[apple/xnu.git] / bsd / kern / kern_synch.c

/*
 * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
 *
 * @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.
 * 
 * This 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,
 * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
 * License for the specific language governing rights and limitations
 * under the License.
 * 
 * @APPLE_LICENSE_HEADER_END@
 */
/* 
 * Mach Operating System
 * Copyright (c) 1987 Carnegie-Mellon University
 * All rights reserved.  The CMU software License Agreement specifies
 * the terms and conditions for use and redistribution.
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <sys/user.h>
#include <sys/file.h>
#include <sys/vnode.h>
#include <sys/kernel.h>
#include <sys/buf.h>

#include <machine/spl.h>

#include <kern/queue.h>
#include <sys/lock.h>
#include <kern/thread.h>
#include <kern/ast.h>

#include <kern/cpu_number.h>
#include <vm/vm_kern.h>

#include <kern/task.h>
#include <mach/time_value.h>

_sleep_continue()
{
	register struct proc *p;
	register thread_t thread = current_thread();
	thread_act_t th_act;
	struct uthread * ut;
	int sig, catch;
	int error = 0;

	th_act = current_act();
	ut = get_bsdthread_info(th_act);
	catch = ut->uu_pri & PCATCH;
	p = current_proc();

#if FIXME  /* [ */
	thread->wait_mesg = NULL;
#endif  /* FIXME ] */
	switch (get_thread_waitresult(thread)) {
		case THREAD_TIMED_OUT:
			error = EWOULDBLOCK;
			break;
		case THREAD_AWAKENED:
			/*
			 * Posix implies any signal should be delivered
			 * first, regardless of whether awakened due
			 * to receiving event.
			 */
			if (!catch)
				break;
			/* else fall through */
		case THREAD_INTERRUPTED:
			if (catch) {
				unix_master();
				if (thread_should_abort(current_thread())) {
					error = EINTR;
				} else if (SHOULDissignal(p,ut)) {
					if (sig = CURSIG(p)) {
						if (p->p_sigacts->ps_sigintr & sigmask(sig))
							error = EINTR;
						else
							error = ERESTART;
					}
					if (thread_should_abort(current_thread())) {
						error = EINTR;
					}
				}
				unix_release();
			}  else
				error = EINTR;
			break;
	}

	if ((error == EINTR) || (error == ERESTART)) {
#ifdef BSD_USE_APC
		thread_apc_set(th_act, bsd_ast);
#else
                thread_ast_set(th_act, AST_BSD);
                ast_on(AST_BSD);
#endif
	}
	if (ut->uu_timo)
		thread_cancel_timer();

#if 0
	/* We should never get here without funnel, so we should not grab again */
	thread_funnel_set(kernel_flock, TRUE);
#endif /* 0 */
	unix_syscall_return((*ut->uu_continuation)(error));
}

/*
 * Give up the processor till a wakeup occurs
 * on chan, at which time the process
 * enters the scheduling queue at priority pri.
 * The most important effect of pri is that when
 * pri<=PZERO a signal cannot disturb the sleep;
 * if pri>PZERO signals will be processed.
 * If pri&PCATCH is set, signals will cause sleep
 * to return 1, rather than longjmp.
 * Callers of this routine must be prepared for
 * premature return, and check that the reason for
 * sleeping has gone away.
 */

#if FIXME
static __inline__
#endif
int
_sleep(chan, pri, wmsg, timo, continuation)
	caddr_t chan;
	int pri;
	char *wmsg;
	int timo;
	int (*continuation)();
{
	register struct proc *p;
	register thread_t thread = current_thread();
	thread_act_t th_act;
	struct uthread * ut;
	int sig, catch = pri & PCATCH;
	int sigttblock = pri & PTTYBLOCK;
	int error = 0;
	spl_t	s;

	s = splhigh();

	th_act = current_act();
	ut = get_bsdthread_info(th_act);
	
	p = current_proc();
#if KTRACE
	if (KTRPOINT(p, KTR_CSW))
		ktrcsw(p->p_tracep, 1, 0);
#endif	
	p->p_priority = pri & PRIMASK;
		
	if (chan)
		assert_wait(chan, (catch) ? THREAD_ABORTSAFE : THREAD_UNINT);
		
