perf: Make promise stack trace collection opt-in.

src/mem.c

@@ -22,8 +22,6 @@ static int64_t s_tls_malloc_size;
 static int64_t s_js_malloc_size;
 static int64_t s_sqlite_malloc_size;
 
-extern uint32_t fnv32a(const void* buffer, int length, uint32_t start);
-
 static size_t _tf_mem_round_up(size_t size)
 {
 	return (size + 7) & ~7;
@@ -156,7 +154,7 @@ static void _tf_mem_summarize(void* ptr, size_t size, int frames_count, void* co
 {
 	summary_t* summary = user_data;
 	tf_mem_allocation_t allocation = {
-		.stack_hash = fnv32a(frames, sizeof(void*) * frames_count, 0),
+		.stack_hash = tf_util_fnv32a(frames, sizeof(void*) * frames_count, 0),
 		.count = 1,
 		.size = size,
 		.frames_count = frames_count,

src/task.c

@@ -164,6 +164,7 @@ typedef struct _tf_task_t
 
 	promise_stack_t* _promise_stacks;
 	int _promise_stack_count;
+	bool _promise_stack_debug;
 
 	timeout_t* timeouts;
 
@@ -1252,10 +1253,13 @@ static void _add_promise_stack(tf_task_t* task, uint32_t hash, const char* stack
 
 static void _remove_promise_stack(tf_task_t* task, uint32_t hash)
 {
-	promise_stack_t* found = bsearch(&hash, task->_promise_stacks, task->_promise_stack_count, sizeof(promise_stack_t), _promise_stack_compare);
+	if (task->_promise_stack_debug)
-	if (found)
 	{
-		found->count--;
+		promise_stack_t* found = bsearch(&hash, task->_promise_stacks, task->_promise_stack_count, sizeof(promise_stack_t), _promise_stack_compare);
+		if (found)
+		{
+			found->count--;
+		}
 	}
 }
 
@@ -1271,33 +1275,26 @@ static void _tf_task_free_promise(tf_task_t* task, promiseid_t id)
 	}
 }
 
-uint32_t fnv32a(const void* buffer, int length, uint32_t start)
-{
-	uint32_t result = 0x811c9dc5;
-	for (int i = 0; i < length; i++)
-	{
-		result ^= ((const uint8_t*)buffer)[i];
-		result += (result << 1) + (result << 4) + (result << 7) + (result << 8) + (result << 24);
-	}
-	return result;
-}
-
 JSValue tf_task_allocate_promise(tf_task_t* task, promiseid_t* out_promise)
 {
-	JSValue error = JS_ThrowInternalError(task->_context, "promise callstack");
+	uint32_t stack_hash = 0;
-	JSValue exception = JS_GetException(task->_context);
+	if (task->_promise_stack_debug)
-	JSValue stack_value = JS_GetPropertyStr(task->_context, exception, "stack");
+	{
-	size_t length = 0;
+		JSValue error = JS_ThrowInternalError(task->_context, "promise callstack");
-	const char* stack = JS_ToCStringLen(task->_context, &length, stack_value);
+		JSValue exception = JS_GetException(task->_context);
-	uint32_t stack_hash = fnv32a((const void*)stack, (int)length, 0);
+		JSValue stack_value = JS_GetPropertyStr(task->_context, exception, "stack");
-	void* buffer[32];
+		size_t length = 0;
-	int count = tf_util_backtrace(buffer, sizeof(buffer) / sizeof(*buffer));
+		const char* stack = JS_ToCStringLen(task->_context, &length, stack_value);
-	stack_hash = fnv32a((const void*)buffer, sizeof(void*) * count, stack_hash);
+		stack_hash = tf_util_fnv32a((const void*)stack, (int)length, 0);
-	_add_promise_stack(task, stack_hash, stack, buffer, count);
+		void* buffer[32];
-	JS_FreeCString(task->_context, stack);
+		int count = tf_util_backtrace(buffer, sizeof(buffer) / sizeof(*buffer));
-	JS_FreeValue(task->_context, stack_value);
+		stack_hash = tf_util_fnv32a((const void*)buffer, sizeof(void*) * count, stack_hash);
-	JS_FreeValue(task->_context, exception);
+		_add_promise_stack(task, stack_hash, stack, buffer, count);
-	JS_FreeValue(task->_context, error);
+		JS_FreeCString(task->_context, stack);
+		JS_FreeValue(task->_context, stack_value);
+		JS_FreeValue(task->_context, exception);
+		JS_FreeValue(task->_context, error);
+	}
 
 	promiseid_t promiseId;
 	do
@@ -1592,6 +1589,10 @@ tf_task_t* tf_task_create()
 	*task = (tf_task_t) { 0 };
 	++_count;
 
+	char buffer[8] = { 0 };
+	size_t buffer_size = sizeof(buffer);
+	task->_promise_stack_debug = uv_os_getenv("TF_PROMISE_DEBUG", buffer, &buffer_size) == 0 && strcmp(buffer, "1") == 0;
+
 	JSMallocFunctions funcs = { 0 };
 	tf_get_js_malloc_functions(&funcs);
 	task->_runtime = JS_NewRuntime2(&funcs, NULL);

src/util.js.c

@@ -683,3 +683,14 @@ bool tf_util_is_mobile()
 {
 	return TF_IS_MOBILE != 0;
 }
+
+uint32_t tf_util_fnv32a(const void* buffer, int length, uint32_t start)
+{
+	uint32_t result = 0x811c9dc5;
+	for (int i = 0; i < length; i++)
+	{
+		result ^= ((const uint8_t*)buffer)[i];
+		result += (result << 1) + (result << 4) + (result << 7) + (result << 8) + (result << 24);
+	}
+	return result;
+}

src/util.js.h

@@ -224,4 +224,13 @@ void tf_util_document_settings(const char* line_prefix);
 */
 bool tf_util_is_mobile();
 
+/**
+** Compute a 32-bit hash of a buffer.
+** @param buffer The data.
+** @param length The size of the buffer in bytes.
+** @param start The hash seed.
+** @return The computed hash.
+*/
+uint32_t tf_util_fnv32a(const void* buffer, int length, uint32_t start);
+
 /** @} */