simplified mutex locking idiom by introducing Mutex class (wrapper around SDL_mutex)

 * can be instantiated
 * can derive from class Mutex to inherit the lock()/unlock() methods

also fixed LayerList destructor

7 files changed, 53 insertions, 70 deletions

diff --git a/src/layer.cpp b/src/layer.cpp
index f1db856..d213d7c 100644
--- a/src/layer.cpp
+++ b/src/layer.cpp
@@ -11,12 +11,20 @@
 #include "osc_server.h"
 #include "layer.h"
 
-Layer::Layer(const char *_name) : mutex(SDL_CreateMutex()), name(strdup(_name))
+Layer::Layer(const char *_name) : Mutex(), name(strdup(_name))
 {
 	geo_osc_id = register_method("geo", GEO_TYPES, geo_osc);
 	alpha_osc_id = register_method("alpha", "f", alpha_osc);
 }
 
+Layer::~Layer()
+{
+	unregister_method(alpha_osc_id);
+	unregister_method(geo_osc_id);
+
+	free(name);
+}
+
 void
 LayerList::insert(int pos, Layer *layer)
 {
@@ -66,11 +74,12 @@ LayerList::render(SDL_Surface *target)
 	unlock();
 }
 
-Layer::~Layer()
+LayerList::~LayerList()
 {
-	unregister_method(alpha_osc_id);
-	unregister_method(geo_osc_id);
+	while (LIST_FIRST(&head)) {
+		Layer *layer = LIST_FIRST(&head);
 
-	free(name);
-	SDL_DestroyMutex(mutex);
+		LIST_REMOVE(layer, layers);
+		delete layer;
+	}
 }
diff --git a/src/layer.h b/src/layer.h
index 21fab50..378acbd 100644
--- a/src/layer.h
+++ b/src/layer.h
@@ -5,7 +5,6 @@
 #include <bsd/sys/queue.h>
 
 #include <SDL.h>
-#include <SDL_thread.h>
 
 #include <lo/lo.h>
 
@@ -14,9 +13,7 @@
 
 extern OSCServer osc_server;
 
-class Layer {
-	SDL_mutex *mutex;
-
+class Layer : public Mutex {
 public:
 	/*
 	 * Every derived class must have a static CtorInfo struct "ctor_info"
@@ -34,17 +31,6 @@ public:
 	Layer(const char *name);
 	virtual ~Layer();
 
-	inline void
-	lock()
-	{
-		SDL_LockMutex(mutex);
-	}
-	inline void
-	unlock()
-	{
-		SDL_UnlockMutex(mutex);
-	}
-
 	/*
 	 * Frame render method
 	 */
@@ -91,31 +77,15 @@ private:
 	}
 };
 
-class LayerList {
+class LayerList : Mutex {
 	LIST_HEAD(layers_head, Layer) head;
 
-	SDL_mutex *mutex;
-
-	inline void
-	lock()
-	{
-		SDL_LockMutex(mutex);
-	}
-	inline void
-	unlock()
-	{
-		SDL_UnlockMutex(mutex);
-	}
-
 public:
-	LayerList() : mutex(SDL_CreateMutex())
+	LayerList() : Mutex()
 	{
 		LIST_INIT(&head);
 	}
-	~LayerList()
-	{
-		SDL_DestroyMutex(mutex);
-	}
+	~LayerList();
 
 	void insert(int pos, Layer *layer);
 	void delete_layer(Layer *layer);
diff --git a/src/layer_video.cpp b/src/layer_video.cpp
index 1734d9e..859455f 100644
--- a/src/layer_video.cpp
+++ b/src/layer_video.cpp
@@ -6,7 +6,6 @@
 #include <math.h>
 
 #include <SDL.h>
-#include <SDL_thread.h>
 #include <SDL_rotozoom.h>
 
 /* HACK: older SDL_gfx versions define GFX_ALPHA_ADJUST in the header */
@@ -37,9 +36,8 @@ static void display_cb(void *data, void *id);
 }
 
 LayerVideo::LayerVideo(const char *name, SDL_Rect geo, float opacity,
-		       const char *url) :
-		      Layer(name), mp(NULL), surf(NULL),
-		      mutex(SDL_CreateMutex())
+		       const char *url)
+		      : Layer(name), mp(NULL), surf(NULL)
 {
 	/* static initialization */
 	if (!vlcinst) {
@@ -243,12 +241,12 @@ LayerVideo::frame(SDL_Surface *target)
 	if (surf->w != geov.w || surf->h != geov.h) {
 		SDL_Surface *surf_scaled;
 
