Is `wasm_runtime_module_malloc` thread-safe?

[vdimir]

I get strange failures when calling wasm_runtime_module_malloc with different module instances from multiple threads, does it mean that this function is not thread safe? I use Alloc_With_Allocator option in RuntimeInitArgs. It's expected that in may be not thread safe with Alloc_With_Pool, but if if calls malloc it should be safe or not?

Also, can Alloc_With_Pool be used with multiple module instance running at the same time, if allocating will be performed under global mutex? What also should be in critical section?

[xujuntwt95329]

Hi, how do you build your wasm application ?

If your wasm application are built as LIBC-WASI mode, you need to hack the wasi-libc's dlmalloc.o as the dlmalloc function implemented by wasi-libc is not thread-safe, please refer to Build with libc-WASI section in pthread_library.md for more details.

If you are using LIBC-BUILTIN mode, then wasm_runtime_module_malloc is thread-safe.

[vdimir]

Hi, how do you build your wasm application ?

I compile it with Emscripten emcc testapp.c -s STANDALONE_WASM -s ERROR_ON_UNDEFINED_SYMBOLS=0 -O2 -s TOTAL_MEMORY=6MB -o testapp.wasm --no-entry, but actually no explicit allocations are performed in wasm app.

Ok, I'll try different emcc options or another compiler.