* cygtls.h (_cygtls::reset_signal_arrived): Actually reset the signal_arrived

event.
(_cygtls::handle_SIGCONT): Declare ew function.
* cygwait.cc (is_cw_sig_handle): Delete.
(is_cw_sig_cont): New convenience define.
(cygwait): Clear signal if is_cw_sig_cont and we got a SIGCONT.
* cygwait.h (cw_wait_mask): Add cw_sig_cont.
* exceptions.cc (sig_handle_tty_stop): Tighten "incyg" region.  Use cw_sig_cont
param for cygwait.  Don't zero signal here outside of lock.
(sigpacket::setup_handler): Don't check for in_forkee since we will now never
get here in that state.
(_cygtls::handle_SIGCONT): Define new function.
(sigpacket::process): Call handle_SIGCONT early to deal with SIGCONT.  Nuke
continue_now handling.  Allow SIGKILL to kill a suspended process.  Delete a
couple of now-unneeded labels.
(_cygtls::call_signal_handler): Reorganize setting of incyg within lock.
* sigproc.cc (pending_signals): Simplify.
(pending_signals::clear): New method.
(_cygtls::remove_wq): Reorganize to always close wq.thread_ev if it exists to
avoid handle leaks.
(sig_clear): Simplify by just calling sigq.clear().
(sig_dispatch_pending): Always call sigq.pending even in signal thread to force
another loop in wait_sig.
(sig_send): Remove a "goto out" just before out: label.
(pending_signals::add): Simplify.
(pending_signals::del): Delete.
(pending_signals::next): Delete.
(wait_sig): Define variable q to be the start of the signal queue.  Just
iterate through sigq queue, deleting processed or zeroed signals.  Only set
clearwait when the current signal is SIGCHLD.
* sigproc.h: Add a comment about an unused enum.

7 files changed, 156 insertions, 141 deletions

diff --git a/winsup/cygwin/ChangeLog b/winsup/cygwin/ChangeLog
index e83a81597..8fbe9a821 100644
--- a/winsup/cygwin/ChangeLog
+++ b/winsup/cygwin/ChangeLog
@@ -1,3 +1,38 @@
+2013-04-08  Christopher Faylor  <me.cygwin2013@cgf.cx>
+
+	* cygtls.h (_cygtls::reset_signal_arrived): Actually reset the
+	signal_arrived event.
+	(_cygtls::handle_SIGCONT): Declare ew function.
+	* cygwait.cc (is_cw_sig_handle): Delete.
+	(is_cw_sig_cont): New convenience define.
+	(cygwait): Clear signal if is_cw_sig_cont and we got a SIGCONT.
+	* cygwait.h (cw_wait_mask): Add cw_sig_cont.
+	* exceptions.cc (sig_handle_tty_stop): Tighten "incyg" region.  Use
+	cw_sig_cont param for cygwait.  Don't zero signal here outside of lock.
+	(sigpacket::setup_handler): Don't check for in_forkee since we will now
+	never get here in that state.
+	(_cygtls::handle_SIGCONT): Define new function.
+	(sigpacket::process): Call handle_SIGCONT early to deal with SIGCONT.
+	Nuke continue_now handling.  Allow SIGKILL to kill a suspended process.
+	Delete a couple of now-unneeded labels.
+	(_cygtls::call_signal_handler): Reorganize setting of incyg within
+	lock.
+	* sigproc.cc (pending_signals): Simplify.
+	(pending_signals::clear): New method.
+	(_cygtls::remove_wq): Reorganize to always close wq.thread_ev if it
+	exists to avoid handle leaks.
+	(sig_clear): Simplify by just calling sigq.clear().
+	(sig_dispatch_pending): Always call sigq.pending even in signal thread
+	to force another loop in wait_sig.
+	(sig_send): Remove a "goto out" just before out: label.
+	(pending_signals::add): Simplify.
+	(pending_signals::del): Delete.
+	(pending_signals::next): Delete.
+	(wait_sig): Define variable q to be the start of the signal queue.
+	Just iterate through sigq queue, deleting processed or zeroed signals.
+	Only set clearwait when the current signal is SIGCHLD.
+	* sigproc.h: Add a comment about an unused enum.
+
 2013-04-08  Corinna Vinschen  <corinna@vinschen.de>
 
