We need to apply some bug fixes that were merged to wasi-libc because wasi-sdk-20
is about half a year old.
It is a temporary solution and the code will be removed when wasi-sdk 21 is released.
- Inherit shared memory from the parent instance, instead of
trying to look it up by the underlying module. The old method
works correctly only when every cluster uses different module.
- Use reference count in WASMMemoryInstance/AOTMemoryInstance
to mark whether the memory is shared or not
- Retire WASMSharedMemNode
- For atomic opcode implementations in the interpreters, use
a global lock for now
- Update the internal API users
(wasi-threads, lib-pthread, wasm_runtime_spawn_thread)
Fixes https://github.com/bytecodealliance/wasm-micro-runtime/issues/1962
We need to make a test that runs longer than the tests we had before to check
some problems that might happen after running for some time (e.g. memory
corruption or something else).
Fix issue reported in #2172: wasm-c-api `wasm_func_call` may use a wrong exec_env
when multi-threading is enabled, with error "invalid exec env" reported
Fix issue reported in #2149: main instance's `c_api_func_imports` are not passed to
the counterpart of new thread's instance in wasi-threads mode
Fix issue of invalid size calculated to copy `c_api_func_imports` in pthread mode
And refactor the code to use `wasm_cluster_dup_c_api_imports` to copy the
`c_api_func_imports` to new thread for wasi-threads mode and pthread mode.
Currently, if a thread is spawned and raises an exception after the main thread
has finished, iwasm returns with success instead of returning 1 (i.e. error).
Since wasm_runtime_get_wasi_exit_code waits for all threads to finish and only
returns the wasi exit code, this PR performs the exception check again and
returns error if an exception was raised.
Update wasi-libc version to resolve the hang issue when running wasi-threads cases.
Implement custom sync primitives as a counterpart of `pthread_barrier_wait` to
attempt to replace pthread sync primitives since they seem to cause data races
when running with the thread sanitizer.
Use pre-created exec_env for instantiation and module_malloc/free,
use the same exec_env of the current thread to avoid potential
unexpected behavior.
And remove unnecessary shared_mem_lock in wasm_module_free,
which may cause dead lock.
`wasi-sdk-20` pre-release can be used to avoid building `wasi-libc` to enable threads.
It's not possible to use `wasi-sdk-20` pre-release on Ubuntu 20.04 because of
incompatibility with the glibc version:
```bash
/opt/wasi-sdk/bin/clang: /lib/x86_64-linux-gnu/libc.so.6: version `GLIBC_2.34' not found
(required by /opt/wasi-sdk/bin/clang)
```
- Remove notify_stale_threads_on_exception and change atomic.wait
to be interruptible by keep waiting and checking every one second,
like the implementation of poll_oneoff in libc-wasi
- Wait all other threads exit and then get wasi exit_code to avoid
getting invalid value
- Inherit suspend_flags of parent thread while creating new thread to
avoid terminated flag isn't set for new thread
- Fix wasi-threads test case update_shared_data_and_alloc_heap
- Add "Lib wasi-threads enabled" prompt for cmake
- Fix aot get exception, use aot_copy_exception instead
Fix a data race for test main_proc_exit_wait.c from #1963.
And fix atomic_wait logic that was wrong before:
- a thread 1 started executing wasm instruction wasm_atomic_wait
but hasn't reached waiting on condition variable
- a main thread calls proc_exit and notifies all the threads that reached
waiting on condition variable
Which leads to thread 1 hang on waiting on condition variable after that
Now it's atomically checked whether proc_exit was already called.
In the WASI thread test modified in this PR, malloc was used in multiple threads
without a lock. But wasi-libc implementation of malloc is not thread-safe.
This syscall doesn't need allocating stack or TLS and it's expected from the application
to do that instead. E.g. WASI-libc already does this for `pthread_create`.
Also fix some of the examples to allocate memory for stack and not use stack before
the stack pointer is set to a correct value.
According to the [WASI thread specification](https://github.com/WebAssembly/wasi-threads/pull/16),
some thread identifiers are reserved and should not be used. In fact, only IDs between `1` and
`0x1FFFFFFF` are valid.
The thread ID allocator has been moved to a separate class to avoid polluting the
`lib_wasi_threads_wrapper` logic.
This PR allows reusing thread ids once they are released. That is done by using
a stack data structure to keep track of the used ids.
When a thread is created, it takes an available identifier from the stack. When
the thread exits, it returns the id to the stack of available identifiers.
For now this implementation uses thread manager.
Not sure whether thread manager is needed in that case. In the future there'll be likely another syscall added (for pthread_exit) and for that we might need some kind of thread management - with that in mind, we keep thread manager for now and will refactor this later if needed.
