/*
- * Copyright 2016 Facebook, Inc.
+ * Copyright 2017 Facebook, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
#include <folly/io/async/HHWheelTimer.h>
#include <folly/io/async/Request.h>
#include <folly/io/async/TimeoutManager.h>
-#include <folly/portability/PThread.h>
#include <glog/logging.h>
#include <event.h> // libevent
public DrivableExecutor {
public:
using Func = folly::Function<void()>;
+ using FuncRef = folly::FunctionRef<void()>;
/**
* A callback interface to use with runInLoop()
std::shared_ptr<RequestContext> context_;
};
+ class FunctionLoopCallback : public LoopCallback {
+ public:
+ explicit FunctionLoopCallback(Func&& function)
+ : function_(std::move(function)) {}
+
+ void runLoopCallback() noexcept override {
+ function_();
+ delete this;
+ }
+
+ private:
+ Func function_;
+ };
+
+ // Like FunctionLoopCallback, but saves one allocation. Use with caution.
+ //
+ // The caller is responsible for maintaining the lifetime of this callback
+ // until after the point at which the contained function is called.
+ class StackFunctionLoopCallback : public LoopCallback {
+ public:
+ explicit StackFunctionLoopCallback(Func&& function)
+ : function_(std::move(function)) {}
+ void runLoopCallback() noexcept override {
+ Func(std::move(function_))();
+ }
+
+ private:
+ Func function_;
+ };
+
/**
* Create a new EventBase object.
*
* Like runInEventBaseThread, but the caller waits for the callback to be
* executed.
*/
- bool runInEventBaseThreadAndWait(Func fn);
+ bool runInEventBaseThreadAndWait(FuncRef fn);
/*
* Like runInEventBaseThreadAndWait, except if the caller is already in the
* Like runInEventBaseThreadAndWait, except if the caller is already in the
* event base thread, the functor is simply run inline.
*/
- bool runImmediatelyOrRunInEventBaseThreadAndWait(Func fn);
+ bool runImmediatelyOrRunInEventBaseThreadAndWait(FuncRef fn);
/**
* Set the maximum desired latency in us and provide a callback which will be
* called when that latency is exceeded.
* OBS: This functionality depends on time-measurement.
*/
- void setMaxLatency(int64_t maxLatency, Func maxLatencyCob) {
+ void setMaxLatency(std::chrono::microseconds maxLatency, Func maxLatencyCob) {
assert(enableTimeMeasurement_);
maxLatency_ = maxLatency;
maxLatencyCob_ = std::move(maxLatencyCob);
* Set smoothing coefficient for loop load average; # of milliseconds
* for exp(-1) (1/2.71828...) decay.
*/
- void setLoadAvgMsec(uint32_t ms);
+ void setLoadAvgMsec(std::chrono::milliseconds ms);
/**
* reset the load average to a desired value
* check if the event base loop is running.
