From bb2b9b1ff447120d539589b31275ad8b7ea6c4a9 Mon Sep 17 00:00:00 2001 From: Tilghman Lesher Date: Tue, 24 Feb 2009 17:51:36 +0000 Subject: 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(-) (limited to 'utils') diff --git a/utils/astcanary.c b/utils/astcanary.c index da91e6dd2..eea228916 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; } -- cgit v1.2.3