`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.
