1*bb722a7dSDimitry Andric //===-- A platform independent abstraction layer for cond vars --*- C++ -*-===// 2*bb722a7dSDimitry Andric // 3*bb722a7dSDimitry Andric // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4*bb722a7dSDimitry Andric // See https://llvm.org/LICENSE.txt for license information. 5*bb722a7dSDimitry Andric // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6*bb722a7dSDimitry Andric // 7*bb722a7dSDimitry Andric //===----------------------------------------------------------------------===// 8*bb722a7dSDimitry Andric 9*bb722a7dSDimitry Andric #ifndef LLVM_LIBC___SUPPORT_SRC_THREADS_LINUX_CNDVAR_H 10*bb722a7dSDimitry Andric #define LLVM_LIBC___SUPPORT_SRC_THREADS_LINUX_CNDVAR_H 11*bb722a7dSDimitry Andric 12*bb722a7dSDimitry Andric #include "src/__support/macros/config.h" 13*bb722a7dSDimitry Andric #include "src/__support/threads/linux/futex_utils.h" // Futex 14*bb722a7dSDimitry Andric #include "src/__support/threads/linux/raw_mutex.h" // RawMutex 15*bb722a7dSDimitry Andric #include "src/__support/threads/mutex.h" // Mutex 16*bb722a7dSDimitry Andric 17*bb722a7dSDimitry Andric #include <stdint.h> // uint32_t 18*bb722a7dSDimitry Andric 19*bb722a7dSDimitry Andric namespace LIBC_NAMESPACE_DECL { 20*bb722a7dSDimitry Andric 21*bb722a7dSDimitry Andric class CndVar { 22*bb722a7dSDimitry Andric enum CndWaiterStatus : uint32_t { 23*bb722a7dSDimitry Andric WS_Waiting = 0xE, 24*bb722a7dSDimitry Andric WS_Signalled = 0x5, 25*bb722a7dSDimitry Andric }; 26*bb722a7dSDimitry Andric 27*bb722a7dSDimitry Andric struct CndWaiter { 28*bb722a7dSDimitry Andric Futex futex_word = WS_Waiting; 29*bb722a7dSDimitry Andric CndWaiter *next = nullptr; 30*bb722a7dSDimitry Andric }; 31*bb722a7dSDimitry Andric 32*bb722a7dSDimitry Andric CndWaiter *waitq_front; 33*bb722a7dSDimitry Andric CndWaiter *waitq_back; 34*bb722a7dSDimitry Andric RawMutex qmtx; 35*bb722a7dSDimitry Andric 36*bb722a7dSDimitry Andric public: init(CndVar * cv)37*bb722a7dSDimitry Andric LIBC_INLINE static int init(CndVar *cv) { 38*bb722a7dSDimitry Andric cv->waitq_front = cv->waitq_back = nullptr; 39*bb722a7dSDimitry Andric RawMutex::init(&cv->qmtx); 40*bb722a7dSDimitry Andric return 0; 41*bb722a7dSDimitry Andric } 42*bb722a7dSDimitry Andric destroy(CndVar * cv)43*bb722a7dSDimitry Andric LIBC_INLINE static void destroy(CndVar *cv) { 44*bb722a7dSDimitry Andric cv->waitq_front = cv->waitq_back = nullptr; 45*bb722a7dSDimitry Andric } 46*bb722a7dSDimitry Andric 47*bb722a7dSDimitry Andric // Returns 0 on success, -1 on error. 48*bb722a7dSDimitry Andric int wait(Mutex *m); 49*bb722a7dSDimitry Andric void notify_one(); 50*bb722a7dSDimitry Andric void broadcast(); 51*bb722a7dSDimitry Andric }; 52*bb722a7dSDimitry Andric 53*bb722a7dSDimitry Andric } // namespace LIBC_NAMESPACE_DECL 54*bb722a7dSDimitry Andric 55*bb722a7dSDimitry Andric #endif // LLVM_LIBC_SRC___SUPPORT_THREADS_LINUX_CNDVAR_H 56