*/
bool isRunning() const {
- return loopThread_.load(std::memory_order_relaxed) != 0;
+ return loopThread_.load(std::memory_order_relaxed) != std::thread::id();
}
/**
*/
void waitUntilRunning();
- int getNotificationQueueSize() const;
+ size_t getNotificationQueueSize() const;
void setMaxReadAtOnce(uint32_t maxAtOnce);
*/
bool isInEventBaseThread() const {
auto tid = loopThread_.load(std::memory_order_relaxed);
- return tid == 0 || pthread_equal(tid, pthread_self());
+ return tid == std::thread::id() || tid == std::this_thread::get_id();
}
bool inRunningEventBaseThread() const {
- return pthread_equal(
- loopThread_.load(std::memory_order_relaxed), pthread_self());
+ return loopThread_.load(std::memory_order_relaxed) ==
+ std::this_thread::get_id();
}
HHWheelTimer& timer() {
class SmoothLoopTime {
public:
- explicit SmoothLoopTime(uint64_t timeInterval)
- : expCoeff_(-1.0/timeInterval)
- , value_(0.0)
- , oldBusyLeftover_(0) {
+ explicit SmoothLoopTime(std::chrono::microseconds timeInterval)
+ : expCoeff_(-1.0 / timeInterval.count()),
+ value_(0.0),
+ oldBusyLeftover_(0) {
VLOG(11) << "expCoeff_ " << expCoeff_ << " " << __PRETTY_FUNCTION__;
}
- void setTimeInterval(uint64_t timeInterval);
+ void setTimeInterval(std::chrono::microseconds timeInterval);
void reset(double value = 0.0);
- void addSample(int64_t idle, int64_t busy);
+ void addSample(
+ std::chrono::microseconds idle,
+ std::chrono::microseconds busy);
double get() const {
return value_;
}
private:
- double expCoeff_;
- double value_;
- int64_t oldBusyLeftover_;
+ double expCoeff_;
+ double value_;
+ std::chrono::microseconds oldBusyLeftover_;
};
void setObserver(const std::shared_ptr<EventBaseObserver>& observer) {
loopOnce();
}
- struct LoopKeepAliveDeleter {
- void operator()(EventBase* evb) {
- DCHECK(evb->isInEventBaseThread());
- evb->loopKeepAliveCount_--;
- }
- };
- using LoopKeepAlive = std::unique_ptr<EventBase, LoopKeepAliveDeleter>;
-
/// Returns you a handle which make loop() behave like loopForever() until
/// destroyed. loop() will return to its original behavior only when all
/// loop keep-alives are released. Loop holder is safe to release only from
/// EventBase thread.
- ///
- /// May return no op LoopKeepAlive if loopForever() is already running.
- LoopKeepAlive loopKeepAlive() {
- DCHECK(isInEventBaseThread());
- loopKeepAliveCount_++;
- return LoopKeepAlive(this);
- }
-
- // Thread-safe version of loopKeepAlive()
- LoopKeepAlive loopKeepAliveAtomic() {
+ KeepAlive getKeepAliveToken() override {
if (inRunningEventBaseThread()) {
- return loopKeepAlive();
+ loopKeepAliveCount_++;
+ } else {
+ loopKeepAliveCountAtomic_.fetch_add(1, std::memory_order_relaxed);
}
- loopKeepAliveCountAtomic_.fetch_add(1, std::memory_order_relaxed);
- return LoopKeepAlive(this);
+ return makeKeepAlive();
}
// TimeoutManager
return isInEventBaseThread();
}
+ protected:
+ void keepAliveRelease() override {
+ DCHECK(isInEventBaseThread());
+ loopKeepAliveCount_--;
+ }
+
private:
void applyLoopKeepAlive();
std::atomic<bool> stop_;
// The ID of the thread running the main loop.
- // 0 if loop is not running.
- // Note: POSIX doesn't guarantee that 0 is an invalid pthread_t (or
- // even that atomic<pthread_t> is valid), but that's how it is
- // everywhere (at least on Linux, FreeBSD, and OSX).
- std::atomic<pthread_t> loopThread_;
+ // std::thread::id{} if loop is not running.
+ std::atomic<std::thread::id> loopThread_;
// pointer to underlying event_base class doing the heavy lifting
event_base* evb_;
bool loopKeepAliveActive_{false};
// limit for latency in microseconds (0 disables)
- int64_t maxLatency_;
+ std::chrono::microseconds maxLatency_;
// exponentially-smoothed average loop time for latency-limiting
SmoothLoopTime avgLoopTime_;
// be supported: avg loop time, observer and max latency.
const bool enableTimeMeasurement_;
- // we'll wait this long before running deferred callbacks if the event
- // loop is idle.
- static const int kDEFAULT_IDLE_WAIT_USEC = 20000; // 20ms
-
// Wrap-around loop counter to detect beginning of each loop
uint64_t nextLoopCnt_;
uint64_t latestLoopCnt_;
- uint64_t startWork_;
+ std::chrono::steady_clock::time_point startWork_;
// Prevent undefined behavior from invoking event_base_loop() reentrantly.
// This is needed since many projects use libevent-1.4, which lacks commit
// b557b175c00dc462c1fce25f6e7dd67121d2c001 from
projects / folly.git / blobdiff