The way ecore handles signals is racy.
The attached patch uses a pipe to avoid races between signals and select/poll().
A fix for before or after 1.0...?
thanks,
Mike
btw. the SIGRTMIN is totally borken and probably should be deleted
>From 1a21c643e08e325b2773e53ecde27bcf46ca5148 Mon Sep 17 00:00:00 2001
From: Mike McCormack <mj.mccorm...@samsung.com>
Date: Mon, 24 Jan 2011 20:36:20 +0900
Subject: [PATCH] Handle ecore signals with a pipe
This removes a race condition in the main loop where
a signal could come after the signal check, and before
entering the select loop, possibly resulting in a hang.
In practice, this hang wouldn't be seen due to other activity
in the main loop.
---
trunk/ecore/src/lib/ecore/ecore_signal.c | 269 ++++++++++++------------------
1 files changed, 110 insertions(+), 159 deletions(-)
diff --git a/trunk/ecore/src/lib/ecore/ecore_signal.c b/trunk/ecore/src/lib/ecore/ecore_signal.c
index f072c06..0a0c038 100644
--- a/trunk/ecore/src/lib/ecore/ecore_signal.c
+++ b/trunk/ecore/src/lib/ecore/ecore_signal.c
@@ -17,20 +17,13 @@
/* valgrind in some versions/setups uses SIGRT's... hmmm */
#undef SIGRTMIN
+static int _ecore_signal_pipe[2];
+
typedef void (*Signal_Handler)(int sig, siginfo_t *si, void *foo);
static void _ecore_signal_callback_set(int sig, Signal_Handler func);
static void _ecore_signal_callback_ignore(int sig, siginfo_t *si, void *foo);
-static void _ecore_signal_callback_sigchld(int sig, siginfo_t *si, void *foo);
-static void _ecore_signal_callback_sigusr1(int sig, siginfo_t *si, void *foo);
-static void _ecore_signal_callback_sigusr2(int sig, siginfo_t *si, void *foo);
-static void _ecore_signal_callback_sighup(int sig, siginfo_t *si, void *foo);
-static void _ecore_signal_callback_sigquit(int sig, siginfo_t *si, void *foo);
-static void _ecore_signal_callback_sigint(int sig, siginfo_t *si, void *foo);
-static void _ecore_signal_callback_sigterm(int sig, siginfo_t *si, void *foo);
-#ifdef SIGPWR
-static void _ecore_signal_callback_sigpwr(int sig, siginfo_t *si, void *foo);
-#endif
+static void _ecore_signal_callback_write_pipe(int sig, siginfo_t *si, void *foo);
#ifdef SIGRTMIN
static void _ecore_signal_callback_sigrt(int sig, siginfo_t *si, void *foo);
@@ -99,6 +92,9 @@ _ecore_signal_shutdown(void)
sigterm_count = 0;
sig_count = 0;
+ close(_ecore_signal_pipe[0]);
+ close(_ecore_signal_pipe[1]);
+
#ifdef SIGRTMIN
for (i = 0; i < num; i++)
{
@@ -123,24 +119,110 @@ _ecore_signal_shutdown(void)
#endif
}
+Eina_Bool
+_ecore_signal_pipe_read(void *data, Ecore_Fd_Handler *fdh)
+{
+ siginfo_t si;
+ int sig = -1;
+ int r;
+ int n;
+
+ r = read(_ecore_signal_pipe[0], &si, sizeof si);
+ if (r != sizeof si)
+ {
+ WRN("failed to read signal\n");
+ return;
+ }
+
+ sig = si.si_signo;
+
+ switch (sig)
+ {
+ case SIGCHLD:
+ n = sigchld_count++;
+ sig_count++;
+ if (n < MAXSIGQ)
+ sigchld_info[n] = si;
+ break;
+ case SIGUSR1:
+ n = sigusr1_count++;
+ sig_count++;
