51 lines · cpp
1//===-- Implementation of the Rwlock's clockrdlock 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-exception6//7//===----------------------------------------------------------------------===//8 9#include "src/pthread/pthread_rwlock_clockrdlock.h"10 11#include "hdr/errno_macros.h"12#include "src/__support/common.h"13#include "src/__support/macros/config.h"14#include "src/__support/threads/linux/rwlock.h"15 16#include <pthread.h>17 18namespace LIBC_NAMESPACE_DECL {19 20static_assert(21 sizeof(RwLock) == sizeof(pthread_rwlock_t) &&22 alignof(RwLock) == alignof(pthread_rwlock_t),23 "The public pthread_rwlock_t type must be of the same size and alignment "24 "as the internal rwlock type.");25 26LLVM_LIBC_FUNCTION(int, pthread_rwlock_clockrdlock,27 (pthread_rwlock_t * rwlock, clockid_t clockid,28 const timespec *abstime)) {29 if (!rwlock)30 return EINVAL;31 if (clockid != CLOCK_MONOTONIC && clockid != CLOCK_REALTIME)32 return EINVAL;33 bool is_realtime = (clockid == CLOCK_REALTIME);34 RwLock *rw = reinterpret_cast<RwLock *>(rwlock);35 LIBC_ASSERT(abstime && "clockrdlock called with a null timeout");36 auto timeout = internal::AbsTimeout::from_timespec(37 *abstime, /*is_realtime=*/is_realtime);38 if (LIBC_LIKELY(timeout.has_value()))39 return static_cast<int>(rw->read_lock(timeout.value()));40 41 switch (timeout.error()) {42 case internal::AbsTimeout::Error::Invalid:43 return EINVAL;44 case internal::AbsTimeout::Error::BeforeEpoch:45 return ETIMEDOUT;46 }47 __builtin_unreachable();48}49 50} // namespace LIBC_NAMESPACE_DECL51