From: Gemini Lasswell <gazally@runbox.com>
Date: Sat, 3 Nov 2018 20:57:55 +0000 (-0700)
Subject: Instrument file descriptor mask code (bug#33198)
X-Git-Url: http://git.eshelyaron.com/gitweb/?a=commitdiff_plain;h=40f179e2257c34ad7f424ef0912dd2c460e6d492;p=emacs.git

Instrument file descriptor mask code (bug#33198)
---

diff --git a/src/process.c b/src/process.c
index 7e78e172d36..c273a4dfeaf 100644
--- a/src/process.c
+++ b/src/process.c
@@ -280,7 +280,7 @@ static void exec_sentinel (Lisp_Object, Lisp_Object);
 static int num_pending_connects;
 
 /* The largest descriptor currently in use; -1 if none.  */
-static int max_desc;
+int max_desc;
 
 /* Set the external socket descriptor for Emacs to use when
    `make-network-process' is called with a non-nil
@@ -459,6 +459,8 @@ static struct fd_callback_data
 void
 add_read_fd (int fd, fd_callback func, void *data)
 {
+  fprintf(stderr, "add_read_fd %d (%p)\n", fd, current_thread);
+
   add_keyboard_wait_descriptor (fd);
 
   fd_callback_info[fd].func = func;
@@ -471,6 +473,8 @@ add_non_keyboard_read_fd (int fd)
   eassert (fd >= 0 && fd < FD_SETSIZE);
   eassert (fd_callback_info[fd].func == NULL);
 
+  fprintf(stderr, "add_non_keyboard_read_fd %d (%p)\n", fd, current_thread);
+
   fd_callback_info[fd].flags &= ~KEYBOARD_FD;
   fd_callback_info[fd].flags |= FOR_READ;
   if (fd > max_desc)
@@ -480,6 +484,8 @@ add_non_keyboard_read_fd (int fd)
 static void
 add_process_read_fd (int fd)
 {
+  fprintf(stderr, "add_process_read_fd %d (%p)\n", fd, current_thread);
+
   add_non_keyboard_read_fd (fd);
   fd_callback_info[fd].flags |= PROCESS_FD;
 }
@@ -489,6 +495,8 @@ add_process_read_fd (int fd)
 void
 delete_read_fd (int fd)
 {
+  fprintf(stderr, "delete_read_fd %d (%p)\n", fd, current_thread);
+
   delete_keyboard_wait_descriptor (fd);
 
   if (fd_callback_info[fd].flags == 0)
@@ -506,6 +514,8 @@ add_write_fd (int fd, fd_callback func, void *data)
 {
   eassert (fd >= 0 && fd < FD_SETSIZE);
 
+  fprintf(stderr, "add_write_fd %d (%p)\n", fd, current_thread);
+
   fd_callback_info[fd].func = func;
   fd_callback_info[fd].data = data;
   fd_callback_info[fd].flags |= FOR_WRITE;
@@ -519,6 +529,8 @@ add_non_blocking_write_fd (int fd)
   eassert (fd >= 0 && fd < FD_SETSIZE);
   eassert (fd_callback_info[fd].func == NULL);
 
+  fprintf(stderr, "add_non_blocking_write_fd %d (%p)\n", fd, current_thread);
+
   fd_callback_info[fd].flags |= FOR_WRITE | NON_BLOCKING_CONNECT_FD;
   if (fd > max_desc)
     max_desc = fd;
@@ -545,6 +557,8 @@ recompute_max_desc (void)
 void
 delete_write_fd (int fd)
 {
+  fprintf(stderr, "delete_write_fd %d (%p)\n", fd, current_thread);
+
   if ((fd_callback_info[fd].flags & NON_BLOCKING_CONNECT_FD) != 0)
     {
       if (--num_pending_connects < 0)
diff --git a/src/xgselect.c b/src/xgselect.c
index fedd3127ef3..cd7eadeadc2 100644
--- a/src/xgselect.c
+++ b/src/xgselect.c
@@ -18,6 +18,9 @@ You should have received a copy of the GNU General Public License
 along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.  */
 
 #include <config.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <fcntl.h>
 
 #include "xgselect.h"
 
@@ -29,6 +32,9 @@ along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.  */
 #include "blockinput.h"
 #include "systime.h"
 
+extern void safe_debug_print (Lisp_Object);
+extern int max_desc;
+
 /* `xg_select' is a `pselect' replacement.  Why do we need a separate function?
    1. Timeouts.  Glib and Gtk rely on timer events.  If we did pselect
       with a greater timeout then the one scheduled by Glib, we would
@@ -45,6 +51,7 @@ xg_select (int fds_lim, fd_set *rfds, fd_set *wfds, fd_set *efds,
 	   struct timespec *timeout, sigset_t *sigmask)
 {
   fd_set all_rfds, all_wfds;
+  fd_set save_all_rfds, save_all_wfds;
   struct timespec tmo;
   struct timespec *tmop = timeout;
 
@@ -113,12 +120,36 @@ xg_select (int fds_lim, fd_set *rfds, fd_set *wfds, fd_set *efds,
 	tmop = &tmo;
     }
 
+  save_all_rfds = all_rfds;
+  save_all_wfds = all_wfds;
+
   fds_lim = max_fds + 1;
   nfds = thread_select (pselect, fds_lim,
 			&all_rfds, have_wfds ? &all_wfds : NULL, efds,
 			tmop, sigmask);
   if (nfds < 0)
-    retval = nfds;
+    {
+      retval = nfds;
+      if (errno == EBADF)
+	{
+	  int fd;
+	  fprintf (stderr, "EBADF in xg_select, thread = %p\n",
+		   current_thread);
+
+	  for (fd = 0; fd <= max_desc; ++fd)
+	    {
+	      if (FD_ISSET (fd, &save_all_rfds) &&
+		  fcntl(fd, F_GETFL) < 0 &&
+		  errno == EBADF)
+		fprintf (stderr, "fd %d in save_all_rfds\n", fd);
+	      if (FD_ISSET (fd, &save_all_wfds) &&
+		  fcntl(fd, F_GETFL) < 0 &&
+		  errno == EBADF)
+		fprintf (stderr, "fd %d in save_all_wfds\n", fd);
+	    }
+	  errno = EBADF;
+	}
+    }
   else if (nfds > 0)
     {
       for (i = 0; i < fds_lim; ++i)