/*
* 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 <errno.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 LIST_HEAD(,sigev_thread) sigev_threads;
static unsigned int sigev_generation;
static pthread_mutex_t *sigev_list_mtx;
static pthread_once_t sigev_once = PTHREAD_ONCE_INIT;
static pthread_once_t sigev_once_default = PTHREAD_ONCE_INIT;
static struct sigev_thread *sigev_default_thread;
static pthread_attr_t sigev_default_attr;
static int atfork_registered;
static void __sigev_fork_prepare(void);
static void __sigev_fork_parent(void);
static void __sigev_fork_child(void);
static struct sigev_thread *sigev_thread_create(int);
static void *sigev_service_loop(void *);
static void *worker_routine(void *);
static void worker_cleanup(void *);
#pragma weak _pthread_create
static void
attrcopy(pthread_attr_t *src, pthread_attr_t *dst)
{
struct sched_param sched;
void *a;
size_t u;
int v;
_pthread_attr_getschedpolicy(src, &v);
_pthread_attr_setschedpolicy(dst, v);
_pthread_attr_getinheritsched(src, &v);
_pthread_attr_setinheritsched(dst, v);
_pthread_attr_getschedparam(src, &sched);
_pthread_attr_setschedparam(dst, &sched);
_pthread_attr_getscope(src, &v);
_pthread_attr_setscope(dst, v);
_pthread_attr_getstacksize(src, &u);
_pthread_attr_setstacksize(dst, u);
_pthread_attr_getstackaddr(src, &a);
_pthread_attr_setstackaddr(src, a);
_pthread_attr_getguardsize(src, &u);
_pthread_attr_setguardsize(dst, u);
}
static __inline int
have_threads(void)
{
return (&_pthread_create != NULL);
}
void
__sigev_thread_init(void)
{
static int inited = 0;
pthread_mutexattr_t mattr;
int i;
_pthread_mutexattr_init(&mattr);
_pthread_mutexattr_settype(&mattr, PTHREAD_MUTEX_NORMAL);
sigev_list_mtx = malloc(sizeof(pthread_mutex_t));
_pthread_mutex_init(sigev_list_mtx, &mattr);
_pthread_mutexattr_destroy(&mattr);
for (i = 0; i < HASH_QUEUES; ++i)
LIST_INIT(&sigev_hash[i]);
LIST_INIT(&sigev_all);
LIST_INIT(&sigev_threads);
sigev_default_thread = NULL;
if (atfork_registered == 0) {
_pthread_atfork(
__sigev_fork_prepare,
__sigev_fork_parent,
__sigev_fork_child);
atfork_registered = 1;
}
if (!inited) {
_pthread_attr_init(&sigev_default_attr);
_pthread_attr_setscope(&sigev_default_attr,
PTHREAD_SCOPE_SYSTEM);
_pthread_attr_setdetachstate(&sigev_default_attr,
PTHREAD_CREATE_DETACHED);
inited = 1;
}
sigev_default_thread = sigev_thread_create(0);
}
int
__sigev_check_init(void)
{
if (!have_threads())
return (-1);
_pthread_once(&sigev_once, __sigev_thread_init);
return (sigev_default_thread != NULL) ? 0 : -1;
}
static void
__sigev_fork_prepare(void)
{
}
static void
__sigev_fork_parent(void)
{
}
static void
__sigev_fork_child(void)
{
/*
* This is a hack, the thread libraries really should
* check if the handlers were already registered in
* pthread_atfork().
*/
atfork_registered = 1;
memcpy(&sigev_once, &sigev_once_default, sizeof(sigev_once));
__sigev_thread_init();
}
void
__sigev_list_lock(void)
{
_pthread_mutex_lock(sigev_list_mtx);
}
void
__sigev_list_unlock(void)
{
_pthread_mutex_unlock(sigev_list_mtx);
}
struct sigev_node *
__sigev_alloc(int type, const struct sigevent *evp, struct sigev_node *prev,
int usedefault)
{
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;
_pthread_attr_init(&sn->sn_attr);
_pthread_attr_setdetachstate(&sn->sn_attr, PTHREAD_CREATE_DETACHED);
if (evp->sigev_notify_attributes)
attrcopy(evp->sigev_notify_attributes, &sn->sn_attr);
if (prev) {
__sigev_list_lock();
prev->sn_tn->tn_refcount++;
__sigev_list_unlock();
sn->sn_tn = prev->sn_tn;
} else {
sn->sn_tn = sigev_thread_create(usedefault);
if (sn->sn_tn == NULL) {
_pthread_attr_destroy(&sn->sn_attr);
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 SIGSERVICE
* signal to the new thread.
