((sizeof(lck_rw_t)-1)/sizeof(unsigned int))), THREAD_UNINT); | |
1886 | if (res == THREAD_WAITING) { | |
1887 | if (lock_stat && !lock_wait) { | |
1888 | lock_wait = TRUE; | |
1889 | lck->lck_rw_grp->lck_grp_stat.lck_grp_rw_stat.lck_grp_rw_wait_cnt++; | |
1890 | } | |
1891 | lck_rw_ilk_unlock(&lck->lck_rw); | |
1892 | res = thread_block(THREAD_CONTINUE_NULL); | |
2d21ac55 A |
1893 | #if CONFIG_DTRACE |
1894 | slept = 1; | |
1895 | #endif | |
91447636 A |
1896 | lck_rw_ilk_lock(&lck->lck_rw); |
1897 | } | |
1898 | } | |
1899 | KERNEL_DEBUG(MACHDBG_CODE(DBG_MACH_LOCKS, LCK_RW_LCK_SH_TO_EX1_CODE) | DBG_FUNC_END, | |
1900 | (int)rlck, lck->lck_rw.lck_rw_shared_cnt, 0, 0, 0); | |
1901 | } | |
1902 | ||
1903 | lck->lck_rw_deb.pc_excl = __builtin_return_address(0); | |
1904 | if (LcksOpts & enaLkExtStck) | |
1905 | lck_rw_ext_backtrace(lck); | |
1906 | lck->lck_rw_deb.thread = current_thread(); | |
1907 | ||
1908 | lck_rw_ilk_unlock(&lck->lck_rw); | |
1909 | ||
2d21ac55 A |
1910 | #if CONFIG_DTRACE |
1911 | /* | |
1912 | * If we've travelled a path with no spin or sleep, then wait_interval | |
1913 | * is still zero. | |
1914 | */ | |
1915 | if (wait_interval != 0 && wait_interval != (unsigned) -1) { | |
1916 | if (slept == 0) { | |
1917 | LOCKSTAT_RECORD2(LS_LCK_RW_LOCK_SHARED_TO_EXCL_SPIN, lck, mach_absolute_time() - wait_interval, 0); | |
1918 | } else { | |
1919 | LOCKSTAT_RECORD2(LS_LCK_RW_LOCK_SHARED_TO_EXCL_BLOCK, lck, mach_absolute_time() - wait_interval, 0); | |
1920 | } | |
1921 | } | |
1922 | #endif | |
1923 | ||
1924 | LOCKSTAT_RECORD(LS_LCK_RW_LOCK_SHARED_TO_EXCL_UPGRADE, lck, 1); | |
1925 | ||
1926 | return (TRUE); | |
91447636 A |
1927 | } |
1928 | ||
1929 | /* | |
1930 | * Routine: lck_rw_lock_exclusive_to_shared_ext | |
1931 | */ | |
1932 | void | |
1933 | lck_rw_lock_exclusive_to_shared_ext( | |
1934 | lck_rw_ext_t *lck, | |
1935 | lck_rw_t *rlck) | |
1936 | { | |
1937 | boolean_t do_wakeup = FALSE; | |
1938 | ||
1939 | lck_rw_check_type(lck, rlck); | |
1940 | ||
1941 | KERNEL_DEBUG(MACHDBG_CODE(DBG_MACH_LOCKS, LCK_RW_LCK_EX_TO_SH_CODE) | DBG_FUNC_START, | |
1942 | (int)rlck, lck->lck_rw.lck_rw_want_excl, lck->lck_rw.lck_rw_want_upgrade, 0, 0); | |
1943 | ||
1944 | lck_rw_ilk_lock(&lck->lck_rw); | |
1945 | ||
1946 | lck->lck_rw.lck_rw_shared_cnt++; | |
1947 | if (lck->lck_rw.lck_rw_want_upgrade) | |
1948 | lck->lck_rw.lck_rw_want_upgrade = FALSE; | |
1949 | else if (lck->lck_rw.lck_rw_want_excl) | |
1950 | lck->lck_rw.lck_rw_want_excl = FALSE; | |
