112787Sgabeblack@google.com/* 212787Sgabeblack@google.com * Copyright 2018 Google, Inc. 312787Sgabeblack@google.com * 412787Sgabeblack@google.com * Redistribution and use in source and binary forms, with or without 512787Sgabeblack@google.com * modification, are permitted provided that the following conditions are 612787Sgabeblack@google.com * met: redistributions of source code must retain the above copyright 712787Sgabeblack@google.com * notice, this list of conditions and the following disclaimer; 812787Sgabeblack@google.com * redistributions in binary form must reproduce the above copyright 912787Sgabeblack@google.com * notice, this list of conditions and the following disclaimer in the 1012787Sgabeblack@google.com * documentation and/or other materials provided with the distribution; 1112787Sgabeblack@google.com * neither the name of the copyright holders nor the names of its 1212787Sgabeblack@google.com * contributors may be used to endorse or promote products derived from 1312787Sgabeblack@google.com * this software without specific prior written permission. 1412787Sgabeblack@google.com * 1512787Sgabeblack@google.com * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 1612787Sgabeblack@google.com * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 1712787Sgabeblack@google.com * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 1812787Sgabeblack@google.com * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 1912787Sgabeblack@google.com * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 2012787Sgabeblack@google.com * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 2112787Sgabeblack@google.com * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 2212787Sgabeblack@google.com * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 2312787Sgabeblack@google.com * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 2412787Sgabeblack@google.com * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 2512787Sgabeblack@google.com * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 2612787Sgabeblack@google.com * 2712787Sgabeblack@google.com * Authors: Gabe Black 2812787Sgabeblack@google.com */ 2912787Sgabeblack@google.com 3012787Sgabeblack@google.com#ifndef __BASE_FIBER_HH__ 3112787Sgabeblack@google.com#define __BASE_FIBER_HH__ 3212787Sgabeblack@google.com 3312846Sgiacomo.travaglini@arm.com// ucontext functions (like getcontext, setcontext etc) have been marked 3412846Sgiacomo.travaglini@arm.com// as deprecated and are hence hidden in latest macOS releases. 3512846Sgiacomo.travaglini@arm.com// By defining _XOPEN_SOURCE we make them available at compilation time. 3612846Sgiacomo.travaglini@arm.com#if defined(__APPLE__) && defined(__MACH__) 3712846Sgiacomo.travaglini@arm.com#define _XOPEN_SOURCE 600 3812787Sgabeblack@google.com#include <ucontext.h> 3912846Sgiacomo.travaglini@arm.com#undef _XOPEN_SOURCE 4012846Sgiacomo.travaglini@arm.com#else 4112846Sgiacomo.travaglini@arm.com#include <ucontext.h> 4212846Sgiacomo.travaglini@arm.com#endif 4312787Sgabeblack@google.com 4412787Sgabeblack@google.com#include <cstddef> 4512787Sgabeblack@google.com#include <cstdint> 4612787Sgabeblack@google.com 4712920Sgabeblack@google.com#include "config/have_valgrind.hh" 4812920Sgabeblack@google.com 4912787Sgabeblack@google.com/** 5012787Sgabeblack@google.com * This class represents a fiber, which is a light weight sort of thread which 5112787Sgabeblack@google.com * is cooperatively scheduled and runs sequentially with other fibers, swapping 5212787Sgabeblack@google.com * in and out of a single actual thread of execution. 5312787Sgabeblack@google.com * 5412787Sgabeblack@google.com * To define your own threads, create a subclass of Fiber and override its 5512787Sgabeblack@google.com * main() function to do what you want your fiber to do. You can start it by 5612787Sgabeblack@google.com * calling its run() method which will stop your execution and start the other 5712787Sgabeblack@google.com * fiber in your place. 