Track thread activities in order to diagnose hangs.

base/process/process_posix.cc

 // Copyright 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "base/process/process.h"
 
 #include <errno.h>
 #include <stdint.h>
 #include <sys/resource.h>
 #include <sys/wait.h>
 
+#include "base/debug/activity_tracker.h"
 #include "base/files/scoped_file.h"
 #include "base/logging.h"
 #include "base/posix/eintr_wrapper.h"
 #include "base/process/kill.h"
 #include "base/third_party/dynamic_annotations/dynamic_annotations.h"
 #include "build/build_config.h"
 
 #if defined(OS_MACOSX)
 #include <sys/event.h>
 #endif
@@ skipping 325 matching lines @@
 
   return result;
 }
 #endif  // !defined(OS_NACL_NONSFI)
 
 bool Process::WaitForExit(int* exit_code) {
   return WaitForExitWithTimeout(TimeDelta::Max(), exit_code);
 }
 
 bool Process::WaitForExitWithTimeout(TimeDelta timeout, int* exit_code) {
+  // Record the event that this thread is blocking upon (for hang diagonsis).

[manzagop (departed), 2016/06/16 15:19:40]

typo

[bcwhite, 2016/06/16 17:04:43]

And of course it would be in a comment copied to multiple files...  <sigh>

Done here and everywhere.

+  base::debug::ScopedProcessWaitActivity process_activity(this);
+
   return WaitForExitWithTimeoutImpl(Handle(), exit_code, timeout);
 }
 
 #if !defined(OS_LINUX)
 bool Process::IsProcessBackgrounded() const {
   // See SetProcessBackgrounded().
   DCHECK(IsValid());
   return false;
 }
 
 bool Process::SetProcessBackgrounded(bool value) {
   // Not implemented for POSIX systems other than Linux. With POSIX, if we were
   // to lower the process priority we wouldn't be able to raise it back to its
   // initial priority.
   NOTIMPLEMENTED();
   return false;
 }
 #endif  // !defined(OS_LINUX)
 
 int Process::GetPriority() const {
   DCHECK(IsValid());
   return getpriority(PRIO_PROCESS, process_);
 }
 
 }  // namespace base