[event system] allocate events and additional payload (e.g. file paths) directly in ring buffer, and copy them to user-supplied arena in mp_next_event()

src/input_state.c

@@ -116,51 +116,51 @@ void mp_input_next_frame(mp_input_state* state)
 	state->frameCounter++;
 }
 
-void mp_input_process_event(mp_input_state* state, mp_event event)
+void mp_input_process_event(mp_input_state* state, mp_event* event)
 {
-	switch(event.type)
+	switch(event->type)
 	{
 		case MP_EVENT_KEYBOARD_KEY:
 		{
-			mp_key_state* key = &state->keyboard.keys[event.key.code];
-			mp_update_key_state(state, key, event.key.action);
-			mp_update_key_mods(state, event.key.mods);
+			mp_key_state* key = &state->keyboard.keys[event->key.code];
+			mp_update_key_state(state, key, event->key.action);
+			mp_update_key_mods(state, event->key.mods);
 		} break;
 
 		case MP_EVENT_KEYBOARD_CHAR:
-			mp_update_text(state, event.character.codepoint);
+			mp_update_text(state, event->character.codepoint);
 			break;
 
 		case MP_EVENT_KEYBOARD_MODS:
-			mp_update_key_mods(state, event.key.mods);
+			mp_update_key_mods(state, event->key.mods);
 			break;
 
 		case MP_EVENT_MOUSE_MOVE:
-			mp_update_mouse_move(state, event.move.x, event.move.y, event.move.deltaX, event.move.deltaY);
+			mp_update_mouse_move(state, event->move.x, event->move.y, event->move.deltaX, event->move.deltaY);
 			break;
 
 		case MP_EVENT_MOUSE_WHEEL:
-			mp_update_mouse_wheel(state, event.move.deltaX, event.move.deltaY);
+			mp_update_mouse_wheel(state, event->move.deltaX, event->move.deltaY);
 			break;
 
 		case MP_EVENT_MOUSE_BUTTON:
 		{
-			mp_key_state* key = &state->mouse.buttons[event.key.code];
-			mp_update_key_state(state, key, event.key.action);
+			mp_key_state* key = &state->mouse.buttons[event->key.code];
+			mp_update_key_state(state, key, event->key.action);
 
-			if(event.key.action == MP_KEY_PRESS)
+			if(event->key.action == MP_KEY_PRESS)
 			{
-				if(event.key.clickCount >= 1)
+				if(event->key.clickCount >= 1)
 				{
 					key->sysClicked = true;
 				}
-				if(event.key.clickCount >= 2)
+				if(event->key.clickCount >= 2)
 				{
 					key->sysDoubleClicked = true;
 				}
 			}
 
-			mp_update_key_mods(state, event.key.mods);
+			mp_update_key_mods(state, event->key.mods);
 		} break;
 
 		default:

src/input_state.h

@@ -70,7 +70,7 @@ typedef struct mp_input_state
 	mp_text_state text;
 } mp_input_state;
 
-MP_API void mp_input_process_event(mp_input_state* state, mp_event event);
+MP_API void mp_input_process_event(mp_input_state* state, mp_event* event);
 MP_API void mp_input_next_frame(mp_input_state* state);
 
 MP_API bool mp_key_down(mp_input_state* state, mp_key_code key);

src/mp_app.c

@@ -97,28 +97,85 @@ static void mp_terminate_common()
 
 void mp_queue_event(mp_event* event)
 {
-	if(ringbuffer_write_available(&__mpApp.eventQueue) < sizeof(mp_event))
+	ringbuffer* queue = &__mpApp.eventQueue;
+
+	if(ringbuffer_write_available(queue) < sizeof(mp_event))
 	{
 		log_error("event queue full\n");
 	}
 	else
 	{
-		u32 written = ringbuffer_write(&__mpApp.eventQueue, sizeof(mp_event), (u8*)event);
-		DEBUG_ASSERT(written == sizeof(mp_event));
+		bool error = false;
+		ringbuffer_reserve(queue, sizeof(mp_event), (u8*)event);
+
+		if(event->type == MP_EVENT_PATHDROP)
+		{
+			for_list(&event->paths.list, elt, str8_elt, listElt)
+			{
+				str8* path = &elt->string;
+				if(ringbuffer_write_available(queue) < (sizeof(u64) + path->len))
+				{
+					log_error("event queue full\n");
+					error = true;
+					break;
+				}
+				else
+				{
+					ringbuffer_reserve(queue, sizeof(u64), (u8*)&path->len);
+					ringbuffer_reserve(queue, path->len, (u8*)path->ptr);
+				}
+			}
+		}
+		if(error)
+		{
+			ringbuffer_rewind(queue);
+		}
+		else
+		{
+			ringbuffer_commit(queue);
+		}
 	}
 }
 
