* DevNotes: Add entry cgf-000003.

* cygheap.h (init_cygheap::pid_handle): Delete.
* dcrt0.cc (child_info_spawn::handle_spawn): Keep parent open if we have
execed.
* pinfo.cc (pinfo::thisproc): Remove pid_handle manipulations.
(pinfo::init): Don't consider a reaped process to be available.
* spawn.cc (child_info_spawn::worker): Remove pid_handle manipulations.  Make
wr_proc_pipe and parent noninheritable when starting a program which doesn't
use the Cygwin DLL.  Conditionally reset wr_proc_pipe to inheritable if
CreateProcess fails.  Inject wr_proc_pipe handle into non-Cygwin process.
Consider a non-cygwin process to be 'synced'.

winsup/cygwin/ChangeLog

@@ -1,3 +1,17 @@
+2012-05-07  Christopher Faylor  <me.cygwin2012@cgf.cx>
+
+	* DevNotes: Add entry cgf-000003.
+	* cygheap.h (init_cygheap::pid_handle): Delete.
+	* dcrt0.cc (child_info_spawn::handle_spawn): Keep parent open if we
+	have execed.
+	* pinfo.cc (pinfo::thisproc): Remove pid_handle manipulations.
+	(pinfo::init): Don't consider a reaped process to be available.
+	* spawn.cc (child_info_spawn::worker): Remove pid_handle manipulations.
+	Make wr_proc_pipe and parent noninheritable when starting a program
+	which doesn't use the Cygwin DLL.  Conditionally reset wr_proc_pipe to
+	inheritable if CreateProcess fails.  Inject wr_proc_pipe handle into
+	non-Cygwin process.  Consider a non-cygwin process to be 'synced'.
+
 2012-05-03  Christopher Faylor  <me.cygwin2012@cgf.cx>
 
 	* DevNotes: Add entry cgf-000002.

winsup/cygwin/DevNotes

@@ -1,3 +1,54 @@
+2012-05-03  cgf-000003
+
+<1.7.15>
+Don't make Cygwin wait for all children of a non-cygwin child program.
+Fixes: http://cygwin.com/ml/cygwin/2012-05/msg00063.html,
+       http://cygwin.com/ml/cygwin/2012-05/msg00075.html
+</1.7.15>
+
+This problem is due to a recent change which added some robustness and
+speed to Cygwin's exec/spawn handling by not trying to force inheritance
+every time a process is started.  See ChangeLog entries starting on
+2012-03-20, and multiple on 2012-03-21.
+
+Making the handle inheritable meant that, as usual, there were problems
+with non-Cygwin processes.  When Cygwin "execs" a non-Cygwin process N,
+all of its N + 1, N + 2, ...  children will also inherit the handle.
+That means that Cygwin will wait until all subprocesses have exited
+before it returns.
+
+I was willing to make this a restriction of starting non-Cygwin
+processes but the problem with allowing that is that it can cause the
+creation of a "limbo" pid when N exits and N + 1 and friends are still
+around.  In this scenario, Cygwin dutifully notices that process N has
+died and sets the exit code to indicate that but N's parent will wait on
+rd_proc_pipe and will only return when every N + ...  windows process
+has exited.
+
+The removal of cygheap::pid_handle was not related to the initial
+problem that I set out to fix.  The change came from the realization
+that we were duping the current process handle into the child twice and
+only needed to do it once.  The current process handle is used by exec
+to keep the Windows pid "alive" so that it will not be reused.  So, now
+we just close parent in child_info_spawn::handle_spawn iff we're not
+execing.
+
+In debugging this it bothered me that 'ps' identified a nonactive pid as
+active.  Part of the reason for this was the 'parent' handle in
+child_info was opened in non-Cygwin processes, keeping the pid alive.
+That has been kluged around (more changes after 1.7.15) but that didn't
+fix the problem.  On further investigation, this seems to be caused by
+the fact that the shared memory region pid handles were still being
+passed to non-cygwin children, keeping the pid alive in a limbo-like
+fashion.  This was easily fixed by having pinfo::init() consider a
+memory region with PID_REAPED as not available.
+
+This fixed the problem where a pid showed up in the list after a user
+does something like: "bash$ cmd /c start notepad" but, for some reason,
+it does not fix the problem where "bash$ setsid cmd /c start notepad".
+That bears investigation after 1.7.15 is released but it is not a
+regression and so is not a blocker for the release.
+
 2012-05-03  cgf-000002
 
