Medical Imaging Interaction Toolkit  2018.4.99-12ad79a3
Medical Imaging Interaction Toolkit
berry::Job Class Referenceabstract

#include <berryJob.h>

Inheritance diagram for berry::Job:
Collaboration diagram for berry::Job:

Public Member Functions

 berryObjectMacro (Job)
 
 Job (const QString &name)
 
void AddJobChangeListener (IJobChangeListener *listener)
 
bool BelongsTo (Object::Pointer family) override
 
bool Cancel ()
 
void Done (IStatus::Pointer result)
 
QString GetName () const
 
int GetPriority () const
 
IStatus::Pointer GetResult () const
 Object GetProperty(QualifiedName key) const ;. More...
 
ISchedulingRule::Pointer GetRule () const
 
int GetState () const
 
Poco::Thread * GetThread () const
 
bool IsBlocking ()
 
bool IsSystem () const
 
bool IsUser () const
 
void RemoveJobChangeListener (IJobChangeListener *listener)
 void Join() ; More...
 
void Schedule ()
 
void Schedule (Poco::Timestamp::TimeDiff delay)
 
void SetName (const QString &name)
 
void SetPriority (int priority)
 
void SetProgressGroup (IProgressMonitor::Pointer group, int ticks)
 
void SetRule (ISchedulingRule::Pointer rule)
 void SetProperty(QualifiedName key, Object value); More...
 
void SetSystem (bool value)
 
void SetUser (bool value)
 
void SetThread (Poco::Thread *thread)
 
virtual bool ShouldRun ()
 
bool ShouldSchedule () override
 
bool Sleep ()
 
void WakeUp ()
 
void WakeUp (long delay)
 

Static Public Member Functions

static const IJobManagerGetJobManager ()
 

Static Public Attributes

static const IStatus::Pointer ASYNC_FINISH
 
static const int INTERACTIVE
 
static const int SHORT
 
static const int LONG
 
static const int BUILD
 
static const int DECORATE
 
static const int NONE
 
static const int SLEEPING
 
static const int WAITING
 
static const int RUNNING
 

Protected Member Functions

void Canceling () override
 
IStatus::Pointer Run (IProgressMonitor::Pointer myProgressMonitor) override=0
 

Detailed Description

Jobs are units of runnable work that can be scheduled to be run with the job manager. Once a job has completed, it can be scheduled to run again (jobs are reusable).

Jobs have a state that indicates what they are currently doing. When constructed, jobs start with a state value of NONE. When a job is scheduled to be run, it moves into the WAITING state. When a job starts running, it moves into the RUNNING state. When execution finishes (either normally or through cancellation), the state changes back to NONE.

A job can also be in the SLEEPING state. This happens if a user calls Job.sleep() on a waiting job, or if a job is scheduled to run after a specified delay. Only jobs in the WAITING state can be put to sleep. Sleeping jobs can be woken at any time using Job.wakeUp(), which will put the job back into the WAITING state.

Jobs can be assigned a priority that is used as a hint about how the job should be scheduled. There is no guarantee that jobs of one priority will be run before all jobs of lower priority. The documentation of the various priority constants provide more detail about what each priority means. By default, jobs start in the LONG priority class.

See also
IJobManager

Definition at line 60 of file berryJob.h.

Constructor & Destructor Documentation

◆ Job()

berry::Job::Job ( const QString &  name)

Creates a new job with the specified name. The job name is a human-readable value that is displayed to users. The name does not need to be unique, but it must not be null.

Parameters
namethe name of the job.

Definition at line 33 of file berryJob.cpp.

Member Function Documentation

◆ AddJobChangeListener()

void berry::Job::AddJobChangeListener ( IJobChangeListener listener)

Registers a job listener with this job Has no effect if an identical listener is already registered.

Parameters
listenerthe listener to be added.

◆ BelongsTo()

bool berry::Job::BelongsTo ( Object::Pointer  family)
override

Returns whether this job belongs to the given family. Job families are represented as objects that are not interpreted or specified in any way by the job manager. Thus, a job can choose to belong to any number of families.

Clients may override this method. This default implementation always returns false. Overriding implementations must return false for families they do not recognize.

Parameters
familythe job family identifier
Returns
true if this job belongs to the given family, and false otherwise.

