folly::ManualExecutor

Synopsis

Declared in <folly/executors/ManualExecutor.h>

class ManualExecutor
    : public DrivableExecutor
    , public ScheduledExecutor
    , public SequencedExecutor

Description

The clock for a manual executor starts at 0 and advances only when you ask it to. i.e. time is also under manual control.

NB No attempt has been made to make anything other than add and schedule threadsafe.

Base Classes

Name	Description
`DrivableExecutor`	An executor that can be driven forward via its `drive()` method.
`ScheduledExecutor`	An executor that supports timed scheduling. Like RxScheduler.
`SequencedExecutor`	An executor that sequences tasks whose submissions were sequenced.

Type Aliases

Name	Description
`Duration`	The duration type used for scheduling.
`KeepAlive`	Alias for ExecutorKeepAlive, a safe pointer to an Executor.
`TimePoint`	The time point type used for scheduling.

Member Functions

Name	Description
`~ManualExecutor` [destructor] [virtual]	Destroy the executor.
`add`	`add` overloads
`addWithPriority` [virtual]	Enqueue a function with a given priority, where 0 is the medium priority This is up to the implementation to enforce
`advance`	Advance the clock. The clock never advances on its own. Advancing the clock causes some work to be done, if work is available to do (perhaps newly available because of the advanced clock). If dur is <= 0 this is a noop.
`advanceTo`	Advance the clock to this absolute time. If t is <= now(), this is a noop.
`clear`	Flush the function queue. Destroys all stored functions without executing them. Returns number of removed functions.
`drain`	Do work until there is no more work to do. Returns the number of functions that were executed (maybe 0). Unlike run, this method is not stable. It will chase an infinite tail of work so should be used with care. There will be no work available to perform at the moment that this returns.
`drive` [virtual]	Implements DrivableExecutor
`getNumPriorities` [virtual]	Returns the number of priority levels this executor supports.
`keepAliveAcquire` [virtual]	Acquire a keep-alive reference to this executor.
`keepAliveRelease` [virtual]	Release a keep-alive reference to this executor.
`makeProgress`	Wait for work to do, and do it.
`now` [virtual]	Return the current time of the manual clock.
`run`	Do work. Returns the number of functions that were executed (maybe 0). Non-blocking, in the sense that we don't wait for work (we can't control whether one of the functions blocks). This is stable, it will not chase an ever-increasing tail of work. This also means, there may be more work available to perform at the moment that this returns.
`schedule`	`schedule` overloads
`scheduleAt`	`scheduleAt` overloads
`step`	Execute only the function at the front of the queue (maybe 0) and remove it from the queue. Non blocking where it does not wait for work if none exists Returns 1 if a function was executed and 0 otherwise
`wait`	Wait for work to do.
`waitFor`	makeProgress until this Future is ready.

Static Member Functions

Name	Description
`getKeepAliveToken`	`getKeepAliveToken` overloads
`invokeCatchingExns`	Invokes `f`, logging and swallowing any exception it throws.

Static Data Members

Name	Description
`HI_PRI`	Highest schedulable priority.
`LO_PRI`	Lowest schedulable priority.
`MID_PRI`	Medium (default) schedulable priority.

Protected Member Functions

Name	Description
`keepAliveAcquire` [virtual]	Acquire a keep alive token. Should return false if keep-alive mechanism is not supported.
`keepAliveRelease` [virtual]	Release a keep alive token previously acquired by keepAliveAcquire(). Will never be called if keepAliveAcquire() returns false.

Protected Static Member Functions

Name	Description
`isKeepAliveDummy`	Returns true if the KeepAlive is constructed from an executor that does not support the keep alive ref-counting functionality
`keepAliveAcquire`	Acquires a keep-alive reference on `executor`.
`keepAliveRelease`	Releases a keep-alive reference on `executor`.
`makeKeepAlive`	Makes a counted (non-dummy, non-alias) keep-alive referring to `executor`.

Non-Member Functions

Name	Description
`async_tracing::logFutureVia`	Trace hook invoked when a Future is rescheduled onto an executor.
`async_tracing::logGetGlobalCPUExecutor`	Trace hook invoked when the global CPU executor is retrieved.
`async_tracing::logGetImmutableCPUExecutor`	Trace hook invoked when the immutable CPU executor is retrieved.
`async_tracing::logSemiFutureVia`	Trace hook invoked when a SemiFuture is rescheduled onto an executor.
`async_tracing::logSetGlobalCPUExecutor`	Trace hook invoked when the global CPU executor is set.