 	* fhandler_socket.cc (get_inet_addr): Handle abstract AF_LOCAL socket.
diff --git a/winsup/cygwin/cygtls.h b/winsup/cygwin/cygtls.h
index 5ddb9e199..5463ed85c 100644
--- a/winsup/cygwin/cygtls.h
+++ b/winsup/cygwin/cygtls.h
@@ -253,7 +253,13 @@ public:
 	will_wait_for_signal = true;
       }
   }
-  void reset_signal_arrived () { will_wait_for_signal = false; }
+  void reset_signal_arrived ()
+  {
+    if (signal_arrived)
+      ResetEvent (signal_arrived);
+    will_wait_for_signal = false;
+  }
+  void handle_SIGCONT ();
 private:
   void __reg3 call2 (DWORD (*) (void *, void *), void *, void *);
   /*gentls_offsets*/
diff --git a/winsup/cygwin/cygwait.cc b/winsup/cygwin/cygwait.cc
index b0476660c..fcf31b39b 100644
--- a/winsup/cygwin/cygwait.cc
+++ b/winsup/cygwin/cygwait.cc
@@ -1,6 +1,6 @@
 /* cygwait.h
 
-   Copyright 2011, 2012 Red Hat, Inc.
+   Copyright 2011, 2012, 2013 Red Hat, Inc.
 
    This file is part of Cygwin.
 
@@ -17,9 +17,9 @@
 #define is_cw_cancel_self	(mask & cw_cancel_self)
 #define is_cw_sig		(mask & cw_sig)
 #define is_cw_sig_eintr		(mask & cw_sig_eintr)
-#define is_cw_sig_return	(mask & cw_sig_return)
+#define is_cw_sig_cont		(mask & cw_sig_cont)
 
-#define is_cw_sig_handle	(mask & (is_cw_sig | is_cw_sig_eintr))
+#define is_cw_sig_handle	(mask & (cw_sig | cw_sig_eintr | cw_sig_cont))
 
 LARGE_INTEGER cw_nowait_storage;
 
@@ -83,10 +83,12 @@ cygwait (HANDLE object, PLARGE_INTEGER timeout, unsigned mask)
 	{
 	  _my_tls.lock ();
 	  int sig = _my_tls.sig;
+	  if (is_cw_sig_cont && sig == SIGCONT)
+	    _my_tls.sig = 0;
 	  _my_tls.unlock ();
 	  if (!sig)
 	    continue;
-	  if (is_cw_sig_eintr)
+	  if (is_cw_sig_eintr || (is_cw_sig_cont && sig == SIGCONT))
 	    res = WAIT_SIGNALED;	/* caller will deal with signals */
 	  else if (_my_tls.call_signal_handler ())
 	    continue;
diff --git a/winsup/cygwin/cygwait.h b/winsup/cygwin/cygwait.h
index 707976786..496817bcf 100644
--- a/winsup/cygwin/cygwait.h
+++ b/winsup/cygwin/cygwait.h
@@ -1,6 +1,6 @@
 /* cygwait.h
 
-   Copyright 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012
+   Copyright 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013
    Red Hat, Inc.
 
