BACKENDS: Refactor the API for creating Mutexes

backends/modular-backend.cpp

@@ -25,7 +25,6 @@
 #include "backends/audiocd/audiocd.h"
 #include "backends/graphics/graphics.h"
 #include "backends/mixer/mixer.h"
-#include "backends/mutex/mutex.h"
 #include "gui/EventRecorder.h"
 
 #include "common/timer.h"
@@ -316,37 +315,3 @@ Audio::Mixer *ModularMixerBackend::getMixer() {
 	return getMixerManager()->getMixer();
 }
 
-
-ModularMutexBackend::ModularMutexBackend()
-	:
-	_mutexManager(0) {
-
-}
-
-ModularMutexBackend::~ModularMutexBackend() {
-	// _timerManager needs to be deleted before _mutexManager to avoid a crash.
-	delete _timerManager;
-	_timerManager = 0;
-	delete _mutexManager;
-	_mutexManager = 0;
-}
-
-OSystem::MutexRef ModularMutexBackend::createMutex() {
-	assert(_mutexManager);
-	return _mutexManager->createMutex();
-}
-
-void ModularMutexBackend::lockMutex(MutexRef mutex) {
-	assert(_mutexManager);
-	_mutexManager->lockMutex(mutex);
-}
-
-void ModularMutexBackend::unlockMutex(MutexRef mutex) {
-	assert(_mutexManager);
-	_mutexManager->unlockMutex(mutex);
-}
-
-void ModularMutexBackend::deleteMutex(MutexRef mutex) {
-	assert(_mutexManager);
-	_mutexManager->deleteMutex(mutex);
-}

backends/modular-backend.h

@@ -27,7 +27,6 @@
 
 class GraphicsManager;
 class MixerManager;
-class MutexManager;
 
 /**
  * Base classes for modular backends.
@@ -38,6 +37,7 @@ class MutexManager;
  * A backend derivated from these classes, will need to implement
  * these functions on its own:
  *   OSystem::pollEvent()
+ *   OSystem::createMutex()
  *   OSystem::getMillis()
  *   OSystem::delayMillis()
  *   OSystem::getTimeAndDate()
@@ -165,28 +165,4 @@ protected:
 	//@}
 };
 
-class ModularMutexBackend : virtual public BaseBackend {
-public:
-	ModularMutexBackend();
-	virtual ~ModularMutexBackend();
-
-	/** @name Mutex handling */
-	//@{
-
-	virtual MutexRef createMutex() override final;
-	virtual void lockMutex(MutexRef mutex) override final;
-	virtual void unlockMutex(MutexRef mutex) override final;
-	virtual void deleteMutex(MutexRef mutex) override final;
-
-	//@}
-
-protected:
-	/** @name Managers variables */
-	//@{
-
-	MutexManager *_mutexManager;
-
-	//@}
-};
-
 #endif

backends/module.mk

@@ -224,6 +224,11 @@ endif
 
 endif
 
+ifeq ($(BACKEND),3ds)
+MODULE_OBJS += \
+	mutex/3ds/3ds-mutex.o
+endif
+
 ifeq ($(BACKEND),android)
 MODULE_OBJS += \
 	mutex/pthread/pthread-mutex.o
@@ -371,6 +376,7 @@ ifeq ($(BACKEND),wii)
 MODULE_OBJS += \
 	fs/wii/wii-fs.o \
 	fs/wii/wii-fs-factory.o \
+	mutex/wii/wii-mutex.o \
 	plugins/wii/wii-provider.o
 endif
 

backends/mutex/3ds/3ds-mutex.cpp

@@ -0,0 +1,54 @@
+/* ScummVM - Graphic Adventure Engine
+ *
+ * ScummVM is the legal property of its developers, whose names
+ * are too numerous to list here. Please refer to the COPYRIGHT
+ * file distributed with this source distribution.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ */
+
+#define FORBIDDEN_SYMBOL_EXCEPTION_printf
+#define FORBIDDEN_SYMBOL_EXCEPTION_time_h
+#define FORBIDDEN_SYMBOL_EXCEPTION_unistd_h
+
+#include "common/scummsys.h"
+
+#if defined(__3DS__)
+
+#include "backends/mutex/3ds/3ds-mutex.h"
+
+#include <3ds.h>
+
+/**
+ * 3DS mutex manager
+ */
+class _3DSMutexInternal final : public Common::MutexInternal {
+public:
+	_3DSMutexInternal() { RecursiveLock_Init(&_mutex); }
+	virtual ~_3DSMutexInternal() override {}
+
+	virtual bool lock() override { RecursiveLock_Lock(&_mutex); return true; }
+	virtual bool unlock() override { RecursiveLock_Unlock(&_mutex); return true; }
+
+private:
+	RecursiveLock _mutex;
+};
+
+Common::MutexInternal *create3DSMutexInternal() {
+	return new _3DSMutexInternal();
+}
+
+#endif

backends/mutex/3ds/3ds-mutex.h

@@ -20,24 +20,11 @@
  *
  */
 
-#ifndef BACKENDS_MUTEX_ABSTRACT_H
-#define BACKENDS_MUTEX_ABSTRACT_H
+#ifndef BACKENDS_MUTEX_3DS_H
+#define BACKENDS_MUTEX_3DS_H
 
-#include "common/system.h"
-#include "common/noncopyable.h"
+#include "common/mutex.h"
 
