add app

lib/isc/Makefile.in

@@ -28,7 +28,7 @@ CWARNINGS =
 OBJS =		@ISC_EXTRA_OBJS@ \
 		assertions.o buffer.o error.o heap.o lex.o mem.o result.o \
 		rwlock.o symtab.o str.o event.o task.o timer.o version.o \
-		unix/time.o unix/stdtime.o unix/socket.o \
+		unix/app.o unix/time.o unix/stdtime.o unix/socket.o \
 		pthreads/condition.o
 
 SUBDIRS =	include unix pthreads

lib/isc/unix/Makefile.in

@@ -24,7 +24,7 @@ CINCLUDES =	-I${srcdir}/.. \
 CDEFINES =
 CWARNINGS =
 
-OBJS =		time.o stdtime.o socket.o
+OBJS =		app.o time.o stdtime.o socket.o
 
 SUBDIRS =	include
 TARGETS =	${OBJS}

lib/isc/unix/app.c

@@ -0,0 +1,231 @@
+/*
+ * Copyright (C) 1999  Internet Software Consortium.
+ * 
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ * 
+ * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
+ * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
+ * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
+ * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
+ * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
+ * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
+ * SOFTWARE.
+ */
+
+#include <config.h>
+
+#include <pthread.h>
+
+#include <sys/types.h>
+
+#include <stddef.h>
+#include <string.h>
+#include <errno.h>
+#include <unistd.h>
+#include <signal.h>
+
+#include <isc/app.h>
+#include <isc/error.h>
+#include <isc/task.h>
+#include <isc/event.h>
+#include <isc/boolean.h>
+#include <isc/mutex.h>
+
+#include "../util.h"	/* XXX */
+
+static isc_eventlist_t		on_run;
+static isc_mutex_t		lock;
+static isc_boolean_t		shutdown_requested = ISC_FALSE;
+
+#ifndef HAVE_SIGWAIT
+static void
+empty_action(int arg) {
+	(void)arg;
+}
+#endif
+
+isc_result_t
+isc_app_start(void) {
+	isc_result_t result;
+	int presult;
+	sigset_t sset;
+#ifndef HAVE_SIGWAIT
+	struct sigaction sa;
+#endif
+
+	/*
+	 * Start an ISC library application.
+	 */
+
+#ifdef NEED_PTHREAD_INIT
+	/*
+	 * BSDI 3.1 seg faults in pthread_sigmask() if we don't do this.
+	 */
+	presult = pthread_init();
+	if (presult != 0) {
+		UNEXPECTED_ERROR(__FILE__, __LINE__,
+				 "isc_app_start() pthread_init: %s", 
+				 strerror(presult));
+		return (ISC_R_UNEXPECTED);
+	}
+#endif
+
+	result = isc_mutex_init(&lock);
+	if (result != ISC_R_SUCCESS)
+		return (result);
+
+#ifndef HAVE_SIGWAIT
+	/*
+	 * Install do-nothing handlers for SIGINT and SIGTERM.
+	 *
+	 * We install them now because BSDI 3.1 won't block
+	 * the default actions, regardless of what we do with
+	 * pthread_sigmask().
+	 */
+	memset(&sa, 0, sizeof sa);
+	sa.sa_handler = empty_action;
+	if (sigfillset(&sa.sa_mask) != 0 ||
+	    sigaction(SIGINT, &sa, NULL) < 0) {
+		UNEXPECTED_ERROR(__FILE__, __LINE__,
+				 "isc_app_run() SIGINT setup: %s", 
+				 strerror(errno));
+		return (ISC_R_UNEXPECTED);
+	}
+	if (sigfillset(&sa.sa_mask) != 0 ||
+	    sigaction(SIGTERM, &sa, NULL) < 0) {
