#include <signal.h>
#include <errno.h>
+#include <stddef.h>
+
+#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);
+# if PTHREAD_SIGMASK_INEFFECTIVE
+ if (ret == 0)
+ {
+ /* Detect whether pthread_sigmask is currently ineffective.
+ 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)
+ {
+ /* 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);
+ }
+ }
+# 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);
return (ret < 0 ? errno : 0);
+#endif
}