* cygwait.h (cancelable_wait): Make extern to avoid always including.

* select.cc (allocfd_set): Try to make a little more efficient.
(cygwin_select): Break into two functions to avoid what seems to be a strange
compiler problem with alloca and sel constructor.
(select): New function.  Always honor return from call_signal_handler.
(select_stuff::wait): Always honor return from call_signal_handler.
* select.h (select_stuff::select_stuff): Use NULL to initialize pointers rather
than 0.

1 files changed, 34 insertions, 27 deletions

diff --git a/winsup/cygwin/select.cc b/winsup/cygwin/select.cc
index 0186af733..8d131291e 100644
--- a/winsup/cygwin/select.cc
+++ b/winsup/cygwin/select.cc
@@ -73,7 +73,13 @@ typedef long fd_mask;
 #define UNIX_FD_ZERO(p, n) \
   memset ((caddr_t) (p), 0, sizeof_fd_set ((n)))
 
-#define allocfd_set(n) ((fd_set *) memset (alloca (sizeof_fd_set (n)), 0, sizeof_fd_set (n)))
+#define allocfd_set(n) ({\
+  size_t __sfds = sizeof_fd_set (n) + 8; \
+  void *__res = alloca (__sfds); \
+  memset (__res, 0, __sfds); \
+  (fd_set *) __res; \
+})
+
 #define copyfd_set(to, from, n) memcpy (to, from, sizeof_fd_set (n));
 
 #define set_handle_or_return_if_not_open(h, s) \
@@ -84,31 +90,15 @@ typedef long fd_mask;
       return -1; \
     }
 
-/* The main select code.
- */
+static int select (int, fd_set *, fd_set *, fd_set *, DWORD);
+
+/* The main select code.  */
 extern "C" int
 cygwin_select (int maxfds, fd_set *readfds, fd_set *writefds, fd_set *exceptfds,
 	       struct timeval *to)
 {
   select_printf ("select(%d, %p, %p, %p, %p)", maxfds, readfds, writefds, exceptfds, to);
 
-  select_stuff sel;
-  fd_set *dummy_readfds = allocfd_set (maxfds);
-  fd_set *dummy_writefds = allocfd_set (maxfds);
-  fd_set *dummy_exceptfds = allocfd_set (maxfds);
-
-  /* Allocate some fd_set structures using the number of fds as a guide. */
-  fd_set *r = allocfd_set (maxfds);
-  fd_set *w = allocfd_set (maxfds);
-  fd_set *e = allocfd_set (maxfds);
-
-  if (!readfds)
-    readfds = dummy_readfds;
-  if (!writefds)
-    writefds = dummy_writefds;
-  if (!exceptfds)
-    exceptfds = dummy_exceptfds;
-
   pthread_testcancel ();
 
   /* Convert to milliseconds or INFINITE if to == NULL */
@@ -121,12 +111,33 @@ cygwin_select (int maxfds, fd_set *readfds, fd_set *writefds, fd_set *exceptfds,
   else
     select_printf ("to NULL, ms %x", ms);
 
-  sel.return_on_signal = &_my_tls == _main_tls;
+  int res = select (maxfds, readfds ?: allocfd_set (maxfds),
+		    writefds ?: allocfd_set (maxfds),
+		    exceptfds ?: allocfd_set (maxfds), ms);
+  syscall_printf ("%R = select(%d, %p, %p, %p, %p)", res, maxfds, readfds,
+		  writefds, exceptfds, to);
+  return res;
+}
 
+/* This function is arbitrarily split out from cygwin_select to avoid odd
+   gcc issues with the use of allocfd_set and improper constructor handling
+   for the sel variable.  */
+static int
+select (int maxfds, fd_set *readfds, fd_set *writefds, fd_set *exceptfds,
+	DWORD ms)
+{
   int res = select_stuff::select_loop;
 
   LONGLONG start_time = gtod.msecs ();	/* Record the current time for later use. */
 
+  select_stuff sel;
+  sel.return_on_signal = 0;
+
+  /* Allocate some fd_set structures using the number of fds as a guide. */
+  fd_set *r = allocfd_set (maxfds);
+  fd_set *w = allocfd_set (maxfds);
+  fd_set *e = allocfd_set (maxfds);
+
   while (res == select_stuff::select_loop)
     {
       /* Build the select record per fd linked list and set state as
@@ -146,8 +157,7 @@ cygwin_select (int maxfds, fd_set *readfds, fd_set *writefds, fd_set *exceptfds,
 	  {
 	  case WAIT_SIGNALED:
 	    select_printf ("signal received");
-	    _my_tls.call_signal_handler ();
-	    if (!sel.return_on_signal)
+	    if (_my_tls.call_signal_handler ())
 	      res = select_stuff::select_loop;		/* Emulate linux behavior */
 	    else
 	      {
@@ -199,8 +209,6 @@ cygwin_select (int maxfds, fd_set *readfds, fd_set *writefds, fd_set *exceptfds,
 
   if (res < -1)
     res = -1;
-  syscall_printf ("%R = select(%d, %p, %p, %p, %p)", res, maxfds, readfds,
-		  writefds, exceptfds, to);
   return res;
 }
 
@@ -365,8 +373,7 @@ next_while:;
 	 be assured that a signal handler won't jump out of select entirely. */
       cleanup ();
       destroy ();
-      _my_tls.call_signal_handler ();
-      if (!return_on_signal)
+      if (_my_tls.call_signal_handler ())
 	res = select_loop;
       else
 	{