PTLib
Version 2.10.10
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This class defines a thread synchronisation object. More...
#include <syncthrd.h>
Public Member Functions | |
virtual void | Signal () |
If there are waiting (blocked) threads then unblock the first one that was blocked. | |
void | Signal (const PTimeInterval &waitTime) |
void | Acknowledge () |
This indicates that the thread that was blocked in a Wait() on this synchronisation object has completed the operation the signal was intended to initiate. | |
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PSyncPoint () | |
Create a new sync point. | |
PSyncPoint (const PSyncPoint &) | |
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unsigned | GetInitial () const |
unsigned | GetMaxCount () const |
PSemaphore (unsigned initial, unsigned maximum) | |
Create a new semaphore with maximum count and initial value specified. | |
PSemaphore (const PSemaphore &) | |
Create a new semaphore with the same initial and maximum values as the original. | |
~PSemaphore () | |
Destroy the semaphore. | |
virtual void | Wait () |
If the semaphore count is > 0, decrement the semaphore and return. | |
virtual PBoolean | Wait (const PTimeInterval &timeout) |
If the semaphore count is > 0, decrement the semaphore and return. | |
virtual PBoolean | WillBlock () const |
Determine if the semaphore would block if the Wait() function were called. | |
Operations | |
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virtual | ~PObject () |
virtual PObject * | Clone () const |
Create a copy of the class on the heap. | |
virtual PINDEX | HashFunction () const |
This function yields a hash value required by the PDictionary class. | |
virtual const char * | GetClass (unsigned ancestor=0) const |
Get the current dynamic type of the object instance. | |
PBoolean | IsClass (const char *cls) const |
virtual PBoolean | InternalIsDescendant (const char *clsName) const |
Determine if the dynamic type of the current instance is a descendent of the specified class. | |
virtual Comparison | Compare (const PObject &obj) const |
Compare the two objects and return their relative rank. | |
virtual Comparison | CompareObjectMemoryDirect (const PObject &obj) const |
Determine the byte wise comparison of two objects. | |
bool | operator== (const PObject &obj) const |
Compare the two objects. | |
bool | operator!= (const PObject &obj) const |
Compare the two objects. | |
bool | operator< (const PObject &obj) const |
Compare the two objects. | |
bool | operator> (const PObject &obj) const |
Compare the two objects. | |
bool | operator<= (const PObject &obj) const |
Compare the two objects. | |
bool | operator>= (const PObject &obj) const |
Compare the two objects. | |
virtual void | PrintOn (ostream &strm) const |
Output the contents of the object to the stream. | |
virtual void | ReadFrom (istream &strm) |
Input the contents of the object from the stream. |
Protected Attributes | |
PSyncPoint | ack |
Additional Inherited Members | |
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enum | Comparison { LessThan = -1, EqualTo = 0, GreaterThan = 1 } |
Result of the comparison operation performed by the Compare() function. More... | |
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static const char * | Class () |
Get the name of the class as a C string. | |
static Comparison | InternalCompareObjectMemoryDirect (const PObject *obj1, const PObject *obj2, PINDEX size) |
Internal function caled from CompareObjectMemoryDirect() | |
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PQUEUE (ThreadQueue, PThread) | |
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This class defines a thread synchronisation object.
This may be used to send signals to a thread and await an acknowldegement that the signal was processed. This can be be used to initiate an action in another thread and wait for the action to be completed.
... thread one
while (condition) {
sync.Wait();
do_something();
sync.Acknowledge();
}
... thread 2
do_something_else();
sync.Signal(); // At this point thread 1 wake up and does something.
do_yet_more(); // However, this does not get done until Acknowledge()
is called in the other thread.
void PSyncPointAck::Acknowledge | ( | ) |
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virtual |
If there are waiting (blocked) threads then unblock the first one that was blocked.
If no waiting threads and the count is less than the maximum then increment the semaphore.
Unlike the PSyncPoint::Signal() this function will block until the target thread that was blocked by the Wait() function has resumed execution and called the Acknowledge() function.
The waitTime
parameter is used as a maximum amount of time to wait for the achnowledgement to be returned from the other thread.
Reimplemented from PSemaphore.
void PSyncPointAck::Signal | ( | const PTimeInterval & | waitTime | ) |
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protected |