libc/src/pthread/pthread_rwlock_rdlock.cpp

   1 //===-- Implementation of the Rwlock's rdlock 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_rdlock.h"
  10
  11 #include "src/__support/common.h"
  12 #include "src/__support/macros/config.h"
  13 #include "src/__support/threads/linux/rwlock.h"
  14
  15 #include <pthread.h>
  16
  17 namespace LIBC_NAMESPACE_DECL {
  18
  19 static_assert(
  20     sizeof(RwLock) == sizeof(pthread_rwlock_t) &&
  21         alignof(RwLock) == alignof(pthread_rwlock_t),
  22     "The public pthread_rwlock_t type must be of the same size and alignment "
  23     "as the internal rwlock type.");
  24
  25 LLVM_LIBC_FUNCTION(int, pthread_rwlock_rdlock, (pthread_rwlock_t * rwlock)) {
  26   if (!rwlock)
  27     return EINVAL;
  28   RwLock *rw = reinterpret_cast<RwLock *>(rwlock);
  29   return static_cast<int>(rw->read_lock());
  30 }
  31
  32 } // namespace LIBC_NAMESPACE_DECL