ThreadWeaver 5.109.0
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Queue implements a ThreadWeaver job queue. More...
#include <queue.h>
Classes | |
struct | GlobalQueueFactory |
Interface for the global queue factory. More... | |
Public Member Functions | |
Queue (QObject *parent=nullptr) | |
Queue (QueueSignals *implementation, QObject *parent=nullptr) | |
Construct a queue with a customized implementation The queue takes ownership and will delete the implementation upon destruction. | |
int | currentNumberOfThreads () const override |
Returns the current number of threads in the inventory. | |
void | dequeue () override |
Remove all queued jobs. | |
bool | dequeue (const JobPointer &) override |
Remove a job from the queue. | |
void | enqueue (const JobPointer &job) |
void | enqueue (const QVector< JobPointer > &jobs) override |
Queue a vector of jobs. | |
void | finish () override |
Finish all queued operations, then return. | |
bool | isEmpty () const override |
Is the queue empty? The queue is empty if no more jobs are queued. | |
bool | isIdle () const override |
Is the weaver idle? The weaver is idle if no jobs are queued and no jobs are processed by the threads. | |
int | maximumNumberOfThreads () const override |
Get the maximum number of threads this Weaver may start. | |
int | queueLength () const override |
Returns the number of pending jobs. | |
void | requestAbort () override |
Request aborts of the currently executed jobs. | |
void | reschedule () override |
Reschedule the jobs in the queue. | |
void | resume () override |
Resume job queueing. | |
void | setMaximumNumberOfThreads (int cap) override |
Set the maximum number of threads this Weaver object may start. | |
void | shutDown () override |
Shut down the queue. | |
const State * | state () const override |
Return the state of the weaver object. | |
QueueStream | stream () |
void | suspend () override |
Suspend job execution. | |
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QueueSignals (QObject *parent=nullptr) | |
QueueSignals (ThreadWeaver::Private::QueueSignals_Private *d, QObject *parent=nullptr) | |
virtual int | currentNumberOfThreads () const =0 |
Returns the current number of threads in the inventory. | |
virtual void | dequeue ()=0 |
Remove all queued jobs. | |
virtual bool | dequeue (const JobPointer &job)=0 |
Remove a job from the queue. | |
virtual void | enqueue (const QVector< JobPointer > &jobs)=0 |
Queue a vector of jobs. | |
virtual void | finish ()=0 |
Finish all queued operations, then return. | |
virtual bool | isEmpty () const =0 |
Is the queue empty? The queue is empty if no more jobs are queued. | |
virtual bool | isIdle () const =0 |
Is the weaver idle? The weaver is idle if no jobs are queued and no jobs are processed by the threads. | |
virtual int | maximumNumberOfThreads () const =0 |
Get the maximum number of threads this Weaver may start. | |
virtual int | queueLength () const =0 |
Returns the number of pending jobs. | |
virtual void | requestAbort ()=0 |
Request aborts of the currently executed jobs. | |
virtual void | reschedule ()=0 |
Reschedule the jobs in the queue. | |
virtual void | resume ()=0 |
Resume job queueing. | |
virtual void | setMaximumNumberOfThreads (int cap)=0 |
Set the maximum number of threads this Weaver object may start. | |
virtual void | shutDown ()=0 |
Shut down the queue. | |
virtual const State * | state () const =0 |
Return the state of the weaver object. | |
virtual void | suspend ()=0 |
Suspend job execution. | |
Static Public Member Functions | |
static ThreadWeaver::Queue * | instance () |
static void | setGlobalQueueFactory (GlobalQueueFactory *factory) |
Additional Inherited Members | |
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void | finished () |
Emitted when the Queue has completed all jobs currently queued. | |
void | stateChanged (ThreadWeaver::State *) |
Emitted when the processing state of the Queue has changed. | |
void | suspended () |
The Queue has been suspended. | |
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ThreadWeaver::Private::QueueSignals_Private * | d () |
const ThreadWeaver::Private::QueueSignals_Private * | d () const |
Queue implements a ThreadWeaver job queue.
Queues process jobs enqueued in them by automatically assigning them to worker threads they manage. Applications using ThreadWeaver can make use of a global Queue which is instantiated on demand, or create multiple queues as needed. A job assigned to a queue will be processed by that specific queue.