1951 | else | |
2d21ac55 A |
1952 | panic("rw lock (%p) bad state (0x%08X) on attempt to release a shared or exlusive right\n", |
1953 | rlck, lck->lck_rw.lck_rw_tag); | |
91447636 | 1954 | if (lck->lck_rw_deb.thread == THREAD_NULL) |
2d21ac55 | 1955 | panic("rw lock (%p) not held\n", |
91447636 A |
1956 | rlck); |
1957 | else if ( ((lck->lck_rw_attr & (LCK_RW_ATTR_DEBUG|LCK_RW_ATTR_DIS_THREAD)) == LCK_RW_ATTR_DEBUG) | |
1958 | && (lck->lck_rw_deb.thread != current_thread())) | |
2d21ac55 | 1959 | panic("rw lock (%p) unlocked by non-owner(%p), current owner(%p)\n", |
91447636 A |
1960 | rlck, current_thread(), lck->lck_rw_deb.thread); |
1961 | ||
1962 | lck->lck_rw_deb.thread = THREAD_NULL; | |
1963 | ||
1964 | if (lck->lck_rw.lck_rw_waiting) { | |
1965 | lck->lck_rw.lck_rw_waiting = FALSE; | |
1966 | do_wakeup = TRUE; | |
1967 | } | |
1968 | ||
1969 | lck_rw_ilk_unlock(&lck->lck_rw); | |
1970 | ||
1971 | if (do_wakeup) | |
1972 | thread_wakeup((event_t)(((unsigned int*)rlck)+((sizeof(lck_rw_t)-1)/sizeof(unsigned int)))); | |
1973 | ||
1974 | KERNEL_DEBUG(MACHDBG_CODE(DBG_MACH_LOCKS, LCK_RW_LCK_EX_TO_SH_CODE) | DBG_FUNC_END, | |
1975 | (int)rlck, lck->lck_rw.lck_rw_want_excl, lck->lck_rw.lck_rw_want_upgrade, lck->lck_rw.lck_rw_shared_cnt, 0); | |
1976 | ||
2d21ac55 | 1977 | LOCKSTAT_RECORD(LS_LCK_RW_LOCK_EXCL_TO_SHARED_DOWNGRADE, lck, 0); |
91447636 A |
1978 | } |
1979 | ||
1980 | ||
1981 | /* | |
1982 | * Routine: lck_rw_try_lock_exclusive_ext | |
1983 | * Function: | |
1984 | * Tries to get a write lock. | |
1985 | * | |
1986 | * Returns FALSE if the lock is not held on return. | |
1987 | */ | |
1988 | ||
1989 | boolean_t | |
1990 | lck_rw_try_lock_exclusive_ext( | |
1991 | lck_rw_ext_t *lck, | |
1992 | lck_rw_t *rlck) | |
1993 | { | |
1994 | boolean_t lock_stat; | |
1995 | ||
1996 | lck_rw_check_type(lck, rlck); | |
1997 | ||
1998 | lck_rw_ilk_lock(&lck->lck_rw); | |
1999 | ||
2000 | lock_stat = (lck->lck_rw_attr & LCK_RW_ATTR_STAT) ? TRUE : FALSE; | |
2001 | ||
2002 | if (lock_stat) | |
2003 | lck->lck_rw_grp->lck_grp_stat.lck_grp_rw_stat.lck_grp_rw_util_cnt++; | |
2004 | ||
2005 | if (lck->lck_rw.lck_rw_want_excl || lck->lck_rw.lck_rw_want_upgrade || lck->lck_rw.lck_rw_shared_cnt) { | |
2006 | /* | |
2007 | * Can't get lock. | |
2008 | */ | |
2009 | if (lock_stat) { | |
2010 | lck->lck_rw_grp->lck_grp_stat.lck_grp_rw_stat.lck_grp_rw_miss_cnt++; | |
2011 | } | |
2012 | lck_rw_ilk_unlock(&lck->lck_rw); | |
2013 | return(FALSE); | |
