Manual

The event loop

The loop beneath the coroutines, for library authors.

Introduction#

Every coroutine runs on one event loop per process. Application code rarely touches it: run(), go() and await() are enough. A library that integrates its own I/O or timers needs more: phasync::getLoop returns the loop, PollerInterface is what waits for streams and sockets, phasync::service starts a background coroutine that does not keep the program alive, and phasync::isRunning and phasync::getFiber tell the library whether it is inside a coroutine and which one.

Concepts#

• Internals – The event loop, the pollers and the scheduler.

Guides#

• Use phasync in a library – Write concurrent library code that runs anywhere PHP runs.

Examples#

• All examples of this topic – 4 with their output.

Reference#

• phasync::service – Starts $fn as a service: a coroutine of no frame, in the root scope, which outlives the code that started it, and returns it.
• phasync::isRunning – Returns true while a phasync::run is in progress, and false otherwise.
• phasync::getLoop – Returns the event loop, for code that waits with its low-level API (getSlot(), park() and unpark() of the returned object), or drives it in place (tick()).
• phasync::getFiber – Returns the running coroutine.
• DeadlockException – Coroutines wait, and nothing can ever wake them: the outermost run() throws this.
• PollerInterface – Waits for streams on behalf of the event loop.