michael@0: /*
michael@0:  * Copyright 2013 Google Inc.
michael@0:  *
michael@0:  * Use of this source code is governed by a BSD-style license that can be
michael@0:  * found in the LICENSE file.
michael@0:  */
michael@0: 
michael@0: #ifndef SkMutex_pthread_DEFINED
michael@0: #define SkMutex_pthread_DEFINED
michael@0: 
michael@0: /** Posix pthread_mutex based mutex. */
michael@0: 
michael@0: #ifdef SK_DEBUG_PTHREAD_MUTEX
michael@0: #include "SkTypes.h"
michael@0: #define SkDEBUGCODE_PTHREAD_MUTEX(code) code
michael@0: #else
michael@0: #define SkDEBUGCODE_PTHREAD_MUTEX(code)
michael@0: #ifndef SkDebugf
michael@0:     void SkDebugf(const char format[], ...);
michael@0: #endif
michael@0: #endif
michael@0: 
michael@0: #include <errno.h>
michael@0: #include <pthread.h>
michael@0: 
michael@0: // A SkBaseMutex is a POD structure that can be directly initialized
michael@0: // at declaration time with SK_DECLARE_STATIC/GLOBAL_MUTEX. This avoids the
michael@0: // generation of a static initializer in the final machine code (and
michael@0: // a corresponding static finalizer).
michael@0: struct SkBaseMutex {
michael@0:     void acquire() { pthread_mutex_lock(&fMutex); }
michael@0:     void release() { pthread_mutex_unlock(&fMutex); }
michael@0:     pthread_mutex_t fMutex;
michael@0: };
michael@0: 
michael@0: // A normal mutex that requires to be initialized through normal C++ construction,
michael@0: // i.e. when it's a member of another class, or allocated on the heap.
michael@0: class SkMutex : public SkBaseMutex {
michael@0: public:
michael@0:     SkMutex() {
michael@0:         SkDEBUGCODE_PTHREAD_MUTEX(int status = )pthread_mutex_init(&fMutex, NULL);
michael@0:         SkDEBUGCODE_PTHREAD_MUTEX(
michael@0:             if (status != 0) {
michael@0:                 print_pthread_error(status);
michael@0:                 SkASSERT(0 == status);
michael@0:             }
michael@0:         )
michael@0:     }
michael@0: 
michael@0:     ~SkMutex() {
michael@0:         SkDEBUGCODE_PTHREAD_MUTEX(int status = )pthread_mutex_destroy(&fMutex);
michael@0:         SkDEBUGCODE_PTHREAD_MUTEX(
michael@0:             if (status != 0) {
michael@0:                 print_pthread_error(status);
michael@0:                 SkASSERT(0 == status);
michael@0:             }
michael@0:         )
michael@0:     }
michael@0: 
michael@0: private:
michael@0:     SkMutex(const SkMutex&);
michael@0:     SkMutex& operator=(const SkMutex&);
michael@0: 
michael@0:     static void print_pthread_error(int status) {
michael@0:         switch (status) {
michael@0:         case 0: // success
michael@0:             break;
michael@0:         case EINVAL:
michael@0:             SkDebugf("pthread error [%d] EINVAL\n", status);
michael@0:             break;
michael@0:         case EBUSY:
michael@0:             SkDebugf("pthread error [%d] EBUSY\n", status);
michael@0:             break;
michael@0:         default:
michael@0:             SkDebugf("pthread error [%d] unknown\n", status);
michael@0:             break;
michael@0:         }
michael@0:     }
michael@0: };
michael@0: 
michael@0: // Using POD-style initialization prevents the generation of a static initializer.
michael@0: #define SK_DECLARE_STATIC_MUTEX(name) static SkBaseMutex name = { PTHREAD_MUTEX_INITIALIZER }
michael@0: 
michael@0: // Special case used when the static mutex must be available globally.
michael@0: #define SK_DECLARE_GLOBAL_MUTEX(name) SkBaseMutex name = { PTHREAD_MUTEX_INITIALIZER }
michael@0: 
michael@0: #endif