    This file is part of Cygwin.
@@ -19,7 +19,8 @@ enum cw_wait_mask
   cw_cancel =		0x0001,
   cw_cancel_self =	0x0002,
   cw_sig =		0x0004,
-  cw_sig_eintr =	0x0008
+  cw_sig_eintr =	0x0008,
+  cw_sig_cont =		0x0010
 };
 
 extern LARGE_INTEGER cw_nowait_storage;
diff --git a/winsup/cygwin/exceptions.cc b/winsup/cygwin/exceptions.cc
index 9815be280..d86635bae 100644
--- a/winsup/cygwin/exceptions.cc
+++ b/winsup/cygwin/exceptions.cc
@@ -686,23 +686,24 @@ extern "C" {
 static void
 sig_handle_tty_stop (int sig, siginfo_t *, void *)
 {
-  _my_tls.incyg = 1;
   /* Silently ignore attempts to suspend if there is no accommodating
      cygwin parent to deal with this behavior. */
   if (!myself->cygstarted)
     myself->process_state &= ~PID_STOPPED;
   else
     {
+      _my_tls.incyg = 1;
       myself->stopsig = sig;
       myself->alert_parent (sig);
       sigproc_printf ("process %d stopped by signal %d", myself->pid, sig);
       /* FIXME! This does nothing to suspend anything other than the main
 	 thread. */
-      DWORD res = cygwait (NULL, cw_infinite, cw_sig_eintr);
+      /* Use special cygwait parameter to handle SIGCONT.  _main_tls.sig will
+	 be cleared under lock when SIGCONT is detected.  */
+      DWORD res = cygwait (NULL, cw_infinite, cw_sig_cont);
       switch (res)
 	{
 	case WAIT_SIGNALED:
-	  _my_tls.sig = 0;
 	  myself->stopsig = SIGCONT;
 	  myself->alert_parent (SIGCONT);
 	  break;
@@ -710,8 +711,8 @@ sig_handle_tty_stop (int sig, siginfo_t *, void *)
 	  api_fatal ("WaitSingleObject returned %d", res);
 	  break;
 	}
+      _my_tls.incyg = 0;
     }
-  _my_tls.incyg = 0;
 }
 } /* end extern "C" */
 
@@ -785,10 +786,6 @@ sigpacket::setup_handler (void *handler, struct sigaction& siga, _cygtls *tls)
       goto out;
     }
 
-  while (in_forkee)
-    yield ();		/* Won't be able to send signals until we're finished
-			   processing fork().  */
-
   for (int n = 0; n < CALL_HANDLER_RETRY_OUTER; n++)
     {
       for (int i = 0; i < CALL_HANDLER_RETRY_INNER; i++)
@@ -1121,31 +1118,56 @@ signal_exit (int sig, siginfo_t *si)
 }
 } /* extern "C" */
 
+/* Attempt to carefully handle SIGCONT when we are stopped. */
+void
+_cygtls::handle_SIGCONT ()
+{
+  if (ISSTATE (myself, PID_STOPPED))
+    {
+      myself->stopsig = 0;
+      myself->process_state &= ~PID_STOPPED;
+      int state = 0;
+      /* Carefully tell sig_handle_tty_stop to wake up.  */
+      while (state < 2)
+	{
+	  lock ();
+	  if (sig)
+	    yield ();		/* state <= 1 */
+	  else if (state)
+	    state++;		/* state == 2 */
+	  else
+	    {
+	      sig = SIGCONT;
+	      SetEvent (signal_arrived);
+	      state++;		/* state == 1 */
+	    }
+	  unlock ();
+	}
+      /* Tell wait_sig to handle any queued signals now that we're alive
+	 again. */
+      sig_dispatch_pending (false);
+    }
+  /* Clear pending stop signals */
+  sig_clear (SIGSTOP);
+  sig_clear (SIGTSTP);
+  sig_clear (SIGTTIN);
+  sig_clear (SIGTTOU);
+}
+
 int __stdcall
 sigpacket::process ()
 {
   int rc = 1;
   bool issig_wait = false;
-  bool continue_now = false;
   struct sigaction& thissig = global_sigs[si.si_signo];
   void *handler = have_execed ? NULL : (void *) thissig.sa_handler;
 
