Merge from trunk.

1 files changed, 116 insertions, 49 deletions

diff --git a/src/w32proc.c b/src/w32proc.c
index e074ece020d..2951df7ed89 100644
--- a/src/w32proc.c
+++ b/src/w32proc.c
@@ -431,13 +431,14 @@ timer_loop (LPVOID arg)
           /* Simulate a signal delivered to the thread which installed
              the timer, by suspending that thread while the handler
              runs.  */
-          DWORD result = SuspendThread (itimer->caller_thread);
+          HANDLE th = itimer->caller_thread;
+          DWORD result = SuspendThread (th);
 
           if (result == (DWORD)-1)
             return 2;
 
           handler (sig);
-          ResumeThread (itimer->caller_thread);
+          ResumeThread (th);
         }
 
       /* Update expiration time and loop.  */
@@ -562,6 +563,7 @@ static int
 start_timer_thread (int which)
 {
   DWORD exit_code;
+  HANDLE th;
   struct itimer_data *itimer =
     (which == ITIMER_REAL) ? &real_itimer : &prof_itimer;
 
@@ -570,9 +572,29 @@ start_timer_thread (int which)
       && exit_code == STILL_ACTIVE)
     return 0;
 
+  /* Clean up after possibly exited thread.  */
+  if (itimer->timer_thread)
+    {
+      CloseHandle (itimer->timer_thread);
+      itimer->timer_thread = NULL;
+    }
+  if (itimer->caller_thread)
+    {
+      CloseHandle (itimer->caller_thread);
+      itimer->caller_thread = NULL;
+    }
+
   /* Start a new thread.  */
+  if (!DuplicateHandle (GetCurrentProcess (), GetCurrentThread (),
+                        GetCurrentProcess (), &th, 0, FALSE,
+                        DUPLICATE_SAME_ACCESS))
+    {
+      errno = ESRCH;
+      return -1;
+    }
   itimer->terminate = 0;
   itimer->type = which;
+  itimer->caller_thread = th;
   /* Request that no more than 64KB of stack be reserved for this
      thread, to avoid reserving too much memory, which would get in
      the way of threads we start to wait for subprocesses.  See also
@@ -591,7 +613,7 @@ start_timer_thread (int which)
   /* This is needed to make sure that the timer thread running for
      profiling gets CPU as soon as the Sleep call terminates. */
   if (which == ITIMER_PROF)
-    SetThreadPriority (itimer->caller_thread, THREAD_PRIORITY_TIME_CRITICAL);
+    SetThreadPriority (itimer->timer_thread, THREAD_PRIORITY_TIME_CRITICAL);
 
   return 0;
 }
@@ -626,17 +648,9 @@ getitimer (int which, struct itimerval *value)
 
   itimer = (which == ITIMER_REAL) ? &real_itimer : &prof_itimer;
 
-  if (!DuplicateHandle (GetCurrentProcess (), GetCurrentThread (),
-                        GetCurrentProcess (), &itimer->caller_thread, 0,
-                        FALSE, DUPLICATE_SAME_ACCESS))
-    {
-      errno = ESRCH;
-      return -1;
-    }
-
   ticks_now = w32_get_timer_time ((which == ITIMER_REAL)
                                   ? NULL
-                                  : itimer->caller_thread);
+                                  : GetCurrentThread ());
 
   t_expire = &itimer->expire;
   t_reload = &itimer->reload;
@@ -775,7 +789,6 @@ alarm (int seconds)
 /* Child process management list.  */
 int child_proc_count = 0;
 child_process child_procs[ MAX_CHILDREN ];
-child_process *dead_child = NULL;
 
 static DWORD WINAPI reader_thread (void *arg);
 
@@ -1028,9 +1041,6 @@ create_child (char *exe, char *cmdline, char *env, int is_gui_app,
   if (cp->pid < 0)
     cp->pid = -cp->pid;
 
-  /* pid must fit in a Lisp_Int */
-  cp->pid = cp->pid & INTMASK;
-
   *pPid = cp->pid;
 
   return TRUE;
@@ -1106,55 +1116,110 @@ reap_subprocess (child_process *cp)
     delete_child (cp);
 }
 
-/* Wait for any of our existing child processes to die
-   When it does, close its handle
-   Return the pid and fill in the status if non-NULL.  */
+/* Wait for a child process specified by PID, or for any of our
+   existing child processes (if PID is nonpositive) to die.  When it
+   does, close its handle.  Return the pid of the process that died
+   and fill in STATUS if non-NULL.  */
 
