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 33