unix_api: Add support for pthreads (#288)

Co-authored-by: google-labs-jules[bot] <161369871+google-labs-jules[bot]@users.noreply.github.com>

Author: brianquinlan

pkgs/unix_api/a.out

@@ -64,9 +64,11 @@
   - EMFILE
   - ENOENT
   - ENOSPC
+  - ENOSYS
   - ENOTDIR
   - ENOTEMPTY
   - EPERM
+  - ETIMEDOUT
 "<fcntl.h>":
   - AT_FDCWD
   - AT_REMOVEDIR

pkgs/unix_api/constants.yaml

@@ -16,6 +16,7 @@ void main(List<String> args) async {
       assetName: 'libc_shim',
       libraries: [
         if ([OS.linux].contains(input.config.code.targetOS)) 'crypt',
+        if (input.config.code.targetOS != OS.android) 'pthread',
       ],
       sources: [
         'src/libc_shim.c',

pkgs/unix_api/hook/build.dart

@@ -6,7 +6,8 @@ import 'dart:ffi' as ffi;
 
 import 'errno.dart';
 import 'libc_bindings.g.dart';
-export 'libc_bindings.g.dart' show DIR, dirent, Stat, timespec;
+export 'libc_bindings.g.dart'
+    show DIR, dirent, Stat, timespec, pthread_t, pthread_attr_t;
 
 /// Gets metadata for a file.
 ///
@@ -65,3 +66,103 @@ extension DirentPtrExtensions on ffi.Pointer<dirent> {
   /// Need because of https://github.com/dart-lang/sdk/issues/41237.
   ffi.Pointer<ffi.Char> get d_name_ptr => libc_shim_d_name_ptr(this);
 }
+
+// <pthread.h>
+
+/// Unlocks all threads waiting on a condition variable.
+///
+/// See the [POSIX specification for `pthread_cond_broadcast`](https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_cond_broadcast.html).
+int pthread_cond_broadcast(ffi.Pointer<pthread_cond_t> cond) =>
+    libc_shim_pthread_cond_broadcast(cond, errnoPtr);
+
+/// Destroys a condition variable.
+///
+/// See the [POSIX specification for `pthread_cond_destroy`](https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_cond_destroy.html).
+int pthread_cond_destroy(ffi.Pointer<pthread_cond_t> cond) =>
+    libc_shim_pthread_cond_destroy(cond, errnoPtr);
+
+/// Initializes a condition variable.
+///
+/// See the [POSIX specification for `pthread_cond_init`](https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_cond_init.html).
+int pthread_cond_init(
+  ffi.Pointer<pthread_cond_t> cond,
+  ffi.Pointer<pthread_condattr_t> attr,
+) => libc_shim_pthread_cond_init(cond, attr, errnoPtr);
+
+/// Unlocks one thread waiting on a condition variable.
+///
+/// See the [POSIX specification for `pthread_cond_signal`](https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_cond_signal.html).
+int pthread_cond_signal(ffi.Pointer<pthread_cond_t> cond) =>
+    libc_shim_pthread_cond_signal(cond, errnoPtr);
+
+/// Waits on a condition variable for a given amount of time.
+///
+/// See the [POSIX specification for `pthread_cond_timedwait`](https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_cond_timedwait.html).
+int pthread_cond_timedwait(
+  ffi.Pointer<pthread_cond_t> cond,
+  ffi.Pointer<pthread_mutex_t> mutex,
+  ffi.Pointer<timespec> abstime,
+) => libc_shim_pthread_cond_timedwait(cond, mutex, abstime, errnoPtr);
+
+/// Waits on a condition variable.
+///
+/// See the [POSIX specification for `pthread_cond_wait`](https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_cond_wait.html).
+int pthread_cond_wait(
+  ffi.Pointer<pthread_cond_t> cond,
+  ffi.Pointer<pthread_mutex_t> mutex,
+) => libc_shim_pthread_cond_wait(cond, mutex, errnoPtr);
+
+/// Creates a new thread.
+///
+/// See the [POSIX specification for `pthread_create`](https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_create.html).
+int pthread_create(
+  ffi.Pointer<pthread_t> thread,
+  ffi.Pointer<pthread_attr_t> attr,
+  ffi.Pointer<
+    ffi.NativeFunction<ffi.Pointer<ffi.Void> Function(ffi.Pointer<ffi.Void>)>
+  >
+  start_routine,
+  ffi.Pointer<ffi.Void> arg,
+) => libc_shim_pthread_create(thread, attr, start_routine, arg, errnoPtr);
+
+/// Detaches a thread.
+///
+/// See the [POSIX specification for `pthread_detach`](https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_detach.html).
+int pthread_detach(pthread_t thread) =>
+    libc_shim_pthread_detach(thread, errnoPtr);
+
+/// Destroys a mutex.
+///
+/// See the [POSIX specification for `pthread_mutex_destroy`](https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_mutex_destroy.html).
+int pthread_mutex_destroy(ffi.Pointer<pthread_mutex_t> mutex) =>
+    libc_shim_pthread_mutex_destroy(mutex, errnoPtr);
+
+/// Initializes a mutex.
+///
+/// See the [POSIX specification for `pthread_mutex_init`](https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_mutex_init.html).
+int pthread_mutex_init(
+  ffi.Pointer<pthread_mutex_t> mutex,
+  ffi.Pointer<pthread_mutexattr_t> attr,
+) => libc_shim_pthread_mutex_init(mutex, attr, errnoPtr);
+
+/// Locks a mutex.
+///
+/// See the [POSIX specification for `pthread_mutex_lock`](https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_mutex_lock.html).
+int pthread_mutex_lock(ffi.Pointer<pthread_mutex_t> mutex) =>
+    libc_shim_pthread_mutex_lock(mutex, errnoPtr);
+
+/// Locks a mutex, failing if the lock is not acquired before a timeout.
+///
+/// Available on Android and Linux.
+///
+/// See the [POSIX specification for `pthread_mutex_timedlock`](https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_mutex_timedlock.html).
+int pthread_mutex_timedlock(
+  ffi.Pointer<pthread_mutex_t> mutex,
+  ffi.Pointer<timespec> abs_timeout,
+) => libc_shim_pthread_mutex_timedlock(mutex, abs_timeout, errnoPtr);
+
+/// Unlocks a mutex.
+///
+/// See the [POSIX specification for `pthread_mutex_unlock`](https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_mutex_unlock.html).
+int pthread_mutex_unlock(ffi.Pointer<pthread_mutex_t> mutex) =>
+    libc_shim_pthread_mutex_unlock(mutex, errnoPtr);