check for successful exit code in WaitForSingleProcess on Windows to

base/process_util_win.cc

Index: base/process_util_win.cc
diff --git a/base/process_util_win.cc b/base/process_util_win.cc
index dc165ec3889cace24d2172c2d91db8c3eb9653f5..5a0e5d13608f2c47c967445d80021c8b0d26f8f5 100644
--- a/base/process_util_win.cc
+++ b/base/process_util_win.cc
@@ -607,8 +607,10 @@ bool WaitForProcessesToExit(const std::wstring& executable_name,
 }
 
 bool WaitForSingleProcess(ProcessHandle handle, int64 wait_milliseconds) {
-  bool retval = WaitForSingleObject(handle, wait_milliseconds) == WAIT_OBJECT_0;
-  return retval;
+  int exit_code;
+  if (!WaitForExitCodeWithTimeout(handle, &exit_code, wait_milliseconds))
+    return false;
+  return exit_code == 0;

[Reid Kleckner, 2011/12/15 22:14:19]

This has slightly different semantics from the POSIX version of
WaitForSingleProcess.  That one uses "return WIFEXITED(exit_code)", which will
return true even if the process exits non-zero.  This should return false only
if the child crashed.

[bruening, 2011/12/16 04:08:06]

The problem is that on Windows exit codes set by the app can be any 32-bit value
so you're never really sure whether the app really crashed or it just used an
unusual exit code.  I suppose this could check for some standard values like
0xc0000005 or 0xc000001d but there are probably 20 or so different codes that
can constitute a crash and they aren't contiguous.  OTOH, no normal exit code is
likely to be in the STATUS_/EXCEPTION_ range.  The docs for this function talk
about a "clean exit": so checking for actual success seems reasonable.  It
depends on how this is meant to be used.  I would lean toward failing on
non-zero to catch more bugs unless we see existing usage that this breaks, which
so far has not been the case.

[Reid Kleckner, 2011/12/20 23:43:24]

I was going to say that the same thing can happen on POSIX, but they do the
return code << 8 dance to make space for the signal bits.  Checking for != 0 is
most conservative, so this seems reasonable.

 }
 
 bool CleanupProcesses(const std::wstring& executable_name,