38 lines · cpp
1//===-- Implementation of pthread_spin_init 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_spin_init.h"10#include "hdr/errno_macros.h"11#include "src/__support/CPP/new.h"12#include "src/__support/common.h"13#include "src/__support/threads/spin_lock.h"14#include <pthread.h> // for PTHREAD_PROCESS_SHARED, PTHREAD_PROCESS_PRIVATE15 16namespace LIBC_NAMESPACE_DECL {17 18static_assert(sizeof(pthread_spinlock_t::__lockword) == sizeof(SpinLock) &&19 alignof(decltype(pthread_spinlock_t::__lockword)) ==20 alignof(SpinLock),21 "pthread_spinlock_t::__lockword and SpinLock must be of the same "22 "size and alignment");23 24LLVM_LIBC_FUNCTION(int, pthread_spin_init,25 (pthread_spinlock_t * lock, [[maybe_unused]] int pshared)) {26 if (!lock)27 return EINVAL;28 if (pshared != PTHREAD_PROCESS_SHARED && pshared != PTHREAD_PROCESS_PRIVATE)29 return EINVAL;30 // The spin lock here is a simple atomic flag, so we don't need to do any31 // special handling for pshared.32 ::new (&lock->__lockword) SpinLock();33 lock->__owner = 0;34 return 0;35}36 37} // namespace LIBC_NAMESPACE_DECL38