	if (timo)
		thread_set_timer(timo, NSEC_PER_SEC / hz);
	/*
	 * We start our timeout
	 * before calling CURSIG, as we could stop there, and a wakeup
	 * or a SIGCONT (or both) could occur while we were stopped.
	 * A SIGCONT would cause us to be marked as SSLEEP
	 * without resuming us, thus we must be ready for sleep
	 * when CURSIG is called.  If the wakeup happens while we're
	 * stopped, p->p_wchan will be 0 upon return from CURSIG.
	 */
	if (catch) {
		unix_master();
		if (SHOULDissignal(p,ut)) {
			if (sig = CURSIG(p)) {
				clear_wait(thread, THREAD_INTERRUPTED);
				/* if SIGTTOU or SIGTTIN then block till SIGCONT */
				if (sigttblock && ((sig == SIGTTOU) || (sig == SIGTTIN))) {
					p->p_flag |= P_TTYSLEEP;
					/* reset signal bits */
					clear_sigbits(p, sig);
					assert_wait(&p->p_siglist, THREAD_ABORTSAFE);
					/* assert wait can block and SIGCONT should be checked */
					if (p->p_flag & P_TTYSLEEP)
						thread_block(0);
					/* return with success */
					error = 0;
					goto out;
				}
				if (p->p_sigacts->ps_sigintr & sigmask(sig))
					error = EINTR;
				else
					error = ERESTART;
				unix_release();
				goto out;
			}
		}
		if (thread_should_abort(current_thread())) {
			clear_wait(thread, THREAD_INTERRUPTED);
			error = EINTR;
			unix_release();
			goto out;
		}
		if (get_thread_waitevent(thread) == 0) {  /*already happened */
			unix_release();
			goto out;
		}
		unix_release();
	}

#if FIXME  /* [ */
	thread->wait_mesg = wmsg;
#endif  /* FIXME ] */
	splx(s);
	p->p_stats->p_ru.ru_nvcsw++;

	if (continuation != (int (*)()) 0 ) {
	  ut->uu_continuation = continuation;
	  ut->uu_pri = pri;
	  ut->uu_timo = timo;
	  thread_block(_sleep_continue);
	  /* NOTREACHED */
	}

	thread_block(0);

#if FIXME  /* [ */
	thread->wait_mesg = NULL;
#endif  /* FIXME ] */
	switch (get_thread_waitresult(thread)) {
		case THREAD_TIMED_OUT:
			error = EWOULDBLOCK;
			break;
		case THREAD_AWAKENED:
			/*
			 * Posix implies any signal should be delivered
			 * first, regardless of whether awakened due
			 * to receiving event.
			 */
			if (!catch)
				break;
			/* else fall through */
		case THREAD_INTERRUPTED:
			if (catch) {
				unix_master();
				if (thread_should_abort(current_thread())) {
					error = EINTR;
				} else if (SHOULDissignal(p,ut)) {
					if (sig = CURSIG(p)) {
						if (p->p_sigacts->ps_sigintr & sigmask(sig))
							error = EINTR;
						else
							error = ERESTART;
					}
					if (thread_should_abort(current_thread())) {
						error = EINTR;
					}
				}
				unix_release();
			}  else
				error = EINTR;
			break;
	}
out:
	if ((error == EINTR) || (error == ERESTART)) {
#ifdef BSD_USE_APC
		thread_apc_set(th_act, bsd_ast);
#else
                thread_ast_set(th_act, AST_BSD);
                ast_on(AST_BSD);
#endif
	}
	if (timo)
		thread_cancel_timer();
	(void) splx(s);
	return (error);
}

int sleep(chan, pri)
	void *chan;
	int pri;
{

	return (_sleep((caddr_t)chan, pri, (char *)NULL, 0, (void (*)())0 ));
	
}

int	tsleep(chan, pri, wmsg, timo)
	void *chan;
	int pri;
	char * wmsg;
	int	timo;
{			
	return(_sleep((caddr_t)chan, pri, wmsg, timo, (void (*)())0 ));
}

int	tsleep0(chan, pri, wmsg, timo, continuation)
	void *chan;
	int pri;
	char * wmsg;
	int	timo;
	int (*continuation)();
{			
#if defined (__i386__)
	return(_sleep((caddr_t)chan, pri, wmsg, timo, (void (*)())0 ));
#else
	return(_sleep((caddr_t)chan, pri, wmsg, timo, continuation));
#endif
}

