vpr::MutexSGI Class Reference

Mutex wrapper for the SGI systems. More...

#include <vpr/Sync/Mutex.h>

Collaboration diagram for vpr::MutexSGI:

[legend]List of all members.

Public Member Functions
	MutexSGI ()
	~MutexSGI ()
vpr::ReturnStatus	acquire () const
	Locks this mutex.
vpr::ReturnStatus	acquireRead () const
	Acquires a read lock.
vpr::ReturnStatus	acquireWrite () const
	Acquires a write lock.
vpr::ReturnStatus	tryAcquire () const
	Tries to acquire a lock on this mutex (does not block).
vpr::ReturnStatus	tryAcquireRead () const
	Tries to acquire a read lock (does not block).
vpr::ReturnStatus	tryAcquireWrite () const
	Tries to acquire a write lock (does not block).
vpr::ReturnStatus	release () const
	Releases the mutex.
int	test () const
	Tests the current lock status.
void	dump (FILE *dest=stdout, const char *message="\n------ Mutex Status -----\n") const
	Dumps the mutex debug stuff and current state.
Protected Member Functions
void	operator= (const MutexSGI &)
	MutexSGI (const MutexSGI &)
Protected Attributes
ulock_t	mMutex
Static Protected Attributes
static MemPoolSGI *	mMutexPool
static int *	mAttachedCounter

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Detailed Description

Mutex wrapper for the SGI systems.

Used for critical section protection. This is typedef'd to vpr::Mutex.

Date:

January 20, 1997

Definition at line 64 of file MutexSGI.h.

---

Constructor & Destructor Documentation

vpr::MutexSGI::MutexSGI

(

)

[inline]

Definition at line 67 of file MutexSGI.h.

References vpr::MemPoolSGI::allocate(), errno, vpr::MemPoolSGI::getArena(), mAttachedCounter, mMutex, mMutexPool, and vprASSERT.

              : mMutex(NULL)
   {
      // BUG: Possible race condition here
      if ( mMutexPool == NULL )
      {
         mMutexPool = new MemPoolSGI(65536, 32,
                                     "/var/tmp/memMutexPoolSGIXXXXXX");
         mAttachedCounter = static_cast<int*>(mMutexPool->allocate(sizeof(int)));
         *mAttachedCounter = 0;
      }

      // Track how many mutexes are allocated
      *mAttachedCounter = *mAttachedCounter + 1;
//      vprDEBUG << " vpr::MutexSGI::MutexSGI: mAttachedCounter: "
//               << *mAttachedCounter << endl << vprDEBUG_FLUSH;

      // ----- Allocate the mutex ----- //
      mMutex = usnewlock(mMutexPool->getArena());

      if ( NULL == mMutex )
      {
         std::cerr << "ERROR: Failed to allocate new mutex -- "
                   << strerror(errno) << std::endl;
         vprASSERT(mMutex != NULL && "in vpr::MutexSGI::MutexSGI() mMutex is NULL");
      }
   }

vpr::MutexSGI::~MutexSGI

(

)

[inline]

Definition at line 94 of file MutexSGI.h.

References vpr::MemPoolSGI::deallocate(), vpr::MemPoolSGI::getArena(), mAttachedCounter, mMutex, and mMutexPool.

   {
      // ---- Delete the mutex --- //
      usfreelock(mMutex, mMutexPool->getArena());

      // ---- Deal with the pool --- //

      // Track how many mutexes are allocated
      *mAttachedCounter = *mAttachedCounter - 1;

//      vprDEBUG << "vpr::MutexSGI::~MutexSGI: mAttachedCounter: "
//               << *mAttachedCounter << endl << vprDEBUG_FLUSH;

      if ( *mAttachedCounter == 0 )
      {
         mMutexPool->deallocate(mAttachedCounter);
         mAttachedCounter = NULL;
         delete mMutexPool;
         mMutexPool = NULL;
      }
   }

vpr::MutexSGI::MutexSGI

(

const MutexSGI &

)

[inline, protected]

Definition at line 287 of file MutexSGI.h.

{;}

---

Member Function Documentation

vpr::ReturnStatus vpr::MutexSGI::acquire

(

)

const [inline]

Locks this mutex.

Postcondition:

A lock on this mutex is acquired by the caller. If a lock has already been acquired by another process/thread, the caller blocks until the mutex has been freed.

Returns:

vpr::ReturnStatus::Succeed is returned if the lock is acquired successfully. vpr::ReturnStatus::Fail is returned otherwise.

Definition at line 126 of file MutexSGI.h.

References vpr::ReturnStatus::Fail, mMutex, and vprASSERT.

Referenced by acquireRead(), and acquireWrite().

   {
      vprASSERT(mMutex != NULL && "in vpr::MutexSGI::aquire() mMutex is NULL");
      if ( ussetlock(mMutex) == 1 )
      {
         return vpr::ReturnStatus();
      }
      else
      {
         return vpr::ReturnStatus(vpr::ReturnStatus::Fail);
      }
   }

vpr::ReturnStatus vpr::MutexSGI::acquireRead

(

)

const [inline]

Acquires a read lock.

Postcondition:

A lock on this mutex is acquired by the caller. If a lock has already been acquired by another process/thread, the caller blocks until the mutex has been freed.

Returns:

vpr::ReturnStatus::Succeed is returned if the read lock is acquired successfully. vpr::ReturnStatus::Fail is returned otherwise.

