xpcom/threads/RecursiveMutex.cpp

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #include "mozilla/RecursiveMutex.h"
   8
   9 #ifdef XP_WIN
  10 #  include <windows.h>
  11
  12 #  define NativeHandle(m) (reinterpret_cast<CRITICAL_SECTION*>(&m))
  13 #endif
  14
  15 namespace mozilla {
  16
  17 RecursiveMutex::RecursiveMutex(const char* aName)
  18     : BlockingResourceBase(aName, eRecursiveMutex)
  19 #ifdef DEBUG
  20       ,
  21       mOwningThread(nullptr),
  22       mEntryCount(0)
  23 #endif
  24 {
  25 #ifdef XP_WIN
  26   // This number was adapted from NSPR.
  27   static const DWORD sLockSpinCount = 100;
  28
  29 #  if defined(RELEASE_OR_BETA)
  30   // Vista and later automatically allocate and subsequently leak a debug info
  31   // object for each critical section that we allocate unless we tell the
  32   // system not to do that.
  33   DWORD flags = CRITICAL_SECTION_NO_DEBUG_INFO;
  34 #  else
  35   DWORD flags = 0;
  36 #  endif
  37   BOOL r =
  38       InitializeCriticalSectionEx(NativeHandle(mMutex), sLockSpinCount, flags);
  39   MOZ_RELEASE_ASSERT(r);
  40 #else
  41   pthread_mutexattr_t attr;
  42
  43   MOZ_RELEASE_ASSERT(pthread_mutexattr_init(&attr) == 0,
  44                      "pthread_mutexattr_init failed");
  45
  46   MOZ_RELEASE_ASSERT(
  47       pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_RECURSIVE) == 0,
  48       "pthread_mutexattr_settype failed");
  49
  50   MOZ_RELEASE_ASSERT(pthread_mutex_init(&mMutex, &attr) == 0,
  51                      "pthread_mutex_init failed");
  52
  53   MOZ_RELEASE_ASSERT(pthread_mutexattr_destroy(&attr) == 0,
  54                      "pthread_mutexattr_destroy failed");
  55 #endif
  56 }
  57
  58 RecursiveMutex::~RecursiveMutex() {
  59 #ifdef XP_WIN
  60   DeleteCriticalSection(NativeHandle(mMutex));
  61 #else
  62   MOZ_RELEASE_ASSERT(pthread_mutex_destroy(&mMutex) == 0,
  63                      "pthread_mutex_destroy failed");
  64 #endif
  65 }
  66
  67 void RecursiveMutex::LockInternal() {
  68 #ifdef XP_WIN
  69   EnterCriticalSection(NativeHandle(mMutex));
  70 #else
  71   MOZ_RELEASE_ASSERT(pthread_mutex_lock(&mMutex) == 0,
  72                      "pthread_mutex_lock failed");
  73 #endif
  74 }
  75
  76 void RecursiveMutex::UnlockInternal() {
  77 #ifdef XP_WIN
  78   LeaveCriticalSection(NativeHandle(mMutex));
  79 #else
  80   MOZ_RELEASE_ASSERT(pthread_mutex_unlock(&mMutex) == 0,
  81                      "pthread_mutex_unlock failed");
  82 #endif
  83 }
  84
  85 }  // namespace mozilla