Encapsulates a thread.
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#include <juce_Thread.h>
Encapsulates a thread.
Subclasses derive from Thread and implement the run() method, in which they do their business. The thread can then be started with the startThread() method and controlled with various other methods.
This class also contains some thread-related static methods, such as sleep(), yield(), getCurrentThreadId() etc.
- See also
- CriticalSection, WaitableEvent, Process, ThreadWithProgressWindow, MessageManagerLock
{Core}
◆ ThreadID
◆ anonymous enum
Special realtime audio thread priority.
This priority will create a high-priority thread which is best suited for realtime audio processing.
Currently, this priority is identical to priority 9, except when building for Android with OpenSL/Oboe support.
In this case, JUCE will ask OpenSL/Oboe to construct a super high priority thread specifically for realtime audio processing.
Note that this priority can only be set before the thread has started. Switching to this priority, or from this priority to a different priority, is not supported under Android and will assert.
For best performance this thread should yield at regular intervals and not call any blocking APIs.
- See also
- startThread, setPriority, sleep, WaitableEvent
| Enumerator |
|---|
| realtimeAudioPriority | |
◆ Thread()
| juce::Thread::Thread |
( |
const String & |
threadName, |
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size_t |
threadStackSize = 0 |
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) |
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explicit |
Creates a thread.
When first created, the thread is not running. Use the startThread() method to start it.
- Parameters
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| threadName | The name of the thread which typically appears in debug logs and profiles. |
| threadStackSize | The size of the stack of the thread. If this value is zero then the default stack size of the OS will be used. |
◆ ~Thread()
| virtual juce::Thread::~Thread |
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virtual |
Destructor.
You must never attempt to delete a Thread object while it's still running - always call stopThread() and make sure your thread has stopped before deleting the object. Failing to do so will throw an assertion, and put you firmly into undefined behaviour territory.
◆ addListener()
| void juce::Thread::addListener |
( |
Listener * |
| ) |
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◆ closeThreadHandle()
| void juce::Thread::closeThreadHandle |
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| ) |
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private |
◆ currentThreadShouldExit()
| static bool juce::Thread::currentThreadShouldExit |
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| ) |
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static |
Checks whether the current thread has been told to stop running.
On the message thread, this will always return false, otherwise it will return threadShouldExit() called on the current thread.
- See also
- threadShouldExit
◆ getCurrentThread()
| static Thread* juce::Thread::getCurrentThread |
( |
| ) |
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static |
Finds the thread object that is currently running.
Note that the main UI thread (or other non-JUCE threads) don't have a Thread object associated with them, so this will return nullptr.
◆ getCurrentThreadId()
◆ getThreadId()
| ThreadID juce::Thread::getThreadId |
( |
| ) |
const |
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noexcept |
Returns the ID of this thread.
That means the ID of this thread object - not of the thread that's calling the method. This can change when the thread is started and stopped, and will be invalid if the thread's not actually running.
- See also
- getCurrentThreadId
◆ getThreadName()
| const String& juce::Thread::getThreadName |
( |
| ) |
const |
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inlinenoexcept |
Returns the name of the thread.
This is the name that gets set in the constructor.
References JUCE_CALLTYPE.
◆ initialiseJUCE()
| static void juce::Thread::initialiseJUCE |
( |
void * |
jniEnv, |
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void * |
jContext |
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) |
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static |
Initialises the JUCE subsystem for projects not created by the Projucer.
On Android, JUCE needs to be initialised once before it is used. The Projucer will automatically generate the necessary java code to do this. However, if you are using JUCE without the Projucer or are creating a library made with JUCE intended for use in non-JUCE apks, then you must call this method manually once on apk startup.
You can call this method from C++ or directly from java by calling the following java method:
com.roli.juce.Java.initialiseJUCE (myContext);
Note that the above java method is only available in Android Studio projects created by the Projucer. If you need to call this from another type of project then you need to add the following java file to your project:
package com.roli.juce;
public class Java
{
static { System.loadLibrary ("juce_jni"); }
}
- Parameters
-
| jniEnv | this is a pointer to JNI's JNIEnv variable. Any callback from Java into C++ will have this passed in as it's first parameter. |
| jContext | this is a jobject referring to your app/service/receiver/ provider's Context. JUCE needs this for many of it's internal functions. |
◆ isThreadRunning()
| bool juce::Thread::isThreadRunning |
( |
| ) |
const |
Returns true if the thread is currently active.
◆ killThread()
| void juce::Thread::killThread |
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| ) |
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private |
◆ launch()
| static void juce::Thread::launch |
( |
std::function< void()> |
functionToRun | ) |
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static |
Invokes a lambda or function on its own thread.
This will spin up a Thread object which calls the function and then exits. Bear in mind that starting and stopping a thread can be a fairly heavyweight operation, so you might prefer to use a ThreadPool if you're kicking off a lot of short background tasks.
Also note that using an anonymous thread makes it very difficult to interrupt the function when you need to stop it, e.g. when your app quits. So it's up to you to deal with situations where the function may fail to stop in time.
◆ launchThread()
| void juce::Thread::launchThread |
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private |
◆ notify()
| void juce::Thread::notify |
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const |
Wakes up the thread.
If the thread has called the wait() method, this will wake it up.
- See also
- wait
◆ removeListener()
| void juce::Thread::removeListener |
( |
Listener * |
| ) |
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Removes a listener added with addListener.
◆ run()
| virtual void juce::Thread::run |
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| ) |
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pure virtual |
◆ setAffinityMask()
| void juce::Thread::setAffinityMask |
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uint32 |
affinityMask | ) |
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Sets the affinity mask for the thread.
