https://bugs.gentoo.org/show_bug.cgi?id=197104 commit a5b8053606d6e786cdcf6734f271acc05f9cc588 Author: Adam Jackson Date: Tue Sep 11 11:37:06 2007 -0400 Ignore - not just block - SIGALRM around Popen()/Pclose(). Because our "popen" implementation uses stdio, and because nobody's stdio library is capable of surviving signals, we need to make absolutely sure that we hide the SIGALRM from the smart scheduler. Otherwise, when you open a menu in openoffice, and it recompiles XKB to deal with the accelerators, and you popen xkbcomp because we suck, then the scheduler will tell you you're taking forever doing something stupid, and the wait() code will get confused, and input will hang and your CPU usage slams to 100%. Down, not across. diff --git a/os/utils.c b/os/utils.c index 3bb7dbe..afcaae4 100644 --- a/os/utils.c +++ b/os/utils.c @@ -1720,6 +1720,8 @@ static struct pid { int pid; } *pidlist; +static sighandler_t old_alarm = NULL; /* XXX horrible awful hack */ + pointer Popen(char *command, char *type) { @@ -1741,11 +1743,15 @@ Popen(char *command, char *type) return NULL; } + /* Ignore the smart scheduler while this is going on */ + old_alarm = signal(SIGALRM, SIG_IGN); + switch (pid = fork()) { case -1: /* error */ close(pdes[0]); close(pdes[1]); xfree(cur); + signal(SIGALRM, old_alarm); return NULL; case 0: /* child */ if (setgid(getgid()) == -1) @@ -1921,6 +1927,8 @@ Pclose(pointer iop) /* allow EINTR again */ OsReleaseSignals (); + signal(SIGALRM, old_alarm); + return pid == -1 ? -1 : pstat; }