Merge from emacs-24; up to 2012-12-19T19:51:40Z!monnier@iro.umontreal.ca

[gnu-emacs] / src / w32proc.c

diff --git a/src/w32proc.c b/src/w32proc.c
index 8bf57602927e60ab0c35ee251ae44dbd6f492c62..8226564c88fe388a844bbda9ba7bc8971be69c1f 100644 (file)
--- a/src/w32proc.c
+++ b/src/w32proc.c
@@ -802,6 +802,48 @@ new_child (void)
   for (cp = child_procs + (child_proc_count-1); cp >= child_procs; cp--)
     if (!CHILD_ACTIVE (cp) && cp->procinfo.hProcess == NULL)
       goto Initialize;
+  if (child_proc_count == MAX_CHILDREN)
+    {
+      int i = 0;
+      child_process *dead_cp = NULL;
+
+      DebPrint (("new_child: No vacant slots, looking for dead processes\n"));
+      for (cp = child_procs + (child_proc_count-1); cp >= child_procs; cp--)
+       if (!CHILD_ACTIVE (cp) && cp->procinfo.hProcess)
+         {
+           DWORD status = 0;
+
+           if (!GetExitCodeProcess (cp->procinfo.hProcess, &status))
+             {
+               DebPrint (("new_child.GetExitCodeProcess: error %lu for PID %lu\n",
+                          GetLastError (), cp->procinfo.dwProcessId));
+               status = STILL_ACTIVE;
+             }
+           if (status != STILL_ACTIVE
+               || WaitForSingleObject (cp->procinfo.hProcess, 0) == WAIT_OBJECT_0)
+             {
+               DebPrint (("new_child: Freeing slot of dead process %d, fd %d\n",
+                          cp->procinfo.dwProcessId, cp->fd));
+               CloseHandle (cp->procinfo.hProcess);
+               cp->procinfo.hProcess = NULL;
+               CloseHandle (cp->procinfo.hThread);
+               cp->procinfo.hThread = NULL;
+               /* Free up to 2 dead slots at a time, so that if we
+                  have a lot of them, they will eventually all be
+                  freed when the tornado ends.  */
+               if (i == 0)
+                 dead_cp = cp;
+               else
+                 break;
+               i++;
+             }
+         }
+      if (dead_cp)
+       {
+         cp = dead_cp;
+         goto Initialize;
+       }
+    }
   if (child_proc_count == MAX_CHILDREN)
     return NULL;
   cp = &child_procs[child_proc_count++];
@@ -975,12 +1017,24 @@ reader_thread (void *arg)
       if (cp->status == STATUS_READ_ERROR || !cp->char_avail)
        break;
 
+      if (!CHILD_ACTIVE (cp) && cp->procinfo.hProcess && cp->fd >= 0)
+       {
+         /* Somebody already called delete_child on this child, since
+            only delete_child zeroes out cp->char_avail.  This means
+            no one will read from cp->fd and will not set the
+            FILE_AT_EOF flag, therefore preventing sys_select from
+            noticing that the process died.  Set the flag here
+            instead.  */
+         fd_info[cp->fd].flags |= FILE_AT_EOF;
+       }
+
       /* The name char_avail is a misnomer - it really just means the
         read-ahead has completed, whether successfully or not. */
       if (!SetEvent (cp->char_avail))
         {
-         DebPrint (("reader_thread.SetEvent failed with %lu for fd %ld\n",
-                    GetLastError (), cp->fd));
+         DebPrint (("reader_thread.SetEvent(0x%x) failed with %lu for fd %ld (PID %d)\n",
+                    (DWORD_PTR)cp->char_avail, GetLastError (),
+                    cp->fd, cp->pid));
          return 1;
        }
 
@@ -1183,6 +1237,11 @@ reap_subprocess (child_process *cp)
      sys_read when the subprocess output is fully read.  */
   if (cp->fd < 0)
     delete_child (cp);
+  else
+    {
+      /* Reset the flag set by reader_thread.  */
+      fd_info[cp->fd].flags &= ~FILE_AT_EOF;
+    }
 }
 
 /* Wait for a child process specified by PID, or for any of our
@@ -2008,7 +2067,7 @@ count_children:
     /* Some child_procs might be sockets; ignore them.  Also some
        children may have died already, but we haven't finished reading
        the process output; ignore them too.  */
-    if (CHILD_ACTIVE (cp) && cp->procinfo.hProcess
+    if ((CHILD_ACTIVE (cp) || cp->procinfo.hProcess)
        && (cp->fd < 0
            || (fd_info[cp->fd].flags & FILE_SEND_SIGCHLD) == 0
            || (fd_info[cp->fd].flags & FILE_AT_EOF) != 0)