 <1.7.15>

winsup/cygwin/cygheap.h

@@ -390,7 +390,6 @@ struct init_cygheap: public mini_cygheap
   struct _cygtls **threadlist;
   size_t sthreads;
   pid_t pid;			/* my pid */
-  HANDLE pid_handle;		/* handle for my pid */
   struct {			/* Equivalent to using LIST_HEAD. */
     struct inode_t *lh_first;
   } inode_list;			/* Global inode pointer for adv. locking. */

winsup/cygwin/dcrt0.cc

@@ -665,10 +665,15 @@ child_info_spawn::handle_spawn ()
 
   ready (true);
 
-  /* Need to do this after debug_fixup_after_fork_exec or DEBUGGING handling of
+  /* Keep pointer to parent open if we've execed so that pid will not be reused.
+     Otherwise, we no longer need this handle so close it.
+     Need to do this after debug_fixup_after_fork_exec or DEBUGGING handling of
      handles might get confused. */
+  if (type != _CH_EXEC)
+    {
       CloseHandle (child_proc_info->parent);
       child_proc_info->parent = NULL;
+    }
 
   signal_fixup_after_exec ();
   fixup_lockf_after_exec ();

winsup/cygwin/pinfo.cc

@@ -77,11 +77,6 @@ pinfo::thisproc (HANDLE h)
   else if (!child_proc_info)	/* child_proc_info is only set when this process
 				   was started by another cygwin process */
     procinfo->start_time = time (NULL); /* Register our starting time. */
-  else if (::cygheap->pid_handle)
-    {
-      ForceCloseHandle (::cygheap->pid_handle);
-      ::cygheap->pid_handle = NULL;
-    }
 }
 
 /* Initialize the process table entry for the current task.
@@ -305,8 +300,9 @@ pinfo::init (pid_t n, DWORD flag, HANDLE h0)
 
       bool created = shloc != SH_JUSTOPEN;
 
-      if ((procinfo->process_state & PID_INITIALIZING) && (flag & PID_NOREDIR)
+      if ((procinfo->process_state & PID_REAPED)
-	  && cygwin_pid (procinfo->dwProcessId) != procinfo->pid)
+	  || ((procinfo->process_state & PID_INITIALIZING) && (flag & PID_NOREDIR)
+	      && cygwin_pid (procinfo->dwProcessId) != procinfo->pid))
 	{
 	  set_errno (ESRCH);
 	  break;

winsup/cygwin/release/1.7.15

@@ -22,3 +22,8 @@ Bug fixes:
 - Avoid "WARNING: Couldn't compute FAST_CWD pointer." message on
   Windows 8 Customer Preview 32 bit. 
   Fixes: http://cygwin.com/ml/cygwin/2012-04/msg00616.html
+
+- Don't make Cygwin wait for all children of a non-cygwin child program.
+  Fixes: http://cygwin.com/ml/cygwin/2012-05/msg00063.html,
+	 http://cygwin.com/ml/cygwin/2012-05/msg00075.html
+

