X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=lib%2Fpthread_sigmask.c;h=19439348ca566819c82eb21bede5c75a12e6ccd0;hb=cd56634a4a8179fd5a4419fbb3e27211b042ab1c;hp=06ee7fc42042bf09d061db6c2caa76e593ad6225;hpb=43243b5fdcf1e0c0e016cabe190f1ab29b984871;p=gnulib.git

diff --git a/lib/pthread_sigmask.c b/lib/pthread_sigmask.c
index 06ee7fc42..19439348c 100644
--- a/lib/pthread_sigmask.c
+++ b/lib/pthread_sigmask.c
@@ -1,5 +1,5 @@
 /* POSIX compatible signal blocking for threads.
-   Copyright (C) 2011 Free Software Foundation, Inc.
+   Copyright (C) 2011-2014 Free Software Foundation, Inc.
 
    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -22,12 +22,35 @@
 #include <errno.h>
 #include <stddef.h>
 
+#if PTHREAD_SIGMASK_INEFFECTIVE
+# include <string.h>
+#endif
+
+#if PTHREAD_SIGMASK_UNBLOCK_BUG
+# include <unistd.h>
+#endif
+
 int
 pthread_sigmask (int how, const sigset_t *new_mask, sigset_t *old_mask)
 #undef pthread_sigmask
 {
 #if HAVE_PTHREAD_SIGMASK
-  int ret = pthread_sigmask (how, new_mask, old_mask);
+  int ret;
+
+# if PTHREAD_SIGMASK_INEFFECTIVE
+  sigset_t omask, omask_copy;
+  sigset_t *old_mask_ptr = &omask;
+  sigemptyset (&omask);
+  /* Add a signal unlikely to be blocked, so that OMASK_COPY
+     is unlikely to match the actual mask.  */
+  sigaddset (&omask, SIGILL);
+  memcpy (&omask_copy, &omask, sizeof omask);
+# else
+  sigset_t *old_mask_ptr = old_mask;
+# endif
+
+  ret = pthread_sigmask (how, new_mask, old_mask_ptr);
+
 # if PTHREAD_SIGMASK_INEFFECTIVE
   if (ret == 0)
     {
@@ -35,18 +58,32 @@ pthread_sigmask (int how, const sigset_t *new_mask, sigset_t *old_mask)
          Don't cache the information: libpthread.so could be dynamically
          loaded after the program started and after pthread_sigmask was
          called for the first time.  */
-      if (pthread_sigmask (1729, NULL, NULL) == 0)
+      if (memcmp (&omask_copy, &omask, sizeof omask) == 0
+          && pthread_sigmask (1729, &omask_copy, NULL) == 0)
         {
           /* pthread_sigmask is currently ineffective.  The program is not
              linked to -lpthread.  So use sigprocmask instead.  */
           return (sigprocmask (how, new_mask, old_mask) < 0 ? errno : 0);
         }
+
+      if (old_mask)
+        memcpy (old_mask, &omask, sizeof omask);
     }
 # endif
 # if PTHREAD_SIGMASK_FAILS_WITH_ERRNO
   if (ret == -1)
     return errno;
 # endif
+# if PTHREAD_SIGMASK_UNBLOCK_BUG
+  if (ret == 0
+      && new_mask != NULL
+      && (how == SIG_UNBLOCK || how == SIG_SETMASK))
+    {
+      /* Give the OS the opportunity to raise signals that were pending before
+         the pthread_sigmask call and have now been unblocked.  */
+      usleep (1);
+    }
+# endif
   return ret;
 #else
   int ret = sigprocmask (how, new_mask, old_mask);