kern_thr.c revision 155501 
1/*-
2 * Copyright (c) 2003, Jeffrey Roberson <jeff@freebsd.org>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice unmodified, this list of conditions, and the following
10 *    disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 */
26
27#include <sys/cdefs.h>
28__FBSDID("$FreeBSD: head/sys/kern/kern_thr.c 155501 2006-02-10 03:34:29Z davidxu $");
29
30#include <sys/param.h>
31#include <sys/kernel.h>
32#include <sys/lock.h>
33#include <sys/mutex.h>
34#include <sys/proc.h>
35#include <sys/resourcevar.h>
36#include <sys/sched.h>
37#include <sys/sysctl.h>
38#include <sys/smp.h>
39#include <sys/sysent.h>
40#include <sys/systm.h>
41#include <sys/sysproto.h>
42#include <sys/signalvar.h>
43#include <sys/ucontext.h>
44#include <sys/thr.h>
45#include <sys/umtx.h>
46#include <sys/limits.h>
47
48#include <machine/frame.h>
49
50extern int max_threads_per_proc;
51extern int max_groups_per_proc;
52
53SYSCTL_DECL(_kern_threads);
54static int thr_scope = 0;
55SYSCTL_INT(_kern_threads, OID_AUTO, thr_scope, CTLFLAG_RW,
56	&thr_scope, 0, "sys or proc scope scheduling");
57
58static int thr_concurrency = 0;
59SYSCTL_INT(_kern_threads, OID_AUTO, thr_concurrency, CTLFLAG_RW,
60	&thr_concurrency, 0, "a concurrency value if not default");
61
62static int create_thread(struct thread *td, mcontext_t *ctx,
63			 void (*start_func)(void *), void *arg,
64			 char *stack_base, size_t stack_size,
65			 char *tls_base,
66			 long *child_tid, long *parent_tid,
67			 int flags);
68
69/*
70 * System call interface.
71 */
72int
73thr_create(struct thread *td, struct thr_create_args *uap)
74    /* ucontext_t *ctx, long *id, int flags */
75{
76	ucontext_t ctx;
77	int error;
78
79	if ((error = copyin(uap->ctx, &ctx, sizeof(ctx))))
80		return (error);
81
82	error = create_thread(td, &ctx.uc_mcontext, NULL, NULL,
83		NULL, 0, NULL, uap->id, NULL, uap->flags);
84	return (error);
85}
86
87int
88thr_new(struct thread *td, struct thr_new_args *uap)
89    /* struct thr_param * */
90{
91	struct thr_param param;
92	int error;
93
94	if (uap->param_size < sizeof(param))
95		return (EINVAL);
96	if ((error = copyin(uap->param, &param, sizeof(param))))
97		return (error);
98	error = create_thread(td, NULL, param.start_func, param.arg,
99		param.stack_base, param.stack_size, param.tls_base,
100		param.child_tid, param.parent_tid, param.flags);
101	return (error);
102}
103
104static int
105create_thread(struct thread *td, mcontext_t *ctx,
106	    void (*start_func)(void *), void *arg,
107	    char *stack_base, size_t stack_size,
108	    char *tls_base,
109	    long *child_tid, long *parent_tid,
110	    int flags)
111{
112	stack_t stack;
113	struct thread *newtd;
114	struct ksegrp *kg, *newkg;
115	struct proc *p;
116	long id;
117	int error, scope_sys, linkkg;
118
119	error = 0;
120	p = td->td_proc;
121	kg = td->td_ksegrp;
122
123	/* Have race condition but it is cheap. */
124	if ((p->p_numksegrps >= max_groups_per_proc) ||
125	    (p->p_numthreads >= max_threads_per_proc)) {
126		return (EPROCLIM);
127	}
128
129	/* Check PTHREAD_SCOPE_SYSTEM */
130	scope_sys = (flags & THR_SYSTEM_SCOPE) != 0;
131
132	/* sysctl overrides user's flag */
133	if (thr_scope == 1)
134		scope_sys = 0;
135	else if (thr_scope == 2)
136		scope_sys = 1;
137
138	/* Initialize our td and new ksegrp.. */
139	newtd = thread_alloc();
140
141	/*
142	 * Try the copyout as soon as we allocate the td so we don't
143	 * have to tear things down in a failure case below.
144	 * Here we copy out tid to two places, one for child and one
145	 * for parent, because pthread can create a detached thread,
146	 * if parent wants to safely access child tid, it has to provide
147	 * its storage, because child thread may exit quickly and
148	 * memory is freed before parent thread can access it.