-/**
- * Abstract class for mutex manager. Subclasses
- * implement the real functionality.
- */
-class MutexManager : Common::NonCopyable {
-public:
-	virtual ~MutexManager() {}
-
-	virtual OSystem::MutexRef createMutex() = 0;
-	virtual void lockMutex(OSystem::MutexRef mutex) = 0;
-	virtual void unlockMutex(OSystem::MutexRef mutex) = 0;
-	virtual void deleteMutex(OSystem::MutexRef mutex) = 0;
-};
+Common::MutexInternal *create3DSMutexInternal();
 
 #endif

backends/mutex/null/null-mutex.h

@@ -23,17 +23,17 @@
 #ifndef BACKENDS_MUTEX_NULL_H
 #define BACKENDS_MUTEX_NULL_H
 
-#include "backends/mutex/mutex.h"
+#include "common/mutex.h"
 
 /**
  * Null mutex manager
  */
-class NullMutexManager : public MutexManager {
+class NullMutexInternal final : public Common::MutexInternal {
 public:
-	virtual OSystem::MutexRef createMutex() { return OSystem::MutexRef(); }
-	virtual void lockMutex(OSystem::MutexRef mutex) {}
-	virtual void unlockMutex(OSystem::MutexRef mutex) {}
-	virtual void deleteMutex(OSystem::MutexRef mutex) {}
+	NullMutexInternal() {}
+	virtual ~NullMutexInternal() {}
+	virtual bool lock() { return true; }
+	virtual bool unlock() { return true; }
 };
 
 #endif

backends/mutex/pthread/pthread-mutex.cpp

@@ -30,41 +30,58 @@
 
 #include <pthread.h>
 
+/**
+ * pthreads mutex implementation
+ */
+class PthreadMutexInternal final : public Common::MutexInternal {
+public:
+	PthreadMutexInternal();
+	virtual ~PthreadMutexInternal() override;
 
-OSystem::MutexRef PthreadMutexManager::createMutex() {
+	virtual bool lock() override;
+	virtual bool unlock() override;
+
+private:
+	pthread_mutex_t _mutex;
+};
+
+
+PthreadMutexInternal::PthreadMutexInternal() {
 	pthread_mutexattr_t attr;
 
 	pthread_mutexattr_init(&attr);
 	pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_RECURSIVE);
 
-	pthread_mutex_t *mutex = new pthread_mutex_t;
-
-	if (pthread_mutex_init(mutex, &attr) != 0) {
+	if (pthread_mutex_init(&_mutex, &attr) != 0) {
 		warning("pthread_mutex_init() failed");
-		delete mutex;
-		return NULL;
 	}
-
-	return (OSystem::MutexRef)mutex;
 }
 
-void PthreadMutexManager::lockMutex(OSystem::MutexRef mutex) {
-	if (pthread_mutex_lock((pthread_mutex_t *)mutex) != 0)
-		warning("pthread_mutex_lock() failed");
-}
-
-void PthreadMutexManager::unlockMutex(OSystem::MutexRef mutex) {
-	if (pthread_mutex_unlock((pthread_mutex_t *)mutex) != 0)
-		warning("pthread_mutex_unlock() failed");
-}
-
-void PthreadMutexManager::deleteMutex(OSystem::MutexRef mutex) {
-	pthread_mutex_t *m = (pthread_mutex_t *)mutex;
-
-	if (pthread_mutex_destroy(m) != 0)
+PthreadMutexInternal::~PthreadMutexInternal() {
+	if (pthread_mutex_destroy(&_mutex) != 0)
 		warning("pthread_mutex_destroy() failed");
-	else
-		delete m;
+}
+
+bool PthreadMutexInternal::lock() {
+	if (pthread_mutex_lock(&_mutex) != 0) {
+		warning("pthread_mutex_lock() failed");
+		return false;
+	} else {
+		return true;
+	}
+}
+
+bool PthreadMutexInternal::unlock() {
+	if (pthread_mutex_unlock(&_mutex) != 0) {
+		warning("pthread_mutex_unlock() failed");
+		return false;
+	} else {
+		return true;
+	}
+}
+
+Common::MutexInternal *createPthreadMutexInternal() {
+	return new PthreadMutexInternal();
 }
 
 #endif

backends/mutex/pthread/pthread-mutex.h

@@ -23,18 +23,8 @@
 #ifndef BACKENDS_MUTEX_PTHREAD_H
 #define BACKENDS_MUTEX_PTHREAD_H
 
-#include "backends/mutex/mutex.h"
-
-/**
- * pthreads mutex manager
- */
-class PthreadMutexManager : public MutexManager {
-public:
-	virtual OSystem::MutexRef createMutex() override;
-	virtual void lockMutex(OSystem::MutexRef mutex) override;
-	virtual void unlockMutex(OSystem::MutexRef mutex) override;
-	virtual void deleteMutex(OSystem::MutexRef mutex) override;
-};
+#include "common/mutex.h"
 
+Common::MutexInternal *createPthreadMutexInternal();
 
 #endif

backends/mutex/sdl/sdl-mutex.cpp

@@ -27,21 +27,23 @@
 #include "backends/mutex/sdl/sdl-mutex.h"
 #include "backends/platform/sdl/sdl-sys.h"
 
