ProcessThrottler.cpp [plain text]
#include "config.h"
#include "ProcessThrottler.h"
#include "Logging.h"
#include "ProcessThrottlerClient.h"
namespace WebKit {
static const unsigned processSuspensionTimeout = 30;
ProcessThrottler::ProcessThrottler(ProcessThrottlerClient& process)
: m_process(process)
, m_suspendTimer(RunLoop::main(), this, &ProcessThrottler::suspendTimerFired)
, m_foregroundCounter([this](RefCounterEvent) { updateAssertion(); })
, m_backgroundCounter([this](RefCounterEvent) { updateAssertion(); })
, m_suspendMessageCount(0)
{
}
AssertionState ProcessThrottler::assertionState()
{
ASSERT(!m_suspendTimer.isActive());
if (m_foregroundCounter.value())
return AssertionState::Foreground;
if (m_backgroundCounter.value())
return AssertionState::Background;
return AssertionState::Suspended;
}
void ProcessThrottler::updateAssertionNow()
{
m_suspendTimer.stop();
if (m_assertion) {
if (m_assertion->state() != assertionState())
RELEASE_LOG(ProcessSuspension, "%p - ProcessThrottler::updateAssertionNow() updating process assertion state to %u (foregroundActivities: %lu, backgroundActivities: %lu)", this, assertionState(), m_foregroundCounter.value(), m_backgroundCounter.value());
m_assertion->setState(assertionState());
m_process.didSetAssertionState(assertionState());
}
}
void ProcessThrottler::updateAssertion()
{
if (m_assertion && m_assertion->state() != AssertionState::Suspended && !m_foregroundCounter.value() && !m_backgroundCounter.value()) {
++m_suspendMessageCount;
RELEASE_LOG(ProcessSuspension, "%p - ProcessThrottler::updateAssertion() sending PrepareToSuspend IPC", this);
m_process.sendPrepareToSuspend();
m_suspendTimer.startOneShot(processSuspensionTimeout);
m_assertion->setState(AssertionState::Background);
m_process.didSetAssertionState(AssertionState::Background);
return;
}
bool shouldBeRunnable = m_foregroundCounter.value() || m_backgroundCounter.value();
if (m_suspendTimer.isActive() && shouldBeRunnable)
m_process.sendCancelPrepareToSuspend();
if (m_assertion && m_assertion->state() == AssertionState::Suspended && shouldBeRunnable)
m_process.sendProcessDidResume();
updateAssertionNow();
}
void ProcessThrottler::didConnectToProcess(pid_t pid)
{
m_suspendTimer.stop();
m_assertion = std::make_unique<ProcessAndUIAssertion>(pid, assertionState());
m_process.didSetAssertionState(assertionState());
m_assertion->setClient(*this);
}
void ProcessThrottler::suspendTimerFired()
{
updateAssertionNow();
}
void ProcessThrottler::processReadyToSuspend()
{
if (!--m_suspendMessageCount)
updateAssertionNow();
ASSERT(m_suspendMessageCount >= 0);
}
void ProcessThrottler::didCancelProcessSuspension()
{
if (!--m_suspendMessageCount)
updateAssertionNow();
ASSERT(m_suspendMessageCount >= 0);
}
void ProcessThrottler::assertionWillExpireImminently()
{
m_process.sendProcessWillSuspendImminently();
}
}