Fixed bug #633 Description From Michael Stone 2008-09-25 19:27:29 (-) [reply] To determine whether a pid is occupied with the kill(pid, 0) idiom, you have to test #include <signal.h> #include <errno.h> kill(pid, 0) < 0 && errno == ESRCH not just #include <signal.h> kill(pid, 0) < 0 otherwise you get incorrect results when pid is running as a different user (causing kill(pid, 0) to return -1 + EPERM). src/audio/alsa/SDL_alsa_audio.c is certainly affected by this bug in both 1.2.13 and 1.3-trunk. It probably occurs in other places as well.

--- a/src/audio/dma/SDL_dmaaudio.c	Tue Feb 17 04:57:39 2009 +0000
+++ b/src/audio/dma/SDL_dmaaudio.c	Tue Feb 17 05:17:51 2009 +0000
@@ -417,7 +417,7 @@
            that use a different process id for each thread.
          */
         if (parent && (((++cnt) % 10) == 0)) {  /* Check every 10 loops */
-            if (kill(parent, 0) < 0) {
+            if (kill(parent, 0) < 0 && errno == ESRCH) {
                 this->enabled = 0;
             }
         }