sandbox/linux/services/thread_helpers.h

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef SANDBOX_LINUX_SERVICES_THREAD_HELPERS_H_
   6 #define SANDBOX_LINUX_SERVICES_THREAD_HELPERS_H_
   7
   8 #include "base/macros.h"
   9 #include "sandbox/sandbox_export.h"
  10
  11 namespace base { class Thread; }
  12
  13 namespace sandbox {
  14
  15 class SANDBOX_EXPORT ThreadHelpers {
  16  public:
  17   // Checks whether the current process is single threaded. |proc_fd|
  18   // must be a file descriptor to /proc/ and remains owned by the
  19   // caller.
  20   static bool IsSingleThreaded(int proc_fd);
  21   static bool IsSingleThreaded();
  22
  23   // Crashes if the current process is not single threaded. This will wait
  24   // on /proc to be updated. In the case where this doesn't crash, this will
  25   // return promptly. In the case where this does crash, this will first wait
  26   // for a few ms in Debug mode, a few seconds in Release mode.
  27   static void AssertSingleThreaded(int proc_fd);
  28   static void AssertSingleThreaded();
  29
  30   // Starts |thread| and ensure that it has an entry in /proc/self/task/ from
  31   // the point of view of the current thread.
  32   static bool StartThreadAndWatchProcFS(int proc_fd, base::Thread* thread);
  33
  34   // Stops |thread| and ensure that it does not have an entry in
  35   // /proc/self/task/ from the point of view of the current thread. This is
  36   // the way to stop threads before calling IsSingleThreaded().
  37   static bool StopThreadAndWatchProcFS(int proc_fd, base::Thread* thread);
  38
  39   static const char* GetAssertSingleThreadedErrorMessageForTests();
  40
  41  private:
  42   DISALLOW_IMPLICIT_CONSTRUCTORS(ThreadHelpers);
  43 };
  44
  45 }  // namespace sandbox
  46
  47 #endif  // SANDBOX_LINUX_SERVICES_THREAD_HELPERS_H_