5812787Sgabeblack@google.com * 5912787Sgabeblack@google.com * If your main() function ends, that fiber will automatically switch to either 6012787Sgabeblack@google.com * the primary fiber, or to a particular fiber you specified at construction 6112787Sgabeblack@google.com * time, and your fiber is considered finished. 6212787Sgabeblack@google.com */ 6312787Sgabeblack@google.com 6412787Sgabeblack@google.comclass Fiber 6512787Sgabeblack@google.com{ 6612787Sgabeblack@google.com public: 6712787Sgabeblack@google.com const static size_t DefaultStackSize = 0x50000; 6812787Sgabeblack@google.com 6912787Sgabeblack@google.com /// stack_size is the size of the stack available to this fiber. 7012787Sgabeblack@google.com /// link points to another fiber which will start executing when this 7112787Sgabeblack@google.com /// fiber's main function returns. 7212787Sgabeblack@google.com Fiber(size_t stack_size=DefaultStackSize); 7312787Sgabeblack@google.com Fiber(Fiber *link, size_t stack_size=DefaultStackSize); 7412787Sgabeblack@google.com 7512787Sgabeblack@google.com virtual ~Fiber(); 7612787Sgabeblack@google.com 7712787Sgabeblack@google.com /// Start executing the fiber represented by this object. This function 7812787Sgabeblack@google.com /// will "return" when the current fiber is switched back to later on. 7912787Sgabeblack@google.com void run(); 8012787Sgabeblack@google.com 8112787Sgabeblack@google.com /// Returns whether the "main" function of this fiber has finished. 8212787Sgabeblack@google.com /// 8312787Sgabeblack@google.com bool finished() const { return _finished; }; 8412787Sgabeblack@google.com 8514042Sgiacomo.travaglini@arm.com /// Returns whether the "main" function of this fiber has started. 8614042Sgiacomo.travaglini@arm.com /// 8714042Sgiacomo.travaglini@arm.com bool started() const { return _started; }; 8814042Sgiacomo.travaglini@arm.com 8912787Sgabeblack@google.com /// Get a pointer to the current running Fiber. 9012787Sgabeblack@google.com /// 9112787Sgabeblack@google.com static Fiber *currentFiber(); 9212787Sgabeblack@google.com /// Get a pointer to the primary Fiber. 9312787Sgabeblack@google.com /// This Fiber represents the thread of execution started by the OS, and 9412787Sgabeblack@google.com /// which has a Fiber attached to it after the fact. 9512787Sgabeblack@google.com static Fiber *primaryFiber(); 9612787Sgabeblack@google.com 9712787Sgabeblack@google.com protected: 9812787Sgabeblack@google.com /// This method is called when this fiber is first run. Override it to 9912787Sgabeblack@google.com /// give your fiber something to do. When main returns, the fiber will 10012787Sgabeblack@google.com /// mark itself as finished and switch to its link fiber. 10112787Sgabeblack@google.com virtual void main() = 0; 10212787Sgabeblack@google.com 10314042Sgiacomo.travaglini@arm.com void setStarted() { _started = true; } 10412787Sgabeblack@google.com 10512787Sgabeblack@google.com private: 10612787Sgabeblack@google.com static void entryTrampoline(); 10712787Sgabeblack@google.com void start(); 10812787Sgabeblack@google.com 10912787Sgabeblack@google.com ucontext_t ctx; 11012787Sgabeblack@google.com Fiber *link; 11112787Sgabeblack@google.com 11212787Sgabeblack@google.com // The stack for this context, or a nullptr if allocated elsewhere. 11313435Sgabeblack@google.com void *stack; 11412787Sgabeblack@google.com size_t stackSize; 11513435Sgabeblack@google.com void *guardPage; 11613435Sgabeblack@google.com size_t guardPageSize; 11712920Sgabeblack@google.com#if HAVE_VALGRIND 11812920Sgabeblack@google.com unsigned valgrindStackId; 11912920Sgabeblack@google.com#endif 12012787Sgabeblack@google.com 12114042Sgiacomo.travaglini@arm.com bool _started; 12212787Sgabeblack@google.com bool _finished; 12312787Sgabeblack@google.com void createContext(); 12412787Sgabeblack@google.com}; 12512787Sgabeblack@google.com 12612787Sgabeblack@google.com#endif // __BASE_FIBER_HH__ 127