This will only have an effect next time the thread is started - i.e. if the thread is already running when called, it'll have no effect.
- See also
- setCurrentThreadAffinityMask
◆ setCurrentThreadAffinityMask()
| void juce::Thread::setCurrentThreadAffinityMask |
( |
uint32 |
affinityMask | ) |
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static |
◆ setCurrentThreadName()
| void juce::Thread::setCurrentThreadName |
( |
const String & |
newThreadName | ) |
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static |
◆ setCurrentThreadPriority()
| static bool juce::Thread::setCurrentThreadPriority |
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int |
priority | ) |
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static |
Changes the priority of the caller thread.
Similar to setPriority(), but this static method acts on the caller thread. May return false if for some reason the priority can't be changed.
- See also
- setPriority
◆ setPriority()
| bool juce::Thread::setPriority |
( |
int |
priority | ) |
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Changes the thread's priority.
May return false if for some reason the priority can't be changed.
- Parameters
-
| priority | the new priority, in the range 0 (lowest) to 10 (highest). A priority of 5 is normal. |
- See also
- realtimeAudioPriority
◆ setThreadPriority()
| bool juce::Thread::setThreadPriority |
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void * |
handle, |
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int |
priority |
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) |
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staticprivate |
◆ signalThreadShouldExit()
| void juce::Thread::signalThreadShouldExit |
( |
| ) |
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Sets a flag to tell the thread it should stop.
Calling this means that the threadShouldExit() method will then return true. The thread should be regularly checking this to see whether it should exit.
If your thread makes use of wait(), you might want to call notify() after calling this method, to interrupt any waits that might be in progress, and allow it to reach a point where it can exit.
- See also
- threadShouldExit, waitForThreadToExit
◆ sleep()
| void juce::Thread::sleep |
( |
int |
milliseconds | ) |
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static |
◆ startThread() [1/2]
| void juce::Thread::startThread |
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| ) |
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Starts the thread running.
This will cause the thread's run() method to be called by a new thread. If this thread is already running, startThread() won't do anything.
- See also
- stopThread
◆ startThread() [2/2]
| void juce::Thread::startThread |
( |
int |
priority | ) |
|
Starts the thread with a given priority.
Launches the thread with a given priority, where 0 = lowest, 10 = highest. If the thread is already running, its priority will be changed.
- See also
- startThread, setPriority, realtimeAudioPriority
◆ stopThread()
| bool juce::Thread::stopThread |
( |
int |
timeOutMilliseconds | ) |
|
Attempts to stop the thread running.
This method will cause the threadShouldExit() method to return true and call notify() in case the thread is currently waiting.
Hopefully the thread will then respond to this by exiting cleanly, and the stopThread method will wait for a given time-period for this to happen.
If the thread is stuck and fails to respond after the timeout, it gets forcibly killed, which is a very bad thing to happen, as it could still be holding locks, etc. which are needed by other parts of your program.
- Parameters
-
| timeOutMilliseconds | The number of milliseconds to wait for the thread to finish before killing it by force. A negative value in here will wait forever. |
- Returns
- true if the thread was cleanly stopped before the timeout, or false if it had to be killed by force.
- See also
- signalThreadShouldExit, threadShouldExit, waitForThreadToExit, isThreadRunning
◆ threadEntryPoint()
| void juce::Thread::threadEntryPoint |
( |
| ) |
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private |
◆ threadShouldExit()
| bool juce::Thread::threadShouldExit |
( |
| ) |
const |
Checks whether the thread has been told to stop running.
Threads need to check this regularly, and if it returns true, they should return from their run() method at the first possible opportunity.
- See also
- signalThreadShouldExit, currentThreadShouldExit
◆ wait()
| bool juce::Thread::wait |
( |
int |
timeOutMilliseconds | ) |
const |
Suspends the execution of this thread until either the specified timeout period has elapsed, or another thread calls the notify() method to wake it up.
A negative timeout value means that the method will wait indefinitely.
- Returns
- true if the event has been signalled, false if the timeout expires.
◆ waitForThreadToExit()
| bool juce::Thread::waitForThreadToExit |
( |
int |
timeOutMilliseconds | ) |
const |
Waits for the thread to stop.
This will wait until isThreadRunning() is false or until a timeout expires.
- Parameters
-
| timeOutMilliseconds | the time to wait, in milliseconds. If this value is less than zero, it will wait forever. |
- Returns
- true if the thread exits, or false if the timeout expires first.
◆ yield()
| void juce::Thread::yield |
( |
| ) |
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static |
Yields the current thread's CPU time-slot and allows a new thread to run.
If there are no other threads of equal or higher priority currently running then this will return immediately and the current thread will continue to run.
◆ affinityMask
| uint32 juce::Thread::affinityMask = 0 |
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private |
◆ defaultEvent
◆ deleteOnThreadEnd
| bool juce::Thread::deleteOnThreadEnd = false |
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private |
◆ isAndroidRealtimeThread
| bool juce::Thread::isAndroidRealtimeThread = false |
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private |
◆ listeners
◆ shouldExit
◆ startStopLock
◆ startSuspensionEvent
◆ threadHandle
| Atomic<void*> juce::Thread::threadHandle { nullptr } |
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private |
◆ threadId
◆ threadName
| const String juce::Thread::threadName |
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private |
◆ threadPriority
| int juce::Thread::threadPriority = 5 |
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private |
◆ threadStackSize
| size_t juce::Thread::threadStackSize |
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private |
The documentation for this class was generated from the following files:
1.8.13