2014 | } | |
2015 | ||
2016 | /* | |
2017 | * Have lock. | |
2018 | */ | |
2019 | ||
2020 | lck->lck_rw.lck_rw_want_excl = TRUE; | |
2021 | lck->lck_rw_deb.pc_excl = __builtin_return_address(0); | |
2022 | if (LcksOpts & enaLkExtStck) | |
2023 | lck_rw_ext_backtrace(lck); | |
2024 | lck->lck_rw_deb.thread = current_thread(); | |
2025 | ||
2026 | lck_rw_ilk_unlock(&lck->lck_rw); | |
2027 | ||
2d21ac55 A |
2028 | LOCKSTAT_RECORD(LS_LCK_RW_TRY_LOCK_EXCL_ACQUIRE, lck, 1); |
2029 | ||
91447636 A |
2030 | return(TRUE); |
2031 | } | |
2032 | ||
2033 | /* | |
2034 | * Routine: lck_rw_try_lock_shared_ext | |
2035 | * Function: | |
2036 | * Tries to get a read lock. | |
2037 | * | |
2038 | * Returns FALSE if the lock is not held on return. | |
2039 | */ | |
2040 | ||
2041 | boolean_t | |
2042 | lck_rw_try_lock_shared_ext( | |
2043 | lck_rw_ext_t *lck, | |
2044 | lck_rw_t *rlck) | |
2045 | { | |
2046 | boolean_t lock_stat; | |
2047 | ||
2048 | lck_rw_check_type(lck, rlck); | |
2049 | ||
2050 | lck_rw_ilk_lock(&lck->lck_rw); | |
2051 | ||
2052 | lock_stat = (lck->lck_rw_attr & LCK_RW_ATTR_STAT) ? TRUE : FALSE; | |
2053 | ||
2054 | if (lock_stat) | |
2055 | lck->lck_rw_grp->lck_grp_stat.lck_grp_rw_stat.lck_grp_rw_util_cnt++; | |
2056 | ||
0c530ab8 A |
2057 | if ((lck->lck_rw.lck_rw_want_excl || lck->lck_rw.lck_rw_want_upgrade) && |
2058 | ((lck->lck_rw.lck_rw_shared_cnt == 0) || (lck->lck_rw.lck_rw_priv_excl))) { | |
91447636 A |
2059 | if (lock_stat) { |
2060 | lck->lck_rw_grp->lck_grp_stat.lck_grp_rw_stat.lck_grp_rw_miss_cnt++; | |
2061 | } | |
2062 | lck_rw_ilk_unlock(&lck->lck_rw); | |
2063 | return(FALSE); | |
2064 | } | |
2065 | ||
2066 | lck->lck_rw.lck_rw_shared_cnt++; | |
2067 | ||
2068 | lck_rw_ilk_unlock(&lck->lck_rw); | |
2069 | ||
2d21ac55 A |
2070 | LOCKSTAT_RECORD(LS_LCK_RW_TRY_LOCK_SHARED_ACQUIRE, lck, 0); |
2071 | ||
91447636 A |
2072 | return(TRUE); |
2073 | } | |
2074 | ||
2075 | void | |
2076 | lck_rw_check_type( | |
2077 | lck_rw_ext_t *lck, | |
2078 | lck_rw_t *rlck) | |
2079 | { | |
2080 | if (lck->lck_rw_deb.type != RW_TAG) | |
2d21ac55 A |
2081 | panic("rw lock (%p) not a rw lock type (0x%08X)\n",rlck, lck->lck_rw_deb.type); |
2082 | } | |
2083 | ||
2084 | void | |
2085 | lck_rw_assert_ext( | |
2086 | lck_rw_ext_t *lck, | |
2087 | lck_rw_t *rlck, | |
2088 | unsigned int type) | |
2089 | { | |
2090 | lck_rw_check_type(lck, rlck); | |
2091 | ||
2092 | switch (type) { | |
2093 | case LCK_RW_ASSERT_SHARED: | |
2094 | if (lck->lck_rw.lck_rw_shared_cnt != 0) { | |
