spinlock_posix.inc (1484B)
1 // Copyright 2017 The Abseil Authors. 2 // 3 // Licensed under the Apache License, Version 2.0 (the "License"); 4 // you may not use this file except in compliance with the License. 5 // You may obtain a copy of the License at 6 // 7 // https://www.apache.org/licenses/LICENSE-2.0 8 // 9 // Unless required by applicable law or agreed to in writing, software 10 // distributed under the License is distributed on an "AS IS" BASIS, 11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12 // See the License for the specific language governing permissions and 13 // limitations under the License. 14 // 15 // This file is a Posix-specific part of spinlock_wait.cc 16 17 #include <sched.h> 18 19 #include <atomic> 20 #include <ctime> 21 22 #include "absl/base/internal/errno_saver.h" 23 #include "absl/base/internal/scheduling_mode.h" 24 #include "absl/base/port.h" 25 26 extern "C" { 27 28 ABSL_ATTRIBUTE_WEAK void ABSL_INTERNAL_C_SYMBOL(AbslInternalSpinLockDelay)( 29 std::atomic<uint32_t>* /* lock_word */, uint32_t /* value */, int loop, 30 absl::base_internal::SchedulingMode /* mode */) { 31 absl::base_internal::ErrnoSaver errno_saver; 32 if (loop == 0) { 33 } else if (loop == 1) { 34 sched_yield(); 35 } else { 36 struct timespec tm; 37 tm.tv_sec = 0; 38 tm.tv_nsec = absl::base_internal::SpinLockSuggestedDelayNS(loop); 39 nanosleep(&tm, nullptr); 40 } 41 } 42 43 ABSL_ATTRIBUTE_WEAK void ABSL_INTERNAL_C_SYMBOL(AbslInternalSpinLockWake)( 44 std::atomic<uint32_t>* /* lock_word */, bool /* all */) {} 45 46 } // extern "C"