Bring in my initial version of POSIX realtime extension library.

Current the library implements mqueue, timer and aio with SIGEV_THREAD
notification supported.

Earlier version reviewed by: deischen

1 files changed, 433 insertions, 0 deletions

diff --git a/lib/librt/sigev_thread.c b/lib/librt/sigev_thread.c
new file mode 100644
index 0000000..3dadc12
--- /dev/null
+++ b/lib/librt/sigev_thread.c
@@ -0,0 +1,433 @@
+/*
+ * 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
+
+__weak_reference(__sigev_stub_zero, pthread_attr_getschedpolicy);
+__weak_reference(__sigev_stub_zero, pthread_attr_getinheritsched);
+__weak_reference(__sigev_stub_zero, pthread_attr_getschedparam);
+__weak_reference(__sigev_stub_zero, pthread_attr_getscope);
+__weak_reference(__sigev_stub_zero, pthread_attr_getstacksize);
+__weak_reference(__sigev_stub_zero, pthread_attr_getstackaddr);
+__weak_reference(__sigev_stub_zero, pthread_attr_getguardsize);
+__weak_reference(__sigev_stub_zero, pthread_attr_init);
+__weak_reference(__sigev_stub_zero, pthread_attr_setscope);
+__weak_reference(__sigev_stub_zero, pthread_attr_setdetachstate);
+__weak_reference(__sigev_stub_zero, pthread_atfork);
+__weak_reference(__sigev_stub_zero, _pthread_once);
+__weak_reference(__sigev_stub_zero, pthread_cleanup_push);
+__weak_reference(__sigev_stub_zero, pthread_cleanup_pop);
+__weak_reference(__sigev_stub_zero, pthread_setcancelstate);
+
+int
+__sigev_stub_zero(void)
+{
+	return (0);
+}
+
+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);
+}