-int
-sys_wait (int *status)
+pid_t
+waitpid (pid_t pid, int *status, int options)
 {
   DWORD active, retval;
   int nh;
-  int pid;
   child_process *cp, *cps[MAX_CHILDREN];
   HANDLE wait_hnd[MAX_CHILDREN];
+  DWORD timeout_ms;
+  int dont_wait = (options & WNOHANG) != 0;
 
   nh = 0;
-  if (dead_child != NULL)
+  /* According to Posix:
+
+     PID = -1 means status is requested for any child process.
+
+     PID > 0 means status is requested for a single child process
+     whose pid is PID.
+
+     PID = 0 means status is requested for any child process whose
+     process group ID is equal to that of the calling process.  But
+     since Windows has only a limited support for process groups (only
+     for console processes and only for the purposes of passing
+     Ctrl-BREAK signal to them), and since we have no documented way
+     of determining whether a given process belongs to our group, we
+     treat 0 as -1.
+
+     PID < -1 means status is requested for any child process whose
+     process group ID is equal to the absolute value of PID.  Again,
+     since we don't support process groups, we treat that as -1.  */
+  if (pid > 0)
     {
-      /* We want to wait for a specific child */
-      wait_hnd[nh] = dead_child->procinfo.hProcess;
-      cps[nh] = dead_child;
-      if (!wait_hnd[nh]) emacs_abort ();
-      nh++;
-      active = 0;
-      goto get_result;
+      int our_child = 0;
+
+      /* We are requested to wait for a specific child.  */
+      for (cp = child_procs + (child_proc_count-1); cp >= child_procs; cp--)
+        {
+          /* Some child_procs might be sockets; ignore them.  Also
+             ignore subprocesses whose output is not yet completely
+             read.  */
+          if (CHILD_ACTIVE (cp)
+              && cp->procinfo.hProcess
+              && cp->pid == pid)
+            {
+              our_child = 1;
+              break;
+            }
+        }
+      if (our_child)
+        {
+          if (cp->fd < 0 || (fd_info[cp->fd].flags & FILE_AT_EOF) != 0)
+            {
+              wait_hnd[nh] = cp->procinfo.hProcess;
+              cps[nh] = cp;
+              nh++;
+            }
+          else if (dont_wait)
+            {
+              /* PID specifies our subprocess, but its status is not
+                 yet available.  */
+              return 0;
+            }
+        }
+      if (nh == 0)
+        {
+          /* No such child process, or nothing to wait for, so fail.  */
+          errno = ECHILD;
+          return -1;
+        }
     }
   else
     {
       for (cp = child_procs + (child_proc_count-1); cp >= child_procs; cp--)
-        /* some child_procs might be sockets; ignore them */
-        if (CHILD_ACTIVE (cp) && cp->procinfo.hProcess
-            && (cp->fd < 0 || (fd_info[cp->fd].flags & FILE_AT_EOF) != 0))
-          {
-            wait_hnd[nh] = cp->procinfo.hProcess;
-            cps[nh] = cp;
-            nh++;
-          }
+        {
+          if (CHILD_ACTIVE (cp)
+              && cp->procinfo.hProcess
+              && (cp->fd < 0 || (fd_info[cp->fd].flags & FILE_AT_EOF) != 0))
+            {
+              wait_hnd[nh] = cp->procinfo.hProcess;
+              cps[nh] = cp;
+              nh++;
+            }
+        }
+      if (nh == 0)
+        {
+          /* Nothing to wait on, so fail.  */
+          errno = ECHILD;
+          return -1;
+        }
     }
 
-  if (nh == 0)
-    {
-      /* Nothing to wait on, so fail */
-      errno = ECHILD;
-      return -1;
-    }
+  if (dont_wait)
+    timeout_ms = 0;
+  else
+    timeout_ms = 1000;  /* check for quit about once a second. */
 
   do
     {
-      /* Check for quit about once a second. */
       QUIT;
-      active = WaitForMultipleObjects (nh, wait_hnd, FALSE, 1000);
+      active = WaitForMultipleObjects (nh, wait_hnd, FALSE, timeout_ms);
     } while (active == WAIT_TIMEOUT);
 
   if (active == WAIT_FAILED)
@@ -1184,8 +1249,10 @@ get_result:
     }
   if (retval == STILL_ACTIVE)
     {
-      /* Should never happen */
+      /* Should never happen.  */
       DebPrint (("Wait.WaitForMultipleObjects returned an active process\n"));
+      if (pid > 0 && dont_wait)
+        return 0;
       errno = EINVAL;
       return -1;
     }
@@ -1199,6 +1266,8 @@ get_result:
   else
     retval <<= 8;
 
+  if (pid > 0 && active != 0)
+    emacs_abort ();
   cp = cps[active];
   pid = cp->pid;
 #ifdef FULL_DEBUG
@@ -2004,9 +2073,7 @@ count_children:
               DebPrint (("select calling SIGCHLD handler for pid %d\n",
                          cp->pid));
 #endif
-              dead_child = cp;
               sig_handlers[SIGCHLD] (SIGCHLD);
-              dead_child = NULL;
             }
         }
       else if (fdindex[active] == -1)