+/**
+ * SDL mutex manager
+ */
+class SdlMutexInternal final : public Common::MutexInternal {
+public:
+	SdlMutexInternal() { _mutex = SDL_CreateMutex(); }
+	virtual ~SdlMutexInternal() override { SDL_DestroyMutex(_mutex); }
 
-OSystem::MutexRef SdlMutexManager::createMutex() {
-	return (OSystem::MutexRef) SDL_CreateMutex();
-}
+	virtual bool lock() override { return (SDL_mutexP(_mutex) == 0); }
+	virtual bool unlock() override { return (SDL_mutexV(_mutex) == 0); }
 
-void SdlMutexManager::lockMutex(OSystem::MutexRef mutex) {
-	SDL_mutexP((SDL_mutex *)mutex);
-}
+private:
+	SDL_mutex *_mutex;
+};
 
-void SdlMutexManager::unlockMutex(OSystem::MutexRef mutex) {
-	SDL_mutexV((SDL_mutex *)mutex);
-}
-
-void SdlMutexManager::deleteMutex(OSystem::MutexRef mutex) {
-	SDL_DestroyMutex((SDL_mutex *)mutex);
+Common::MutexInternal *createSdlMutexInternal() {
+	return new SdlMutexInternal();
 }
 
 #endif

backends/mutex/sdl/sdl-mutex.h

@@ -23,18 +23,8 @@
 #ifndef BACKENDS_MUTEX_SDL_H
 #define BACKENDS_MUTEX_SDL_H
 
-#include "backends/mutex/mutex.h"
-
-/**
- * SDL mutex manager
- */
-class SdlMutexManager : public MutexManager {
-public:
-	virtual OSystem::MutexRef createMutex();
-	virtual void lockMutex(OSystem::MutexRef mutex);
-	virtual void unlockMutex(OSystem::MutexRef mutex);
-	virtual void deleteMutex(OSystem::MutexRef mutex);
-};
+#include "common/mutex.h"
 
+Common::MutexInternal *createSdlMutexInternal();
 
 #endif

backends/mutex/wii/wii-mutex.cpp

@@ -0,0 +1,90 @@
+/* ScummVM - Graphic Adventure Engine
+ *
+ * ScummVM is the legal property of its developers, whose names
+ * are too numerous to list here. Please refer to the COPYRIGHT
+ * file distributed with this source distribution.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ */
+
+#define FORBIDDEN_SYMBOL_ALLOW_ALL
+
+#include "common/scummsys.h"
+
+#if defined(__WII__)
+
+#include "backends/mutex/wii/wii-mutex.h"
+
+#include <ogc/mutex.h>
+
+/**
+ * Wii mutex implementation
+ */
+class WiiMutexInternal final : public Common::MutexInternal {
+public:
+	WiiMutexInternal();
+	virtual ~WiiMutexInternal() override;
+
+	virtual bool lock() override;
+	virtual bool unlock() override;
+
+private:
+	mutex_t _mutex;
+};
+
+
+WiiMutexInternal::WiiMutexInternal() {
+	s32 res = LWP_MutexInit(&_mutex, true);
+
+	if (res) {
+		printf("ERROR creating mutex\n");
+	}
+}
+
+WiiMutexInternal::~WiiMutexInternal() {
+	s32 res = LWP_MutexDestroy(_mutex);
+
+	if (res)
+		printf("ERROR destroying mutex (%d)\n", res);
+}
+
+bool WiiMutexInternal::lock() {
+	s32 res = LWP_MutexLock(_mutex);
+
+	if (res) {
+		printf("ERROR locking mutex (%d)\n", res);
+		return false;
+	} else {
+		return true;
+	}
+}
+
+bool WiiMutexInternal::unlock() {
+	s32 res = LWP_MutexUnlock(_mutex);
+
+	if (res) {
+		printf("ERROR unlocking mutex (%d)\n", res);
+		return false;
+	} else {
+		return true;
+	}
+}
+
+Common::MutexInternal *createWiiMutexInternal() {
+	return new WiiMutexInternal();
+}
+
+#endif

backends/mutex/wii/wii-mutex.h

@@ -0,0 +1,30 @@
+/* ScummVM - Graphic Adventure Engine
+ *
+ * ScummVM is the legal property of its developers, whose names
+ * are too numerous to list here. Please refer to the COPYRIGHT
+ * file distributed with this source distribution.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ */
+
+#ifndef BACKENDS_MUTEX_WII_H
+#define BACKENDS_MUTEX_WII_H
+
+#include "common/mutex.h"
+
+Common::MutexInternal *createWiiMutexInternal();
+
+#endif

backends/platform/3ds/osystem.cpp

@@ -28,6 +28,7 @@
 #include "osystem.h"
 
 #include "backends/platform/3ds/config.h"
+#include "backends/mutex/3ds/3ds-mutex.h"
 #include "backends/saves/default/default-saves.h"
 #include "backends/timer/default/default-timer.h"
 #include "backends/events/default/default-events.h"
@@ -198,19 +199,8 @@ void OSystem_3DS::getTimeAndDate(TimeDate& td, bool skipRecord) const {
 	td.tm_wday = t.tm_wday;
 }
 