+		UNEXPECTED_ERROR(__FILE__, __LINE__,
+				 "isc_app_run() SIGTERM setup: %s", 
+				 strerror(errno));
+		return (ISC_R_UNEXPECTED);
+	}
+#endif
+
+	/*
+	 * Block SIGINT and SIGTERM.
+	 *
+	 * If isc_app_start() is called from the main thread before any other
+	 * threads have been created, then the pthread_sigmask() call below
+	 * will result in all threads having SIGINT and SIGTERM blocked by
+	 * default.
+	 */
+	if (sigemptyset(&sset) != 0 ||
+	    sigaddset(&sset, SIGINT) != 0 ||
+	    sigaddset(&sset, SIGTERM) != 0) {
+		UNEXPECTED_ERROR(__FILE__, __LINE__,
+				 "isc_app_start() sigsetops: %s", 
+				 strerror(errno));
+		return (ISC_R_UNEXPECTED);
+	}
+	presult = pthread_sigmask(SIG_BLOCK, &sset, NULL);
+	if (presult != 0) {
+		UNEXPECTED_ERROR(__FILE__, __LINE__,
+				 "isc_app_start() pthread_sigmask: %s", 
+				 strerror(presult));
+		return (ISC_R_UNEXPECTED);
+	}
+
+	ISC_LIST_INIT(on_run);
+
+	return (ISC_R_SUCCESS);
+}
+
+isc_result_t
+isc_app_run(void) {
+	int result;
+	sigset_t sset;
+#if 0
+	isc_event_t *event, *next_event;
+#endif
+#ifdef HAVE_SIGWAIT
+	int sig;
+#endif
+
+	/*
+	 * Run an ISC library application.
+	 */
+
+#if 0
+	/*
+	 * Post any on-run events (in LIFO order).
+	 */
+	for (event = ISC_LIST_HEAD(on_run);
+	     event != NULL;
+	     event = next_event) {
+		next_event = ISC_LIST_NEXT(event, link);
+		ISC_LIST_DEQUEUE(task->on_run, event, link);
+		isc_task_send(task, &event);
+		isc_task_detach(&task);
+	}
+#endif
+
+#ifdef HAVE_SIGWAIT
+	/*
+	 * Wait for SIGINT or SIGTERM.
+	 */
+	if (sigemptyset(&sset) != 0 ||
+	    sigaddset(&sset, SIGINT) != 0 ||
+	    sigaddset(&sset, SIGTERM) != 0) {
+		UNEXPECTED_ERROR(__FILE__, __LINE__,
+				 "isc_app_run() sigsetops: %s", 
+				 strerror(errno));
+		return (ISC_R_UNEXPECTED);
+	}
+	result = sigwait(&sset, &sig);
+#else
+	/*
+	 * Block all signals except for SIGINT and SIGTERM, and then
+	 * wait for one of them to occur.
+	 */
+	if (sigfillset(&sset) != 0 ||
+	    sigdelset(&sset, SIGINT) != 0 ||
+	    sigdelset(&sset, SIGTERM) != 0 ||
+	    sigdelset(&sset, SIGABRT) != 0) {
+		UNEXPECTED_ERROR(__FILE__, __LINE__,
+				 "isc_app_run() sigsetops: %s", 
+				 strerror(errno));
+		return (ISC_R_UNEXPECTED);
+	}
+	result = sigsuspend(&sset);
+#endif
+
+	return (ISC_R_SUCCESS);
+}
+
+isc_result_t
+isc_app_shutdown(void) {
+	isc_boolean_t want_kill = ISC_TRUE;
+
+	/*
+	 * Request application shutdown.
+	 */
+
+	LOCK(&lock);
+	
+	if (shutdown_requested)
+		want_kill = ISC_FALSE;
+	else
+		shutdown_requested = ISC_TRUE;
+
+	UNLOCK(&lock);
+
+	if (want_kill && kill(getpid(), SIGTERM) < 0) {
+		UNEXPECTED_ERROR(__FILE__, __LINE__,
+				 "isc_app_shutdown() kill: %s",
+				 strerror(errno));
+		return (ISC_R_UNEXPECTED);
+	}
+
+	return (ISC_R_SUCCESS);
+}
+
+void
+isc_app_finish(void) {
+	/*
+	 * Finish an ISC library application.
+	 */
+
+	(void)isc_mutex_destroy(&lock);
+}