+ if (n < MAXSIGQ)
+ sigusr1_info[n] = si;
+ break;
+ case SIGUSR2:
+ n = sigusr2_count++;
+ sig_count++;
+ if (n < MAXSIGQ)
+ sigusr2_info[n] = si;
+ break;
+ case SIGHUP:
+ n = sighup_count++;
+ sig_count++;
+ if (n < MAXSIGQ)
+ sighup_info[n] = si;
+ break;
+ case SIGQUIT:
+ n = sigquit_count++;
+ sig_count++;
+ if (n < MAXSIGQ)
+ sigquit_info[n] = si;
+ break;
+ case SIGINT:
+ n = sigint_count++;
+ sig_count++;
+ if (n < MAXSIGQ)
+ sigint_info[n] = si;
+ break;
+ case SIGTERM:
+ n = sigterm_count++;
+ sig_count++;
+ if (n < MAXSIGQ)
+ sigterm_info[n] = si;
+ break;
+#ifdef SIGPWR
+ case SIGPWR:
+ n = sigpwr_count++;
+ sig_count++;
+ if (n < MAXSIGQ)
+ sigpwr_info[n] = si;
+ break;
+#endif
+ default:
+ ERR("unknown signal %d\n", sig);
+ break;
+ }
+}
+
void
_ecore_signal_init(void)
{
#ifdef SIGRTMIN
int i, num = SIGRTMAX - SIGRTMIN;
#endif
+ int pfd[2];
+ int r;
+
+ r = pipe(_ecore_signal_pipe);
+ if (r < 0)
+ {
+ ERR("pipe failed (%d)\n", r);
+ exit(1);
+ }
+ ecore_main_fd_handler_add(_ecore_signal_pipe[0], ECORE_FD_READ,
+ &_ecore_signal_pipe_read, NULL, NULL, NULL);
_ecore_signal_callback_set(SIGPIPE, _ecore_signal_callback_ignore);
_ecore_signal_callback_set(SIGALRM, _ecore_signal_callback_ignore);
- _ecore_signal_callback_set(SIGCHLD, _ecore_signal_callback_sigchld);
- _ecore_signal_callback_set(SIGUSR1, _ecore_signal_callback_sigusr1);
- _ecore_signal_callback_set(SIGUSR2, _ecore_signal_callback_sigusr2);
- _ecore_signal_callback_set(SIGHUP, _ecore_signal_callback_sighup);
- _ecore_signal_callback_set(SIGQUIT, _ecore_signal_callback_sigquit);
- _ecore_signal_callback_set(SIGINT, _ecore_signal_callback_sigint);
- _ecore_signal_callback_set(SIGTERM, _ecore_signal_callback_sigterm);
+ _ecore_signal_callback_set(SIGCHLD, _ecore_signal_callback_write_pipe);
+ _ecore_signal_callback_set(SIGUSR1, _ecore_signal_callback_write_pipe);
+ _ecore_signal_callback_set(SIGUSR2, _ecore_signal_callback_write_pipe);
+ _ecore_signal_callback_set(SIGHUP, _ecore_signal_callback_write_pipe);
+ _ecore_signal_callback_set(SIGQUIT, _ecore_signal_callback_write_pipe);
+ _ecore_signal_callback_set(SIGINT, _ecore_signal_callback_write_pipe);
+ _ecore_signal_callback_set(SIGTERM, _ecore_signal_callback_write_pipe);
#ifdef SIGPWR
- _ecore_signal_callback_set(SIGPWR, _ecore_signal_callback_sigpwr);
+ _ecore_signal_callback_set(SIGPWR, _ecore_signal_callback_write_pipe);
#endif
#ifdef SIGRTMIN
@@ -450,159 +532,28 @@ _ecore_signal_callback_set(int sig, Signal_Handler func)
sigaction(sig, &sa, NULL);
}
-static void
-_ecore_signal_callback_ignore(int sig __UNUSED__, siginfo_t *si __UNUSED__, void *foo __UNUSED__)
-{
-}
-
-static void
-_ecore_signal_callback_sigchld(int sig __UNUSED__, siginfo_t *si, void *foo __UNUSED__)
-{
- volatile sig_atomic_t n;
- n = sigchld_count;
- if (n < MAXSIGQ)
- {
- if (si)
- sigchld_info[n] = *si;
- else
- sigchld_info[n].si_signo = 0;
- }
-
- sigchld_count++;