-OSystem::MutexRef OSystem_3DS::createMutex() {
-	RecursiveLock *mutex = new RecursiveLock();
-	RecursiveLock_Init(mutex);
-	return (OSystem::MutexRef) mutex;
-}
-void OSystem_3DS::lockMutex(MutexRef mutex) {
-	RecursiveLock_Lock((RecursiveLock*)mutex);
-}
-void OSystem_3DS::unlockMutex(MutexRef mutex) {
-	RecursiveLock_Unlock((RecursiveLock*)mutex);
-}
-void OSystem_3DS::deleteMutex(MutexRef mutex) {
-	delete (RecursiveLock*)mutex;
+Common::MutexInternal *OSystem_3DS::createMutex() {
+	return create3DSMutexInternal();
 }
 
 Common::String OSystem_3DS::getSystemLanguage() const {

backends/platform/3ds/osystem.h

@@ -25,7 +25,6 @@
 
 #define FORBIDDEN_SYMBOL_EXCEPTION_time_h
 
-#include "backends/mutex/mutex.h"
 #include "backends/base-backend.h"
 #include "graphics/palette.h"
 #include "base/main.h"
@@ -118,10 +117,7 @@ public:
 	virtual void delayMillis(uint msecs);
 	virtual void getTimeAndDate(TimeDate &td, bool skipRecord = false) const;
 
-	virtual MutexRef createMutex();
-	virtual void lockMutex(MutexRef mutex);
-	virtual void unlockMutex(MutexRef mutex);
-	virtual void deleteMutex(MutexRef mutex);
+	virtual Common::MutexInternal *createMutex();
 
 	virtual void logMessage(LogMessageType::Type type, const char *message);
 

backends/platform/android/android.cpp

@@ -425,7 +425,6 @@ void OSystem_Android::initBackend() {
 	// TODO remove the debug message eventually
 	LOGD("Setting DefaultSaveFileManager path to: %s", ConfMan.get("savepath").c_str());
 
-	_mutexManager = new PthreadMutexManager();
 	_timerManager = new DefaultTimerManager();
 
 	_event_queue_lock = new Common::Mutex();
@@ -559,6 +558,10 @@ void OSystem_Android::delayMillis(uint msecs) {
 	usleep(msecs * 1000);
 }
 
+Common::MutexInternal *OSystem_Android::createMutex() {
+	return createPthreadMutexInternal();
+}
+
 void OSystem_Android::quit() {
 	ENTER();
 

backends/platform/android/android.h

@@ -57,7 +57,7 @@ extern const char *android_log_tag;
 #define ENTER(fmt, args...) do {  } while (false)
 #endif
 
-class OSystem_Android : public ModularMutexBackend, public ModularGraphicsBackend, Common::EventSource {
+class OSystem_Android : public ModularGraphicsBackend, Common::EventSource {
 private:
 	// passed from the dark side
 	int _audio_sample_rate;
@@ -129,6 +129,7 @@ public:
 
 	virtual uint32 getMillis(bool skipRecord = false) override;
 	virtual void delayMillis(uint msecs) override;
+	virtual Common::MutexInternal *createMutex() override;
 
 	virtual void quit() override;
 

backends/platform/android3d/android.cpp

@@ -362,7 +362,6 @@ void OSystem_Android::initBackend() {
 	// TODO remove the debug message eventually
 	LOGD("Setting DefaultSaveFileManager path to: %s", ConfMan.get("savepath").c_str());
 
-	_mutexManager = new PthreadMutexManager();
 	_timerManager = new DefaultTimerManager();
 
 	_event_queue_lock = new Common::Mutex();
@@ -476,6 +475,10 @@ void OSystem_Android::delayMillis(uint msecs) {
 	usleep(msecs * 1000);
 }
 
+Common::MutexInternal *OSystem_Android::createMutex() {
+	return createPthreadMutexInternal();
+}
+
 void OSystem_Android::quit() {
 	ENTER();
 

backends/platform/android3d/android.h

@@ -102,7 +102,7 @@ extern void checkGlError(const char *expr, const char *file, int line);
 #define GLTHREADCHECK do {  } while (false)
 #endif
 
-class OSystem_Android : public ModularMutexBackend, public ModularGraphicsBackend, Common::EventSource {
+class OSystem_Android : public ModularGraphicsBackend, Common::EventSource {
 private:
 	// passed from the dark side
 	int _audio_sample_rate;
@@ -172,6 +172,7 @@ public:
 
 	virtual uint32 getMillis(bool skipRecord = false);
 	virtual void delayMillis(uint msecs);
+	virtual Common::MutexInternal *createMutex();
 
 	virtual void quit();
 

backends/platform/dc/dc.h

@@ -163,10 +163,7 @@ public:
   virtual Graphics::PixelFormat getOverlayFormat() const { return Graphics::PixelFormat(2, 4, 4, 4, 4, 8, 4, 0, 12); }
 
   // Mutex handling
-  MutexRef createMutex();
-  void lockMutex(MutexRef mutex);
-  void unlockMutex(MutexRef mutex);
-  void deleteMutex(MutexRef mutex);
+  Common::MutexInternal *createMutex();
 
   // Set a window caption or any other comparable status display to the
   // given value.

backends/platform/dc/dcmain.cpp

@@ -30,6 +30,7 @@
 #include "dcutils.h"
 #include "icon.h"
 #include "DCLauncherDialog.h"
+#include "backends/mutex/null/null-mutex.h"
 #include <common/config-manager.h>
 #include <common/memstream.h>
 #include <common/endian.h>
@@ -153,24 +154,11 @@ void OSystem_Dreamcast::quit() {
 }
 