lib/isc/unix/include/isc/Makefile.in

@@ -19,7 +19,7 @@ top_srcdir =	@top_srcdir@
 
 @BIND9_VERSION@
 
-HEADERS =	sockaddr.h time.h stdtime.h
+HEADERS =	app.h sockaddr.h time.h stdtime.h
 
 SUBDIRS =
 TARGETS =

lib/isc/unix/include/isc/app.h

@@ -0,0 +1,127 @@
+/*
+ * Copyright (C) 1999  Internet Software Consortium.
+ * 
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ * 
+ * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
+ * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
+ * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
+ * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
+ * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
+ * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
+ * SOFTWARE.
+ */
+
+#ifndef ISC_APP_H
+#define ISC_APP_H 1
+
+/*****
+ ***** Module Info
+ *****/
+
+/*
+ * ISC Application Support
+ *
+ * Dealing with program termination can be difficult, especially in a
+ * multithreaded program.  The routines in this module help coordinate
+ * the shutdown process.  They are used as follows by the initial (main)
+ * thread of the application:
+ *
+ *		isc_app_start();	Call very early in main(), before
+ *					any other threads have been created.
+ *
+ *		isc_app_run();		This will post any on-run events,
+ *					and then block until application
+ *					shutdown is requested.  A shutdown
+ *					request is made by calling
+ *					isc_app_shutdown(), or by sending
+ *					SIGINT or SIGTERM to the process.
+ *					After isc_app_run() returns, the
+ *					application should shutdown itself.
+ *
+ *		isc_app_finish();	Call very late in main().
+ *
+ * Use of this module is not required.  In particular, isc_app_start() is
+ * NOT an ISC library initialization routine.
+ *
+ * MP:
+ *	Clients must ensure that isc_app_start(), isc_app_run(), and
+ *	isc_app_finish() are called at most once.  isc_app_shutdown()
+ *	is safe to use by any thread (provided isc_app_start() has been
+ *	called previously).
+ *
+ * Reliability:
+ *	No anticipated impact.
+ *
+ * Resources:
+ *	None.
+ *
+ * Security:
+ *	No anticipated impact.
+ *
+ * Standards:
+ *	None.
+ */
+
+#include <isc/lang.h>
+#include <isc/result.h>
+#include <isc/event.h>
+
+ISC_LANG_BEGINDECLS
+
+typedef isc_event_t isc_appevent_t;
+
+isc_result_t
+isc_app_start(void);
+/*
+ * Start an ISC library application.
+ *
+ * Notes:
+ *	This call should be made before any other ISC library call, and as
+ *	close to the beginning of the application as possible.
+ */
+
+isc_result_t
+isc_app_run(void);
+/*
+ * Run an ISC library application.
+ *
+ * Notes:
+ *	The caller (typically the initial thread of an application) will
+ *	block until shutdown is requested.  When the call returns, the
+ *	caller should start shutting down the application.
+ */
+
+isc_result_t
+isc_app_shutdown(void);
+/*
+ * Request application shutdown.
+ *
+ * Notes:
+ *	It is safe to call isc_app_shutdown() multiple times.
+ *
+ * Requires:
+ *	isc_app_start() has been called.
+ */
+
+void
+isc_app_finish(void);
+/*
+ * Finish an ISC library application.
+ *
+ * Notes:
+ *	This call should be made at or near the end of main().
+ *
+ * Requires:
+ *	isc_app_start() has been called.
+ *
+ * Ensures:
+ *	Any resources allocated by isc_app_start() have been released.
+ */
+
+ISC_LANG_ENDDECLS
+
+#endif /* ISC_APP_H */