freebsd-dev/lib/librt/sigev_thread.c

427 lines
10 KiB
C

/*
* Copyright (c) 2005 David Xu <davidxu@freebsd.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice unmodified, this list of conditions, and the following
* disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* $FreeBSD$
*
*/
#include <sys/types.h>
#include <machine/atomic.h>
#include "namespace.h"
#include <err.h>
#include <ucontext.h>
#include <sys/thr.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <signal.h>
#include <pthread.h>
#include "un-namespace.h"
#include "sigev_thread.h"
LIST_HEAD(sigev_list_head, sigev_node);
#define HASH_QUEUES 17
#define HASH(t, id) ((((id) << 3) + (t)) % HASH_QUEUES)
static struct sigev_list_head sigev_hash[HASH_QUEUES];
static struct sigev_list_head sigev_all;
static int sigev_generation;
static pthread_mutex_t *sigev_list_mtx;
static TAILQ_HEAD(,sigev_thread_node) sigev_threads;
static pthread_mutex_t *sigev_threads_mtx;
static pthread_attr_t sigev_default_attr;
static pthread_once_t sigev_once = PTHREAD_ONCE_INIT;
static void __sigev_fork_prepare(void);
static void __sigev_fork_parent(void);
static void __sigev_fork_child(void);
static struct sigev_thread_node *sigev_thread_create(pthread_attr_t *);
static void *sigev_service_loop(void *);
#pragma weak pthread_create
#pragma weak pthread_attr_getschedpolicy
#pragma weak pthread_attr_getinheritsched
#pragma weak pthread_attr_getschedparam
#pragma weak pthread_attr_getscope
#pragma weak pthread_attr_getstacksize
#pragma weak pthread_attr_getstackaddr
#pragma weak pthread_attr_getguardsize
#pragma weak pthread_attr_init
#pragma weak pthread_attr_setscope
#pragma weak pthread_attr_setdetachstate
#pragma weak pthread_atfork
#pragma weak _pthread_once
#pragma weak pthread_cleanup_push
#pragma weak pthread_cleanup_pop
#pragma weak pthread_setcancelstate
static __inline void
attr2sna(pthread_attr_t *attr, struct sigev_thread_attr *sna)
{
struct sched_param sched_param;
pthread_attr_getschedpolicy(attr, &sna->sna_policy);
pthread_attr_getinheritsched(attr, &sna->sna_inherit);
pthread_attr_getschedparam(attr, &sched_param);
sna->sna_prio = sched_param.sched_priority;
pthread_attr_getscope(attr, &sna->sna_scope);
pthread_attr_getstacksize(attr, &sna->sna_stacksize);
pthread_attr_getstackaddr(attr, &sna->sna_stackaddr);
pthread_attr_getguardsize(attr, &sna->sna_guardsize);
}
static __inline int
sna_eq(const struct sigev_thread_attr *a, const struct sigev_thread_attr *b)
{
return memcmp(a, b, sizeof(*a)) == 0;
}
static __inline int
have_threads(void)
{
return (pthread_create != NULL);
}
void
__sigev_thread_init(void)
{
static int notfirst = 0;
int i;
sigev_list_mtx = malloc(sizeof(pthread_mutex_t));
_pthread_mutex_init(sigev_list_mtx, NULL);
sigev_threads_mtx = malloc(sizeof(pthread_mutex_t));
_pthread_mutex_init(sigev_threads_mtx, NULL);
for (i = 0; i < HASH_QUEUES; ++i)
LIST_INIT(&sigev_hash[i]);
LIST_INIT(&sigev_all);
TAILQ_INIT(&sigev_threads);
if (!notfirst) {
pthread_attr_init(&sigev_default_attr);
pthread_attr_setscope(&sigev_default_attr, PTHREAD_SCOPE_SYSTEM);
pthread_attr_setdetachstate(&sigev_default_attr,
PTHREAD_CREATE_DETACHED);
pthread_atfork(__sigev_fork_prepare, __sigev_fork_parent,
__sigev_fork_child);
notfirst = 1;
}
}
int