 /* Mutex handling */
-OSystem::MutexRef OSystem_Dreamcast::createMutex()
+Common::MutexInternal *OSystem_Dreamcast::createMutex()
 {
-  return NULL;
+  return new NullMutexInternal();
 }
 
-void OSystem_Dreamcast::lockMutex(MutexRef mutex)
-{
-}
-
-void OSystem_Dreamcast::unlockMutex(MutexRef mutex)
-{
-}
-
-void OSystem_Dreamcast::deleteMutex(MutexRef mutex)
-{
-}
-
-
 /* Features */
 bool OSystem_Dreamcast::hasFeature(Feature f)
 {

backends/platform/ds/osystem_ds.cpp

@@ -56,7 +56,6 @@ OSystem_DS::OSystem_DS()
 
 	nitroFSInit(NULL);
 	_fsFactory = new DevoptabFilesystemFactory();
-	_mutexManager = new NullMutexManager();
 }
 
 OSystem_DS::~OSystem_DS() {
@@ -129,6 +128,10 @@ void OSystem_DS::getTimeAndDate(TimeDate &td, bool skipRecord) const {
 	td.tm_wday = t.tm_wday;
 }
 
+Common::MutexInternal *OSystem_DS::createMutex() {
+	return new NullMutexInternal();
+}
+
 void OSystem_DS::quit() {
 }
 

backends/platform/ds/osystem_ds.h

@@ -38,7 +38,7 @@ enum {
 	GFX_SWSCALE = 2
 };
 
-class OSystem_DS : public ModularMutexBackend, public ModularMixerBackend, public PaletteManager {
+class OSystem_DS : public ModularMixerBackend, public PaletteManager {
 protected:
 	DS::Background _framebuffer, _overlay;
 #ifdef DISABLE_TEXT_CONSOLE
@@ -130,6 +130,7 @@ public:
 	virtual void delayMillis(uint msecs);
 	virtual void getTimeAndDate(TimeDate &td, bool skipRecord = false) const;
 	void doTimerCallback(int interval = 10);
+	virtual Common::MutexInternal *createMutex();
 
 	virtual Common::EventSource *getDefaultEventSource() { return _eventSource; }
 	virtual Common::HardwareInputSet *getHardwareInputSet();

backends/platform/ios7/ios7_osys_main.cpp

@@ -131,8 +131,6 @@ int OSystem_iOS7::timerHandler(int t) {
 }
 
 void OSystem_iOS7::initBackend() {
-	_mutexManager = new PthreadMutexManager();
-
 #ifdef IPHONE_SANDBOXED
 	_savefileManager = new SandboxedSaveFileManager(_chrootBasePath, "/Savegames");
 #else
@@ -309,6 +307,10 @@ void OSystem_iOS7::setTimerCallback(TimerProc callback, int interval) {
 		_timerCallback = NULL;
 }
 
+Common::MutexInternal *OSystem_iOS7::createMutex() {
+	return createPthreadMutexInternal();
+}
+
 void OSystem_iOS7::quit() {
 }
 

backends/platform/ios7/ios7_osys_main.h

@@ -53,7 +53,7 @@ struct AQCallbackStruct {
 	AudioStreamBasicDescription dataFormat;
 };
 
-class OSystem_iOS7 : public EventsBaseBackend, public ModularMutexBackend, public PaletteManager {
+class OSystem_iOS7 : public EventsBaseBackend, public PaletteManager {
 protected:
 	static AQCallbackStruct s_AudioQueue;
 	static SoundProc s_soundCallback;
@@ -180,6 +180,7 @@ public:
 	virtual bool pollEvent(Common::Event &event) override;
 	virtual uint32 getMillis(bool skipRecord = false) override;
 	virtual void delayMillis(uint msecs) override;
+	virtual Common::MutexInternal *createMutex() override;
 
 	static void mixCallback(void *sys, byte *samples, int len);
 	virtual void setupMixer(void);

backends/platform/iphone/osys_main.cpp

@@ -84,8 +84,6 @@ int OSystem_IPHONE::timerHandler(int t) {
 }
 
 void OSystem_IPHONE::initBackend() {
-	_mutexManager = new PthreadMutexManager();
-
 #ifdef IPHONE_SANDBOXED
 	_savefileManager = new DefaultSaveFileManager(iPhone_getDocumentsDir());
 #else
@@ -195,6 +193,10 @@ void OSystem_IPHONE::setTimerCallback(TimerProc callback, int interval) {
 		_timerCallback = NULL;
 }
 
+Common::MutexInternal *OSystem_IPHONE::createMutex() {
+	return createPthreadMutexInternal();
+}
+
 void OSystem_IPHONE::quit() {
 }
 

backends/platform/iphone/osys_main.h

@@ -51,7 +51,7 @@ struct AQCallbackStruct {
 	AudioStreamBasicDescription dataFormat;
 };
 
-class OSystem_IPHONE : public EventsBaseBackend, public ModularMutexBackend, public PaletteManager {
+class OSystem_IPHONE : public EventsBaseBackend, public PaletteManager {
 protected:
 	static AQCallbackStruct s_AudioQueue;
 	static SoundProc s_soundCallback;
@@ -165,6 +165,7 @@ public:
 	virtual bool pollEvent(Common::Event &event);
 	virtual uint32 getMillis(bool skipRecord = false);
 	virtual void delayMillis(uint msecs);
+	virtual Common::MutexInternal *createMutex();
 
 	static void mixCallback(void *sys, byte *samples, int len);
 	virtual void setupMixer(void);

backends/platform/n64/osys_n64.h

@@ -187,10 +187,7 @@ public:
 	virtual uint32 getMillis(bool skipRecord = false);
 	virtual void delayMillis(uint msecs);
 