Definition at line 44 of file berryJob.cpp.

◆ berryObjectMacro()

berry::Job::berryObjectMacro ( Job  )

◆ Cancel()

bool berry::Job::Cancel ( )

Stops the job. If the job is currently waiting, it will be removed from the queue. If the job is sleeping, it will be discarded without having a chance to resume and its sleeping state will be cleared. If the job is currently executing, it will be asked to stop but there is no guarantee that it will do so.

Returns
false if the job is currently running (and thus may not respond to cancellation), and true in all other cases.

Definition at line 49 of file berryJob.cpp.

◆ Canceling()

void berry::Job::Canceling ( )
overrideprotected

A hook method indicating that this job is running and cancel() is being called for the first time.

Subclasses may override this method to perform additional work when a cancellation request is made. This default implementation does nothing.

Definition at line 201 of file berryJob.cpp.

◆ Done()

void berry::Job::Done ( IStatus::Pointer  result)

Jobs that complete their execution asynchronously must indicate when they are finished by calling this method. This method must not be called by a job that has not indicated that it is executing asynchronously.

This method must not be called from within the scope of a job's run method. Jobs should normally indicate completion by returning an appropriate status from the run method. Jobs that return a status of ASYNC_FINISH from their run method must later call done to indicate completion.

Parameters
resulta status object indicating the result of the job's execution.
See also
ASYNC_FINISH
Run(IProgressMonitor::Pointer)

Definition at line 54 of file berryJob.cpp.

◆ GetJobManager()

const IJobManager * berry::Job::GetJobManager ( )
static

Returns the job manager.

Returns
the job manager

Definition at line 38 of file berryJob.cpp.

◆ GetName()

QString berry::Job::GetName ( ) const

Returns the human readable name of this job. The name is never null.

Returns
the name of this job

Definition at line 59 of file berryJob.cpp.

References GetName().

◆ GetPriority()

int berry::Job::GetPriority ( ) const

Returns the priority of this job. The priority is used as a hint when the job is scheduled to be run.

Returns
the priority of the job. One of INTERACTIVE, SHORT, LONG, BUILD, or DECORATE.

Definition at line 64 of file berryJob.cpp.

◆ GetResult()

IStatus::Pointer berry::Job::GetResult ( ) const

Object GetProperty(QualifiedName key) const ;.

Returns the value of the property of this job identified by the given key, or null if this job has no such property.

Parameters
keythe name of the property
Returns
the value of the property, or null if this job has no such property
See also
#SetProperty(QualifiedName, Object) Returns the result of this job's last run.
Returns
the result of this job's last run, or null if this job has never finished running.

Definition at line 76 of file berryJob.cpp.

◆ GetRule()

ISchedulingRule::Pointer berry::Job::GetRule ( ) const

Returns the scheduling rule for this job. Returns null if this job has no scheduling rule.

Returns
the scheduling rule for this job, or null.
See also
ISchedulingRule
SetRule(ISchedulingRule::Pointer)

Definition at line 81 of file berryJob.cpp.

◆ GetState()

int berry::Job::GetState ( ) const

Returns the state of the job. Result will be one of:

Note that job state is inherently volatile, and in most cases clients cannot rely on the result of this method being valid by the time the result is obtained. For example, if getState returns RUNNING, the job may have actually completed by the time the getState method returns. All clients can infer from invoking this method is that the job was recently in the returned state.

Returns
the job state

Definition at line 86 of file berryJob.cpp.

◆ GetThread()

Poco::Thread * berry::Job::GetThread ( ) const

Returns the thread that this job is currently running in.

Returns
the thread this job is running in, or null if this job is not running or the thread is unknown.

Definition at line 92 of file berryJob.cpp.

◆ IsBlocking()

bool berry::Job::IsBlocking ( )

Returns whether this job is blocking a higher priority non-system job from starting due to a conflicting scheduling rule. Returns false if this job is not running, or is not blocking a higher priority non-system job.

Returns
true if this job is blocking a higher priority non-system job, and false otherwise.
See also
GetRule()
IsSystem()

Definition at line 97 of file berryJob.cpp.

