1*03841e7aSSchrodinger ZHU Yifan //===-- Implementation of pthread_spin_init function ----------------------===// 2*03841e7aSSchrodinger ZHU Yifan // 3*03841e7aSSchrodinger ZHU Yifan // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4*03841e7aSSchrodinger ZHU Yifan // See https://llvm.org/LICENSE.txt for license information. 5*03841e7aSSchrodinger ZHU Yifan // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6*03841e7aSSchrodinger ZHU Yifan // 7*03841e7aSSchrodinger ZHU Yifan //===----------------------------------------------------------------------===// 8*03841e7aSSchrodinger ZHU Yifan 9*03841e7aSSchrodinger ZHU Yifan #include "src/pthread/pthread_spin_init.h" 10*03841e7aSSchrodinger ZHU Yifan #include "hdr/errno_macros.h" 11*03841e7aSSchrodinger ZHU Yifan #include "src/__support/CPP/new.h" 12*03841e7aSSchrodinger ZHU Yifan #include "src/__support/common.h" 13*03841e7aSSchrodinger ZHU Yifan #include "src/__support/threads/spin_lock.h" 14*03841e7aSSchrodinger ZHU Yifan #include <pthread.h> // for PTHREAD_PROCESS_SHARED, PTHREAD_PROCESS_PRIVATE 15*03841e7aSSchrodinger ZHU Yifan 16*03841e7aSSchrodinger ZHU Yifan namespace LIBC_NAMESPACE_DECL { 17*03841e7aSSchrodinger ZHU Yifan 18*03841e7aSSchrodinger ZHU Yifan static_assert(sizeof(pthread_spinlock_t::__lockword) == sizeof(SpinLock) && 19*03841e7aSSchrodinger ZHU Yifan alignof(decltype(pthread_spinlock_t::__lockword)) == 20*03841e7aSSchrodinger ZHU Yifan alignof(SpinLock), 21*03841e7aSSchrodinger ZHU Yifan "pthread_spinlock_t::__lockword and SpinLock must be of the same " 22*03841e7aSSchrodinger ZHU Yifan "size and alignment"); 23*03841e7aSSchrodinger ZHU Yifan 24*03841e7aSSchrodinger ZHU Yifan LLVM_LIBC_FUNCTION(int, pthread_spin_init, 25*03841e7aSSchrodinger ZHU Yifan (pthread_spinlock_t * lock, [[maybe_unused]] int pshared)) { 26*03841e7aSSchrodinger ZHU Yifan if (!lock) 27*03841e7aSSchrodinger ZHU Yifan return EINVAL; 28*03841e7aSSchrodinger ZHU Yifan if (pshared != PTHREAD_PROCESS_SHARED && pshared != PTHREAD_PROCESS_PRIVATE) 29*03841e7aSSchrodinger ZHU Yifan return EINVAL; 30*03841e7aSSchrodinger ZHU Yifan // The spin lock here is a simple atomic flag, so we don't need to do any 31*03841e7aSSchrodinger ZHU Yifan // special handling for pshared. 32*03841e7aSSchrodinger ZHU Yifan ::new (&lock->__lockword) SpinLock(); 33*03841e7aSSchrodinger ZHU Yifan lock->__owner = 0; 34*03841e7aSSchrodinger ZHU Yifan return 0; 35*03841e7aSSchrodinger ZHU Yifan } 36*03841e7aSSchrodinger ZHU Yifan 37*03841e7aSSchrodinger ZHU Yifan } // namespace LIBC_NAMESPACE_DECL 38