xref: /aosp_15_r20/external/llvm-libc/src/pthread/pthread_rwlock_rdlock.cpp (revision 71db0c75aadcf003ffe3238005f61d7618a3fead)

//===-- Implementation of the Rwlock's rdlock 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_rdlock.h"

#include "src/__support/common.h"
#include "src/__support/macros/config.h"
#include "src/__support/threads/linux/rwlock.h"

#include <pthread.h>

namespace LIBC_NAMESPACE_DECL {

static_assert(
    sizeof(RwLock) == sizeof(pthread_rwlock_t) &&
        alignof(RwLock) == alignof(pthread_rwlock_t),
    "The public pthread_rwlock_t type must be of the same size and alignment "
    "as the internal rwlock type.");

LLVM_LIBC_FUNCTION(int, pthread_rwlock_rdlock, (pthread_rwlock_t * rwlock)) {
  if (!rwlock)
    return EINVAL;
  RwLock *rw = reinterpret_cast<RwLock *>(rwlock);
  return static_cast<int>(rw->read_lock());
}

} // namespace LIBC_NAMESPACE_DECL