__sigev_check_init(void)
{
if (!have_threads())
return (-1);
_pthread_once(&sigev_once, __sigev_thread_init);
return (0);
}
void
__sigev_fork_prepare(void)
{
__sigev_thread_list_lock();
}
void
__sigev_fork_parent(void)
{
__sigev_thread_list_unlock();
}
void
__sigev_fork_child(void)
{
__sigev_thread_init();
}
int
__sigev_list_lock(void)
{
return _pthread_mutex_lock(sigev_list_mtx);
}
int
__sigev_list_unlock(void)
{
return _pthread_mutex_unlock(sigev_list_mtx);
}
int
__sigev_thread_list_lock(void)
{
return _pthread_mutex_lock(sigev_threads_mtx);
}
int
__sigev_thread_list_unlock(void)
{
return _pthread_mutex_unlock(sigev_threads_mtx);
}
struct sigev_node *
__sigev_alloc(int type, const struct sigevent *evp)
{
struct sigev_node *sn;
sn = calloc(1, sizeof(*sn));
if (sn != NULL) {
sn->sn_value = evp->sigev_value;
sn->sn_func = evp->sigev_notify_function;
sn->sn_gen = atomic_fetchadd_int(&sigev_generation, 1);
sn->sn_type = type;
sn->sn_tn = sigev_thread_create(evp->sigev_notify_attributes);
if (sn->sn_tn == NULL) {
free(sn);
sn = NULL;
}
}
return (sn);
}
void
__sigev_get_sigevent(struct sigev_node *sn, struct sigevent *newevp,
sigev_id_t id)
{
/*
* Build a new sigevent, and tell kernel to deliver SIGEV_SIGSERVICE
* signal to the new thread.
*/
newevp->sigev_notify = SIGEV_THREAD_ID;
newevp->sigev_signo = SIGEV_SIGSERVICE;
newevp->sigev_notify_thread_id = (lwpid_t)sn->sn_tn->tn_lwpid;
newevp->sigev_value.sival_ptr = (void *)id;
}
void
__sigev_free(struct sigev_node *sn)
{
free(sn);
}
struct sigev_node *
__sigev_find(int type, sigev_id_t id)
{
struct sigev_node *sn;
int chain = HASH(type, id);
LIST_FOREACH(sn, &sigev_hash[chain], sn_link) {
if (sn->sn_type == type && sn->sn_id == id)
break;
}
return (sn);
}
int
__sigev_register(struct sigev_node *sn)
{
int chain = HASH(sn->sn_type, sn->sn_id);
LIST_INSERT_HEAD(&sigev_hash[chain], sn, sn_link);
LIST_INSERT_HEAD(&sigev_all, sn, sn_allist);
return (0);
}
int
__sigev_delete(int type, sigev_id_t id)
{
struct sigev_node *sn;
sn = __sigev_find(type, id);
if (sn != NULL)
return (__sigev_delete_node(sn));
return (0);
}
int
__sigev_delete_node(struct sigev_node *sn)
{
LIST_REMOVE(sn, sn_link);
LIST_REMOVE(sn, sn_allist);
if (sn->sn_flags & SNF_WORKING)
sn->sn_flags |= SNF_REMOVED;
else
__sigev_free(sn);
return (0);
}
static
sigev_id_t
sigev_get_id(siginfo_t *si)
{
switch(si->si_code) {
case SI_TIMER:
return (si->si_timerid);
case SI_MESGQ:
return (si->si_mqd);
case SI_ASYNCIO:
return (sigev_id_t)si->si_value.sival_ptr;
default:
warnx("%s %s : unknown si_code %d\n", __FILE__, __func__,
si->si_code);
}
return (-1);
}
static struct sigev_thread_node *
sigev_thread_create(pthread_attr_t *pattr)
{
struct sigev_thread_node *tn;
struct sigev_thread_attr sna;
sigset_t set;
int ret;
if (pattr == NULL)
pattr = &sigev_default_attr;
else {
pthread_attr_setscope(pattr, PTHREAD_SCOPE_SYSTEM);
pthread_attr_setdetachstate(pattr, PTHREAD_CREATE_DETACHED);
}
attr2sna(pattr, &sna);
__sigev_thread_list_lock();
/* Search a thread matching the required pthread_attr. */
TAILQ_FOREACH(tn, &sigev_threads, tn_link) {
if (sna.sna_stackaddr == NULL) {
if (sna_eq(&tn->tn_sna, &sna))
break;
} else {
/*
* Reuse the thread if it has same stack address,
* because two threads can not run on same stack.