2095 | return; | |
2096 | } | |
2097 | break; | |
2098 | case LCK_RW_ASSERT_EXCLUSIVE: | |
2099 | if ((lck->lck_rw.lck_rw_want_excl || | |
2100 | lck->lck_rw.lck_rw_want_upgrade) && | |
2101 | lck->lck_rw.lck_rw_shared_cnt == 0) { | |
2102 | return; | |
2103 | } | |
2104 | break; | |
2105 | case LCK_RW_ASSERT_HELD: | |
2106 | if (lck->lck_rw.lck_rw_want_excl || | |
2107 | lck->lck_rw.lck_rw_want_upgrade || | |
2108 | lck->lck_rw.lck_rw_shared_cnt != 0) { | |
2109 | return; | |
2110 | } | |
2111 | break; | |
2112 | default: | |
2113 | break; | |
2114 | } | |
2115 | ||
2116 | panic("rw lock (%p -> %p) not held (mode=%u)\n", rlck, lck, type); | |
2117 | } | |
2118 | ||
2119 | void | |
2120 | lck_rw_assert( | |
2121 | lck_rw_t *lck, | |
2122 | unsigned int type) | |
2123 | { | |
2124 | if (lck->lck_rw_tag != LCK_RW_TAG_INDIRECT) { | |
2125 | switch (type) { | |
2126 | case LCK_RW_ASSERT_SHARED: | |
2127 | if (lck->lck_rw_shared_cnt != 0) { | |
2128 | return; | |
2129 | } | |
2130 | break; | |
2131 | case LCK_RW_ASSERT_EXCLUSIVE: | |
2132 | if (lck->lck_rw_shared_cnt == 0 && | |
2133 | (lck->lck_rw_want_excl || | |
2134 | lck->lck_rw_want_upgrade)) { | |
2135 | return; | |
2136 | } | |
2137 | break; | |
2138 | case LCK_RW_ASSERT_HELD: | |
2139 | if (lck->lck_rw_shared_cnt != 0 || | |
2140 | lck->lck_rw_want_excl || | |
2141 | lck->lck_rw_want_upgrade) { | |
2142 | return; | |
2143 | } | |
2144 | break; | |
2145 | default: | |
2146 | break; | |
2147 | } | |
2148 | panic("rw lock (%p) not held (mode=%u)\n", lck, type); | |
2149 | } else { | |
2150 | lck_rw_assert_ext((lck_rw_ext_t *)lck->lck_rw_ptr, | |
2151 | (lck_rw_t *)lck, | |
2152 | type); | |
2153 | } | |
91447636 A |
2154 | } |
2155 | ||
2156 | /* | |
2157 | * The C portion of the mutex package. These routines are only invoked | |
2158 | * if the optimized assembler routines can't do the work. | |
2159 | */ | |
2160 | ||
2161 | /* | |
2162 | * Forward definition | |
2163 | */ | |
2164 | ||
2165 | void lck_mtx_ext_init( | |
2166 | lck_mtx_ext_t *lck, | |
2167 | lck_grp_t *grp, | |
2168 | lck_attr_t *attr); | |
2169 | ||
2170 | /* | |
2171 | * Routine: mutex_alloc | |
2172 | * Function: | |
2173 | * Allocate a mutex for external users who cannot | |
2174 | * hard-code the structure definition into their | |
2175 | * objects. | |
2176 | * For now just use kalloc, but a zone is probably | |
2177 | * warranted. | |
2178 | */ | |
2179 | mutex_t * | |
2180 | mutex_alloc( | |