+  /* Don't try to send signals if we're just starting up since signal masks
+     may not be available.  */
   if (!cygwin_finished_initializing)
     {
       rc = -1;
-      goto really_done;
-    }
-
-  if (si.si_signo == SIGCONT)
-    {
-      continue_now = ISSTATE (myself, PID_STOPPED);
-      myself->stopsig = 0;
-      myself->process_state &= ~PID_STOPPED;
-      /* Clear pending stop signals */
-      sig_clear (SIGSTOP);
-      sig_clear (SIGTSTP);
-      sig_clear (SIGTTIN);
-      sig_clear (SIGTTOU);
+      goto done;
     }
 
   sigproc_printf ("signal %d processing", si.si_signo);
@@ -1153,7 +1175,17 @@ sigpacket::process ()
   myself->rusage_self.ru_nsignals++;
 
   _cygtls *tls;
-  if (!sigtls)
+  if (si.si_signo == SIGCONT)
+    _main_tls->handle_SIGCONT ();
+
+  if (si.si_signo == SIGKILL)
+    tls = _main_tls;	/* SIGKILL is special.  It always goes through.  */
+  else if (ISSTATE (myself, PID_STOPPED))
+    {
+      rc = -1;		/* Don't send signals when stopped */
+      goto done;
+    }
+  else if (!sigtls)
     {
       tls = cygheap->find_tls (si.si_signo, issig_wait);
       sigproc_printf ("using tls %p", tls);
@@ -1169,7 +1201,8 @@ sigpacket::process ()
 	tls = NULL;
     }
 
-  if (!tls || ISSTATE (myself, PID_STOPPED))
+  /* !tls means no threads available to catch a signal. */
+  if (!tls)
     {
       sigproc_printf ("signal %d blocked", si.si_signo);
       rc = -1;
@@ -1225,6 +1258,7 @@ sigpacket::process ()
   goto dosig;
 
 stop:
+  tls = _main_tls;
   handler = (void *) sig_handle_tty_stop;
   thissig = global_sigs[SIGSTOP];
   goto dosig;
@@ -1232,17 +1266,8 @@ stop:
 exit_sig:
   handler = (void *) signal_exit;
   thissig.sa_flags |= SA_SIGINFO;
-  if (si.si_signo == SIGKILL)
-    goto dispatch_sig;
 
 dosig:
-  if (ISSTATE (myself, PID_STOPPED) && !continue_now)
-    {
-      rc = -1;		/* No signals delivered if stopped */
-      goto done;
-    }
-
-dispatch_sig:
   if (have_execed)
     {
       sigproc_printf ("terminating captive process");
@@ -1251,15 +1276,8 @@ dispatch_sig:
   /* Dispatch to the appropriate function. */
   sigproc_printf ("signal %d, signal handler %p", si.si_signo, handler);
   rc = setup_handler (handler, thissig, tls);
-  continue_now = false;
 
 done:
-  if (continue_now)
-    {
-      (tls ?: _main_tls)->sig = SIGCONT;
-      SetEvent (tls->signal_arrived);
-    }
-really_done:
   sigproc_printf ("returning %d", rc);
   return rc;
 
@@ -1293,11 +1311,11 @@ _cygtls::call_signal_handler ()
 
       sigset_t this_oldmask = set_process_mask_delta ();
       int this_errno = saved_errno;
-      sig = 0;		/* Flag that we can accept another signal */
       reset_signal_arrived ();
+      incyg = false;
+      sig = 0;		/* Flag that we can accept another signal */
       unlock ();	/* unlock signal stack */
 
