[libc-commits] [libc] [libc] add rwlock (PR #94156)

[Michael Jones via libc-commits]

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@@ -0,0 +1,42 @@
+//===-- Implementation for Rwlock's timedwrlock function ------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "src/pthread/pthread_rwlock_timedwrlock.h"
+
+#include "src/__support/common.h"
+#include "src/__support/libc_assert.h"
+#include "src/__support/macros/optimization.h"
+#include "src/__support/threads/linux/rwlock.h"
+#include "src/__support/time/linux/abs_timeout.h"
+
+#include <errno.h>
+#include <pthread.h>
+
+namespace LIBC_NAMESPACE {
+
+LLVM_LIBC_FUNCTION(int, pthread_rwlock_timedwrlock,
+                   (pthread_rwlock_t *__restrict rwlock,
+                    const struct timespec *__restrict abstime)) {
+  if (!rwlock)
+    return EINVAL;
+  RwLock *rw = reinterpret_cast<RwLock *>(rwlock);
+  LIBC_ASSERT(abstime && "timedwrlock called with a null timeout");
+  auto timeout =
+      internal::AbsTimeout::from_timespec(*abstime, /*is_realtime=*/true);
+  if (LIBC_LIKELY(timeout.has_value()))
+    return static_cast<int>(rw->write_lock(timeout.value()));
+
+  switch (timeout.error()) {
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michaelrj-google wrote:

does this `switch` need a `default`?

https://github.com/llvm/llvm-project/pull/94156