xnu-344.49.tar.gz

[apple/xnu.git] / osfmk / kern / lock.c

diff --git a/osfmk/kern/lock.c b/osfmk/kern/lock.c
index 383bf774b8604213bbdfe97a3fb24821d46b41db..4883f2bef7638ab23bfee0bc5e97418ab7283b44 100644 (file)
--- a/osfmk/kern/lock.c
+++ b/osfmk/kern/lock.c
@@ -3,19 +3,22 @@
  *
  * @APPLE_LICENSE_HEADER_START@
  * 
  *
  * @APPLE_LICENSE_HEADER_START@
  * 

- * The contents of this file constitute Original Code as defined in and
- * are subject to the Apple Public Source License Version 1.1 (the
- * "License").  You may not use this file except in compliance with the
- * License.  Please obtain a copy of the License at
- * http://www.apple.com/publicsource and read it before using this file.
+ * Copyright (c) 1999-2003 Apple Computer, Inc.  All Rights Reserved.

  * 
  * 

- * This Original Code and all software distributed under the License are
- * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
+ * This file contains Original Code and/or Modifications of Original Code
+ * as defined in and that are subject to the Apple Public Source License
+ * Version 2.0 (the 'License'). You may not use this file except in
+ * compliance with the License. Please obtain a copy of the License at
+ * http://www.opensource.apple.com/apsl/ and read it before using this
+ * file.
+ * 
+ * The Original Code and all software distributed under the License are
+ * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER

  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,

- * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
- * License for the specific language governing rights and limitations
- * under the License.
+ * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
+ * Please see the License for the specific language governing rights and
+ * limitations under the License.

  * 
  * @APPLE_LICENSE_HEADER_END@
  */
  * 
  * @APPLE_LICENSE_HEADER_END@
  */


@@ -63,6 +66,7 @@
 #include <kern/etap_macros.h>
 #include <kern/misc_protos.h>
 #include <kern/thread.h>
 #include <kern/etap_macros.h>
 #include <kern/misc_protos.h>
 #include <kern/thread.h>

+#include <kern/processor.h>

 #include <kern/sched_prim.h>
 #include <kern/xpr.h>
 #include <kern/debug.h>
 #include <kern/sched_prim.h>
 #include <kern/xpr.h>
 #include <kern/debug.h>


@@ -80,6 +84,8 @@
 #include <ppc/POWERMAC/mp/MPPlugIn.h>
 #endif
 
 #include <ppc/POWERMAC/mp/MPPlugIn.h>
 #endif
 

+#include <sys/kdebug.h>
+

 #define        ANY_LOCK_DEBUG  (USLOCK_DEBUG || LOCK_DEBUG || MUTEX_DEBUG)
 
 /*
 #define        ANY_LOCK_DEBUG  (USLOCK_DEBUG || LOCK_DEBUG || MUTEX_DEBUG)
 
 /*


@@ -243,43 +249,9 @@ usimple_lock(
        ETAP_TIME_CLEAR(start_wait_time);
 #endif /* ETAP_LOCK_TRACE */
 
        ETAP_TIME_CLEAR(start_wait_time);
 #endif /* ETAP_LOCK_TRACE */
 

-#ifdef __ppc__
-       if(!hw_lock_to(&l->interlock, LockTimeOut)) {   /* Try to get the lock with a timeout */ 
-       
+       if(!hw_lock_to(&l->interlock, LockTimeOut))     /* Try to get the lock with a timeout */ 

                panic("simple lock deadlock detection - l=%08X, cpu=%d, ret=%08X", l, cpu_number(), pc);
 
                panic("simple lock deadlock detection - l=%08X, cpu=%d, ret=%08X", l, cpu_number(), pc);
 

