From: Evan Hunt <each@isc.org>
Date: Sun, 7 Jul 2013 01:23:41 +0000 (-0700)
Subject: [master] prevent exportlib deadlock
X-Git-Tag: v9.10.0a1~235
X-Git-Url: http://git.ipfire.org/gitweb/?a=commitdiff_plain;h=eb4458b4784a2206d939f9c4cfed4b37b076b5bc;p=thirdparty%2Fbind9.git

[master] prevent exportlib deadlock

3609.	[bug]		Corrected a possible deadlock in applications using
			the export version of the isc_app API. [RT #33967]
---

diff --git a/CHANGES b/CHANGES
index 9fcb86bb582..c7e421adde5 100644
--- a/CHANGES
+++ b/CHANGES
@@ -1,3 +1,6 @@
+3609.	[bug]		Corrected a possible deadlock in applications using
+			the export version of the isc_app API. [RT #33967]
+
 3608.	[port]		win32: added todos.pl script to ensure all text files
 			the win32 build depends on are converted to DOS
 			newline format. [RT #22067]
diff --git a/lib/isc/unix/app.c b/lib/isc/unix/app.c
index 81eb29cf89e..2cea67ab5ff 100644
--- a/lib/isc/unix/app.c
+++ b/lib/isc/unix/app.c
@@ -690,6 +690,11 @@ isc__app_ctxrun(isc_appctx_t *ctx0) {
 			 * wait until woken up.
 			 */
 			LOCK(&ctx->readylock);
+			if (ctx->want_shutdown) {
+				/* shutdown() won the race. */
+				UNLOCK(&ctx->readylock);
+				break;
+			}
 			if (!ctx->want_reload)
 				WAIT(&ctx->ready, &ctx->readylock);
 			UNLOCK(&ctx->readylock);
@@ -719,7 +724,13 @@ isc__app_ctxrun(isc_appctx_t *ctx0) {
 			 * wait until woken up.
 			 */
 			LOCK(&ctx->readylock);
-			WAIT(&ctx->ready, &ctx->readylock);
+			if (ctx->want_shutdown) {
+				/* shutdown() won the race. */
+				UNLOCK(&ctx->readylock);
+				break;
+			}
+			if (!ctx->want_reload)
+				WAIT(&ctx->ready, &ctx->readylock);
 			UNLOCK(&ctx->readylock);
 		}
 #endif /* HAVE_SIGWAIT */
@@ -802,7 +813,9 @@ isc__app_ctxshutdown(isc_appctx_t *ctx0) {
 #endif /* HAVE_LINUXTHREADS */
 			else {
 				/* External, multiple contexts */
+				LOCK(&ctx->readylock);
 				ctx->want_shutdown = ISC_TRUE;
+				UNLOCK(&ctx->readylock);
 				SIGNAL(&ctx->ready);
 			}
 #endif /* ISC_PLATFORM_USETHREADS */
@@ -878,7 +891,9 @@ isc__app_ctxsuspend(isc_appctx_t *ctx0) {
 #endif /* HAVE_LINUXTHREADS */
 			else {
 				/* External, multiple contexts */
+				LOCK(&ctx->readylock);
 				ctx->want_reload = ISC_TRUE;
+				UNLOCK(&ctx->readylock);
 				SIGNAL(&ctx->ready);
 			}
 #endif /* ISC_PLATFORM_USETHREADS */