Increase stack size for all secondary threads on Apple platforms

Author: mihe

core/object/worker_thread_pool.cpp

@@ -364,24 +364,12 @@ WorkerThreadPool::TaskID WorkerThreadPool::_add_task(const Callable &p_callable,
 		if (pump_task_count >= thread_count) {
 			print_verbose(vformat("A greater number of dedicated threads were requested (%d) than threads available (%d). Please increase the number of available worker task threads. Recovering this session by spawning more worker task threads.", pump_task_count + 1, thread_count)); // +1 because we want to keep a Thread without any pump tasks free.
 
-			Thread::Settings settings;
-#ifdef __APPLE__
-			// The default stack size for new threads on Apple platforms is 512KiB.
-			// This is insufficient when using a library like SPIRV-Cross,
-			// which can generate deep stacks and result in a stack overflow.
-#ifdef DEV_ENABLED
-			// Debug builds need an even larger stack size.
-			settings.stack_size = 2 * 1024 * 1024; // 2 MiB
-#else
-			settings.stack_size = 1 * 1024 * 1024; // 1 MiB
-#endif
-#endif
 			// Re-sizing implies relocation, which is not supported for this array.
 			CRASH_COND_MSG(thread_count + 1 > (int)threads.get_capacity(), "Reserve trick for worker thread pool failed. Crashing.");
 			threads.resize_initialized(thread_count + 1);
 			threads[thread_count].index = thread_count;
 			threads[thread_count].pool = this;
-			threads[thread_count].thread.start(&WorkerThreadPool::_thread_function, &threads[thread_count], settings);
+			threads[thread_count].thread.start(&WorkerThreadPool::_thread_function, &threads[thread_count]);
 			thread_ids.insert(threads[thread_count].thread.get_id(), thread_count);
 		}
 	}
@@ -838,23 +826,10 @@ void WorkerThreadPool::init(int p_thread_count, float p_low_priority_task_ratio)
 #endif
 	threads.resize(p_thread_count);
 
-	Thread::Settings settings;
-#ifdef __APPLE__
-	// The default stack size for new threads on Apple platforms is 512KiB.
-	// This is insufficient when using a library like SPIRV-Cross,
-	// which can generate deep stacks and result in a stack overflow.
-#ifdef DEV_ENABLED
-	// Debug builds need an even larger stack size.
-	settings.stack_size = 2 * 1024 * 1024; // 2 MiB
-#else
-	settings.stack_size = 1 * 1024 * 1024; // 1 MiB
-#endif
-#endif
-
 	for (uint32_t i = 0; i < threads.size(); i++) {
 		threads[i].index = i;
 		threads[i].pool = this;
-		threads[i].thread.start(&WorkerThreadPool::_thread_function, &threads[i], settings);
+		threads[i].thread.start(&WorkerThreadPool::_thread_function, &threads[i]);
 		thread_ids.insert(threads[i].thread.get_id(), i);
 	}
 }

drivers/apple/thread_apple.cpp

@@ -92,9 +92,20 @@ Thread::ID Thread::start(Thread::Callback p_callback, void *p_user, const Settin
 			break;
 	}
 
-	if (p_settings.stack_size > 0) {
-		pthread_attr_setstacksize(&attr, p_settings.stack_size);
-	}
+	// The default stack size for secondary threads on Apple platforms is 512KiB.
+	// This is insufficient when using a library like SPIRV-Cross, which can generate deep stacks and result in a stack overflow.
+	// It also creates a problematic discrepancy with other platforms, where secondary threads are often at least 1 MiB.
+	pthread_attr_setstacksize(&attr,
+#if __has_feature(address_sanitizer) || __has_feature(thread_sanitizer)
+			// ASan (and to some degree TSan) needs a lot of extra stack size.
+			4 * 1024 * 1024 // 4 MiB
+#elif !defined(__OPTIMIZE__)
+			// Unoptimized builds also need a larger stack size.
+			2 * 1024 * 1024 // 2 MiB
+#else
+			1 * 1024 * 1024 // 1 MiB
+#endif
+	);
 
 	// Create the thread
 	pthread_create(&pthread, &attr, thread_callback, thread_data);

drivers/apple/thread_apple.h

@@ -57,8 +57,6 @@ class Thread {
 
 	struct Settings {
 		Priority priority;
-		/// Override the default stack size (0 means default)
-		uint64_t stack_size = 0;
 		Settings() { priority = PRIORITY_NORMAL; }
 	};