-		SDL_LockMutex(mutex);
+		mutex.lock();
 		surf_scaled = zoomSurface(surf,
 					  (double)geov.w/surf->w,
 					  (double)geov.h/surf->h,
 					  SMOOTHING_ON);
-		SDL_UnlockMutex(mutex);
+		mutex.unlock();
 
 		if (alpha < SDL_ALPHA_OPAQUE) {
 			if (surf_scaled->format->Amask)
@@ -267,9 +265,9 @@ LayerVideo::frame(SDL_Surface *target)
 		else
 			SDL_SetAlpha(surf, SDL_SRCALPHA | SDL_RLEACCEL, alpha);
 
-		SDL_LockMutex(mutex);
+		mutex.lock();
 		SDL_BlitSurface(surf, NULL, target, &geov);
-		SDL_UnlockMutex(mutex);
+		mutex.unlock();
 	}
 }
 
@@ -283,7 +281,6 @@ LayerVideo::~LayerVideo()
 	if (mp)
 		libvlc_media_player_release(mp);
 	libvlc_release(vlcinst);
-	SDL_DestroyMutex(mutex);
 	if (surf)
 		SDL_FreeSurface(surf);
 }
diff --git a/src/layer_video.h b/src/layer_video.h
index c3a4806..1ae3e18 100644
--- a/src/layer_video.h
+++ b/src/layer_video.h
@@ -2,7 +2,6 @@
 #define __LAYER_VIDEO_H
 
 #include <SDL.h>
-#include <SDL_thread.h>
 
 #include <lo/lo.h>
 
@@ -16,7 +15,7 @@ class LayerVideo : public Layer {
 	libvlc_media_player_t *mp;
 
 	SDL_Surface *surf;
-	SDL_mutex *mutex;
+	Mutex mutex;
 
 	SDL_Rect geov;
 	float alphav;
@@ -42,7 +41,7 @@ public:
 	inline void *
 	lock_surf()
 	{
-		SDL_LockMutex(mutex);
+		mutex.lock();
 		SDL_MAYBE_LOCK(surf);
 		return surf->pixels;
 	}
@@ -50,7 +49,7 @@ public:
 	unlock_surf()
 	{
 		SDL_MAYBE_UNLOCK(surf);
-		SDL_UnlockMutex(mutex);
+		mutex.unlock();
 	}
 
 	void frame(SDL_Surface *target);
diff --git a/src/osc_graphics.h b/src/osc_graphics.h
index c36ef54..47afa7d 100644
--- a/src/osc_graphics.h
+++ b/src/osc_graphics.h
@@ -4,6 +4,29 @@
 #include <stdio.h>
 
 #include <SDL.h>
+#include <SDL_thread.h>
+
+class Mutex {
+	SDL_mutex *mutex;
+
+public:
+	Mutex() : mutex(SDL_CreateMutex()) {}
+	virtual ~Mutex()
+	{
+		SDL_DestroyMutex(mutex);
+	}
+
+	inline void
+	lock()
+	{
+		SDL_LockMutex(mutex);
+	}
+	inline void
+	unlock()
+	{
+		SDL_UnlockMutex(mutex);
+	}
+};
 
 #include "osc_server.h"
 #include "layer.h"
diff --git a/src/recorder.cpp b/src/recorder.cpp
index 6859f1b..0bd7b23 100644
--- a/src/recorder.cpp
+++ b/src/recorder.cpp
@@ -126,5 +126,4 @@ Recorder::~Recorder()
 	osc_server.del_method("",  "/recorder/stop");
 
 	SDL_FFMPEGFREE_SAFE(file);
-	SDL_DestroyMutex(mutex);
 }
diff --git a/src/recorder.h b/src/recorder.h
index b2ee5e6..591312e 100644
--- a/src/recorder.h
+++ b/src/recorder.h
@@ -2,29 +2,15 @@
 #define __RECORDER_H
 
 #include <SDL.h>
-#include <SDL_thread.h>
 #include <SDL/SDL_ffmpeg.h>
 
 #include "osc_graphics.h"
 
-class Recorder {
+class Recorder : Mutex {
 	SDL_ffmpegFile *file;
 
-	SDL_mutex *mutex;
-
-	inline void
-	lock()
-	{
-		SDL_LockMutex(mutex);
-	}
-	inline void
-	unlock()
-	{
-		SDL_UnlockMutex(mutex);
-	}
-
 public:
-	Recorder() : file(NULL), mutex(SDL_CreateMutex()) {}
+	Recorder() : Mutex(), file(NULL) {}
 	~Recorder();
 
 	void register_methods();