Use libuv thread instead of std::thread to avoid musl issues (JuliaLa…

…ng#52149)

See
https://ariadne.space/2021/06/25/understanding-thread-stack-sizes-and-how-alpine-is-different/
and
https://git.alpinelinux.org/aports/commit/?id=4ab6ef38f167f4983008f8b213e5beace8d453f0

---------

Co-authored-by: Mosè Giordano <[email protected]>

src/aotcompile.cpp

@@ -1263,6 +1263,12 @@ static void construct_vars(Module &M, Partition &partition) {
  gidxs_var->setDSOLocal(true);
 }
 
+extern "C" void lambda_trampoline(void* arg) {
+ std::function<void()>* func = static_cast<std::function<void()>*>(arg);
+ (*func)();
+ delete func;
+}
+
 // Entrypoint to optionally-multithreaded image compilation. This handles global coordination of the threading,
 // as well as partitioning, serialization, and deserialization.
 template<typename ModuleReleasedFunc>
@@ -1351,9 +1357,9 @@ static SmallVector<AOTOutputs, 16> add_output(Module &M, TargetMachine &TM, Stri
  // Start all of the worker threads
  {
  JL_TIMING(NATIVE_AOT, NATIVE_Opt);
- std::vector<std::thread> workers(threads);
+ std::vector<uv_thread_t> workers(threads);
  for (unsigned i = 0; i < threads; i++) {
- workers[i] = std::thread([&, i]() {
+ std::function<void()> func = [&, i]() {
  LLVMContext ctx;
  // Lazily deserialize the entire module
  timers[i].deserialize.startTimer();
@@ -1375,12 +1381,14 @@ static SmallVector<AOTOutputs, 16> add_output(Module &M, TargetMachine &TM, Stri
  timers[i].construct.stopTimer();
 
  outputs[i] = add_output_impl(*M, TM, timers[i], unopt_out, opt_out, obj_out, asm_out);
- });
+ };
+ auto arg = new std::function<void()>(func);
+ uv_thread_create(&workers[i], lambda_trampoline, arg); // Use libuv thread to avoid issues with stack sizes
  }
 
  // Wait for all of the worker threads to finish
- for (auto &w : workers)
- w.join();
+ for (unsigned i = 0; i < threads; i++)
+ uv_thread_join(&workers[i]);
  }
 
  output_timer.stopTimer();
@@ -1418,7 +1426,6 @@ static unsigned compute_image_thread_count(const ModuleInfo &info) {
  LLVM_DEBUG(dbgs() << "COFF is restricted to a single thread for large images\n");
  return 1;
  }
-
  // This is not overridable because empty modules do occasionally appear, but they'll be very small and thus exit early to
  // known easy behavior. Plus they really don't warrant multiple threads
  if (info.weight < 1000) {