Secondary threads on Apple platforms are more susceptible to stack overflow than on other platforms

[mihe]

Tested versions

• Reproducible in: 4.6.dev [0fdb93c]

System information

Godot v4.6.dev (0fdb93c) - macOS Tahoe (26.0.1) - Multi-window, 1 monitor - Metal (Forward+) - integrated Apple M2 Pro (Apple8) - Apple M2 Pro (10 threads) - 32.00 GiB memory

Issue description

Apple platforms (e.g. macOS, iOS) use a default stack size of 512 KiB for secondary threads. This is unlike most other platforms where it instead is at least 1 MiB.

We currently increase the stack size for WorkerThreadPool threads specifically on Apple platforms, in order to not run into stack overflows as a result of SPIRV-Cross, as seen here:

godot/core/object/worker_thread_pool.cpp

Lines 367 to 378 in 0fdb93c

	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

This however does nothing to resolve the problem for threads spawned from scripts (i.e. Thread), where you're still more likely to run into a stack overflow on Apple platforms.

Steps to reproduce

1. Build a non-optimized editor build for macOS (i.e. target=editor dev_build=yes).
2. Run the main scene in the MRP.
3. Note the crash.
4. Build a non-optimized editor build for Windows or Linux.
5. Run the main scene again.
6. Note how there's no crash.

Minimal reproduction project (MRP)

apple-stack-overflow.zip