dispenso::ConcurrentTaskSet Class Reference

#include <task_set.h>

Inherits TaskSetBase.

Public Member Functions
	ConcurrentTaskSet (ThreadPool &pool, ParentCascadeCancel registerForParentCancel, ssize_t stealingLoadMultiplier=kDefaultStealingMultiplier)
	ConcurrentTaskSet (ThreadPool &p)
	ConcurrentTaskSet (ThreadPool &p, ssize_t stealingLoadMultiplier)
	ConcurrentTaskSet (ConcurrentTaskSet &&other)=delete
ConcurrentTaskSet &	operator= (ConcurrentTaskSet &&other)=delete
template<typename F >
void	schedule (F &&f, bool skipRecheck=false)
template<typename F >
void	schedule (F &&f, ForceQueuingTag fq)
DISPENSO_DLL_ACCESS bool	wait ()
DISPENSO_DLL_ACCESS bool	tryWait (size_t maxToExecute)
void	cancel ()
bool	canceled () const
	~ConcurrentTaskSet ()

Detailed Description

ConcurrentTaskSet fulfills the same API as TaskSet with one minor difference: It may be used to schedule tasks concurrently from multiple threads (see more below). It is an object that allows scheduling multiple function-like objects to a thread pool, and allows to wait on that set of tasks.

ConcurrentTaskSet is "thread-compatible". This means that you can safely use different ConcurrentTaskSet objects on different threads concurrently. ConcurrentTaskSet also allows multiple threads to concurrently schedule against it. It is an error to call wait() concurrently with schedule() on the same ConcurrentTaskSet.

Definition at line 173 of file task_set.h.

Constructor & Destructor Documentation

ConcurrentTaskSet() [1/3]

dispenso::ConcurrentTaskSet::ConcurrentTaskSet ( ThreadPool &  pool, ParentCascadeCancel  registerForParentCancel, ssize_t  stealingLoadMultiplier = kDefaultStealingMultiplier  )

inline

Construct a ConcurrentTaskSet with the given backing pool.

Parameters

pool	The backing pool for this ConcurrentTaskSet
stealingLoadMultiplier	An over-load factor. If this factor of load is reached by the underlying pool, scheduled tasks may run immediately in the calling thread.

Definition at line 182 of file task_set.h.

ConcurrentTaskSet() [2/3]

dispenso::ConcurrentTaskSet::ConcurrentTaskSet ( ThreadPool &  p )

inline

Definition at line 188 of file task_set.h.

ConcurrentTaskSet() [3/3]

dispenso::ConcurrentTaskSet::ConcurrentTaskSet ( ThreadPool &  p, ssize_t  stealingLoadMultiplier  )

inline

Definition at line 190 of file task_set.h.

~ConcurrentTaskSet()

dispenso::ConcurrentTaskSet::~ConcurrentTaskSet ( )

inline

Destroy the ConcurrentTaskSet, first waiting for all currently scheduled functors to finish execution.

Definition at line 284 of file task_set.h.

Member Function Documentation

cancel()

void dispenso::ConcurrentTaskSet::cancel ( )

inline

Set the ConcurrentTaskSet to canceled state. No unexecuted tasks will execute once this is set. Already executing tasks may check canceled() status to exit early.

Note

This will be reset automatically by wait.

Definition at line 267 of file task_set.h.

canceled()

bool dispenso::ConcurrentTaskSet::canceled ( ) const

inline

Check the canceled status of the ConcurrentTaskSet.

Returns

a boolean indicating whether or not the ConcurrentTaskSet has been canceled.

Definition at line 276 of file task_set.h.

schedule() [1/2]

template<typename F >

void dispenso::ConcurrentTaskSet::schedule ( F &&  f, bool  skipRecheck = false  )

inline

Schedule a functor for execution on the underlying pool. If the load on the underlying pool is high, immediate inline execution may occur on the current thread.

Parameters

f	A functor matching signature void(). Best performance will come from passing lambdas, other concrete functors, or OnceFunction, but std::function or similarly type-erased objects will also work.
skipRecheck	A poweruser knob that says that if we don't have enough outstanding tasks to immediately work steal, we should bypass the similar check in the ThreadPool.

Note

If f can throw exceptions, then schedule may throw if the task is run inline. Otherwise, exceptions will be caught on the running thread and best-effort propagated to the ConcurrentTaskSet, where the first one from the set is rethrown in wait.

Definition at line 213 of file task_set.h.

schedule() [2/2]

template<typename F >

void dispenso::ConcurrentTaskSet::schedule ( F &&  f, ForceQueuingTag  fq  )

inline

Schedule a functor for execution on the underlying pool.

Parameters

f	A functor matching signature void(). Best performance will come from passing lambdas, other concrete functors, or OnceFunction, but std::function or similarly type-erased objects will also work.

Note

If f can throw exceptions, then exceptions will be caught on the running thread and best-effort propagated to the ConcurrentTaskSet, where the first one from the set is rethrown in wait.

Definition at line 236 of file task_set.h.

tryWait()

bool dispenso::ConcurrentTaskSet::tryWait

(

size_t

maxToExecute

)

See if the currently scheduled functors can be completed while stealing and executing at most maxToExecute of them from the pool. If not used in conjunction with wait, there may be cases that tryWait must be called multiple times with maxToExecute &gt 0 to prevent livelock/deadlock. If exceptions have been propagated since the last call to wait or tryWait, tryWait will propagate the first of them.

Parameters

maxToExecute

The maximum number of tasks to proactively execute on the current thread.

Returns

true if all currently scheduled functors have been completed prior to returning, and false otherwise (including cancelled cases).

Definition at line 93 of file task_set.cpp.

wait()

bool dispenso::ConcurrentTaskSet::wait

(

)

Wait for all currently scheduled functors to finish execution. If exceptions are thrown during execution of the set of tasks, wait will propagate the first exception.

Definition at line 76 of file task_set.cpp.

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The documentation for this class was generated from the following files:

• /github/workspace/dispenso/task_set.h
• /github/workspace/dispenso/task_set.cpp