◆ IsSystem()

bool berry::Job::IsSystem ( ) const

Returns whether this job is a system job. System jobs are typically not revealed to users in any UI presentation of jobs. Other than their UI presentation, system jobs act exactly like other jobs. If this value is not explicitly set, jobs are treated as non-system jobs. The default value is false.

Returns
true if this job is a system job, and false otherwise.
See also
SetSystem(bool)

Definition at line 102 of file berryJob.cpp.

◆ IsUser()

bool berry::Job::IsUser ( ) const

Returns whether this job has been directly initiated by a UI end user. These jobs may be presented differently in the UI. The default value is false.

Returns
true if this job is a user-initiated job, and false otherwise.
See also
SetUser(bool)

Definition at line 107 of file berryJob.cpp.

◆ RemoveJobChangeListener()

void berry::Job::RemoveJobChangeListener ( IJobChangeListener listener)

void Join() ;

Waits until this job is finished. This method will block the calling thread until the job has finished executing, or until this thread has been interrupted. If the job has not been scheduled, this method returns immediately. A job must not be joined from within the scope of its run method.

If this method is called on a job that reschedules itself from within the run method, the join will return at the end of the first execution. In other words, join will return the first time this job exits the RUNNING state, or as soon as this job enters the NONE state.

If this method is called while the job manager is suspended, this job will only be joined if it is already running; if this job is waiting or sleeping, this method returns immediately.

Note that there is a deadlock risk when using join. If the calling thread owns a lock or object monitor that the joined thread is waiting for, deadlock will occur.

Exceptions
InterruptedExceptionif this thread is interrupted while waiting
See also
ILock
IJobManager::Suspend() Removes a job listener from this job. Has no effect if an identical listener is not already registered.
Parameters
listenerthe listener to be removed

Definition at line 119 of file berryJob.cpp.

◆ Run()

IStatus::Pointer berry::Job::Run ( IProgressMonitor::Pointer  myProgressMonitor)
overrideprotectedpure virtual

Executes this job. Returns the result of the execution.

The provided monitor can be used to report progress and respond to cancellation. If the progress monitor has been canceled, the job should finish its execution at the earliest convenience and return a result status of severity IStatus#CANCEL. The singleton cancel status Status#CANCEL_STATUS can be used for this purpose. The monitor is only valid for the duration of the invocation of this method.

This method must not be called directly by clients. Clients should call schedule, which will in turn cause this method to be called.

Jobs can optionally finish their execution asynchronously (in another thread) by returning a result status of ASYNC_FINISH. Jobs that finish asynchronously must specify the execution thread by calling setThread, and must indicate when they are finished by calling the method done.

Parameters
monitorthe monitor to be used for reporting progress and responding to cancellation. The monitor is never null
Returns
resulting status of the run. The result must not be null
See also
ASYNC_FINISH
#Done(IStatus)

◆ Schedule() [1/2]

void berry::Job::Schedule ( )

Schedules this job to be run. The job is added to a queue of waiting jobs, and will be run when it arrives at the beginning of the queue.

This is a convenience method, fully equivalent to Schedule(0L).

See also
#Schedule(long)

Definition at line 124 of file berryJob.cpp.

◆ Schedule() [2/2]

void berry::Job::Schedule ( Poco::Timestamp::TimeDiff  delay)

Schedules this job to be run after a specified delay. The job is put in the SLEEPING state until the specified delay has elapsed, after which the job is added to a queue of WAITING jobs. Once the job arrives at the beginning of the queue, it will be run at the first available opportunity.

Jobs of equal priority and delay with conflicting scheduling rules are guaranteed to run in the order they are scheduled. No guarantees are made about the relative execution order of jobs with unrelated or null scheduling rules, or different priorities.

If this job is currently running, it will be rescheduled with the specified delay as soon as it finishes. If this method is called multiple times while the job is running, the job will still only be rescheduled once, with the most recent delay value that was provided.

Scheduling a job that is waiting or sleeping has no effect.

Parameters
delaya time delay in milliseconds before the job should run
See also
ISchedulingRule

Definition at line 130 of file berryJob.cpp.

◆ SetName()

void berry::Job::SetName ( const QString &  name)

Changes the name of this job. If the job is currently running, waiting, or sleeping, the new job name may not take effect until the next time the job is scheduled.