-#else /* __ppc__ */
-       while (!hw_lock_try(&l->interlock)) {
-               ETAPCALL(if (no_miss_info++ == 0)
-                       start_wait_time = etap_simplelock_miss(l));
-               while (hw_lock_held(&l->interlock)) {
-                       /*
-                        *      Spin watching the lock value in cache,
-                        *      without consuming external bus cycles.
-                        *      On most SMP architectures, the atomic
-                        *      instruction(s) used by hw_lock_try
-                        *      cost much, much more than an ordinary
-                        *      memory read.
-                        */
-#if    USLOCK_DEBUG
-                       if (count++ > max_lock_loops
-#if    MACH_KDB && NCPUS > 1
-                           && l != &kdb_lock
-#endif /* MACH_KDB && NCPUS > 1 */
-                           ) {
-                               if (l == &printf_lock) {
-                                       return;
-                               }
-                               mp_disable_preemption();
-                               panic("simple lock deadlock detection - l=%08X (=%08X), cpu=%d, ret=%08X", 
-                                  l, *hw_lock_addr(l->interlock), cpu_number(), pc);
-                               count = 0;
-                               mp_enable_preemption();
-                       }
-#endif         /* USLOCK_DEBUG */
-               }
-#endif /* 0 */
-       }

        ETAPCALL(etap_simplelock_hold(l, pc, start_wait_time));
        USLDBG(usld_lock_post(l, pc));
 }
        ETAPCALL(etap_simplelock_hold(l, pc, start_wait_time));
        USLDBG(usld_lock_post(l, pc));
 }


@@ -1084,8 +1056,9 @@ lock_write(
                        ETAP_SET_REASON(current_thread(),
                                        BLOCKED_ON_COMPLEX_LOCK);
                        thread_sleep_simple_lock((event_t) l,
                        ETAP_SET_REASON(current_thread(),
                                        BLOCKED_ON_COMPLEX_LOCK);
                        thread_sleep_simple_lock((event_t) l,

-                                       simple_lock_addr(l->interlock), FALSE);
-                       simple_lock(&l->interlock);
+                                       simple_lock_addr(l->interlock),
+                                       THREAD_UNINT);
+                       /* interlock relocked */

                }
        }
        l->want_write = TRUE;
                }
        }
        l->want_write = TRUE;


@@ -1119,8 +1092,9 @@ lock_write(
                         ETAP_SET_REASON(current_thread(),
                                         BLOCKED_ON_COMPLEX_LOCK);
                        thread_sleep_simple_lock((event_t) l,
                         ETAP_SET_REASON(current_thread(),
                                         BLOCKED_ON_COMPLEX_LOCK);
                        thread_sleep_simple_lock((event_t) l,

-                               simple_lock_addr(l->interlock), FALSE);
-                       simple_lock(&l->interlock);
+                               simple_lock_addr(l->interlock),
+                               THREAD_UNINT);
+                       /* interlock relocked */

                }
        }
 
                }
        }
 


@@ -1303,8 +1277,9 @@ lock_read(
                if (l->can_sleep && (l->want_write || l->want_upgrade)) {
                        l->waiting = TRUE;
                        thread_sleep_simple_lock((event_t) l,
                if (l->can_sleep && (l->want_write || l->want_upgrade)) {
                        l->waiting = TRUE;
                        thread_sleep_simple_lock((event_t) l,

-                                       simple_lock_addr(l->interlock), FALSE);
-                       simple_lock(&l->interlock);
+                                       simple_lock_addr(l->interlock),
+                                       THREAD_UNINT);
+                       /* interlock relocked */

                }
        }
 
                }
        }
 


@@ -1454,8 +1429,9 @@ lock_read_to_write(
                if (l->can_sleep && l->read_count != 0) {
                        l->waiting = TRUE;
                        thread_sleep_simple_lock((event_t) l,
                if (l->can_sleep && l->read_count != 0) {
                        l->waiting = TRUE;
                        thread_sleep_simple_lock((event_t) l,

-                                       simple_lock_addr(l->interlock), FALSE);
-                       simple_lock(&l->interlock);
+                                       simple_lock_addr(l->interlock),
+                                       THREAD_UNINT);
+                       /* interlock relocked */

                }
        }
 
                }
        }
 


@@ -1715,35 +1691,173 @@ mutex_free(
        kfree((vm_offset_t)m, sizeof(mutex_t));
 }
 
        kfree((vm_offset_t)m, sizeof(mutex_t));
 }
 

-

 /*
 /*

- * mutex_lock_wait: Invoked if the assembler routine mutex_lock () fails
- * because the mutex is already held by another thread.  Called with the
- * interlock locked and returns with the interlock unlocked.
+ * mutex_lock_wait
+ *
+ * Invoked in order to wait on contention.
+ *
+ * Called with the interlock locked and
+ * returns it unlocked.