Worker threads are created by the queues as needed. To create a customized global queue, see GlobalQueueFactory.
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explicit |
Construct a queue with a customized implementation The queue takes ownership and will delete the implementation upon destruction.
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overridevirtual |
Returns the current number of threads in the inventory.
Implements ThreadWeaver::QueueInterface.
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overridevirtual |
Remove all queued jobs.
All waiting jobs will be dequeued. The semantics are the same as for dequeue(JobInterface).
Implements ThreadWeaver::QueueInterface.
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overridevirtual |
Remove a job from the queue.
If the job was queued but not started so far, it is removed from the queue.
You can always call dequeue, it will return true if the job was dequeued. However if the job is not in the queue anymore, it is already being executed, it is too late to dequeue, and dequeue will return false. The return value is thread-safe - if true is returned, the job was still waiting, and has been dequeued. If not, the job was not waiting in the queue.
Modifying queued jobs is best done on a suspended queue. Often, for example at the end of an application, it is sufficient to dequeue all jobs (which leaves only the ones mid-air in threads), call finish (that will wait for all the mid air jobs to complete), and then exit. Without dequeue(), all jobs in the queue would be executed during finish().
Implements ThreadWeaver::QueueInterface.
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overridevirtual |
Queue a vector of jobs.
It depends on the state if execution of the job will be attempted immediately. In suspended state, jobs can be added to the queue, but the threads remain suspended. In WorkongHard state, an idle thread may immediately execute the job, or it might be queued if all threads are busy.
JobPointer is a shared pointer. This means the object pointed to will be deleted if this object is the last remaining reference to it. Keep a JobPointer to the job to avoid automatic deletion.
Implements ThreadWeaver::QueueInterface.
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overridevirtual |
Finish all queued operations, then return.
This method is used in imperative (not event driven) programs that cannot react on events to have the controlling (main) thread wait wait for the jobs to finish. The call will block the calling thread and return when all queued jobs have been processed.
Warning: This will suspend your thread! Warning: If one of your jobs enters an infinite loop, this will never return!
Implements ThreadWeaver::QueueInterface.
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overridevirtual |
Is the queue empty? The queue is empty if no more jobs are queued.
Implements ThreadWeaver::QueueInterface.
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overridevirtual |
Is the weaver idle? The weaver is idle if no jobs are queued and no jobs are processed by the threads.
Implements ThreadWeaver::QueueInterface.
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overridevirtual |
Get the maximum number of threads this Weaver may start.
Implements ThreadWeaver::QueueInterface.
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overridevirtual |
Returns the number of pending jobs.
This will return the number of queued jobs. Jobs that are currently being executed are not part of the queue. All jobs in the queue are waiting to be executed.
Implements ThreadWeaver::QueueInterface.
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overridevirtual |
Request aborts of the currently executed jobs.
It is important to understand that aborts are requested, but cannot be guaranteed, as not all Job classes support it. It is up to the application to decide if and how job aborts are necessary.
Implements ThreadWeaver::QueueInterface.
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overridevirtual |
Reschedule the jobs in the queue.
This method triggers a scheduling attempt to perform jobs. It will schedule enqueued jobs to be executed by idle threads. It should only be necessary to call it if the canRun() status of a job changed spontaneously due to external reasons.
Implements ThreadWeaver::QueueInterface.
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overridevirtual |
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overridevirtual |
Set the maximum number of threads this Weaver object may start.
Implements ThreadWeaver::QueueInterface.
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overridevirtual |
Shut down the queue.
Tells all threads to exit, and changes to Destructed state. It is safe to destroy the queue once this method returns.
Implements ThreadWeaver::QueueInterface.
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overridevirtual |
Return the state of the weaver object.
Implements ThreadWeaver::QueueInterface.
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overridevirtual |
Suspend job execution.
When suspending, all threads are allowed to finish the currently assigned job but will not receive a new assignment. When all threads are done processing the assigned job, the signal suspended will() be emitted. If you call suspend() and there are no jobs left to be done, you will immediately receive the suspended() signal.
Implements ThreadWeaver::QueueInterface.