mcell/libs/cpptime

C++ Timeouts

A portable, header-only C++11 timer component.

It manages a set of timeouts that, when expired, invoke a callback. It uses features of C++11 in order to avoid platform specific code.

It supports one-shot and periodic timeouts.

Documentation

Please see the documentation in cpptime.h for more detailed information about the implementation.

Implementation Status

This is a new component and not much testing has been done. We already use it in some of our products but expect that it receives some updates over time.

Possible Features

While the current implementation serves us well, there are some features that might potentially be interesting for other use cases. Contact us in case you are interested.

• Ability to have multiple timer components running.
• Distribute it as a header only library.
• Optionally avoid locking.
• API to use client thread instead of creating its own.
• API to use client mutex instead of its own.

Use Cases and Limitations

Naturally the implementation makes some trade-offs. This makes it useful for some cases, and less so for others.

• The timer runs completely in user space. This makes it slightly less efficient than other solutions, such as timer_create() or timerfd_create(). However, in many cases, this overhead is acceptable.

• Given a C++11 capable compiler, the code is portable.

• The API to add or remove a timeout is arguably nicer than the platform specific alternatives. E.g.

timer.add(seconds(2), [](CppTime::timer_id) { ... });

• The implementation is small and easy to understand. It is not difficult to change to make it better suitable for specific cases.

Examples

A one shot timer.

using namespace std::chrono;
CppTime::Timer t;
t.add(seconds(2), [](CppTime::timer_id) { std::cout << "yes\n"; });
std::this_thread::sleep_for(seconds(3));

A periodic timer that is first executed after 2 seconds, and after this every second. The event is removed after 10 seconds.

using namespace std::chrono;
CppTime::Timer t;
auto id = t.add(seconds(2), [](CppTime::timer_id) { std::cout << "yes\n"; }, seconds(1));
std::this_thread::sleep_for(seconds(10));
t.remove(id);

See the tests for more examples.

Usage

To use the timer component, Simply copy cpptime.h into you project. Everything is contained in this single header file.

Tests can be compiled and executed with the following commands, assuming you are on a POSIX machine.

cd tests
g++ -g -std=c++11 -Wall -Wextra -o run_tests timer_test.cpp -l pthread
./run_tests

Contributions

Contributions, suggestions, and feature requests are welcome. Please use the Github issue tracker.