1//===-- Implementation of the Rwlock's timedrdlock function ---------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8
9#include "src/pthread/pthread_rwlock_timedrdlock.h"
10#include "src/__support/common.h"
11#include "src/__support/libc_assert.h"
12#include "src/__support/libc_errno.h"
13#include "src/__support/macros/config.h"
14#include "src/__support/macros/optimization.h"
15#include "src/__support/threads/linux/rwlock.h"
16#include "src/__support/time/linux/abs_timeout.h"
17
18#include <pthread.h>
19
20namespace LIBC_NAMESPACE_DECL {
21
22static_assert(
23 sizeof(RwLock) == sizeof(pthread_rwlock_t) &&
24 alignof(RwLock) == alignof(pthread_rwlock_t),
25 "The public pthread_rwlock_t type must be of the same size and alignment "
26 "as the internal rwlock type.");
27
28LLVM_LIBC_FUNCTION(int, pthread_rwlock_timedrdlock,
29 (pthread_rwlock_t * rwlock,
30 const struct timespec *abstime)) {
31 if (!rwlock)
32 return EINVAL;
33 RwLock *rw = reinterpret_cast<RwLock *>(rwlock);
34 LIBC_ASSERT(abstime && "timedrdlock called with a null timeout");
35 auto timeout =
36 internal::AbsTimeout::from_timespec(*abstime, /*is_realtime=*/true);
37 if (LIBC_LIKELY(timeout.has_value()))
38 return static_cast<int>(rw->read_lock(timeout.value()));
39
40 switch (timeout.error()) {
41 case internal::AbsTimeout::Error::Invalid:
42 return EINVAL;
43 case internal::AbsTimeout::Error::BeforeEpoch:
44 return ETIMEDOUT;
45 }
46 __builtin_unreachable();
47}
48
49} // namespace LIBC_NAMESPACE_DECL
50

source code of libc/src/pthread/pthread_rwlock_timedrdlock.cpp