-	virtual MutexRef createMutex(void);
-	virtual void lockMutex(MutexRef mutex);
-	virtual void unlockMutex(MutexRef mutex);
-	virtual void deleteMutex(MutexRef mutex);
+	virtual Common::MutexInternal *createMutex(void);
 
 	virtual void quit();
 

backends/platform/n64/osys_n64_base.cpp

@@ -30,6 +30,7 @@
 #include "pakfs_save_manager.h"
 #include "framfs_save_manager.h"
 #include "backends/fs/n64/n64-fs-factory.h"
+#include "backends/mutex/null/null-mutex.h"
 #include "backends/saves/default/default-saves.h"
 #include "backends/timer/default/default-timer.h"
 #include "graphics/conversion.h"
@@ -812,20 +813,8 @@ void OSystem_N64::delayMillis(uint msecs) {
 }
 
 // As we don't have multi-threading, no need for mutexes
-OSystem::MutexRef OSystem_N64::createMutex(void) {
-	return NULL;
-}
-
-void OSystem_N64::lockMutex(MutexRef mutex) {
-	return;
-}
-
-void OSystem_N64::unlockMutex(MutexRef mutex) {
-	return;
-}
-
-void OSystem_N64::deleteMutex(MutexRef mutex) {
-	return;
+Common::MutexInternal *OSystem_N64::createMutex(void) {
+	return new NullMutexInternal();
 }
 
 void OSystem_N64::quit() {

backends/platform/null/null.cpp

@@ -49,6 +49,7 @@ typedef void (*sighandler_t)(int);
 
 #if defined(USE_NULL_DRIVER)
 #include "backends/modular-backend.h"
+#include "backends/mutex/null/null-mutex.h"
 #include "base/main.h"
 
 #ifndef NULL_DRIVER_USE_FOR_TEST
@@ -56,7 +57,6 @@ typedef void (*sighandler_t)(int);
 #include "backends/timer/default/default-timer.h"
 #include "backends/events/default/default-events.h"
 #include "backends/mixer/null/null-mixer.h"
-#include "backends/mutex/null/null-mutex.h"
 #include "backends/graphics/null/null-graphics.h"
 #include "gui/debugger.h"
 #endif
@@ -76,7 +76,7 @@ typedef void (*sighandler_t)(int);
 	#include "backends/fs/windows/windows-fs-factory.h"
 #endif
 
-class OSystem_NULL : public ModularMutexBackend, public ModularMixerBackend, public ModularGraphicsBackend, Common::EventSource {
+class OSystem_NULL : public ModularMixerBackend, public ModularGraphicsBackend, Common::EventSource {
 public:
 	OSystem_NULL();
 	virtual ~OSystem_NULL();
@@ -85,6 +85,7 @@ public:
 
 	virtual bool pollEvent(Common::Event &event);
 
+	virtual Common::MutexInternal *createMutex();
 	virtual uint32 getMillis(bool skipRecord = false);
 	virtual void delayMillis(uint msecs);
 	virtual void getTimeAndDate(TimeDate &td, bool skipRecord = false) const;
@@ -145,7 +146,6 @@ void OSystem_NULL::initBackend() {
 	last_handler = signal(SIGINT, intHandler);
 #endif
 
-	_mutexManager = new NullMutexManager();
 	_timerManager = new DefaultTimerManager();
 	_eventManager = new DefaultEventManager(this);
 	_savefileManager = new DefaultSaveFileManager();
@@ -185,6 +185,10 @@ bool OSystem_NULL::pollEvent(Common::Event &event) {
 	return false;
 }
 
+Common::MutexInternal *OSystem_NULL::createMutex() {
+	return new NullMutexInternal();
+}
+
 uint32 OSystem_NULL::getMillis(bool skipRecord) {
 #ifdef POSIX
 	timeval curTime;

backends/platform/psp/osys_psp.cpp

@@ -358,20 +358,8 @@ void OSystem_PSP::delayMillis(uint msecs) {
 	PspThread::delayMillis(msecs);
 }
 
-OSystem::MutexRef OSystem_PSP::createMutex(void) {
-	return (MutexRef) new PspMutex(true);	// start with a full mutex
-}
-
-void OSystem_PSP::lockMutex(MutexRef mutex) {
-	((PspMutex *)mutex)->lock();
-}
-
-void OSystem_PSP::unlockMutex(MutexRef mutex) {
-	((PspMutex *)mutex)->unlock();
-}
-
-void OSystem_PSP::deleteMutex(MutexRef mutex) {
-	delete (PspMutex *)mutex;
+Common::MutexInternal *OSystem_PSP::createMutex(void) {
+	return new PspMutex(true);	// start with a full mutex
 }
 
 void OSystem_PSP::mixCallback(void *sys, byte *samples, int len) {

backends/platform/psp/osys_psp.h

@@ -126,10 +126,7 @@ public:
 	void delayMillis(uint msecs);
 
