From 5e31c80e4e8d48fd6941ee3a5ba6f3b6c8c74cb7 Mon Sep 17 00:00:00 2001
From: Christopher Faylor <me@cgf.cx>
Date: Fri, 29 Mar 2013 01:22:14 +0000
Subject: [PATCH] * sigproc.cc (pending_signals::retry): Declare new element.
 (pending_signals::pending): Force an additional loop through wait_sig by
 setting retry whenever this function is called. (sig_send): Reorganize to
 wait for SIGHOLD at bottom.  Always add signal to pending queue and work on
 whole queue rather than just the one signal.  Loop when sigq.retry is set. 
 Fix long-broken check for SIGCHLD after queued signals.

---
 winsup/cygwin/ChangeLog  | 10 +++++++
 winsup/cygwin/sigproc.cc | 63 ++++++++++++++--------------------------
 2 files changed, 32 insertions(+), 41 deletions(-)

diff --git a/winsup/cygwin/ChangeLog b/winsup/cygwin/ChangeLog
index 8fb699363..1ccbcf1ef 100644
--- a/winsup/cygwin/ChangeLog
+++ b/winsup/cygwin/ChangeLog
@@ -1,3 +1,13 @@
+2013-03-28  Christopher Faylor  <me.cygwin2013@cgf.cx>
+
+	* sigproc.cc (pending_signals::retry): Declare new element.
+	(pending_signals::pending): Force an additional loop through wait_sig
+	by setting retry whenever this function is called.
+	(sig_send): Reorganize to wait for SIGHOLD at bottom.  Always add
+	signal to pending queue and work on whole queue rather than just the
+	one signal.  Loop when sigq.retry is set.  Fix long-broken check for
+	SIGCHLD after queued signals.
+
 2013-03-28  Christopher Faylor  <me.cygwin2013@cgf.cx>
 
 	* exceptions.cc (exception::handle): Generalize comment.
diff --git a/winsup/cygwin/sigproc.cc b/winsup/cygwin/sigproc.cc
index b49ba4b5e..a38ff0251 100644
--- a/winsup/cygwin/sigproc.cc
+++ b/winsup/cygwin/sigproc.cc
@@ -76,11 +76,12 @@ class pending_signals
   sigpacket *end;
   sigpacket *prev;
   sigpacket *curr;
+  bool retry;
 public:
   void reset () {curr = &start; prev = &start;}
   void add (sigpacket&);
   void del ();
-  bool pending () const {return !!start.next;}
+  bool pending () {retry = true; return !!start.next;}
   sigpacket *next ();
   sigpacket *save () const {return curr;}
   void restore (sigpacket *saved) {curr = saved;}
@@ -627,7 +628,8 @@ sig_send (_pinfo *p, siginfo_t& si, _cygtls *tls)
 	}
     }
 
-  sigproc_printf ("sendsig %p, pid %d, signal %d, its_me %d", sendsig, p->pid, si.si_signo, its_me);
+  sigproc_printf ("sendsig %p, pid %d, signal %d, its_me %d", sendsig, p->pid,
+		  si.si_signo, its_me);
 
   sigset_t pending;
   if (!its_me)
@@ -1231,9 +1233,9 @@ void
 pending_signals::add (sigpacket& pack)
 {
   sigpacket *se;
-  if (sigs[pack.si.si_signo].si.si_signo)
-    return;
   se = sigs + pack.si.si_signo;
+  if (se->si.si_signo)
+    return;
   *se = pack;
   se->mask = &pack.sigtls->sigmask;
   se->next = NULL;
@@ -1281,18 +1283,17 @@ wait_sig (VOID *)
   sigproc_printf ("entering ReadFile loop, my_readsig %p, my_sendsig %p",
 		  my_readsig, my_sendsig);
 
-  sigpacket pack;
-  pack.si.si_signo = 0;
   for (;;)
     {
-      if (pack.si.si_signo == __SIGHOLD)
-	WaitForSingleObject (sig_hold, INFINITE);
-
       DWORD nb;
-      pack.sigtls = NULL;
-      if (!ReadFile (my_readsig, &pack, sizeof (pack), &nb, NULL))
-	break;
-
+      sigpacket pack = {};
+      if (sigq.retry)
+	{
+	  sigq.retry = false;
+	  pack.si.si_signo = __SIGFLUSH;
+	}
+      else if (!ReadFile (my_readsig, &pack, sizeof (pack), &nb, NULL))
+	Sleep (INFINITE);	/* Never exit this thread */
       if (nb != sizeof (pack))
 	{
 	  system_printf ("short read from signal pipe: %d != %d", nb,
@@ -1340,6 +1341,11 @@ wait_sig (VOID *)
 	case __SIGHOLD:
 	  goto loop;
 	  break;
+	default:
+	  if (pack.si.si_signo < 0)
+	    sig_clear (-pack.si.si_signo);
+	  else
+	    sigq.add (pack);
 	case __SIGNOHOLD:
 	case __SIGFLUSH:
 	case __SIGFLUSHFAST:
@@ -1349,7 +1355,7 @@ wait_sig (VOID *)
 	      int sig = q->si.si_signo;
 	      if (sig == __SIGDELETE || q->process () > 0)
 		sigq.del ();
-	      if (sig == __SIGNOHOLD && q->si.si_signo == SIGCHLD)
+	      if (sig == SIGCHLD)
 		clearwait = true;
 	    }
 	  break;
@@ -1373,33 +1379,6 @@ wait_sig (VOID *)
 	      system_printf ("WaitForSingleObject(%p) for thread exit returned %u", h, res);
 	  }
 	  break;
-	default:
-	  if (pack.si.si_signo < 0)
-	    sig_clear (-pack.si.si_signo);
-	  else
-	    {
-	      int sig = pack.si.si_signo;
-	      // FIXME: REALLY not right when taking threads into consideration.
-	      // We need a per-thread queue since each thread can have its own
-	      // list of blocked signals.  CGF 2005-08-24
-	      if (sigq.sigs[sig].si.si_signo && sigq.sigs[sig].sigtls == pack.sigtls)
-		sigproc_printf ("signal %d already queued", pack.si.si_signo);
-	      else
-		{
-		  int sigres = pack.process ();
-		  if (sigres <= 0)
-		    {
-#ifdef DEBUGGING2
-		      if (!sigres)
-			system_printf ("Failed to arm signal %d from pid %d", pack.si.si_signo, pack.pid);
-#endif
-		      sigq.add (pack);	// FIXME: Shouldn't add this in !sh condition
-		    }
-		}
-	      if (sig == SIGCHLD)
-		clearwait = true;
-	    }
-	  break;
 	}
       if (clearwait && !have_execed)
 	proc_subproc (PROC_CLEARWAIT, 0);
@@ -1409,5 +1388,7 @@ wait_sig (VOID *)
 	  sigproc_printf ("signalling pack.wakeup %p", pack.wakeup);
 	  SetEvent (pack.wakeup);
 	}
+      if (pack.si.si_signo == __SIGHOLD)
+	WaitForSingleObject (sig_hold, INFINITE);
     }
 }