/*
 * Wake up all processes sleeping on chan.
 */
void
wakeup(chan)
	register void *chan;
{
	thread_wakeup_prim((caddr_t)chan,FALSE, THREAD_AWAKENED);
}

/*
 * Wake up the first process sleeping on chan.
 *
 * Be very sure that the first process is really
 * the right one to wakeup.
 */
wakeup_one(chan)
	register caddr_t chan;
{
	thread_wakeup_prim((caddr_t)chan, TRUE, THREAD_AWAKENED);
}

/*
 * Compute the priority of a process when running in user mode.
 * Arrange to reschedule if the resulting priority is better
 * than that of the current process.
 */
void
resetpriority(p)
	register struct proc *p;
{
	int newpri;
#if FIXME
	if (p->p_nice < 0)
	    newpri = BASEPRI_USER +
		(p->p_nice * (MAXPRI_USER - BASEPRI_USER)) / PRIO_MIN;
	else
	    newpri = BASEPRI_USER -
		(p->p_nice * BASEPRI_USER) / PRIO_MAX;

	(void)task_priority(p->task, newpri, TRUE);
#endif /* FIXME */
}
Commit	Line	Data
1c79356b A	1	/*
	2	* Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
	3	*
	4	* @APPLE_LICENSE_HEADER_START@
	5	*
	6	* The contents of this file constitute Original Code as defined in and
	7	* are subject to the Apple Public Source License Version 1.1 (the
	8	* "License"). You may not use this file except in compliance with the
	9	* License. Please obtain a copy of the License at
	10	* http://www.apple.com/publicsource and read it before using this file.
	11	*
	12	* This Original Code and all software distributed under the License are
	13	* distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
	14	* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
	15	* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
	16	* FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT. Please see the
	17	* License for the specific language governing rights and limitations
	18	* under the License.
	19	*
	20	* @APPLE_LICENSE_HEADER_END@
	21	*/
	22	/*
	23	* Mach Operating System
	24	* Copyright (c) 1987 Carnegie-Mellon University
	25	* All rights reserved. The CMU software License Agreement specifies
	26	* the terms and conditions for use and redistribution.
	27	*/
	28
	29	#include <sys/param.h>
	30	#include <sys/systm.h>
	31	#include <sys/proc.h>
	32	#include <sys/user.h>
	33	#include <sys/file.h>
	34	#include <sys/vnode.h>
	35	#include <sys/kernel.h>
	36	#include <sys/buf.h>
	37
	38	#include <machine/spl.h>
	39
	40	#include <kern/queue.h>
	41	#include <sys/lock.h>
	42	#include <kern/thread.h>
	43	#include <kern/ast.h>
	44
	45	#include <kern/cpu_number.h>
	46	#include <vm/vm_kern.h>
	47
	48	#include <kern/task.h>
	49	#include <mach/time_value.h>
	50
	51	_sleep_continue()
	52	{
	53	register struct proc *p;
	54	register thread_t thread = current_thread();
	55	thread_act_t th_act;
	56	struct uthread * ut;
	57	int sig, catch;
	58	int error = 0;
	59
	60	th_act = current_act();
	61	ut = get_bsdthread_info(th_act);
	62	catch = ut->uu_pri & PCATCH;
	63	p = current_proc();
	64
65	#if FIXME /* [ */
66	thread->wait_mesg = NULL;
67	#endif /* FIXME ] */
68	switch (get_thread_waitresult(thread)) {
69	case THREAD_TIMED_OUT:
70	error = EWOULDBLOCK;
71	break;
72	case THREAD_AWAKENED:
73	/*
74	* Posix implies any signal should be delivered
75	* first, regardless of whether awakened due
76	* to receiving event.
77	*/
78	if (!catch)
79	break;
80	/* else fall through */
81	case THREAD_INTERRUPTED:
82	if (catch) {
83	unix_master();
84	if (thread_should_abort(current_thread())) {
