1/* 2 * Copyright (C) 2014 Apple Inc. All rights reserved. 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 1. Redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer. 9 * 2. Redistributions in binary form must reproduce the above copyright 10 * notice, this list of conditions and the following disclaimer in the 11 * documentation and/or other materials provided with the distribution. 12 * 13 * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS'' 14 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, 15 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 16 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS 17 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 18 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO , PROCUREMENT OF 19 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 20 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 21 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 22 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF 23 * THE POSSIBILITY OF SUCH DAMAGE. 24 */ 25 26#include "config.h" 27#include "ProcessThrottler.h" 28 29#include "WebProcessProxy.h" 30 31namespace WebKit { 32 33static const unsigned processSuspensionTimeout = 30; 34 35ProcessThrottler::ForegroundActivityToken::ForegroundActivityToken(ProcessThrottler& throttler) 36 : m_throttler(throttler.weakPtr()) 37{ 38 throttler.m_foregroundCount++; 39 throttler.updateAssertion(); 40} 41 42ProcessThrottler::ForegroundActivityToken::~ForegroundActivityToken() 43{ 44 if (ProcessThrottler* throttler = m_throttler.get()) { 45 throttler->m_foregroundCount--; 46 throttler->updateAssertion(); 47 } 48} 49 50ProcessThrottler::BackgroundActivityToken::BackgroundActivityToken(ProcessThrottler& throttler) 51 : m_throttler(throttler.weakPtr()) 52{ 53 throttler.m_backgroundCount++; 54 throttler.updateAssertion(); 55} 56 57ProcessThrottler::BackgroundActivityToken::~BackgroundActivityToken() 58{ 59 if (ProcessThrottler* throttler = m_throttler.get()) { 60 throttler->m_backgroundCount--; 61 throttler->updateAssertion(); 62 } 63} 64 65ProcessThrottler::ProcessThrottler(WebProcessProxy* process) 66 : m_process(process) 67 , m_weakPtrFactory(this) 68 , m_suspendTimer(RunLoop::main(), this, &ProcessThrottler::suspendTimerFired) 69 , m_foregroundCount(0) 70 , m_backgroundCount(0) 71 , m_suspendMessageCount(0) 72{ 73} 74 75AssertionState ProcessThrottler::assertionState() 76{ 77 ASSERT(!m_suspendTimer.isActive()); 78 79 if (m_foregroundCount) 80 return AssertionState::Foreground; 81 if (m_backgroundCount) 82 return AssertionState::Background; 83 return AssertionState::Suspended; 84} 85 86void ProcessThrottler::updateAssertionNow() 87{ 88 m_suspendTimer.stop(); 89 if (m_assertion) 90 m_assertion->setState(assertionState()); 91} 92 93void ProcessThrottler::updateAssertion() 94{ 95 // If the process is currently runnable but will be suspended then first give it a chance to complete what it was doing 96 // and clean up - move it to the background and send it a message to notify. Schedule a timeout so it can't stay running 97 // in the background for too long. 98 if (m_assertion && m_assertion->state() != AssertionState::Suspended && !m_foregroundCount && !m_backgroundCount) { 99 ++m_suspendMessageCount; 100 m_process->sendProcessWillSuspend(); 101 m_suspendTimer.startOneShot(processSuspensionTimeout); 102 m_assertion->setState(AssertionState::Background); 103 return; 104 } 105 106 // If we're currently waiting for the Web process to do suspension cleanup, but no longer need to be suspended, tell the Web process to cancel the cleanup. 107 if (m_suspendTimer.isActive() && (m_foregroundCount || m_backgroundCount)) 108 m_process->sendCancelProcessWillSuspend(); 109 110 updateAssertionNow(); 111} 112 113void ProcessThrottler::didConnnectToProcess(pid_t pid) 114{ 115 m_suspendTimer.stop(); 116 m_assertion = std::make_unique<ProcessAndUIAssertion>(pid, assertionState()); 117} 118 119void ProcessThrottler::suspendTimerFired() 120{ 121 updateAssertionNow(); 122} 123 124void ProcessThrottler::processReadyToSuspend() 125{ 126 if (!--m_suspendMessageCount) 127 updateAssertionNow(); 128 ASSERT(m_suspendMessageCount >= 0); 129} 130 131void ProcessThrottler::didCancelProcessSuspension() 132{ 133 if (!--m_suspendMessageCount) 134 updateAssertionNow(); 135 ASSERT(m_suspendMessageCount >= 0); 136} 137 138} 139