From bb2b9b1ff447120d539589b31275ad8b7ea6c4a9 Mon Sep 17 00:00:00 2001
From: Tilghman Lesher <tilghman@meg.abyt.es>
Date: Tue, 24 Feb 2009 17:51:36 +0000
Subject: [PATCH] Cause astcanary to exit if Asterisk exits abnormally and
doesn't kill astcanary. Also, add some documentation supporting the use of
astcanary. (closes issue #14538) Reported by: KNK Patches:
asterisk-1.6.x-astcanary.diff uploaded by KNK (license 545)
git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@178303 65c4cc65-6c06-0410-ace0-fbb531ad65f3
---
utils/astcanary.c | 18 +++++++++++++++---
1 file changed, 15 insertions(+), 3 deletions(-)
diff --git a/utils/astcanary.c b/utils/astcanary.c
index da91e6dd2e..eea228916d 100644
--- a/utils/astcanary.c
+++ b/utils/astcanary.c
@@ -30,7 +30,7 @@
* At one time, canaries were carried along with coal miners down
* into a mine. Their purpose was to alert the miners when they
* had drilled into a pocket of methane gas or another noxious
- * substance. The canary, being the most sensitive animal would
+ * substance. The canary, being the most sensitive animal, would
* immediately fall over. Seeing this, the miners could take
* action to escape the mine, seeing an imminent danger.
*
@@ -57,6 +57,18 @@
* the same time. This is also why this canary must exist as a
* completely separate process and not simply as a thread within
* Asterisk itself.
+ *
+ * Quote:
+ * "The nice value set with setpriority() shall be applied to the
+ * process. If the process is multi-threaded, the nice value shall
+ * affect all system scope threads in the process."
+ *
+ * Source:
+ * http://www.opengroup.org/onlinepubs/000095399/functions/setpriority.html
+ *
+ * In answer to the question, what aren't system scope threads, the
+ * answer is, in Asterisk, nothing. Process scope threads are the
+ * alternative, but they aren't supported in Linux.
*/
static const char explanation[] =
@@ -77,7 +89,7 @@ int main(int argc, char *argv[])
int fd;
/* Run at normal priority */
setpriority(PRIO_PROCESS, 0, 0);
- for (;;) {
+ for (; getppid() != 1;) {
/* Update the modification times (checked from Asterisk) */
if (utime(argv[1], NULL)) {
/* Recreate the file if it doesn't exist */
@@ -96,7 +108,7 @@ int main(int argc, char *argv[])
sleep(5);
}
- /* Never reached */
+ /* Reached if asterisk (our parent process) dies - its chldren are inherited by the init process (pid is 1). */
return 0;
}
--
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