The job name is a human-readable value that is displayed to users. The name does not need to be unique, but it must not be null.

Parameters
namethe name of the job.

Definition at line 135 of file berryJob.cpp.

◆ SetPriority()

void berry::Job::SetPriority ( int  priority)

Sets the priority of the job. This will not affect the execution of a running job, but it will affect how the job is scheduled while it is waiting to be run.

Parameters
prioritythe new job priority. One of INTERACTIVE, SHORT, LONG, BUILD, or DECORATE.

Definition at line 140 of file berryJob.cpp.

◆ SetProgressGroup()

void berry::Job::SetProgressGroup ( IProgressMonitor::Pointer  group,
int  ticks 
)

Associates this job with a progress group. Progress feedback on this job's next execution will be displayed together with other jobs in that group. The provided monitor must be a monitor created by the method IJobManager.createProgressGroup and must have at least ticks units of available work.

The progress group must be set before the job is scheduled. The group will be used only for a single invocation of the job's run method, after which any association of this job to the group will be lost.

See also
IJobManager::createProgressGroup()
Parameters
groupThe progress group to use for this job
ticksthe number of work ticks allocated from the parent monitor, or IProgressMonitor#UNKNOWN

Definition at line 145 of file berryJob.cpp.

◆ SetRule()

void berry::Job::SetRule ( ISchedulingRule::Pointer  rule)

void SetProperty(QualifiedName key, Object value);

Sets the value of the property of this job identified by the given key. If the supplied value is null, the property is removed from this resource.

Properties are intended to be used as a caching mechanism by ISV plug-ins. They allow key-object associations to be stored with a job instance. These key-value associations are maintained in memory (at all times), and the information is never discarded automatically.

The qualifier part of the property name must be the unique identifier of the declaring plug-in (e.g. "com.example.plugin").

Parameters
keythe qualified name of the property
valuethe value of the property, or null if the property is to be removed
See also
#GetProperty(QualifiedName) Sets the scheduling rule to be used when scheduling this job. This method must be called before the job is scheduled.
Parameters
rulethe new scheduling rule, or null if the job should have no scheduling rule
See also
GetRule()

Definition at line 156 of file berryJob.cpp.

◆ SetSystem()

void berry::Job::SetSystem ( bool  value)

Sets whether or not this job is a system job. System jobs are typically not revealed to users in any UI presentation of jobs. Other than their UI presentation, system jobs act exactly like other jobs. If this value is not explicitly set, jobs are treated as non-system jobs. This method must be called before the job is scheduled.

Parameters
valuetrue if this job should be a system job, and false otherwise.
See also
IsSystem()

Definition at line 161 of file berryJob.cpp.

◆ SetThread()

void berry::Job::SetThread ( Poco::Thread *  thread)

Sets the thread that this job is currently running in, or null if this job is not running or the thread is unknown.

Jobs that use the ASYNC_FINISH return code should tell the job what thread it is running in. This is used to prevent deadlocks.

Parameters
threadthe thread that this job is running in.
See also
ASYNC_FINISH
Run(IProgressMonitor::Pointer)

Definition at line 171 of file berryJob.cpp.

◆ SetUser()

void berry::Job::SetUser ( bool  value)

Sets whether or not this job has been directly initiated by a UI end user. These jobs may be presented differently in the UI. This method must be called before the job is scheduled.

Parameters
valuetrue if this job is a user-initiated job, and false otherwise.
See also
IsUser()

Definition at line 166 of file berryJob.cpp.

◆ ShouldRun()

bool berry::Job::ShouldRun ( )
virtual

Returns whether this job should be run. If false is returned, this job will be discarded by the job manager without running.

This method is called immediately prior to calling the job's run method, so it can be used for last minute pre-condition checking before a job is run. This method must not attempt to schedule or change the state of any other job.

Clients may override this method. This default implementation always returns true.

Returns
true if this job should be run and false otherwise

Definition at line 176 of file berryJob.cpp.

◆ ShouldSchedule()

bool berry::Job::ShouldSchedule ( )
override

Returns whether this job should be scheduled. If false is returned, this job will be discarded by the job manager without being added to the queue.

This method is called immediately prior to adding the job to the waiting job queue.,so it can be used for last minute pre-condition checking before a job is scheduled.