2181 | unsigned short tag) | |
2182 | { | |
2183 | mutex_t *m; | |
2184 | ||
2185 | if ((m = (mutex_t *)kalloc(sizeof(mutex_t))) != 0) | |
2186 | mutex_init(m, tag); | |
2187 | return(m); | |
2188 | } | |
2189 | ||
2190 | /* | |
2191 | * Routine: mutex_free | |
2192 | */ | |
2193 | void | |
2194 | mutex_free( | |
2195 | mutex_t *m) | |
2196 | { | |
2197 | kfree((void *)m, sizeof(mutex_t)); | |
2198 | } | |
2199 | ||
2200 | /* | |
2201 | * Routine: lck_mtx_alloc_init | |
2202 | */ | |
2203 | lck_mtx_t * | |
2204 | lck_mtx_alloc_init( | |
2205 | lck_grp_t *grp, | |
2206 | lck_attr_t *attr) { | |
2207 | lck_mtx_t *lck; | |
2208 | ||
2209 | if ((lck = (lck_mtx_t *)kalloc(sizeof(lck_mtx_t))) != 0) | |
2210 | lck_mtx_init(lck, grp, attr); | |
2211 | ||
2212 | return(lck); | |
2213 | } | |
2214 | ||
2215 | /* | |
2216 | * Routine: lck_mtx_free | |
2217 | */ | |
2218 | void | |
2219 | lck_mtx_free( | |
2220 | lck_mtx_t *lck, | |
2221 | lck_grp_t *grp) { | |
2222 | lck_mtx_destroy(lck, grp); | |
2223 | kfree((void *)lck, sizeof(lck_mtx_t)); | |
2224 | } | |
2225 | ||
2226 | /* | |
2227 | * Routine: lck_mtx_init | |
2228 | */ | |
2229 | void | |
2230 | lck_mtx_init( | |
2231 | lck_mtx_t *lck, | |
2232 | lck_grp_t *grp, | |
2233 | lck_attr_t *attr) { | |
2234 | lck_mtx_ext_t *lck_ext; | |
2235 | lck_attr_t *lck_attr; | |
2236 | ||
2237 | if (attr != LCK_ATTR_NULL) | |
2238 | lck_attr = attr; | |
2239 | else | |
2240 | lck_attr = &LockDefaultLckAttr; | |
2241 | ||
2242 | if ((lck_attr->lck_attr_val) & LCK_ATTR_DEBUG) { | |
2243 | if ((lck_ext = (lck_mtx_ext_t *)kalloc(sizeof(lck_mtx_ext_t))) != 0) { | |
2244 | lck_mtx_ext_init(lck_ext, grp, lck_attr); | |
2245 | lck->lck_mtx_tag = LCK_MTX_TAG_INDIRECT; | |
2246 | lck->lck_mtx_ptr = lck_ext; | |
2247 | } | |
2248 | } else { | |
2249 | lck->lck_mtx_data = 0; | |
2250 | lck->lck_mtx_waiters = 0; | |
2251 | lck->lck_mtx_pri = 0; | |
2252 | } | |
2253 | lck_grp_reference(grp); | |
2254 | lck_grp_lckcnt_incr(grp, LCK_TYPE_MTX); | |
2255 | } | |
2256 | ||
2d21ac55 A |
2257 | /* |
2258 | * Routine: lck_mtx_init_ext | |
2259 | */ | |
2260 | void | |
2261 | lck_mtx_init_ext( | |
2262 | lck_mtx_t *lck, | |
2263 | lck_mtx_ext_t *lck_ext, | |
2264 | lck_grp_t *grp, | |
2265 | lck_attr_t *attr) | |
2266 | { | |
2267 | lck_attr_t *lck_attr; | |
2268 | ||
2269 | if (attr != LCK_ATTR_NULL) | |
2270 | lck_attr = attr; | |
2271 | else | |
2272 | lck_attr = &LockDefaultLckAttr; | |
2273 | ||
2274 | if ((lck_attr->lck_attr_val) & LCK_ATTR_DEBUG) { | |