- sig_count++;
-}
-
-static void
-_ecore_signal_callback_sigusr1(int sig __UNUSED__, siginfo_t *si, void *foo __UNUSED__)
-{
- volatile sig_atomic_t n;
- n = sigusr1_count;
- if (n < MAXSIGQ)
- {
- if (si)
- sigusr1_info[n] = *si;
- else
- sigusr1_info[n].si_signo = 0;
- }
- sigusr1_count++;
- sig_count++;
-}
-
-static void
-_ecore_signal_callback_sigusr2(int sig __UNUSED__, siginfo_t *si, void *foo __UNUSED__)
-{
- volatile sig_atomic_t n;
- n = sigusr2_count;
- if (n < MAXSIGQ)
- {
- if (si)
- sigusr2_info[n] = *si;
- else
- sigusr2_info[n].si_signo = 0;
- }
- sigusr2_count++;
- sig_count++;
-}
-
-static void
-_ecore_signal_callback_sighup(int sig __UNUSED__, siginfo_t *si, void *foo __UNUSED__)
-{
- volatile sig_atomic_t n;
- n = sighup_count;
- if (n < MAXSIGQ)
- {
- if (si)
- sighup_info[n] = *si;
- else
- sighup_info[n].si_signo = 0;
- }
- sighup_count++;
- sig_count++;
-}
-
-static void
-_ecore_signal_callback_sigquit(int sig __UNUSED__, siginfo_t *si, void *foo __UNUSED__)
-{
- volatile sig_atomic_t n;
- n = sigquit_count;
- if (n < MAXSIGQ)
- {
- if (si)
- sigquit_info[n] = *si;
- else
- sigquit_info[n].si_signo = 0;
- }
- sigquit_count++;
- sig_count++;
-}
static void
-_ecore_signal_callback_sigint(int sig __UNUSED__, siginfo_t *si, void *foo __UNUSED__)
+_ecore_signal_callback_write_pipe(int sig __UNUSED__, siginfo_t *si __UNUSED__, void *foo __UNUSED__)
{
- volatile sig_atomic_t n;
- n = sigint_count;
- if (n < MAXSIGQ)
- {
- if (si)
- sigint_info[n] = *si;
- else
- sigint_info[n].si_signo = 0;
- }
- sigint_count++;
- sig_count++;
-}
+ int r;
+ siginfo_t dummy = {0};
-static void
-_ecore_signal_callback_sigterm(int sig __UNUSED__, siginfo_t *si, void *foo __UNUSED__)
-{
- volatile sig_atomic_t n;
- n = sigterm_count;
- if (n < MAXSIGQ)
- {
- if (si)
- sigterm_info[n] = *si;
- else
- sigterm_info[n].si_signo = 0;
- }
- sigterm_count++;
- sig_count++;
-}
+ if (!si)
+ si = &dummy;
-#ifdef SIGPWR
-static void
-_ecore_signal_callback_sigpwr(int sig __UNUSED__, siginfo_t *si, void *foo __UNUSED__)
-{
- volatile sig_atomic_t n;
- n = sigpwr_count;
- if (n < MAXSIGQ)
+ r = write(_ecore_signal_pipe[1], si, sizeof *si);
+ if (r != sizeof *si)
{
- if (si)
- sigpwr_info[n] = *si;
- else
- sigpwr_info[n].si_signo = 0;
+ ERR("failed to write signal pipe\n");
+ _exit(1);
}
- sigpwr_count++;
- sig_count++;
}
-#endif
-#ifdef SIGRTMIN
static void
-_ecore_signal_callback_sigrt(int sig, siginfo_t *si, void *foo __UNUSED__)
+_ecore_signal_callback_ignore(int sig __UNUSED__, siginfo_t *si __UNUSED__, void *foo __UNUSED__)
{
- volatile sig_atomic_t n;
- n = sigrt_count[sig - SIGRTMIN];
- if (n < MAXSIGQ)
- {
- if (si)
- sigrt_info[n][sig - SIGRTMIN] = *si;
- else
- sigrt_info[n][sig - SIGRTMIN].si_signo = 0;
- }
- sigrt_count[sig - SIGRTMIN]++;
- sig_count++;
}
-#endif
static Eina_Bool
_ecore_signal_exe_exit_delay(void *data)
--
1.7.0.4
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