-bool mp_next_event(mp_event* event)
+mp_event* mp_next_event(mem_arena* arena)
 {
-	//NOTE pop and return event from queue
-	if(ringbuffer_read_available(&__mpApp.eventQueue) >= sizeof(mp_event))
+	//NOTE: pop and return event from queue
+	mp_event* event = 0;
+	ringbuffer* queue = &__mpApp.eventQueue;
+
+	if(ringbuffer_read_available(queue) >= sizeof(mp_event))
 	{
-		u64 read = ringbuffer_read(&__mpApp.eventQueue, sizeof(mp_event), (u8*)event);
+		event = mem_arena_alloc_type(arena, mp_event);
+		u64 read = ringbuffer_read(queue, sizeof(mp_event), (u8*)event);
 		DEBUG_ASSERT(read == sizeof(mp_event));
-		return(true);
-	}
-	else
-	{
-		return(false);
+
+		if(event->type == MP_EVENT_PATHDROP)
+		{
+			u64 pathCount = event->paths.eltCount;
+			event->paths = (str8_list){0};
+
+			for(int i=0; i<pathCount; i++)
+			{
+				if(ringbuffer_read_available(queue) < sizeof(u64))
+				{
+					log_error("malformed path payload: no string size\n");
+					break;
+				}
+
+				u64 len = 0;
+				ringbuffer_read(queue, sizeof(u64), (u8*)&len);
+				if(ringbuffer_read_available(queue) < len)
+				{
+					log_error("malformed path payload: string shorter than expected\n");
+					break;
+				}
+
+				char* buffer = mem_arena_alloc_array(arena, char, len);
+				ringbuffer_read(queue, len, (u8*)buffer);
+
+				str8_list_push(arena, &event->paths, str8_from_buffer(len, buffer));
+			}
+		}
 	}
+	return(event);
 }

src/mp_app.h

@@ -12,6 +12,7 @@
 #include"typedefs.h"
 #include"utf8.h"
 #include"lists.h"
+#include"memory.h"
 
 #ifdef __cplusplus
 extern "C" {
@@ -237,7 +238,6 @@ typedef struct mp_frame_event		// window resize / move
 typedef struct mp_event
 {
 	//TODO clipboard and path drop
-
 	mp_window window;
 	mp_event_type type;
 
@@ -247,11 +247,9 @@ typedef struct mp_event
 		mp_char_event  character;
 		mp_move_event  move;
 		mp_frame_event frame;
-		str8 path;
+		str8_list paths;
 	};
 
-	//TODO(martin): chain externally ?
-	list_elt list;
 } mp_event;
 
 //--------------------------------------------------------------------
@@ -272,7 +270,7 @@ MP_API void mp_set_cursor(mp_mouse_cursor cursor);
 //--------------------------------------------------------------------
 
 MP_API void mp_pump_events(f64 timeout);
-MP_API bool mp_next_event(mp_event* event);
+MP_API mp_event* mp_next_event(mem_arena* arena);
 
 typedef void(*mp_live_resize_callback)(mp_event event, void* data);
 MP_API void mp_set_live_resize_callback(mp_live_resize_callback callback, void* data);

src/osx_app.m

@@ -475,12 +475,20 @@ void mp_install_keyboard_layout_listener()
 