-      incyg = false;
       /* no ucontext_t information provided yet, so third arg is NULL */
       thisfunc (thissig, &thissi, NULL);
       incyg = true;
diff --git a/winsup/cygwin/sigproc.cc b/winsup/cygwin/sigproc.cc
index 4bf6f5630..e585877b9 100644
--- a/winsup/cygwin/sigproc.cc
+++ b/winsup/cygwin/sigproc.cc
@@ -73,20 +73,15 @@ class pending_signals
 {
   sigpacket sigs[NSIG + 1];
   sigpacket start;
-  sigpacket *end;
-  sigpacket *prev;
-  sigpacket *curr;
   bool retry;
+
 public:
-  void reset () {curr = &start; prev = &start;}
   void add (sigpacket&);
-  void del ();
   bool pending () {retry = true; return !!start.next;}
-  sigpacket *next ();
-  sigpacket *save () const {return curr;}
-  void restore (sigpacket *saved) {curr = saved;}
+  void clear (int sig) {sigs[sig].si.si_signo = 0;}
   friend void __reg1 sig_dispatch_pending (bool);;
   friend void WINAPI wait_sig (VOID *arg);
+  friend void sigproc_init ();
 };
 
 Static pending_signals sigq;
@@ -338,18 +333,22 @@ out1:
 void
 _cygtls::remove_wq (DWORD wait)
 {
-  if (exit_state < ES_FINAL && waitq_head.next && sync_proc_subproc
-      && sync_proc_subproc.acquire (wait))
+  if (wq.thread_ev)
     {
-      for (waitq *w = &waitq_head; w->next != NULL; w = w->next)
-	if (w->next == &wq)
-	  {
-	    ForceCloseHandle1 (wq.thread_ev, wq_ev);
-	    w->next = wq.next;
-	    break;
-	  }
-      sync_proc_subproc.release ();
+      if (exit_state < ES_FINAL && waitq_head.next && sync_proc_subproc
+	  && sync_proc_subproc.acquire (wait))
+	{
+	  for (waitq *w = &waitq_head; w->next != NULL; w = w->next)
+	    if (w->next == &wq)
+	      {
+		w->next = wq.next;
+		break;
+	      }
+	  sync_proc_subproc.release ();
+	}
+      ForceCloseHandle1 (wq.thread_ev, wq_ev);
     }
+
 }
 
 /* Terminate the wait_subproc thread.
@@ -392,23 +391,9 @@ proc_terminate ()
 
 /* Clear pending signal */
 void __reg1
-sig_clear (int target_sig)
+sig_clear (int sig)
 {
-  if (&_my_tls != _sig_tls)
-    sig_send (myself, -target_sig);
-  else
-    {
-      sigpacket *q;
-      sigpacket *save = sigq.save ();
-      sigq.reset ();
-      while ((q = sigq.next ()))
-	if (q->si.si_signo == target_sig)
-	  {
-	    q->si.si_signo = __SIGDELETE;
-	    break;
-	  }
-      sigq.restore (save);
-    }
+  sigq.clear (sig);
 }
 
 extern "C" int
@@ -425,21 +410,10 @@ sigpending (sigset_t *mask)
 void __reg1
 sig_dispatch_pending (bool fast)
 {
-  if (&_my_tls == _sig_tls)
-    {
-#ifdef DEBUGGING
-      sigproc_printf ("exit_state %d, cur thread id %p, _sig_tls %p, sigq.start.next %p",
-		      exit_state, GetCurrentThreadId (), _sig_tls, sigq.start.next);
-#endif
-      return;
-    }
-
   /* Non-atomically test for any signals pending and wake up wait_sig if any are
      found.  It's ok if there's a race here since the next call to this function
-     should catch it.
-     FIXME: Eventually, wait_sig should wake up on its own to deal with pending
-     signals. */
-  if (sigq.pending ())
+     should catch it.  */
+  if (sigq.pending () && &_my_tls != _sig_tls)
     sig_send (myself, fast ? __SIGFLUSHFAST : __SIGFLUSH);
 }
 
@@ -728,7 +702,6 @@ sig_send (_pinfo *p, siginfo_t& si, _cygtls *tls)
 
   if (wait_for_completion && si.si_signo != __SIGFLUSHFAST)
     _my_tls.call_signal_handler ();
-  goto out;
 
 out:
   if (communing && rc)
@@ -1232,46 +1205,19 @@ talktome (siginfo_t *si)
     new cygthread (commune_process, size, si, "commune");
 }
 