85	error = EINTR;
86	} else if (SHOULDissignal(p,ut)) {
87	if (sig = CURSIG(p)) {
88	if (p->p_sigacts->ps_sigintr & sigmask(sig))
89	error = EINTR;
90	else
91	error = ERESTART;
92	}
93	if (thread_should_abort(current_thread())) {
94	error = EINTR;
95	}
96	}
97	unix_release();
98	} else
99	error = EINTR;
100	break;
101	}
102
103	if ((error == EINTR) \|\| (error == ERESTART)) {
104	#ifdef BSD_USE_APC
105	thread_apc_set(th_act, bsd_ast);
106	#else
107	thread_ast_set(th_act, AST_BSD);
108	ast_on(AST_BSD);
109	#endif
110	}
111	if (ut->uu_timo)
112	thread_cancel_timer();
113
114	#if 0
115	/* We should never get here without funnel, so we should not grab again */
116	thread_funnel_set(kernel_flock, TRUE);
117	#endif /* 0 */
118	unix_syscall_return((*ut->uu_continuation)(error));
119	}
120
121	/*
122	* Give up the processor till a wakeup occurs
123	* on chan, at which time the process
124	* enters the scheduling queue at priority pri.
125	* The most important effect of pri is that when
126	* pri<=PZERO a signal cannot disturb the sleep;
127	* if pri>PZERO signals will be processed.
128	* If pri&PCATCH is set, signals will cause sleep
129	* to return 1, rather than longjmp.
130	* Callers of this routine must be prepared for
131	* premature return, and check that the reason for
132	* sleeping has gone away.
133	*/
134
135	#if FIXME
136	static __inline__
137	#endif
138	int
139	_sleep(chan, pri, wmsg, timo, continuation)
140	caddr_t chan;
141	int pri;
142	char *wmsg;
143	int timo;
144	int (*continuation)();
145	{
146	register struct proc *p;
147	register thread_t thread = current_thread();
148	thread_act_t th_act;
149	struct uthread * ut;
150	int sig, catch = pri & PCATCH;
151	int sigttblock = pri & PTTYBLOCK;
152	int error = 0;
153	spl_t s;
154
155	s = splhigh();
156
157	th_act = current_act();
158	ut = get_bsdthread_info(th_act);
159
160	p = current_proc();
161	#if KTRACE
162	if (KTRPOINT(p, KTR_CSW))
163	ktrcsw(p->p_tracep, 1, 0);
164	#endif
165	p->p_priority = pri & PRIMASK;
166
167	if (chan)
168	assert_wait(chan, (catch) ? THREAD_ABORTSAFE : THREAD_UNINT);
169
170	if (timo)
171	thread_set_timer(timo, NSEC_PER_SEC / hz);
172	/*
173	* We start our timeout
174	* before calling CURSIG, as we could stop there, and a wakeup
175	* or a SIGCONT (or both) could occur while we were stopped.
176	* A SIGCONT would cause us to be marked as SSLEEP
177	* without resuming us, thus we must be ready for sleep
178	* when CURSIG is called. If the wakeup happens while we're
179	* stopped, p->p_wchan will be 0 upon return from CURSIG.
180	*/
181	if (catch) {
182	unix_master();
183	if (SHOULDissignal(p,ut)) {
184	if (sig = CURSIG(p)) {
185	clear_wait(thread, THREAD_INTERRUPTED);
186	/* if SIGTTOU or SIGTTIN then block till SIGCONT */
187	if (sigttblock && ((sig == SIGTTOU) \|\| (sig == SIGTTIN))) {
188	p->p_flag \|= P_TTYSLEEP;
189	/* reset signal bits */
190	clear_sigbits(p, sig);
191	assert_wait(&p->p_siglist, THREAD_ABORTSAFE);
192	/* assert wait can block and SIGCONT should be checked */
193	if (p->p_flag & P_TTYSLEEP)
194	thread_block(0);
195	/* return with success */
196	error = 0;
197	goto out;
198	}
199	if (p->p_sigacts->ps_sigintr & sigmask(sig))
200	error = EINTR;
201	else
202	error = ERESTART;
203	unix_release();
204	goto out;
205	}
206	}
207	if (thread_should_abort(current_thread())) {
208	clear_wait(thread, THREAD_INTERRUPTED);