 - (BOOL)application:(NSApplication *)application openFile:(NSString *)filename
 {
-	mp_event event = {};
+	mp_event event = {0};
 	event.window = (mp_window){0};
 	event.type = MP_EVENT_PATHDROP;
-	event.path = str8_push_cstring(&__mpApp.eventArena, [filename UTF8String]);
+
+	mem_arena* scratch = mem_scratch();
+	mem_arena_marker mark = mem_arena_mark(scratch);
+
+	str8 path = str8_push_cstring(scratch, [filename UTF8String]);
+	str8_list_push(scratch, &event.paths, path);
 
 	mp_queue_event(&event);
+
+	mem_arena_clear_to(scratch, mark);
+
 	return(YES);
 }
 
@@ -491,11 +499,20 @@ void mp_install_keyboard_layout_listener()
 	mp_event event = {};
 	event.window = (mp_window){0};
 	event.type = MP_EVENT_PATHDROP;
-	event.path = str8_push_cstring(&__mpApp.eventArena, [nsPath UTF8String]);
+
+	mem_arena* scratch = mem_scratch();
+	mem_arena_marker mark = mem_arena_mark(scratch);
+
+	str8 path = str8_push_cstring(scratch, [nsPath UTF8String]);
+	str8_list_push(scratch, &event.paths, path);
 
 	mp_queue_event(&event);
+
+	mem_arena_clear_to(scratch, mark);
 }
 
+//TODO: drag and drop paths
+
 @end // @implementation MPAppDelegate
 
 //---------------------------------------------------------------

src/ui.c

@@ -327,7 +327,7 @@ void ui_style_box_after(ui_box* box, ui_pattern pattern, ui_style* style, ui_sty
 // input
 //-----------------------------------------------------------------------------
 
-void ui_process_event(mp_event event)
+void ui_process_event(mp_event* event)
 {
 	ui_context* ui = ui_get_context();
 	mp_input_process_event(&ui->input, event);

src/ui.h

@@ -395,7 +395,7 @@ MP_API void ui_init(ui_context* context);
 MP_API ui_context* ui_get_context(void);
 MP_API void ui_set_context(ui_context* context);
 
-MP_API void ui_process_event(mp_event event);
+MP_API void ui_process_event(mp_event* event);
 MP_API void ui_begin_frame(ui_style* defaultStyle, ui_style_mask mask);
 MP_API void ui_end_frame(void);
 MP_API void ui_draw(void);

src/util/ringbuffer.c

@@ -11,9 +11,10 @@
 
 void ringbuffer_init(ringbuffer* ring, u8 capExp)
 {
-	u32 cap = 1<<capExp;
+	u64 cap = 1<<capExp;
 	ring->mask = cap - 1;
 	ring->readIndex = 0;
+	ring->reserveIndex = 0;
 	ring->writeIndex = 0;
 	ring->buffer = (u8*)malloc(cap);
 }
@@ -23,54 +24,24 @@ void ringbuffer_cleanup(ringbuffer* ring)
 	free(ring->buffer);
 }
 
-u32 ringbuffer_read_available(ringbuffer* ring)
+u64 ringbuffer_read_available(ringbuffer* ring)
 {
 	return((ring->writeIndex - ring->readIndex) & ring->mask);
 }
 
-u32 ringbuffer_write_available(ringbuffer* ring)
+u64 ringbuffer_write_available(ringbuffer* ring)
 {
 	//NOTE(martin): we keep one sentinel byte between write index and read index,
 	//              when the buffer is full, to avoid overrunning read index.
-	//              Hence, available write space is size - 1 - available read space.
-	return(ring->mask - ringbuffer_read_available(ring));
+	return(((ring->readIndex - ring->reserveIndex) & ring->mask) - 1);
 }
 
-u32 ringbuffer_write(ringbuffer* ring, u32 size, u8* data)
+u64 ringbuffer_read(ringbuffer* ring, u64 size, u8* data)
 {
-	u32 read = ring->readIndex;
-	u32 write = ring->writeIndex;
+	u64 read = ring->readIndex;
+	u64 write = ring->writeIndex;
 