*/
newevp->sigev_notify = SIGEV_THREAD_ID;
newevp->sigev_signo = 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)
{
_pthread_attr_destroy(&sn->sn_attr);
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);
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);
if (--sn->sn_tn->tn_refcount == 0)
_pthread_kill(sn->sn_tn->tn_thread, SIGSERVICE);
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;
}
return (-1);
}
static struct sigev_thread *
sigev_thread_create(int usedefault)
{
struct sigev_thread *tn;
sigset_t set, oset;
int ret;
if (usedefault && sigev_default_thread) {
__sigev_list_lock();
sigev_default_thread->tn_refcount++;
__sigev_list_unlock();
return (sigev_default_thread);
}
tn = malloc(sizeof(*tn));
tn->tn_cur = NULL;
tn->tn_lwpid = -1;
tn->tn_refcount = 1;
_pthread_cond_init(&tn->tn_cv, NULL);
/* for debug */
__sigev_list_lock();
LIST_INSERT_HEAD(&sigev_threads, tn, tn_link);
__sigev_list_unlock();
sigfillset(&set); /* SIGSERVICE is masked. */
sigdelset(&set, SIGBUS);
sigdelset(&set, SIGILL);
sigdelset(&set, SIGFPE);
sigdelset(&set, SIGSEGV);
sigdelset(&set, SIGTRAP);
_sigprocmask(SIG_SETMASK, &set, &oset);
ret = _pthread_create(&tn->tn_thread, &sigev_default_attr,
sigev_service_loop, tn);
_sigprocmask(SIG_SETMASK, &oset, NULL);
if (ret != 0) {
__sigev_list_lock();
LIST_REMOVE(tn, tn_link);
__sigev_list_unlock();
free(tn);
tn = NULL;
} else {
/* wait the thread to get its lwpid */
__sigev_list_lock();
while (tn->tn_lwpid == -1)
_pthread_cond_wait(&tn->tn_cv, sigev_list_mtx);
__sigev_list_unlock();
}
return (tn);
}
/*
* The thread receives notification from kernel and creates
* a thread to call user callback function.
*/
static void *
sigev_service_loop(void *arg)
{
static int failure;
siginfo_t si;
sigset_t set;
struct sigev_thread *tn;
struct sigev_node *sn;
sigev_id_t id;
pthread_t td;
int ret;
tn = arg;
thr_self(&tn->tn_lwpid);
__sigev_list_lock();
_pthread_cond_broadcast(&tn->tn_cv);
__sigev_list_unlock();
sigemptyset(&set);
sigaddset(&set, SIGSERVICE);
for (;;) {
ret = sigwaitinfo(&set, &si);
__sigev_list_lock();
if (tn->tn_refcount == 0) {
LIST_REMOVE(tn, tn_link);
__sigev_list_unlock();
free(tn);
break;
}
if (ret == -1) {
__sigev_list_unlock();
continue;
}
id = sigev_get_id(&si);
sn = __sigev_find(si.si_code, id);
if (sn == NULL) {
__sigev_list_unlock();
continue;
}
sn->sn_info = si;
if (sn->sn_flags & SNF_SYNC)
tn->tn_cur = sn;
else
tn->tn_cur = NULL;
sn->sn_flags |= SNF_WORKING;
__sigev_list_unlock();
ret = _pthread_create(&td, &sn->sn_attr, worker_routine, sn);
if (ret != 0) {
if (failure++ < 5)
warnc(ret, "%s:%s failed to create thread.\n",
__FILE__, __func__);
__sigev_list_lock();
sn->sn_flags &= ~SNF_WORKING;
if (sn->sn_flags & SNF_REMOVED)
__sigev_free(sn);
__sigev_list_unlock();
} else if (tn->tn_cur) {
__sigev_list_lock();
while (tn->tn_cur)
_pthread_cond_wait(&tn->tn_cv, sigev_list_mtx);
__sigev_list_unlock();
}
}
return (0);
}
/*
* newly created worker thread to call user callback function.
*/
static void *
worker_routine(void *arg)
{
struct sigev_node *sn = arg;
pthread_cleanup_push(worker_cleanup, sn);
sn->sn_dispatch(sn);
pthread_cleanup_pop(1);
return (0);
}
/* clean up a notification after dispatch. */
static void
worker_cleanup(void *arg)
{
struct sigev_node *sn = arg;
__sigev_list_lock();
if (sn->sn_flags & SNF_SYNC) {
sn->sn_tn->tn_cur = NULL;
_pthread_cond_broadcast(&sn->sn_tn->tn_cv);
}
if (sn->sn_flags & SNF_REMOVED)
__sigev_free(sn);
else
sn->sn_flags &= ~SNF_WORKING;
__sigev_list_unlock();
}
