48 lines · cpp
1//===-- Implementation of pthread_spin_destroy 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_destroy.h"10#include "hdr/errno_macros.h"11#include "src/__support/common.h"12#include "src/__support/threads/spin_lock.h"13namespace LIBC_NAMESPACE_DECL {14 15static_assert(sizeof(pthread_spinlock_t::__lockword) == sizeof(SpinLock) &&16 alignof(decltype(pthread_spinlock_t::__lockword)) ==17 alignof(SpinLock),18 "pthread_spinlock_t::__lockword and SpinLock must be of the same "19 "size and alignment");20 21LLVM_LIBC_FUNCTION(int, pthread_spin_destroy,22 ([[maybe_unused]] pthread_spinlock_t * lock)) {23 // If an implementation detects that the value specified by the lock argument24 // to pthread_spin_lock() or pthread_spin_trylock() does not refer to an25 // initialized spin lock object, it is recommended that the function should26 // fail and report an [EINVAL] error.27 if (!lock)28 return EINVAL;29 auto spin_lock = reinterpret_cast<SpinLock *>(&lock->__lockword);30 if (!spin_lock || spin_lock->is_invalid())31 return EINVAL;32 33 // If an implementation detects that the value specified by the lock argument34 // to pthread_spin_destroy() or pthread_spin_init() refers to a locked spin35 // lock object, or detects that the value specified by the lock argument to36 // pthread_spin_init() refers to an already initialized spin lock object, it37 // is recommended that the function should fail and report an [EBUSY] error.38 if (spin_lock->is_locked())39 return EBUSY;40 41 // poison the lock42 spin_lock->~SpinLock();43 lock->__owner = 0;44 return 0;45}46 47} // namespace LIBC_NAMESPACE_DECL48