Add SF patch #468347 -- mask signals for non-main pthreads, by Jason Lowe:
This patch updates Python/thread_pthread.h to mask all
signals for any thread created. This will keep all
signals masked for any thread that isn't the initial
thread. For Solaris and Linux, the two platforms I was
able to test it on, it solves bug #465673 (pthreads
need signal protection) and probably will solve bug
#219772 (Interactive InterPreter+ Thread -> core dump
at exit).
I'd be great if this could get some testing on other
platforms, especially HP-UX pre 11.00 and post 11.00,
as I had to make some guesses for the DCE thread case.
AIX is also a concern as I saw some mention of using
sigthreadmask() as a pthread_sigmask() equivalent, but
this patch doesn't use sigthreadmask(). I don't have
access to AIX.
diff --git a/Python/thread_pthread.h b/Python/thread_pthread.h
index 26120d6..2592d39 100644
--- a/Python/thread_pthread.h
+++ b/Python/thread_pthread.h
@@ -4,6 +4,7 @@
#include <stdlib.h>
#include <string.h>
#include <pthread.h>
+#include <signal.h>
/* try to determine what version of the Pthread Standard is installed.
@@ -69,6 +70,18 @@
#endif
+/* On platforms that don't use standard POSIX threads pthread_sigmask()
+ * isn't present. DEC threads uses sigprocmask() instead as do most
+ * other UNIX International compliant systems that don't have the full
+ * pthread implementation.
+ */
+#ifdef PY_PTHREAD_STD
+# define SET_THREAD_SIGMASK pthread_sigmask
+#else
+# define SET_THREAD_SIGMASK sigprocmask
+#endif
+
+
/* A pthread mutex isn't sufficient to model the Python lock type
* because, according to Draft 5 of the docs (P1003.4a/D5), both of the
* following are undefined:
@@ -135,6 +148,7 @@
{
pthread_t th;
int success;
+ sigset_t oldmask, newmask;
#if defined(THREAD_STACK_SIZE) || defined(PTHREAD_SYSTEM_SCHED_SUPPORTED)
pthread_attr_t attrs;
#endif
@@ -151,6 +165,14 @@
#ifdef PTHREAD_SYSTEM_SCHED_SUPPORTED
pthread_attr_setscope(&attrs, PTHREAD_SCOPE_SYSTEM);
#endif
+
+ /* Mask all signals in the current thread before creating the new
+ * thread. This causes the new thread to start with all signals
+ * blocked.
+ */
+ sigfillset(&newmask);
+ SET_THREAD_SIGMASK(SIG_BLOCK, &newmask, &oldmask);
+
success = pthread_create(&th,
#if defined(PY_PTHREAD_D4)
pthread_attr_default,
@@ -174,6 +196,10 @@
(void *)arg
#endif
);
+
+ /* Restore signal mask for original thread */
+ SET_THREAD_SIGMASK(SIG_SETMASK, &oldmask, NULL);
+
#ifdef THREAD_STACK_SIZE
pthread_attr_destroy(&attrs);
#endif