1 files changed, 63 insertions, 42 deletions

diff --git a/winsup/cygwin/poll.cc b/winsup/cygwin/poll.cc
index 2ac606849..3c61c565e 100644
--- a/winsup/cygwin/poll.cc
+++ b/winsup/cygwin/poll.cc
@@ -1,6 +1,6 @@
 /* poll.cc. Implements poll(2) via usage of select(2) call.
 
-   Copyright 2000, 2001 Red Hat, Inc.
+   Copyright 2000, 2001, 2002 Red Hat, Inc.
 
    This file is part of Cygwin.
 
@@ -11,13 +11,15 @@
 #include "winsup.h"
 #include <sys/time.h>
 #include <sys/poll.h>
+#include <sys/socket.h>
 #include <errno.h>
+#include <stdlib.h>
 #include "security.h"
 #include "fhandler.h"
 #include "path.h"
 #include "dtable.h"
-#include "cygheap.h"
 #include "cygerrno.h"
+#include "cygheap.h"
 #include "sigproc.h"
 
 extern "C"
@@ -25,7 +27,7 @@ int
 poll (struct pollfd *fds, unsigned int nfds, int timeout)
 {
   int max_fd = 0;
-  fd_set *open_fds, *read_fds, *write_fds, *except_fds;
+  fd_set *read_fds, *write_fds, *except_fds;
   struct timeval tv = { timeout / 1000, (timeout % 1000) * 1000 };
   sigframe thisframe (mainthread);
 
@@ -33,66 +35,85 @@ poll (struct pollfd *fds, unsigned int nfds, int timeout)
     if (fds[i].fd > max_fd)
       max_fd = fds[i].fd;
 
-  size_t fds_size = howmany(max_fd + 1, NFDBITS) * sizeof (fd_mask);
+  size_t fds_size = howmany (max_fd + 1, NFDBITS) * sizeof (fd_mask);
 
-  open_fds = (fd_set *) alloca (fds_size);
   read_fds = (fd_set *) alloca (fds_size);
   write_fds = (fd_set *) alloca (fds_size);
   except_fds = (fd_set *) alloca (fds_size);
 
-  if (!open_fds || !read_fds || !write_fds || !except_fds)
+  if (!read_fds || !write_fds || !except_fds)
     {
       set_errno (ENOMEM);
       return -1;
     }
 
-  memset (open_fds, 0, fds_size);
   memset (read_fds, 0, fds_size);
   memset (write_fds, 0, fds_size);
   memset (except_fds, 0, fds_size);
 
-  bool invalid_fds = false;
-  for (unsigned int i = 0; i < nfds; ++i)
-    if (!cygheap->fdtab.not_open (fds[i].fd))
-      {
-	FD_SET (fds[i].fd, open_fds);
-	if (fds[i].events & POLLIN)
-	  FD_SET (fds[i].fd, read_fds);
-	if (fds[i].events & POLLOUT)
-	  FD_SET (fds[i].fd, write_fds);
-	if (fds[i].events & POLLPRI)
-	  FD_SET (fds[i].fd, except_fds);
-      }
-      else
-	invalid_fds = true;
-
-  int ret = 0;
-  if (!invalid_fds)
-    ret = cygwin_select (max_fd + 1, read_fds, write_fds, except_fds,
-			 timeout < 0 ? NULL : &tv);
-
+  int invalid_fds = 0;
   for (unsigned int i = 0; i < nfds; ++i)
     {
-      if (!FD_ISSET (fds[i].fd, open_fds))
+      fds[i].revents = 0;
+      if (!cygheap->fdtab.not_open (fds[i].fd))
 	{
-	  fds[i].revents = POLLNVAL;
-	  ret++;
+	  if (fds[i].events & POLLIN)
+	    FD_SET(fds[i].fd, read_fds);
+	  if (fds[i].events & POLLOUT)
+	    FD_SET(fds[i].fd, write_fds);
+	  if (fds[i].events & POLLPRI)
+	    FD_SET(fds[i].fd, except_fds);
 	}
-      else if (cygheap->fdtab.not_open(fds[i].fd))
-	fds[i].revents = POLLHUP;
-      else if (ret < 0)
-	fds[i].revents = POLLERR;
-      else
+      else if (fds[i].fd >= 0)
 	{
-	  fds[i].revents = 0;
-	  if (FD_ISSET (fds[i].fd, read_fds))
-	    fds[i].revents |= POLLIN;
-	  if (FD_ISSET (fds[i].fd, write_fds))
-	    fds[i].revents |= POLLOUT;
-	  if (FD_ISSET (fds[i].fd, except_fds))
-	    fds[i].revents |= POLLPRI;
+	  ++invalid_fds;
+	  fds[i].revents = POLLNVAL;
 	}
     }
 
+  if (invalid_fds)
+    return invalid_fds;
+
+  int ret = cygwin_select (max_fd + 1, read_fds, write_fds, except_fds, timeout < 0 ? NULL : &tv);
+
+  if (ret > 0)
+    for (unsigned int i = 0; i < nfds; ++i)
+      {
+	if (fds[i].fd >= 0)
+	  {
+	    if (cygheap->fdtab.not_open (fds[i].fd))
+	      fds[i].revents = POLLHUP;
+	    else
+	      {
+		if (FD_ISSET(fds[i].fd, read_fds))
+		  {
+		    char peek[1];
+		    fhandler_socket *sock =
+				      cygheap->fdtab[fds[i].fd]->is_socket ();
+		    if (!sock)
+		      fds[i].revents |= POLLIN;
+		    else
+		      switch (sock->recvfrom (peek, sizeof (peek), MSG_PEEK,
+					      NULL, NULL))
+			{
+			  case -1: /* Something weird happened */
+			    fds[i].revents |= POLLERR;
+			    break;
+			  case 0:  /* Closed on the read side. */
+			    fds[i].revents |= POLLHUP;
+			    break;
+			  default:
+			    fds[i].revents |= POLLIN;
+			    break;
+			}
+		  }
+		if (FD_ISSET(fds[i].fd, write_fds))
+		  fds[i].revents |= POLLOUT;
+		if (FD_ISSET(fds[i].fd, except_fds))
+		  fds[i].revents |= POLLPRI;
+	      }
+	  }
+      }
+
   return ret;
 }