Note:

No special read mutex has been defined for now.

Definition at line 152 of file MutexSGI.h.

References acquire().

   {
      return this->acquire();      // No special "read" semaphore -- For now
   }

vpr::ReturnStatus vpr::MutexSGI::acquireWrite

(

)

const [inline]

Acquires a write lock.

Postcondition:

A lock on this mutex is acquired by the caller. If a lock has already been acquired by another process/thread, the caller blocks until the mutex has been freed.

Returns:

vpr::ReturnStatus::Succeed is returned if the write lock is acquired successfully. vpr::ReturnStatus::Fail is returned otherwise.

Note:

No special write mutex has been defined for now.

Definition at line 170 of file MutexSGI.h.

References acquire().

   {
      return this->acquire();      // No special "write" semaphore -- For now
   }

vpr::ReturnStatus vpr::MutexSGI::tryAcquire

(

)

const [inline]

Tries to acquire a lock on this mutex (does not block).

Postcondition:

A lock on this mutex is acquired by the caller. If a lock has already been acquired by another process/thread, the caller returns does not wait for it to be unlocked.

Returns:

vpr::ReturnStatus::Succeed is returned if the lock is acquired. vpr::ReturnStatus::Fail is returned if another thread is holding the lock already.

Definition at line 186 of file MutexSGI.h.

References vpr::ReturnStatus::Fail, and mMutex.

Referenced by tryAcquireRead(), and tryAcquireWrite().

   {
      // Try 100 spins.
      if ( uscsetlock(mMutex, 100) == 1 )
      {
         return vpr::ReturnStatus();
      }
      else
      {
         return vpr::ReturnStatus(vpr::ReturnStatus::Fail);
      }
   }

vpr::ReturnStatus vpr::MutexSGI::tryAcquireRead

(

)

const [inline]

Tries to acquire a read lock (does not block).

Postcondition:

A lock on this mutex is acquired by the caller. If a lock has already been acquired by another process/thread, the caller returns does not wait for it to be unlocked.

Returns:

vpr::ReturnStatus::Succeed is returned if the read lock is acquired. vpr::ReturnStatus::Fail is returned if another thread is holding the lock already.

Definition at line 210 of file MutexSGI.h.

References tryAcquire().

   {
      return this->tryAcquire();
   }

vpr::ReturnStatus vpr::MutexSGI::tryAcquireWrite

(

)

const [inline]

Tries to acquire a write lock (does not block).

Postcondition:

A lock on this mutex is acquired by the caller. If a lock has already been acquired by another process/thread, the caller returns does not wait for it to be unlocked.

Returns:

vpr::ReturnStatus::Succeed is returned if the write lock is acquired. vpr::ReturnStatus::Fail is returned if another thread is holding the lock already.

Definition at line 226 of file MutexSGI.h.

References tryAcquire().

   {
      return this->tryAcquire();
   }

vpr::ReturnStatus vpr::MutexSGI::release

(

)

const [inline]

Releases the mutex.

Precondition:

This mutex must be locked.

Postcondition:

This mutex is unlocked.

Returns:

vpr::ReturnStatus::Succeed is returned if this mutex is unlocked successfully. vpr::ReturnStatus::Fail is returned otherwise.

Definition at line 240 of file MutexSGI.h.

References vpr::ReturnStatus::Fail, and mMutex.

   {
      if ( usunsetlock(mMutex) == 0 )
      {
         return vpr::ReturnStatus();
      }
      else
      {
         return vpr::ReturnStatus(vpr::ReturnStatus::Fail);
      }
   }

int vpr::MutexSGI::test

(

)

const [inline]

Tests the current lock status.

Postcondition:

The state of this mutex is returned.

Returns:

0 is returned if this mutex is not locked. 1 is returned if it is locked.

Definition at line 260 of file MutexSGI.h.

References mMutex.

   {
      return ustestlock(const_cast<ulock_t>(mMutex));
   }

void vpr::MutexSGI::dump	(	FILE *	dest = stdout,
		const char *	message = "\n------ Mutex Status -----\n"
	)			const [inline]

Dumps the mutex debug stuff and current state.

Postcondition:

All important data and debugging information related to the mutex are dumped to the specified file descriptor (or to stderr if none is given).

Parameters:

	dest	File descriptor to which the output will be written. It defaults to stderr if no descriptor is specified.
	message	Message printed out before the output is dumped.

Definition at line 276 of file MutexSGI.h.

References mMutex.

   {
      usdumplock(mMutex, dest, message);
   }

void vpr::MutexSGI::operator=

(

const MutexSGI &

)

[inline, protected]

Definition at line 286 of file MutexSGI.h.

{;}

---

Member Data Documentation

ulock_t vpr::MutexSGI::mMutex [protected]

Definition at line 283 of file MutexSGI.h.

Referenced by acquire(), dump(), MutexSGI(), release(), test(), tryAcquire(), and ~MutexSGI().

vpr::MemPoolSGI * vpr::MutexSGI::mMutexPool [static, protected]

Definition at line 289 of file MutexSGI.h.

Referenced by MutexSGI(), and ~MutexSGI().

int * vpr::MutexSGI::mAttachedCounter [static, protected]

Definition at line 290 of file MutexSGI.h.

Referenced by MutexSGI(), and ~MutexSGI().

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

• MutexSGI.h
• MutexSGI.cpp

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