*/
if (sna.sna_stackaddr == tn->tn_sna.sna_stackaddr)
break;
}
}
if (tn != NULL) {
__sigev_thread_list_unlock();
return (tn);
}
tn = malloc(sizeof(*tn));
tn->tn_sna = sna;
tn->tn_cur = NULL;
TAILQ_INSERT_TAIL(&sigev_threads, tn, tn_link);
sigemptyset(&set);
sigaddset(&set, SIGEV_SIGSERVICE);
_sigprocmask(SIG_BLOCK, &set, NULL);
_pthread_cond_init(&tn->tn_cv, NULL);
ret = pthread_create(&tn->tn_thread, pattr, sigev_service_loop, tn);
_sigprocmask(SIG_UNBLOCK, &set, NULL);
if (ret != 0) {
TAILQ_REMOVE(&sigev_threads, tn, tn_link);
__sigev_thread_list_unlock();
_pthread_cond_destroy(&tn->tn_cv);
free(tn);
tn = NULL;
} else {
/* wait the thread to get its lwpid */
_pthread_cond_wait(&tn->tn_cv, sigev_threads_mtx);
__sigev_thread_list_unlock();
}
return (tn);
}
static void
after_dispatch(struct sigev_thread_node *tn)
{
struct sigev_node *sn;
if ((sn = tn->tn_cur) != NULL) {
__sigev_list_lock();
sn->sn_flags &= ~SNF_WORKING;
if (sn->sn_flags & SNF_REMOVED)
__sigev_free(sn);
else if (sn->sn_flags & SNF_ONESHOT)
__sigev_delete_node(sn);
tn->tn_cur = NULL;
__sigev_list_unlock();
}
}
/*
* This function is called if user callback calls
* pthread_exit() or pthread_cancel() for the thread.
*/
static void
thread_cleanup(void *arg)
{
struct sigev_thread_node *tn = arg;
fprintf(stderr, "Dangerous Robinson, calling pthread_exit() from "
"SIGEV_THREAD is undefined.");
after_dispatch(tn);
/* longjmp(tn->tn_jbuf, 1); */
abort();
}
static void *
sigev_service_loop(void *arg)
{
siginfo_t si;
sigset_t set;
struct sigev_thread_node *tn;
struct sigev_node *sn;
sigev_id_t id;
tn = arg;
thr_self(&tn->tn_lwpid);
__sigev_list_lock();
_pthread_cond_broadcast(&tn->tn_cv);
__sigev_list_unlock();
/*
* Service thread should not be killed by callback, if user
* attempts to do so, the thread will be restarted.
*/
setjmp(tn->tn_jbuf);
pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, NULL);
sigemptyset(&set);
sigaddset(&set, SIGEV_SIGSERVICE);
pthread_cleanup_push(thread_cleanup, tn);
for (;;) {
if (__predict_false(sigwaitinfo(&set, &si) == -1))
continue;
id = sigev_get_id(&si);
__sigev_list_lock();
sn = __sigev_find(si.si_code, id);
if (sn != NULL) {
tn->tn_cur = sn;
sn->sn_flags |= SNF_WORKING;
__sigev_list_unlock();
sn->sn_dispatch(sn, &si);
after_dispatch(tn);
} else
tn->tn_cur = NULL;
__sigev_list_unlock();
}
pthread_cleanup_pop(0);
return (0);
}