Clients may override this method. This default implementation always returns true.

Returns
true if the job manager should schedule this job and false otherwise

Definition at line 181 of file berryJob.cpp.

◆ Sleep()

bool berry::Job::Sleep ( )

Requests that this job be suspended. If the job is currently waiting to be run, it will be removed from the queue move into the SLEEPING state. The job will remain asleep until either resumed or canceled. If this job is not currently waiting to be run, this method has no effect.

Sleeping jobs can be resumed using wakeUp.

Returns
false if the job is currently running (and thus cannot be put to sleep), and true in all other cases
See also
WakeUp()

Definition at line 186 of file berryJob.cpp.

◆ WakeUp() [1/2]

void berry::Job::WakeUp ( )

Puts this job immediately into the WAITING state so that it is eligible for immediate execution. If this job is not currently sleeping, the request is ignored.

This is a convenience method, fully equivalent to wakeUp(0L).

See also
Sleep()

Definition at line 191 of file berryJob.cpp.

◆ WakeUp() [2/2]

void berry::Job::WakeUp ( long  delay)

Puts this job back into the WAITING state after the specified delay. This is equivalent to canceling the sleeping job and rescheduling with the given delay. If this job is not currently sleeping, the request is ignored.

Parameters
delaythe number of milliseconds to delay
See also
Sleep()

Definition at line 196 of file berryJob.cpp.

Member Data Documentation

◆ ASYNC_FINISH

const IStatus::Pointer berry::Job::ASYNC_FINISH
static

Job status return value that is used to indicate asynchronous job completion.

See also
Job::Run(IProgressMonitor::Pointer)
Job::Done(IStatus::Pointer)

Definition at line 72 of file berryJob.h.

◆ BUILD

const int berry::Job::BUILD
static

Job priority constant (value 40) for build jobs. Build jobs are generally run after all other background jobs complete.

See also
GetPriority()
SetPriority(int)
#Run(IProgressMonitor)

Definition at line 113 of file berryJob.h.

◆ DECORATE

const int berry::Job::DECORATE
static

Job priority constant (value 50) for decoration jobs. Decoration jobs have lowest priority. Decoration jobs generally compute extra information that the user may be interested in seeing but is generally not waiting for.

See also
GetPriority()
SetPriority(int)
#Run(IProgressMonitor)

Definition at line 125 of file berryJob.h.

◆ INTERACTIVE

const int berry::Job::INTERACTIVE
static

Job priority constant (value 10) for interactive jobs. Interactive jobs generally have priority over all other jobs. Interactive jobs should be either fast running or very low on CPU usage to avoid blocking other interactive jobs from running.

See also
GetPriority()
SetPriority(int)
Run(IProgressMonitor::Pointer)

Definition at line 85 of file berryJob.h.

◆ LONG

const int berry::Job::LONG
static

Job priority constant (value 30) for long-running background jobs.

See also
GetPriority()
SetPriority(int)
Run(IProgressMonitor::Pointer)

Definition at line 104 of file berryJob.h.

◆ NONE

const int berry::Job::NONE
static

Job state code (value 0) indicating that a job is not currently sleeping, waiting, or running (i.e., the job manager doesn't know anything about the job).

See also
GetState()

Definition at line 133 of file berryJob.h.

◆ RUNNING

const int berry::Job::RUNNING
static

Job state code (value 4) indicating that a job is currently running

See also
GetState()

Definition at line 152 of file berryJob.h.

◆ SHORT

const int berry::Job::SHORT
static

Job priority constant (value 20) for short background jobs. Short background jobs are jobs that typically complete within a second, but may take longer in some cases. Short jobs are given priority over all other jobs except interactive jobs.

See also
GetPriority()
SetPriority(int)
Run(IProgressMonitor::Pointer)

Definition at line 96 of file berryJob.h.

◆ SLEEPING

const int berry::Job::SLEEPING
static

Job state code (value 1) indicating that a job is sleeping.

See also
#Run(IProgressMonitor)
GetState()

Definition at line 140 of file berryJob.h.

◆ WAITING

const int berry::Job::WAITING
static

Job state code (value 2) indicating that a job is waiting to be run.

See also
GetState()

Definition at line 146 of file berryJob.h.


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