  */
  */

-

 void
 mutex_lock_wait (
 void
 mutex_lock_wait (

-       mutex_t         * m)
+       mutex_t                 *mutex,
+       thread_act_t    holder)

 {
 {

-       m->waiters++;
-       ETAP_SET_REASON(current_thread(), BLOCKED_ON_MUTEX_LOCK);
-       thread_sleep_interlock ((event_t) m, &m->interlock, THREAD_UNINT);
+       thread_t                thread, self = current_thread();
+#if            !defined(i386)
+       integer_t               priority;
+       spl_t                   s = splsched();
+
+       priority = self->last_processor->current_pri;
+       if (priority < self->priority)
+               priority = self->priority;
+       if (priority > MINPRI_KERNEL)
+               priority = MINPRI_KERNEL;
+       else
+       if (priority < BASEPRI_DEFAULT)
+               priority = BASEPRI_DEFAULT;
+
+       thread = holder->thread;
+       assert(thread->top_act == holder);      /* XXX */
+       thread_lock(thread);
+       if (mutex->promoted_pri == 0)
+               thread->promotions++;
+       if (thread->priority < MINPRI_KERNEL) {
+               thread->sched_mode |= TH_MODE_PROMOTED;
+               if (    mutex->promoted_pri < priority  &&
+                               thread->sched_pri < priority            ) {
+                       KERNEL_DEBUG_CONSTANT(
+                               MACHDBG_CODE(DBG_MACH_SCHED,MACH_PROMOTE) | DBG_FUNC_NONE,
+                                       thread->sched_pri, priority, (int)thread, (int)mutex, 0);
+
+                       set_sched_pri(thread, priority);
+               }
+       }
+       thread_unlock(thread);
+       splx(s);
+
+       if (mutex->promoted_pri < priority)
+               mutex->promoted_pri = priority;
+#endif
+
+       if (self->pending_promoter[self->pending_promoter_index] == NULL) {
+               self->pending_promoter[self->pending_promoter_index] = mutex;
+               mutex->waiters++;
+       }
+       else
+       if (self->pending_promoter[self->pending_promoter_index] != mutex) {
+               self->pending_promoter[++self->pending_promoter_index] = mutex;
+               mutex->waiters++;
+       }
+
+       assert_wait(mutex, THREAD_UNINT);
+       interlock_unlock(&mutex->interlock);
+
+       thread_block(THREAD_CONTINUE_NULL);

 }
 
 /*
 }
 
 /*

- * mutex_unlock_wakeup: Invoked if the assembler routine mutex_unlock ()
- * fails because there are thread(s) waiting for this mutex.  Called and
- * returns with the interlock locked.
+ * mutex_lock_acquire
+ *
+ * Invoked on acquiring the mutex when there is
+ * contention.
+ *
+ * Returns the current number of waiters.
+ *
+ * Called with the interlock locked.