 	// Mutex
-	MutexRef createMutex(void);
-	void lockMutex(MutexRef mutex);
-	void unlockMutex(MutexRef mutex);
-	void deleteMutex(MutexRef mutex);
+	Common::MutexInternal *createMutex(void);
 
 	// Sound
 	static void mixCallback(void *sys, byte *samples, int len);

backends/platform/psp/thread.h

@@ -24,7 +24,7 @@
 #define PSP_THREAD_H
 
 #include <pspthreadman.h>
-#include "common/scummsys.h"
+#include "common/mutex.h"
 
 // class to inherit for creating threads
 class PspThreadable {
@@ -60,7 +60,7 @@ public:
 	int getValue();
 };
 
-class PspMutex {
+class PspMutex : public Common::MutexInternal {
 private:
 	PspSemaphore _semaphore;
 	int _recursiveCount;

backends/platform/sdl/sdl.cpp

@@ -133,8 +133,6 @@ OSystem_SDL::~OSystem_SDL() {
 #endif
 
 	_timerManager = 0;
-	delete _mutexManager;
-	_mutexManager = 0;
 
 	delete _logger;
 	_logger = 0;
@@ -163,11 +161,6 @@ void OSystem_SDL::init() {
 	// Disable OS cursor
 	SDL_ShowCursor(SDL_DISABLE);
 
-	// Creates the early needed managers, if they don't exist yet
-	// (we check for this to allow subclasses to provide their own).
-	if (_mutexManager == 0)
-		_mutexManager = new SdlMutexManager();
-
 	if (_window == 0)
 		_window = new SdlWindow();
 
@@ -650,6 +643,10 @@ bool OSystem_SDL::openUrl(const Common::String &url) {
 }
 #endif
 
+Common::MutexInternal *OSystem_SDL::createMutex() {
+	return createSdlMutexInternal();
+}
+
 uint32 OSystem_SDL::getMillis(bool skipRecord) {
 	uint32 millis = SDL_GetTicks();
 

backends/platform/sdl/sdl.h

@@ -40,7 +40,7 @@ class DiscordPresence;
 /**
  * Base OSystem class for all SDL ports.
  */
-class OSystem_SDL : public ModularMutexBackend, public ModularMixerBackend, public ModularGraphicsBackend {
+class OSystem_SDL : public ModularMixerBackend, public ModularGraphicsBackend {
 public:
 	OSystem_SDL();
 	virtual ~OSystem_SDL();
@@ -83,6 +83,7 @@ public:
 
 	virtual void setWindowCaption(const Common::U32String &caption) override;
 	virtual void addSysArchivesToSearchSet(Common::SearchSet &s, int priority = 0) override;
+	virtual Common::MutexInternal *createMutex() override;
 	virtual uint32 getMillis(bool skipRecord = false) override;
 	virtual void delayMillis(uint msecs) override;
 	virtual void getTimeAndDate(TimeDate &td, bool skipRecord = false) const override;

backends/platform/wii/osystem.cpp

@@ -25,12 +25,12 @@
 #include <unistd.h>
 
 #include <ogc/conf.h>
-#include <ogc/mutex.h>
 #include <ogc/lwp_watchdog.h>
 
 #include "common/config-manager.h"
 #include "common/textconsole.h"
 #include "backends/fs/wii/wii-fs-factory.h"
+#include "backends/mutex/wii/wii-mutex.h"
 #include "backends/saves/default/default-saves.h"
 #include "backends/timer/default/default-timer.h"
 
@@ -221,40 +221,8 @@ void OSystem_Wii::delayMillis(uint msecs) {
 	usleep(msecs * 1000);
 }
 
-OSystem::MutexRef OSystem_Wii::createMutex() {
-	mutex_t *mutex = (mutex_t *) malloc(sizeof(mutex_t));
-	s32 res = LWP_MutexInit(mutex, true);
-
-	if (res) {
-		printf("ERROR creating mutex\n");
-		free(mutex);
-		return NULL;
-	}
-
-	return (MutexRef) mutex;
-}
-
-void OSystem_Wii::lockMutex(MutexRef mutex) {
-	s32 res = LWP_MutexLock(*(mutex_t *)mutex);
-
-	if (res)
-		printf("ERROR locking mutex %p (%d)\n", mutex, res);
-}
-
-void OSystem_Wii::unlockMutex(MutexRef mutex) {
-	s32 res = LWP_MutexUnlock(*(mutex_t *)mutex);
-
-	if (res)
-		printf("ERROR unlocking mutex %p (%d)\n", mutex, res);
-}
-
-void OSystem_Wii::deleteMutex(MutexRef mutex) {
-	s32 res = LWP_MutexDestroy(*(mutex_t *)mutex);
-
-	if (res)
-		printf("ERROR destroying mutex %p (%d)\n", mutex, res);
-
-	free(mutex);
+Common::MutexInternal *OSystem_Wii::createMutex() {
+	return createWiiMutexInternal();
 }
 
 Audio::Mixer *OSystem_Wii::getMixer() {

backends/platform/wii/osystem.h

@@ -197,10 +197,7 @@ public:
 	virtual uint32 getMillis(bool skipRecord = false) override;
 	virtual void delayMillis(uint msecs) override;
 