149	 */
150	id = newtd->td_tid;
151	if ((child_tid != NULL &&
152	    (error = copyout(&id, child_tid, sizeof(long)))) ||
153	    (parent_tid != NULL &&
154	    (error = copyout(&id, parent_tid, sizeof(long))))) {
155	    	thread_free(newtd);
156		return (error);
157	}
158	bzero(&newtd->td_startzero,
159	    __rangeof(struct thread, td_startzero, td_endzero));
160	bcopy(&td->td_startcopy, &newtd->td_startcopy,
161	    __rangeof(struct thread, td_startcopy, td_endcopy));
162	newtd->td_proc = td->td_proc;
163	newtd->td_ucred = crhold(td->td_ucred);
164
165	cpu_set_upcall(newtd, td);
166
167	if (ctx != NULL) { /* old way to set user context */
168		error = set_mcontext(newtd, ctx);
169		if (error != 0) {
170			thread_free(newtd);
171			crfree(td->td_ucred);
172			return (error);
173		}
174	} else {
175		/* Set up our machine context. */
176		stack.ss_sp = stack_base;
177		stack.ss_size = stack_size;
178		/* Set upcall address to user thread entry function. */
179		cpu_set_upcall_kse(newtd, start_func, arg, &stack);
180		/* Setup user TLS address and TLS pointer register. */
181		error = cpu_set_user_tls(newtd, tls_base);
182		if (error != 0) {
183			thread_free(newtd);
184			crfree(td->td_ucred);
185			return (error);
186		}
187	}
188
189	if ((td->td_proc->p_flag & P_HADTHREADS) == 0) {
190		/* Treat initial thread as it has PTHREAD_SCOPE_PROCESS. */
191		p->p_procscopegrp = kg;
192		mtx_lock_spin(&sched_lock);
193		sched_set_concurrency(kg,
194		    thr_concurrency ? thr_concurrency : (2*mp_ncpus));
195		mtx_unlock_spin(&sched_lock);
196	}
197
198	linkkg = 0;
199	if (scope_sys) {
200		linkkg = 1;
201		newkg = ksegrp_alloc();
202		bzero(&newkg->kg_startzero,
203		    __rangeof(struct ksegrp, kg_startzero, kg_endzero));
204		bcopy(&kg->kg_startcopy, &newkg->kg_startcopy,
205		    __rangeof(struct ksegrp, kg_startcopy, kg_endcopy));
206		sched_init_concurrency(newkg);
207		PROC_LOCK(td->td_proc);
208	} else {
209		/*
210		 * Try to create a KSE group which will be shared
211		 * by all PTHREAD_SCOPE_PROCESS threads.
212		 */
213retry:
214		PROC_LOCK(td->td_proc);
215		if ((newkg = p->p_procscopegrp) == NULL) {
216			PROC_UNLOCK(p);
217			newkg = ksegrp_alloc();
218			bzero(&newkg->kg_startzero,
219			    __rangeof(struct ksegrp, kg_startzero, kg_endzero));
220			bcopy(&kg->kg_startcopy, &newkg->kg_startcopy,
221			    __rangeof(struct ksegrp, kg_startcopy, kg_endcopy));
222			PROC_LOCK(p);
223			if (p->p_procscopegrp == NULL) {
224				p->p_procscopegrp = newkg;
225				sched_init_concurrency(newkg);
226				sched_set_concurrency(newkg,
227				    thr_concurrency ? thr_concurrency : (2*mp_ncpus));
228				linkkg = 1;
229			} else {
230				PROC_UNLOCK(p);
231				ksegrp_free(newkg);
232				goto retry;
233			}
234		}
235	}
236
237	td->td_proc->p_flag |= P_HADTHREADS;
238	newtd->td_sigmask = td->td_sigmask;
239	mtx_lock_spin(&sched_lock);
240	if (linkkg)
241		ksegrp_link(newkg, p);
242	thread_link(newtd, newkg);
243	PROC_UNLOCK(p);
244
245	/* let the scheduler know about these things. */
246	if (linkkg)
247		sched_fork_ksegrp(td, newkg);
248	sched_fork_thread(td, newtd);
249	TD_SET_CAN_RUN(newtd);
250	/* if ((flags & THR_SUSPENDED) == 0) */
251		setrunqueue(newtd, SRQ_BORING);
252	mtx_unlock_spin(&sched_lock);
253
254	return (error);
255}
256
257int
258thr_self(struct thread *td, struct thr_self_args *uap)
259    /* long *id */
260{
261	long id;
262	int error;
263
264	id = td->td_tid;
265	if ((error = copyout(&id, uap->id, sizeof(long))))
266		return (error);
267
268	return (0);
269}
270
271int
272thr_exit(struct thread *td, struct thr_exit_args *uap)
273    /* long *state */
274{
275	struct proc *p;
276
277	p = td->td_proc;
278
279	/* Signal userland that it can free the stack. */
280	if ((void *)uap->state != NULL) {
281		suword((void *)uap->state, 1);
282		kern_umtx_wake(td, uap->state, INT_MAX);
283	}
284
285	PROC_LOCK(p);
286	sigqueue_flush(&td->td_sigqueue);
287	mtx_lock_spin(&sched_lock);
288
289	/*
290	 * Shutting down last thread in the proc.  This will actually
291	 * call exit() in the trampoline when it returns.
