vpr::CondVarNSPR Class Reference

Condition variable wrapper for NSPR condition variables. More...

#include <vpr/Sync/CondVar.h>

Collaboration diagram for vpr::CondVarNSPR:

[legend]List of all members.

Public Member Functions
	CondVarNSPR (MutexNSPR *mutex=NULL)
	Constructor.
	~CondVarNSPR ()
	Destructor.
vpr::ReturnStatus	wait (vpr::Interval timeToWait=vpr::Interval::NoTimeout)
	Blocks on a condition.
vpr::ReturnStatus	signal ()
	Signals another thread waiting on this condition variable.
vpr::ReturnStatus	broadcast ()
	Signals all threads waiting on the condition variable.
vpr::ReturnStatus	acquire ()
	Acquires a lock on the mutex variable associated with the condition variable.
vpr::ReturnStatus	tryAcquire ()
	Tries to acquire a lock on the mutex variable associated with the condition variable.
vpr::ReturnStatus	release ()
	Releases the lock on the mutex variable associated with the condition variable.
void	setMutex (MutexNSPR *mutex)
	Changes the condition variable mutex to be the specifiec mutex variable.
int	test ()
	Tests the mutex to see if it is held.
void	dump () const
	Prints out information about the condition variable to stderr.

---

Detailed Description

Condition variable wrapper for NSPR condition variables.

This is typedef'd to vpr::CondVar.

Definition at line 70 of file CondVarNSPR.h.

---

Constructor & Destructor Documentation

vpr::CondVarNSPR::CondVarNSPR

(

MutexNSPR *

mutex = NULL

)

[inline]

Constructor.

Postcondition:

The condition variable is intialized, and the mutex variable associated with it is defined. These two steps must be done before any other member functions can use them.

Parameters:

mutex

Pointer to a vpr::MutexNSPR variable that is used in association with the condition variable in this class (optional).

Definition at line 84 of file CondVarNSPR.h.

References vprASSERT.

   {
      // If the caller did not specify a mutex variable to use with
      // the condition variable, use mDefaultMutex.
      if ( mutex == NULL )
      {
         mCondMutex = &mDefaultMutex;
      }
      else
      {
         mCondMutex = mutex;
      }

      // Initialize the condition variable.
      mCondVar = PR_NewCondVar(mCondMutex->mMutex);

      vprASSERT(mCondVar != NULL);
   }

vpr::CondVarNSPR::~CondVarNSPR

(

)

[inline]

Destructor.

Precondition:

The condition variable is no longer in use.

Postcondition:

The condition variable is destroyed.

Definition at line 109 of file CondVarNSPR.h.

   {
      PR_DestroyCondVar(mCondVar);
   }

---

Member Function Documentation

vpr::ReturnStatus vpr::CondVarNSPR::wait

(

vpr::Interval

timeToWait = vpr::Interval::NoTimeout

)

[inline]

Blocks on a condition.

The lock asociated with this condition variable must be held prior to invoking this method. When invoked, the lock on the variable is released, and the calling thread is blocked until another thread informs it that the condition has changed or until the timeout expires.

Precondition:

The mutex variable associated with the condition variable must be locked.

Postcondition:

The condition variable is locked. If it was previously locked, the caller blocks until signaled.

Returns:

vpr::ReturnStatus::Succeed is returned when the calling thread is signaled.

vpr::ReturnStatus::Fail is returned if something went wrong in blocking on the condition.

Definition at line 131 of file CondVarNSPR.h.

References vpr::ReturnStatus::Fail, vpr::NSPR_getInterval(), vpr::ReturnStatus::setCode(), vpr::ReturnStatus::success(), and vprASSERT.

Referenced by vpr::ThreadNSPR::start().

   {
      vpr::ReturnStatus status;

      // ASSERT:  We have been locked.
      if ( PR_WaitCondVar(mCondVar, NSPR_getInterval(timeToWait)) != PR_SUCCESS )
      {
         status.setCode(vpr::ReturnStatus::Fail);
      }

      // XXX: Use error status to print a message before the assertion.
      vprASSERT(status.success());

      return status;
   }

vpr::ReturnStatus vpr::CondVarNSPR::signal

(

)

[inline]

Signals another thread waiting on this condition variable.

Precondition:

The condition variable must be locked.

Postcondition:

The condition variable is unlocked, and a signal is sent to a thread waiting on it.

Returns:

vpr::ReturnStatus::Succeed is returned when the signal is sent successfully.

vpr::ReturnStatus::Fail is returned otherwise.

Definition at line 158 of file CondVarNSPR.h.