  */
  */

+int
+mutex_lock_acquire(
+       mutex_t                 *mutex)
+{
+       thread_t                thread = current_thread();
+
+       if (thread->pending_promoter[thread->pending_promoter_index] == mutex) {
+               thread->pending_promoter[thread->pending_promoter_index] = NULL;
+               if (thread->pending_promoter_index > 0)
+                       thread->pending_promoter_index--;
+               mutex->waiters--;
+       }
+
+#if            !defined(i386)
+       if (mutex->waiters > 0) {
+               integer_t               priority = mutex->promoted_pri;
+               spl_t                   s = splsched();
+
+               thread_lock(thread);
+               thread->promotions++;
+               if (thread->priority < MINPRI_KERNEL) {
+                       thread->sched_mode |= TH_MODE_PROMOTED;
+                       if (thread->sched_pri < priority) {
+                               KERNEL_DEBUG_CONSTANT(
+                                       MACHDBG_CODE(DBG_MACH_SCHED,MACH_PROMOTE) | DBG_FUNC_NONE,
+                                               thread->sched_pri, priority, 0, (int)mutex, 0);
+
+                               set_sched_pri(thread, priority);
+                       }
+               }
+               thread_unlock(thread);
+               splx(s);
+       }
+       else
+               mutex->promoted_pri = 0;
+#endif
+
+       return (mutex->waiters);
+}

 
 

+/*
+ * mutex_unlock_wakeup
+ *
+ * Invoked on unlock when there is contention.
+ *
+ * Called with the interlock locked.
+ */

 void
 mutex_unlock_wakeup (
 void
 mutex_unlock_wakeup (

-       mutex_t         * m)
+       mutex_t                 *mutex,
+       thread_act_t    holder)

 {
 {

-       assert(m->waiters);
-       m->waiters--;
-       thread_wakeup_one ((event_t) m);
+#if            !defined(i386)
+       thread_t                thread = current_thread();
+
+       if (thread->top_act != holder)
+               panic("mutex_unlock_wakeup: mutex %x holder %x\n", mutex, holder);
+
+       if (thread->promotions > 0) {
+               spl_t           s = splsched();
+
+               thread_lock(thread);
+               if (    --thread->promotions == 0                               &&
+                               (thread->sched_mode & TH_MODE_PROMOTED)         ) {
+                       thread->sched_mode &= ~TH_MODE_PROMOTED;
+                       if (thread->sched_mode & TH_MODE_ISDEPRESSED) {
+                               KERNEL_DEBUG_CONSTANT(
+                                       MACHDBG_CODE(DBG_MACH_SCHED,MACH_DEMOTE) | DBG_FUNC_NONE,
+                                                 thread->sched_pri, DEPRESSPRI, 0, (int)mutex, 0);
+
+                               set_sched_pri(thread, DEPRESSPRI);
+                       }
+                       else {
+                               if (thread->priority < thread->sched_pri) {
+                                       KERNEL_DEBUG_CONSTANT(
+                                               MACHDBG_CODE(DBG_MACH_SCHED,MACH_DEMOTE) |
+                                                                                                                       DBG_FUNC_NONE,
+                                                       thread->sched_pri, thread->priority,
+                                                                       0, (int)mutex, 0);
+                               }
+
+                               compute_priority(thread, FALSE);
+                       }
+               }
+               thread_unlock(thread);
+               splx(s);
+       }
+#endif
+
+       assert(mutex->waiters > 0);
+       thread_wakeup_one(mutex);

 }
 
 /*
 }
 
 /*


@@ -1753,13 +1867,15 @@ mutex_unlock_wakeup (
 void
 mutex_pause(void)
 {
 void
 mutex_pause(void)
 {

-       int wait_result;
+       wait_result_t wait_result;
+
+       wait_result = assert_wait_timeout( 1, THREAD_UNINT);
+       assert(wait_result == THREAD_WAITING);

 
 

-       assert_wait_timeout( 1, THREAD_INTERRUPTIBLE);

        ETAP_SET_REASON(current_thread(), BLOCKED_ON_MUTEX_LOCK);
        ETAP_SET_REASON(current_thread(), BLOCKED_ON_MUTEX_LOCK);

-       wait_result = thread_block((void (*)(void))0);
-       if (wait_result != THREAD_TIMED_OUT)
-               thread_cancel_timer();
+
+       wait_result = thread_block(THREAD_CONTINUE_NULL);
+       assert(wait_result == THREAD_TIMED_OUT);

 }
 
 #if    MACH_KDB
 }
 
 #if    MACH_KDB