292	 */
293	if (p->p_numthreads != 1) {
294		thread_stopped(p);
295		thread_exit();
296		/* NOTREACHED */
297	}
298	mtx_unlock_spin(&sched_lock);
299	PROC_UNLOCK(p);
300	return (0);
301}
302
303int
304thr_kill(struct thread *td, struct thr_kill_args *uap)
305    /* long id, int sig */
306{
307	struct thread *ttd;
308	struct proc *p;
309	int error;
310
311	p = td->td_proc;
312	error = 0;
313	PROC_LOCK(p);
314	if (uap->id == -1) {
315		if (uap->sig != 0 && !_SIG_VALID(uap->sig)) {
316			error = EINVAL;
317		} else {
318			error = ESRCH;
319			FOREACH_THREAD_IN_PROC(p, ttd) {
320				if (ttd != td) {
321					error = 0;
322					if (uap->sig == 0)
323						break;
324					tdsignal(p, ttd, uap->sig, NULL);
325				}
326			}
327		}
328	} else {
329		if (uap->id != td->td_tid)
330			ttd = thread_find(p, uap->id);
331		else
332			ttd = td;
333		if (ttd == NULL)
334			error = ESRCH;
335		else if (uap->sig == 0)
336			;
337		else if (!_SIG_VALID(uap->sig))
338			error = EINVAL;
339		else
340			tdsignal(p, ttd, uap->sig, NULL);
341	}
342	PROC_UNLOCK(p);
343	return (error);
344}
345
346int
347thr_suspend(struct thread *td, struct thr_suspend_args *uap)
348	/* const struct timespec *timeout */
349{
350	struct timespec ts;
351	struct timeval	tv;
352	int error;
353	int hz;
354
355	hz = 0;
356	error = 0;
357	if (uap->timeout != NULL) {
358		error = copyin((const void *)uap->timeout, (void *)&ts,
359		    sizeof(struct timespec));
360		if (error != 0)
361			return (error);
362		if (ts.tv_nsec < 0 || ts.tv_nsec > 1000000000)
363			return (EINVAL);
364		if (ts.tv_sec == 0 && ts.tv_nsec == 0)
365			return (ETIMEDOUT);
366		TIMESPEC_TO_TIMEVAL(&tv, &ts);
367		hz = tvtohz(&tv);
368	}
369	PROC_LOCK(td->td_proc);
370	if ((td->td_flags & TDF_THRWAKEUP) == 0)
371		error = msleep((void *)td, &td->td_proc->p_mtx,
372		    td->td_priority | PCATCH, "lthr", hz);
373	if (td->td_flags & TDF_THRWAKEUP) {
374		mtx_lock_spin(&sched_lock);
375		td->td_flags &= ~TDF_THRWAKEUP;
376		mtx_unlock_spin(&sched_lock);
377		PROC_UNLOCK(td->td_proc);
378		return (0);
379	}
380	PROC_UNLOCK(td->td_proc);
381	if (error == EWOULDBLOCK)
382		error = ETIMEDOUT;
383	else if (error == ERESTART) {
384		if (hz != 0)
385			error = EINTR;
386	}
387	return (error);
388}
389
390int
391thr_wake(struct thread *td, struct thr_wake_args *uap)
392	/* long id */
393{
394	struct proc *p;
395	struct thread *ttd;
396
397	p = td->td_proc;
398	PROC_LOCK(p);
399	ttd = thread_find(p, uap->id);
400	if (ttd == NULL) {
401		PROC_UNLOCK(p);
402		return (ESRCH);
403	}
404	mtx_lock_spin(&sched_lock);
405	ttd->td_flags |= TDF_THRWAKEUP;
406	mtx_unlock_spin(&sched_lock);
407	wakeup((void *)ttd);
408	PROC_UNLOCK(p);
409	return (0);
410}
411
412int
413thr_set_name(struct thread *td, struct thr_set_name_args *uap)
414{
415	struct proc *p = td->td_proc;
416	char name[MAXCOMLEN + 1];
417	struct thread *ttd;
418	int error;
419
420	error = 0;
421	name[0] = '\0';
422	if (uap->name != NULL) {
423		error = copyinstr(uap->name, name, sizeof(name),
424			NULL);
425		if (error)
426			return (error);
427	}
428	PROC_LOCK(p);
429	if (uap->id == td->td_tid)
430		ttd = td;
431	else
432		ttd = thread_find(p, uap->id);
433	if (ttd != NULL)
434		strcpy(ttd->td_name, name);
435	else
436		error = ESRCH;
437	PROC_UNLOCK(p);
438	return (error);
439}
440