209	error = EINTR;
210	unix_release();
211	goto out;
212	}
213	if (get_thread_waitevent(thread) == 0) { /already happened /
214	unix_release();
215	goto out;
216	}
217	unix_release();
218	}
219
220	#if FIXME /* [ */
221	thread->wait_mesg = wmsg;
222	#endif /* FIXME ] */
223	splx(s);
224	p->p_stats->p_ru.ru_nvcsw++;
225
226	if (continuation != (int (*)()) 0 ) {
227	ut->uu_continuation = continuation;
228	ut->uu_pri = pri;
229	ut->uu_timo = timo;
230	thread_block(_sleep_continue);
231	/* NOTREACHED */
232	}
233
234	thread_block(0);
235
236	#if FIXME /* [ */
237	thread->wait_mesg = NULL;
238	#endif /* FIXME ] */
239	switch (get_thread_waitresult(thread)) {
240	case THREAD_TIMED_OUT:
241	error = EWOULDBLOCK;
242	break;
243	case THREAD_AWAKENED:
244	/*
245	* Posix implies any signal should be delivered
246	* first, regardless of whether awakened due
247	* to receiving event.
248	*/
249	if (!catch)
250	break;
251	/* else fall through */
252	case THREAD_INTERRUPTED:
253	if (catch) {
254	unix_master();
255	if (thread_should_abort(current_thread())) {
256	error = EINTR;
257	} else if (SHOULDissignal(p,ut)) {
258	if (sig = CURSIG(p)) {
259	if (p->p_sigacts->ps_sigintr & sigmask(sig))
260	error = EINTR;
261	else
262	error = ERESTART;
263	}
264	if (thread_should_abort(current_thread())) {
265	error = EINTR;
266	}
267	}
268	unix_release();
269	} else
270	error = EINTR;
271	break;
272	}
273	out:
274	if ((error == EINTR) \|\| (error == ERESTART)) {
275	#ifdef BSD_USE_APC
276	thread_apc_set(th_act, bsd_ast);
277	#else
278	thread_ast_set(th_act, AST_BSD);
279	ast_on(AST_BSD);
280	#endif
281	}
282	if (timo)
283	thread_cancel_timer();
284	(void) splx(s);
285	return (error);
286	}
287
288	int sleep(chan, pri)
289	void *chan;
290	int pri;
291	{
292
293	return (_sleep((caddr_t)chan, pri, (char )NULL, 0, (void ()())0 ));
294
295	}
296
297	int tsleep(chan, pri, wmsg, timo)
298	void *chan;
299	int pri;
300	char * wmsg;
301	int timo;
302	{
303	return(_sleep((caddr_t)chan, pri, wmsg, timo, (void (*)())0 ));
304	}
305
306	int tsleep0(chan, pri, wmsg, timo, continuation)
307	void *chan;
308	int pri;
309	char * wmsg;
310	int timo;
311	int (*continuation)();
312	{
313	#if defined (__i386__)
314	return(_sleep((caddr_t)chan, pri, wmsg, timo, (void (*)())0 ));
315	#else
316	return(_sleep((caddr_t)chan, pri, wmsg, timo, continuation));
317	#endif
318	}
319
320	/*
321	* Wake up all processes sleeping on chan.
322	*/
323	void
324	wakeup(chan)
325	register void *chan;
326	{
327	thread_wakeup_prim((caddr_t)chan,FALSE, THREAD_AWAKENED);
328	}
329
330	/*
331	* Wake up the first process sleeping on chan.
332	*
333	* Be very sure that the first process is really
334	* the right one to wakeup.
335	*/
336	wakeup_one(chan)
337	register caddr_t chan;
338	{
339	thread_wakeup_prim((caddr_t)chan, TRUE, THREAD_AWAKENED);
340	}
341
342	/*
343	* Compute the priority of a process when running in user mode.
344	* Arrange to reschedule if the resulting priority is better
345	* than that of the current process.
346	*/
347	void
348	resetpriority(p)
349	register struct proc *p;
350	{
351	int newpri;
352	#if FIXME
353	if (p->p_nice < 0)
354	newpri = BASEPRI_USER +
355	(p->p_nice * (MAXPRI_USER - BASEPRI_USER)) / PRIO_MIN;
356	else
357	newpri = BASEPRI_USER -
358	(p->p_nice * BASEPRI_USER) / PRIO_MAX;
359
360	(void)task_priority(p->task, newpri, TRUE);
361	#endif /* FIXME */
362	}
363