winsup/cygwin/spawn.cc

@@ -517,17 +517,6 @@ child_info_spawn::worker (const char *prog_arg, const char *const *argv,
 	  myself->sendsig = NULL;
 	  reset_sendsig = true;
 	}
-      /* Save a copy of a handle to the current process around the first time we
-	 exec so that the pid will not be reused.  Why did I stop cygwin from
-	 generating its own pids again? */
-      if (::cygheap->pid_handle)
-	/* already done previously */;
-      else if (DuplicateHandle (GetCurrentProcess (), GetCurrentProcess (),
-				GetCurrentProcess (), &::cygheap->pid_handle,
-				PROCESS_QUERY_INFORMATION, TRUE, 0))
-	ProtectHandleINH (::cygheap->pid_handle);
-      else
-	system_printf ("duplicate to pid_handle failed, %E");
     }
 
   if (null_app_name)
@@ -613,6 +602,19 @@ child_info_spawn::worker (const char *prog_arg, const char *const *argv,
   else
     wr_proc_pipe = my_wr_proc_pipe;
 
+  /* Don't allow child to inherit these handles if it's not a Cygwin program.
+     wr_proc_pipe will be injected later.  parent won't be used by the child
+     so there is no reason for the child to have it open as it can confuse
+     ps into thinking that children of windows processes are all part of
+     the same "execed" process.
+     FIXME: Someday, make it so that parent is never created when starting
+     non-Cygwin processes. */
+  if (!iscygwin ())
+    {
+      SetHandleInformation (wr_proc_pipe, HANDLE_FLAG_INHERIT, 0);
+      SetHandleInformation (parent, HANDLE_FLAG_INHERIT, 0);
+    }
+
   /* When ruid != euid we create the new process under the current original
      account and impersonate in child, this way maintaining the different
      effective vs. real ids.
@@ -734,6 +736,12 @@ loop:
 	  myself->exec_sendsig = NULL;
 	}
       myself->process_state &= ~PID_NOTCYGWIN;
+      /* Reset handle inheritance to default when the execution of a non-Cygwin
+	 process fails.  Only need to do this for _P_OVERLAY since the handle will
+	 be closed otherwise.  Don't need to do this for 'parent' since it will
+         be closed in every case.  See FIXME above. */
+      if (!real_path.iscygexec () && mode == _P_OVERLAY)
+	SetHandleInformation (wr_proc_pipe, HANDLE_FLAG_INHERIT, HANDLE_FLAG_INHERIT);
       if (wr_proc_pipe == my_wr_proc_pipe)
 	wr_proc_pipe = NULL;	/* We still own it: don't nuke in destructor */
       res = -1;
@@ -755,7 +763,7 @@ loop:
     cygpid = myself->pid;
 
   /* We print the original program name here so the user can see that too.  */
-  syscall_printf ("%d = child_info_spawn::worker(%s, %.9500s)",
+  syscall_printf ("pid %d, prog_arg %s, cmd line %.9500s)",
 		  rc ? cygpid : (unsigned int) -1, prog_arg, one_line.buf);
 
   /* Name the handle similarly to proc_subproc. */
@@ -815,6 +823,12 @@ loop:
   /* Start the child running */
   if (c_flags & CREATE_SUSPENDED)
     {
+      /* Inject a non-inheritable wr_proc_pipe handle into child so that we
+	 can accurately track when the child exits without keeping this
+	 process waiting around for it to exit.  */
+      if (!iscygwin ())
+	DuplicateHandle (GetCurrentProcess (), wr_proc_pipe, pi.hProcess, NULL,
+			 0, false, DUPLICATE_SAME_ACCESS);
       ResumeThread (pi.hThread);
       if (iscygwin ())
 	strace.write_childpid (pi.dwProcessId);
@@ -827,7 +841,9 @@ loop:
   if ((mode == _P_DETACH || mode == _P_NOWAIT) && !iscygwin ())
     synced = false;
   else
-    synced = sync (pi.dwProcessId, pi.hProcess, INFINITE);
+    /* Just mark a non-cygwin process as 'synced'.  We will still eventually
+       wait for it to exit in maybe_set_exit_code_from_windows(). */
+    synced = iscygwin () ? sync (pi.dwProcessId, pi.hProcess, INFINITE) : true;
 
   switch (mode)
     {