+/* Add a packet to the beginning of the queue.
+   Should only be called from signal thread.  */
 void
 pending_signals::add (sigpacket& pack)
 {
   sigpacket *se;
+
   se = sigs + pack.si.si_signo;
   if (se->si.si_signo)
     return;
   *se = pack;
   se->next = NULL;
-  if (end)
-    end->next = se;
-  end = se;
-  if (!start.next)
-    start.next = se;
-}
-
-void
-pending_signals::del ()
-{
-  sigpacket *next = curr->next;
-  prev->next = next;
-  curr->si.si_signo = 0;
-#ifdef DEBUGGING
-  curr->next = NULL;
-#endif
-  if (end == curr)
-    end = prev;
-  curr = next;
-}
-
-sigpacket *
-pending_signals::next ()
-{
-  sigpacket *res;
-  prev = curr;
-  if (!curr || !(curr = curr->next))
-    res = NULL;
-  else
-    res = curr;
-  return res;
+  start.next = se;
 }
 
 /* Process signals by waiting for signal data to arrive in a pipe.
@@ -1311,7 +1257,7 @@ wait_sig (VOID *)
 	  pack.mask = &dummy_mask;
 	}
 
-      sigpacket *q;
+      sigpacket *q = &sigq.start;
       bool clearwait = false;
       switch (pack.si.si_signo)
 	{
@@ -1324,8 +1270,7 @@ wait_sig (VOID *)
 	case __SIGPENDING:
 	  *pack.mask = 0;
 	  unsigned bit;
-	  sigq.reset ();
-	  while ((q = sigq.next ()))
+	  while ((q = q->next))
 	    if (pack.sigtls->sigmask & (bit = SIGTOMASK (q->si.si_signo)))
 	      *pack.mask |= bit;
 	  break;
@@ -1340,15 +1285,23 @@ wait_sig (VOID *)
 	case __SIGNOHOLD:
 	case __SIGFLUSH:
 	case __SIGFLUSHFAST:
-	  sigq.reset ();
-	  while ((q = sigq.next ()))
-	    {
-	      int sig = q->si.si_signo;
-	      if (sig == __SIGDELETE || q->process () > 0)
-		sigq.del ();
-	      if (sig == SIGCHLD)
-		clearwait = true;
-	    }
+	  {
+	    sigpacket *qnext;
+	    /* Check the queue for signals.  There will always be at least one
+	       thing on the queue if this was a valid signal.  */
+	    while ((qnext = q->next))
+	      {
+		if (qnext->si.si_signo && qnext->process () <= 0)
+		  q = q->next;
+		else
+		  {
+		    q->next = qnext->next;
+		    qnext->si.si_signo = 0;
+		  }
+	      }
+	    if (pack.si.si_signo == SIGCHLD)
+	      clearwait = true;
+	  }
 	  break;
 	case __SIGSETPGRP:
 	  init_console_handler (true);
diff --git a/winsup/cygwin/sigproc.h b/winsup/cygwin/sigproc.h
index 9c70c2c2d..c4313f056 100644
--- a/winsup/cygwin/sigproc.h
+++ b/winsup/cygwin/sigproc.h
@@ -20,7 +20,7 @@ enum
   __SIGSTRACE	    = -(NSIG + 2),
   __SIGCOMMUNE	    = -(NSIG + 3),
   __SIGPENDING	    = -(NSIG + 4),
-  __SIGDELETE	    = -(NSIG + 5),
+  __SIGDELETE	    = -(NSIG + 5),	/* Not currently used */
   __SIGFLUSHFAST    = -(NSIG + 6),
   __SIGHOLD	    = -(NSIG + 7),
   __SIGNOHOLD	    = -(NSIG + 8),