-	u32 writeAvailable = ringbuffer_write_available(ring);
-	if(size > writeAvailable)
-	{
-		DEBUG_ASSERT("not enough space available");
-		size = writeAvailable;
-	}
-
-	if(read <= write)
-	{
-		u32 copyCount = minimum(size, ring->mask + 1 - write);
-		memcpy(ring->buffer + write, data, copyCount);
-
-		data += copyCount;
-		copyCount = size - copyCount;
-		memcpy(ring->buffer, data, copyCount);
-	}
-	else
-	{
-		memcpy(ring->buffer + write, data, size);
-	}
-	ring->writeIndex = (write + size) & ring->mask;
-	return(size);
-}
-
-u32 ringbuffer_read(ringbuffer* ring, u32 size, u8* data)
-{
-	u32 read = ring->readIndex;
-	u32 write = ring->writeIndex;
-
-	u32 readAvailable = ringbuffer_read_available(ring);
+	u64 readAvailable = ringbuffer_read_available(ring);
 	if(size > readAvailable)
 	{
 		size = readAvailable;
@@ -82,7 +53,7 @@ u32 ringbuffer_read(ringbuffer* ring, u32 size, u8* data)
 	}
 	else
 	{
-		u32 copyCount = minimum(size, ring->mask + 1 - read);
+		u64 copyCount = minimum(size, ring->mask + 1 - read);
 		memcpy(data, ring->buffer + read, copyCount);
 
 		data += copyCount;
@@ -92,3 +63,50 @@ u32 ringbuffer_read(ringbuffer* ring, u32 size, u8* data)
 	ring->readIndex = (read + size) & ring->mask;
 	return(size);
 }
+
+u64 ringbuffer_reserve(ringbuffer* ring, u64 size, u8* data)
+{
+	u64 read = ring->readIndex;
+	u64 reserve = ring->reserveIndex;
+
+	u64 writeAvailable = ringbuffer_write_available(ring);
+	if(size > writeAvailable)
+	{
+		DEBUG_ASSERT("not enough space available");
+		size = writeAvailable;
+	}
+
+	if(read <= reserve)
+	{
+		u64 copyCount = minimum(size, ring->mask + 1 - reserve);
+		memcpy(ring->buffer + reserve, data, copyCount);
+
+		data += copyCount;
+		copyCount = size - copyCount;
+		memcpy(ring->buffer, data, copyCount);
+	}
+	else
+	{
+		memcpy(ring->buffer + reserve, data, size);
+	}
+	ring->reserveIndex = (reserve + size) & ring->mask;
+	return(size);
+}
+
+u64 ringbuffer_write(ringbuffer* ring, u64 size, u8* data)
+{
+	ringbuffer_commit(ring);
+	u64 res = ringbuffer_reserve(ring, size, data);
+	ringbuffer_commit(ring);
+	return(res);
+}
+
+void ringbuffer_commit(ringbuffer* ring)
+{
+	ring->writeIndex = ring->reserveIndex;
+}
+
+void ringbuffer_rewind(ringbuffer* ring)
+{
+	ring->reserveIndex = ring->writeIndex;
+}

src/util/ringbuffer.h

@@ -18,9 +18,10 @@ extern "C" {
 
 typedef struct ringbuffer
 {
-	u32 mask;
-	_Atomic(u32) readIndex;
-	_Atomic(u32) writeIndex;
+	u64 mask;
+	_Atomic(u64) readIndex;
+	_Atomic(u64) writeIndex;
+	u64 reserveIndex;
 
 	u8* buffer;
 
@@ -28,10 +29,13 @@ typedef struct ringbuffer
 
 void ringbuffer_init(ringbuffer* ring, u8 capExp);
 void ringbuffer_cleanup(ringbuffer* ring);
-u32 ringbuffer_read_available(ringbuffer* ring);
-u32 ringbuffer_write_available(ringbuffer* ring);
-u32 ringbuffer_write(ringbuffer* ring, u32 size, u8* data);
-u32 ringbuffer_read(ringbuffer* ring, u32 size, u8* data);
+u64 ringbuffer_read_available(ringbuffer* ring);
+u64 ringbuffer_write_available(ringbuffer* ring);
+u64 ringbuffer_read(ringbuffer* ring, u64 size, u8* data);
+u64 ringbuffer_write(ringbuffer* ring, u64 size, u8* data);
+u64 ringbuffer_reserve(ringbuffer* ring, u64 size, u8* data);
+void ringbuffer_commit(ringbuffer* ring);
+void ringbuffer_rewind(ringbuffer* ring);
 
 #ifdef __cplusplus
 } // extern "C"