src/third_party/skia/src/ports/SkMutex_win.h

   1 /*
   2  * Copyright 2013 Google Inc.
   3  *
   4  * Use of this source code is governed by a BSD-style license that can be
   5  * found in the LICENSE file.
   6  */
   7
   8 #ifndef SkMutex_win_DEFINED
   9 #define SkMutex_win_DEFINED
  10
  11 /** Windows CriticalSection based mutex. */
  12
  13 #ifndef WIN32_LEAN_AND_MEAN
  14 #  define WIN32_LEAN_AND_MEAN
  15 #  define WIN32_IS_MEAN_WAS_LOCALLY_DEFINED
  16 #endif
  17 #ifndef NOMINMAX
  18 #  define NOMINMAX
  19 #  define NOMINMAX_WAS_LOCALLY_DEFINED
  20 #endif
  21 #
  22 #include <windows.h>
  23 #
  24 #ifdef WIN32_IS_MEAN_WAS_LOCALLY_DEFINED
  25 #  undef WIN32_IS_MEAN_WAS_LOCALLY_DEFINED
  26 #  undef WIN32_LEAN_AND_MEAN
  27 #endif
  28 #ifdef NOMINMAX_WAS_LOCALLY_DEFINED
  29 #  undef NOMINMAX_WAS_LOCALLY_DEFINED
  30 #  undef NOMINMAX
  31 #endif
  32
  33 // On Windows, SkBaseMutex and SkMutex are the same thing,
  34 // we can't easily get rid of static initializers. However,
  35 // we preserve the same inheritance pattern as other platforms
  36 // so that we can forward-declare cleanly.
  37 struct SkBaseMutex {
  38 public:
  39     SkBaseMutex() {
  40         InitializeCriticalSection(&fStorage);
  41         SkDEBUGCODE(fOwner = 0;)
  42     }
  43
  44     ~SkBaseMutex() {
  45         SkASSERT(0 == fOwner);
  46         DeleteCriticalSection(&fStorage);
  47     }
  48
  49     void acquire() {
  50         EnterCriticalSection(&fStorage);
  51         SkDEBUGCODE(fOwner = GetCurrentThreadId();)
  52     }
  53
  54     void release() {
  55         this->assertHeld();
  56         SkDEBUGCODE(fOwner = 0;)
  57         LeaveCriticalSection(&fStorage);
  58     }
  59
  60     void assertHeld() {
  61         SkASSERT(GetCurrentThreadId() == fOwner);
  62     }
  63
  64 protected:
  65     CRITICAL_SECTION fStorage;
  66     SkDEBUGCODE(DWORD fOwner;)
  67
  68 private:
  69     SkBaseMutex(const SkBaseMutex&);
  70     SkBaseMutex& operator=(const SkBaseMutex&);
  71 };
  72
  73 class SkMutex : public SkBaseMutex { };
  74
  75 // Windows currently provides no documented means of POD initializing a CRITICAL_SECTION.
  76 // As a result, it is illegal to SK_DECLARE_STATIC_MUTEX in a function.
  77 #define SK_DECLARE_STATIC_MUTEX(name) namespace{} static SkBaseMutex name
  78
  79 #endif