-	virtual MutexRef createMutex() override;
-	virtual void lockMutex(MutexRef mutex) override;
-	virtual void unlockMutex(MutexRef mutex) override;
-	virtual void deleteMutex(MutexRef mutex) override;
+	virtual Common::MutexInternal *createMutex() override;
 
 	typedef void (*SoundProc)(void *param, byte *buf, int len);
 

backends/timer/sdl/sdl-timer.cpp

@@ -29,11 +29,7 @@
 
 #include "common/textconsole.h"
 
-OSystem::MutexRef timerMutex;
-
 static Uint32 timer_handler(Uint32 interval, void *param) {
-	Common::StackLock lock(timerMutex);
-
 	((DefaultTimerManager *)param)->handler();
 	return interval;
 }
@@ -49,8 +45,6 @@ SdlTimerManager::SdlTimerManager() {
 }
 
 SdlTimerManager::~SdlTimerManager() {
-	Common::StackLock lock(timerMutex);
-
 	// Removes the timer callback
 	SDL_RemoveTimer(_timerID);
 

common/mutex.cpp

@@ -32,22 +32,22 @@ Mutex::Mutex() {
 }
 
 Mutex::~Mutex() {
-	g_system->deleteMutex(_mutex);
+	delete _mutex;
 }
 
-void Mutex::lock() {
-	g_system->lockMutex(_mutex);
+bool Mutex::lock() {
+	return _mutex->lock();
 }
 
-void Mutex::unlock() {
-	g_system->unlockMutex(_mutex);
+bool Mutex::unlock() {
+	return _mutex->unlock();
 }
 
 
 #pragma mark -
 
 
-StackLock::StackLock(OSystem::MutexRef mutex, const char *mutexName)
+StackLock::StackLock(MutexInternal *mutex, const char *mutexName)
 	: _mutex(mutex), _mutexName(mutexName) {
 	lock();
 }
@@ -61,18 +61,18 @@ StackLock::~StackLock() {
 	unlock();
 }
 
-void StackLock::lock() {
+bool StackLock::lock() {
 	if (_mutexName != nullptr)
 		debug(6, "Locking mutex %s", _mutexName);
 
-	g_system->lockMutex(_mutex);
+	return _mutex->lock();
 }
 
-void StackLock::unlock() {
+bool StackLock::unlock() {
 	if (_mutexName != nullptr)
 		debug(6, "Unlocking mutex %s", _mutexName);
 
-	g_system->unlockMutex(_mutex);
+	return _mutex->unlock();
 }
 
 } // End of namespace Common

common/mutex.h

@@ -38,17 +38,25 @@ namespace Common {
 
 class Mutex;
 
+class MutexInternal {
+public:
+	virtual ~MutexInternal() {}
+
+	virtual bool lock() = 0;
+	virtual bool unlock() = 0;
+};
+
 /**
  * Auxillary class to (un)lock a mutex on the stack.
  */
 class StackLock {
-	OSystem::MutexRef _mutex;
+	MutexInternal *_mutex;
 	const char *_mutexName;
 
-	void lock();
-	void unlock();
+	bool lock();
+	bool unlock();
 public:
-	explicit StackLock(OSystem::MutexRef mutex, const char *mutexName = nullptr);
+	explicit StackLock(MutexInternal *mutex, const char *mutexName = nullptr);
 	explicit StackLock(const Mutex &mutex, const char *mutexName = nullptr);
 	~StackLock();
 };
@@ -60,14 +68,14 @@ public:
 class Mutex {
 	friend class StackLock;
 
-	OSystem::MutexRef _mutex;
+	MutexInternal *_mutex;
 
 public:
 	Mutex();
 	~Mutex();
 
-	void lock();
-	void unlock();
+	bool lock();
+	bool unlock();
 };
 
 /** @} */

common/system.h

@@ -47,6 +47,7 @@ class OptionsContainerWidget;
 
 namespace Common {
 class EventManager;
+class MutexInternal;
 struct Rect;
 class SaveFileManager;
 class SearchSet;
@@ -1436,44 +1437,12 @@ public:
 	 * use dummy implementations for these methods.
 	 */
 
-	typedef struct OpaqueMutex *MutexRef;
-
 	/**
 	 * Create a new mutex.
 	 *
 	 * @return The newly created mutex, or 0 if an error occurred.
 	 */
-	virtual MutexRef createMutex() = 0;
-
-	/**
-	 * Lock the given mutex.
-	 *
-	 * @note ScummVM code assumes that the mutex implementation supports
-	 * recursive locking. That is, a thread can lock a mutex twice without
-	 * deadlocking. In case of a multilock, the mutex must be unlocked
-	 * as many times as it was locked befored it really becomes unlocked.
-	 *
-	 * @param mutex	The mutex to lock.
-	 */
-	virtual void lockMutex(MutexRef mutex) = 0;
-
-	/**
-	 * Unlock the given mutex.
-	 *
-	 * @param mutex	The mutex to unlock.
-	 */
-	virtual void unlockMutex(MutexRef mutex) = 0;
-
-	/**
-	 * Delete the given mutex.
-	 *
-	 * Make sure the mutex is unlocked before you delete it.
-	 * If you delete a locked mutex, the behavior is undefined.
-	 * In particular, your program may crash.
-	 *
-	 * @param mutex	The mutex to delete.
-	 */
-	virtual void deleteMutex(MutexRef mutex) = 0;
+	virtual Common::MutexInternal *createMutex() = 0;
 
 	/** @} */