2275 | lck_mtx_ext_init(lck_ext, grp, lck_attr); | |
2276 | lck->lck_mtx_tag = LCK_MTX_TAG_INDIRECT; | |
2277 | lck->lck_mtx_ptr = lck_ext; | |
2278 | } else { | |
2279 | lck->lck_mtx_data = 0; | |
2280 | lck->lck_mtx_waiters = 0; | |
2281 | lck->lck_mtx_pri = 0; | |
2282 | } | |
2283 | lck_grp_reference(grp); | |
2284 | lck_grp_lckcnt_incr(grp, LCK_TYPE_MTX); | |
2285 | } | |
2286 | ||
91447636 A |
2287 | /* |
2288 | * Routine: lck_mtx_ext_init | |
2289 | */ | |
2290 | void | |
2291 | lck_mtx_ext_init( | |
2292 | lck_mtx_ext_t *lck, | |
2293 | lck_grp_t *grp, | |
2294 | lck_attr_t *attr) { | |
2295 | ||
2296 | bzero((void *)lck, sizeof(lck_mtx_ext_t)); | |
2297 | ||
2298 | if ((attr->lck_attr_val) & LCK_ATTR_DEBUG) { | |
2299 | lck->lck_mtx_deb.type = MUTEX_TAG; | |
2300 | lck->lck_mtx_attr |= LCK_MTX_ATTR_DEBUG; | |
2301 | } | |
2302 | ||
2303 | lck->lck_mtx_grp = grp; | |
2304 | ||
2305 | if (grp->lck_grp_attr & LCK_GRP_ATTR_STAT) | |
2306 | lck->lck_mtx_attr |= LCK_MTX_ATTR_STAT; | |
2307 | } | |
2308 | ||
2309 | /* | |
2310 | * Routine: lck_mtx_destroy | |
2311 | */ | |
2312 | void | |
2313 | lck_mtx_destroy( | |
2314 | lck_mtx_t *lck, | |
2315 | lck_grp_t *grp) { | |
2316 | boolean_t lck_is_indirect; | |
2317 | ||
2318 | if (lck->lck_mtx_tag == LCK_MTX_TAG_DESTROYED) | |
2319 | return; | |
2320 | lck_is_indirect = (lck->lck_mtx_tag == LCK_MTX_TAG_INDIRECT); | |
2321 | lck->lck_mtx_tag = LCK_MTX_TAG_DESTROYED; | |
2322 | if (lck_is_indirect) | |
2323 | kfree((void *)lck->lck_mtx_ptr, sizeof(lck_mtx_ext_t)); | |
2324 | ||
2325 | lck_grp_lckcnt_decr(grp, LCK_TYPE_MTX); | |
2326 | lck_grp_deallocate(grp); | |
2327 | return; | |
2328 | } | |
2329 | ||
2330 | ||
2331 | #if MACH_KDB | |
2332 | /* | |
2333 | * Routines to print out simple_locks and mutexes in a nicely-formatted | |
2334 | * fashion. | |
2335 | */ | |
2336 | ||
2d21ac55 A |
2337 | const char *simple_lock_labels = "ENTRY ILK THREAD DURATION CALLER"; |
2338 | const char *mutex_labels = "ENTRY LOCKED WAITERS THREAD CALLER"; | |
91447636 A |
2339 | |
2340 | void db_print_simple_lock( | |
2341 | simple_lock_t addr); | |
2342 | ||
2343 | void db_print_mutex( | |
2344 | mutex_t * addr); | |
2345 | ||
2346 | void | |
2d21ac55 A |
2347 | db_show_one_simple_lock (db_expr_t addr, boolean_t have_addr, |
2348 | __unused db_expr_t count, | |
2349 | __unused char *modif) | |
91447636 | 2350 | { |
2d21ac55 | 2351 | simple_lock_t saddr = (simple_lock_t)(unsigned long)addr; |
91447636 A |