References vpr::ReturnStatus::Fail, vpr::ReturnStatus::setCode(), vpr::ReturnStatus::success(), and vprASSERT.

   {
      vpr::ReturnStatus status;

      // ASSERT:  We have been locked
      if ( PR_NotifyCondVar(mCondVar) != PR_SUCCESS )
      {
         status.setCode(vpr::ReturnStatus::Fail);
      }

      vprASSERT(status.success());

      return status;
   }

vpr::ReturnStatus vpr::CondVarNSPR::broadcast

(

)

[inline]

Signals all threads waiting on the condition variable.

Precondition:

The mutex variable associated with the condition variable should be locked.

Postcondition:

The condition variable is unlocked, and all waiting threads are signaled of this event.

Returns:

vpr::ReturnStatus::Succeed is returned if the broadcast message is sent successfully.

vpr::ReturnStatus::Fail is returned otherwise.

Definition at line 185 of file CondVarNSPR.h.

References vpr::ReturnStatus::Fail, vpr::ReturnStatus::setCode(), vpr::ReturnStatus::success(), and vprASSERT.

   {
      vpr::ReturnStatus status;

      // ASSERT:  We have been locked
      if ( PR_NotifyAllCondVar(mCondVar) != PR_SUCCESS )
      {
         status.setCode(vpr::ReturnStatus::Fail);
      }

      vprASSERT(status.success());

      return status;
   }

vpr::ReturnStatus vpr::CondVarNSPR::acquire

(

)

[inline]

Acquires a lock on the mutex variable associated with the condition variable.

Postcondition:

A lock is acquired on the mutex variable associated with the condition variable. If a lock is acquired, the caller controls the mutex variable. If it was previously locked, the caller blocks until it is unlocked.

Returns:

vpr::ReturnStatus::Succeed is returned if the lock on this condition variable is acquired successfully.

vpr::ReturnStatus::Fail is returned otherwise.

Definition at line 213 of file CondVarNSPR.h.

Referenced by vpr::ThreadNSPR::start().

   {
      return mCondMutex->acquire();
   }

vpr::ReturnStatus vpr::CondVarNSPR::tryAcquire

(

)

[inline]

Tries to acquire a lock on the mutex variable associated with the condition variable.

Postcondition:

If the mutex variable is not already locked, the caller obtains a lock on it. If it is already locked, the routine returns immediately to the caller.

Returns:

vpr::ReturnStatus::Succeed is returned if the lock on this condition variable is acquired successfully.

vpr::ReturnStatus::Fail is returned if the lock is already held by another thread.

Definition at line 231 of file CondVarNSPR.h.

   {
      return mCondMutex->tryAcquire();
   }

vpr::ReturnStatus vpr::CondVarNSPR::release

(

)

[inline]

Releases the lock on the mutex variable associated with the condition variable.

Postcondition:

The lock held by the caller on the mutex variable is released.

Returns:

vpr::ReturnStatus::Succeed is returned if the lock on this condition variable is released successfully.

vpr::ReturnStatus::Fail is returned otherwise.

Definition at line 246 of file CondVarNSPR.h.

Referenced by vpr::ThreadNSPR::start().

   {
      return mCondMutex->release();
   }

void vpr::CondVarNSPR::setMutex

(

MutexNSPR *

mutex

)

[inline]

Changes the condition variable mutex to be the specifiec mutex variable.

Precondition:

The specified mutex variable must be initialized.

Postcondition:

The condition variable associated with the mutex variable is reset to the specified variable.

Parameters:

mutex

Pointer to a vpr::MutexNSPR variable that is used in association with the condition variable in this class.

Note:

NEVER call except to initialize explicitly.

Definition at line 264 of file CondVarNSPR.h.

References vpr::MutexNSPR::release().

   {
      // NOT exactly correct, but just make sure not to leave it locked
      mutex->release();
      mCondMutex = mutex;
   }

int vpr::CondVarNSPR::test

(

)

[inline]

Tests the mutex to see if it is held.

Definition at line 272 of file CondVarNSPR.h.

References vpr::MutexNSPR::test().

   {
      return mCondMutex->test();
   }

void vpr::CondVarNSPR::dump

(

)

const [inline]

Prints out information about the condition variable to stderr.

Postcondition:

All important data and debugging information related to the condition variable and its mutex are dumped to stderr.

Definition at line 283 of file CondVarNSPR.h.

   {
      std::cerr << "------------- vpr::CondVarNSPR::Dump ---------\n"
                << "Not Implemented yet.\n";
   }

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

• CondVarNSPR.h

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