Improve multi instance support for osx desktop capture

Fixes behavior with multiple desktop captures in the same scene

Also create the dispatch_queue without a name to prevent name collisions

test/test-input/test-desktop.h

@@ -13,8 +13,13 @@ extern "C" {
 struct desktop_tex {
 	samplerstate_t sampler;
 	effect_t whatever;
+
 	CGDisplayStreamRef disp;
 	uint32_t width, height;
+
+	texture_t tex;
+	pthread_mutex_t mutex;
+	IOSurfaceRef current, prev;
 };
 
 EXPORT const char *osx_desktop_test_getname(const char *locale);

test/test-input/test-desktop.m

@@ -20,7 +20,8 @@ static IOSurfaceRef current = NULL,
 static texture_t tex = NULL;
 static pthread_mutex_t c_mutex;
 
-struct desktop_tex *osx_desktop_test_create(const char *settings, obs_source_t source)
+struct desktop_tex *osx_desktop_test_create(const char *settings,
+		obs_source_t source)
 {
 	struct desktop_tex *rt = bmalloc(sizeof(struct desktop_tex));
 	char *effect_file;
@@ -59,9 +60,7 @@ struct desktop_tex *osx_desktop_test_create(const char *settings, obs_source_t s
 	rt->width = frame.size.width;
 	rt->height = frame.size.height;
 
-	printf("%u %u\n", rt->width, rt->height);
-
-	pthread_mutex_init(&c_mutex, NULL);
+	pthread_mutex_init(&rt->mutex, NULL);
 
 	NSDictionary *dict = @{
 		(__bridge NSString*)kCGDisplayStreamSourceRect:
@@ -73,25 +72,25 @@ struct desktop_tex *osx_desktop_test_create(const char *settings, obs_source_t s
 	rt->disp = CGDisplayStreamCreateWithDispatchQueue(CGMainDisplayID(),
 			rt->width, rt->height, 'BGRA',
 			(__bridge CFDictionaryRef)dict,
-			dispatch_queue_create("dispstream", NULL),
+			dispatch_queue_create(NULL, NULL),
 			^(CGDisplayStreamFrameStatus status, uint64_t
 				displayTime, IOSurfaceRef frameSurface,
 				CGDisplayStreamUpdateRef updateRef)
 			{
 				if (!frameSurface ||
-					pthread_mutex_trylock(&c_mutex))
+					pthread_mutex_trylock(&rt->mutex))
 					return;
 
-				if (current) {
-					IOSurfaceDecrementUseCount(current);
-					CFRelease(current);
-					current = NULL;
+				if (rt->current) {
+					IOSurfaceDecrementUseCount(rt->current);
+					CFRelease(rt->current);
+					rt->current = NULL;
 				}
 
-				current = frameSurface;
-				CFRetain(current);
-				IOSurfaceIncrementUseCount(current);
-				pthread_mutex_unlock(&c_mutex);
+				rt->current = frameSurface;
+				CFRetain(rt->current);
+				IOSurfaceIncrementUseCount(rt->current);
+				pthread_mutex_unlock(&rt->mutex);
 			}
 	);
 
@@ -108,23 +107,23 @@ struct desktop_tex *osx_desktop_test_create(const char *settings, obs_source_t s
 void osx_desktop_test_destroy(struct desktop_tex *rt)
 {
 	if (rt) {
-		pthread_mutex_lock(&c_mutex);
+		pthread_mutex_lock(&rt->mutex);
 		gs_entercontext(obs_graphics());
 
 		if (current) {
-			IOSurfaceDecrementUseCount(current);
-			CFRelease(current);
+			IOSurfaceDecrementUseCount(rt->current);
+			CFRelease(rt->current);
 		}
 		if (rt->sampler)
 			samplerstate_destroy(rt->sampler);
 		if (tex)
-			texture_destroy(tex);
+			texture_destroy(rt->tex);
 		CGDisplayStreamStop(rt->disp);
 		effect_destroy(rt->whatever);
 		bfree(rt);
 
 		gs_leavecontext();
-		pthread_mutex_unlock(&c_mutex);
+		pthread_mutex_unlock(&rt->mutex);
 	}
 }
 
@@ -136,32 +135,33 @@ uint32_t osx_desktop_test_get_output_flags(struct desktop_tex *rt)
 void osx_desktop_test_video_render(struct desktop_tex *rt,
 		obs_source_t filter_target)
 {
-	pthread_mutex_lock(&c_mutex);
+	pthread_mutex_lock(&rt->mutex);
 
-	if (prev != current) {
+	if (rt->prev != rt->current) {
 		if (tex)
-			texture_rebind_iosurface(tex, current);
+			texture_rebind_iosurface(rt->tex, rt->current);
 		else
-			tex = gs_create_texture_from_iosurface(current);
-		prev = current;
+			rt->tex = gs_create_texture_from_iosurface(
+					rt->current);
+		rt->prev = rt->current;
 	}
 
-	if (!tex) goto fail;
+	if (!rt->tex) goto fail;
 
 	gs_load_samplerstate(rt->sampler, 0);
 	technique_t tech = effect_gettechnique(rt->whatever, "Default");
 	effect_settexture(rt->whatever, effect_getparambyidx(rt->whatever, 1),
-			tex);
+			rt->tex);
 	technique_begin(tech);
 	technique_beginpass(tech, 0);
 
-	gs_draw_sprite(tex, 0, 0, 0);
+	gs_draw_sprite(rt->tex, 0, 0, 0);
 
 	technique_endpass(tech);
 	technique_end(tech);
 
 fail:
-	pthread_mutex_unlock(&c_mutex);
+	pthread_mutex_unlock(&rt->mutex);
 }
 
 uint32_t osx_desktop_test_getwidth(struct desktop_tex *rt)