2352 | |
2353 | if (saddr == (simple_lock_t)0 || !have_addr) { | |
2354 | db_error ("No simple_lock\n"); | |
2355 | } | |
2356 | #if USLOCK_DEBUG | |
2357 | else if (saddr->lock_type != USLOCK_TAG) | |
2358 | db_error ("Not a simple_lock\n"); | |
2359 | #endif /* USLOCK_DEBUG */ | |
2360 | ||
2361 | db_printf ("%s\n", simple_lock_labels); | |
2362 | db_print_simple_lock (saddr); | |
2363 | } | |
2364 | ||
2365 | void | |
2366 | db_print_simple_lock ( | |
2367 | simple_lock_t addr) | |
2368 | { | |
2369 | ||
2370 | db_printf ("%08x %3d", addr, *hw_lock_addr(addr->interlock)); | |
2371 | #if USLOCK_DEBUG | |
2372 | db_printf (" %08x", addr->debug.lock_thread); | |
2373 | db_printf (" %08x ", addr->debug.duration[1]); | |
2374 | db_printsym ((int)addr->debug.lock_pc, DB_STGY_ANY); | |
2375 | #endif /* USLOCK_DEBUG */ | |
2376 | db_printf ("\n"); | |
2377 | } | |
2378 | ||
2379 | void | |
2d21ac55 A |
2380 | db_show_one_mutex (db_expr_t addr, boolean_t have_addr, |
2381 | __unused db_expr_t count, | |
2382 | __unused char *modif) | |
91447636 | 2383 | { |
2d21ac55 | 2384 | mutex_t * maddr = (mutex_t *)(unsigned long)addr; |
91447636 A |
2385 | |
2386 | if (maddr == (mutex_t *)0 || !have_addr) | |
2387 | db_error ("No mutex\n"); | |
2388 | #if MACH_LDEBUG | |
2389 | else if (maddr->lck_mtx_deb.type != MUTEX_TAG) | |
2390 | db_error ("Not a mutex\n"); | |
2391 | #endif /* MACH_LDEBUG */ | |
2392 | ||
2393 | db_printf ("%s\n", mutex_labels); | |
2394 | db_print_mutex (maddr); | |
2395 | } | |
2396 | ||
2397 | void | |
2398 | db_print_mutex ( | |
2399 | mutex_t * addr) | |
2400 | { | |
2401 | db_printf ("%08x %6d %7d", | |
2402 | addr, *addr, addr->lck_mtx.lck_mtx_waiters); | |
2403 | #if MACH_LDEBUG | |
2404 | db_printf (" %08x ", addr->lck_mtx_deb.thread); | |
2405 | db_printsym (addr->lck_mtx_deb.stack[0], DB_STGY_ANY); | |
2406 | #endif /* MACH_LDEBUG */ | |
2407 | db_printf ("\n"); | |
2408 | } | |
2409 | ||
2410 | void | |
2411 | db_show_one_lock( | |
2412 | lock_t *lock) | |
2413 | { | |
2414 | db_printf("shared_count = 0x%x, %swant_upgrade, %swant_exclusive, ", | |
2415 | lock->lck_rw.lck_rw_shared_cnt, | |
2416 | lock->lck_rw.lck_rw_want_upgrade ? "" : "!", | |
2417 | lock->lck_rw.lck_rw_want_excl ? "" : "!"); | |
2418 | db_printf("%swaiting\n", | |
2419 | lock->lck_rw.lck_rw_waiting ? "" : "!"); | |
2420 | db_printf("%sInterlock\n", | |
2421 | lock->lck_rw.lck_rw_interlock ? "" : "!"); | |
2422 | } | |
2423 | ||
2424 | #endif /* MACH_KDB */ | |
2425 |