1 files changed, 78 insertions, 0 deletions
diff --git a/sysdeps/hurd/include/hurd/signal.h b/sysdeps/hurd/include/hurd/signal.h
index 1dc8a1f353..fab8d1b67c 100644
--- a/sysdeps/hurd/include/hurd/signal.h
+++ b/sysdeps/hurd/include/hurd/signal.h
@@ -9,6 +9,84 @@ libc_hidden_proto (_hurd_self_sigstate)
 #include_next <hurd/signal.h>
 
 #ifndef _ISOMAC
+
+#if defined __USE_EXTERN_INLINES
+# if IS_IN (libc) || IS_IN (libpthread)
+#  include <sigsetops.h>
+#  include <tls.h>
+# endif
+#endif
+
+#ifndef _HURD_SIGNAL_H_EXTERN_INLINE
+#define _HURD_SIGNAL_H_EXTERN_INLINE __extern_inline
+#endif
+
+#if defined __USE_EXTERN_INLINES && IS_IN (libc)
+_HURD_SIGNAL_H_EXTERN_INLINE struct hurd_sigstate *
+_hurd_self_sigstate (void)
+{
+  struct hurd_sigstate *ss = THREAD_GETMEM (THREAD_SELF, _hurd_sigstate);
+  if (__glibc_unlikely (ss == NULL))
+    {
+      thread_t self = __mach_thread_self ();
+
+      /* The thread variable is unset; this must be the first time we've
+        asked for it.  In this case, the critical section flag cannot
+        possible already be set.  Look up our sigstate structure the slow
+        way.  */
+      ss = _hurd_thread_sigstate (self);
+      THREAD_SETMEM (THREAD_SELF, _hurd_sigstate, ss);
+      __mach_port_deallocate (__mach_task_self (), self);
+    }
+  return ss;
+}
+
+_HURD_SIGNAL_H_EXTERN_INLINE void *
+_hurd_critical_section_lock (void)
+{
+  struct hurd_sigstate *ss;
+
+  if (__LIBC_NO_TLS ())
+    /* TLS is currently initializing, no need to enter critical section.  */
+    return NULL;
+
+  ss = _hurd_self_sigstate ();
+
+  if (! __spin_try_lock (&ss->critical_section_lock))
+    /* We are already in a critical section, so do nothing.  */
+    return NULL;
+
+  /* With the critical section lock held no signal handler will run.
+     Return our sigstate pointer; this will be passed to
+     _hurd_critical_section_unlock to unlock it.  */
+  return ss;
+}
+
+_HURD_SIGNAL_H_EXTERN_INLINE void
+_hurd_critical_section_unlock (void *our_lock)
+{
+  if (our_lock == NULL)
+    /* The critical section lock was held when we began.  Do nothing.  */
+    return;
+  else
+    {
+      /* It was us who acquired the critical section lock.  Unlock it.  */
+      struct hurd_sigstate *ss = (struct hurd_sigstate *) our_lock;
+      sigset_t pending;
+      _hurd_sigstate_lock (ss);
+      __spin_unlock (&ss->critical_section_lock);
+      pending = _hurd_sigstate_pending (ss) & ~ss->blocked;
+      _hurd_sigstate_unlock (ss);
+      if (__glibc_unlikely (!__sigisemptyset (&pending)))
+	/* There are unblocked signals pending, which weren't
+	   delivered because we were in the critical section.
+	   Tell the signal thread to deliver them now.  */
+	__msg_sig_post (_hurd_msgport, 0, 0, __mach_task_self ());
+    }
+}
+#endif /* defined __USE_EXTERN_INLINES && IS_IN (libc) */
+
+
 libc_hidden_proto (_hurd_exception2signal)
 libc_hidden_proto (_hurd_intr_rpc_mach_msg)
 libc_hidden_proto (_hurd_thread_sigstate)