The Tor Browser: nsprpub/pr/src/misc/prcountr.c@6474c204b198 (annotated)

nsprpub/pr/src/misc/prcountr.c@6474c204b198 (annotated)

nsprpub/pr/src/misc/prcountr.c

Wed, 31 Dec 2014 06:09:35 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Wed, 31 Dec 2014 06:09:35 +0100
changeset 0: 6474c204b198
permissions: -rw-r--r--

Cloned upstream origin tor-browser at tor-browser-31.3.0esr-4.5-1-build1
revision ID fc1c9ff7c1b2defdbc039f12214767608f46423f for hacking purpose.

 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 /*
 ** prcountr.c -- NSPR Instrumentation Counters
 **
 ** Implement the interface defined in prcountr.h
 **
 ** Design Notes:
 **
 ** The Counter Facility (CF) has a single anchor: qNameList.
 ** The anchor is a PRCList. qNameList is a list of links in QName
 ** structures. From qNameList any QName structure and its
 ** associated RName structure can be located.
 **
 ** For each QName, a list of RName structures is anchored at
 ** rnLink in the QName structure.
 **
 ** The counter itself is embedded in the RName structure.
 **
 ** For manipulating the counter database, single lock is used to
 ** protect the entire list: counterLock.
 **
 ** A PRCounterHandle, defined in prcountr.h, is really a pointer
 ** to a RName structure. References by PRCounterHandle are
 ** dead-reconed to the RName structure. The PRCounterHandle is
 ** "overloaded" for traversing the QName structures; only the
 ** function PR_FindNextQnameHandle() uses this overloading.
 **
 **
 ** ToDo (lth): decide on how to lock or atomically update
 ** individual counters. Candidates are: the global lock; a lock
 ** per RName structure; Atomic operations (Note that there are
 ** not adaquate atomic operations (yet) to achieve this goal). At
 ** this writing (6/19/98) , the update of the counter variable in
 ** a QName structure is unprotected.
 **
 */
 #include "prcountr.h"
 #include "prclist.h"
 #include "prlock.h"
 #include "prlog.h"
 #include "prmem.h"
 #include <string.h>
 /*
 **
 */
 typedef struct QName
 {
     PRCList link;
     PRCList rNameList;
     char    name[PRCOUNTER_NAME_MAX+1];
 } QName;
 /*
 **
 */
 typedef struct RName
 {
     PRCList link;
     QName   *qName;
     PRLock  *lock;
     volatile PRUint32   counter;
     char    name[PRCOUNTER_NAME_MAX+1];
     char    desc[PRCOUNTER_DESC_MAX+1];
 } RName;
 /*
 ** Define the Counter Facility database
 */
 static PRLock  *counterLock;
 static PRCList qNameList;
 static PRLogModuleInfo *lm;
 /*
 ** _PR_CounterInitialize() -- Initialize the Counter Facility
 **
 */
 static void _PR_CounterInitialize( void )
 {
     /*
     ** This function should be called only once
     */
     PR_ASSERT( counterLock == NULL );
     counterLock = PR_NewLock();
     PR_INIT_CLIST( &qNameList );
     lm = PR_NewLogModule("counters");
     PR_LOG( lm, PR_LOG_DEBUG, ("PR_Counter: Initialization complete"));
     return;
 } /* end _PR_CounterInitialize() */
 /*
 ** PR_CreateCounter() -- Create a counter
 **
 **  ValidateArguments
 **  Lock
 **  if (qName not already in database)
 **      NewQname
 **  if (rName already in database )
 **      Assert
 **  else NewRname
 **  NewCounter
 **  link 'em up
 **  Unlock
 **
 */
 PR_IMPLEMENT(PRCounterHandle)
 	PR_CreateCounter(
 		const char *qName,
     	const char *rName,
         const char *description
 )
 {
     QName   *qnp;
     RName   *rnp;
     PRBool  matchQname = PR_FALSE;
     /* Self initialize, if necessary */
     if ( counterLock == NULL )
         _PR_CounterInitialize();
     /* Validate input arguments */
     PR_ASSERT( strlen(qName) <= PRCOUNTER_NAME_MAX );
     PR_ASSERT( strlen(rName) <= PRCOUNTER_NAME_MAX );
     PR_ASSERT( strlen(description) <= PRCOUNTER_DESC_MAX );
     /* Lock the Facility */
     PR_Lock( counterLock );
     /* Do we already have a matching QName? */
     if (!PR_CLIST_IS_EMPTY( &qNameList ))
     {
         qnp = (QName *) PR_LIST_HEAD( &qNameList );
         do {
             if ( strcmp(qnp->name, qName) == 0)
             {
                 matchQname = PR_TRUE;
                 break;
             }
             qnp = (QName *)PR_NEXT_LINK( &qnp->link );
         } while( qnp != (QName *)&qNameList );
     }
     /*
     ** If we did not find a matching QName,
     **    allocate one and initialize it.
     **    link it onto the qNameList.
     **
     */
     if ( matchQname != PR_TRUE )
     {
         qnp = PR_NEWZAP( QName );
         PR_ASSERT( qnp != NULL );
         PR_INIT_CLIST( &qnp->link );
         PR_INIT_CLIST( &qnp->rNameList );
         strcpy( qnp->name, qName );
         PR_APPEND_LINK( &qnp->link, &qNameList );
     }
     /* Do we already have a matching RName? */
     if (!PR_CLIST_IS_EMPTY( &qnp->rNameList ))
     {
         rnp = (RName *) PR_LIST_HEAD( &qnp->rNameList );
         do {
             /*
             ** No duplicate RNames are allowed within a QName
             **
             */
             PR_ASSERT( strcmp(rnp->name, rName));
             rnp = (RName *)PR_NEXT_LINK( &rnp->link );
         } while( rnp != (RName *)&qnp->rNameList );
     }
     /* Get a new RName structure; initialize its members */
     rnp = PR_NEWZAP( RName );
     PR_ASSERT( rnp != NULL );
     PR_INIT_CLIST( &rnp->link );
     strcpy( rnp->name, rName );
     strcpy( rnp->desc, description );
     rnp->lock = PR_NewLock();
     if ( rnp->lock == NULL )
     {
         PR_ASSERT(0);
     }
     PR_APPEND_LINK( &rnp->link, &qnp->rNameList ); /* add RName to QName's rnList */
     rnp->qName = qnp;                       /* point the RName to the QName */
     /* Unlock the Facility */
     PR_Unlock( counterLock );
     PR_LOG( lm, PR_LOG_DEBUG, ("PR_Counter: Create: QName: %s %p, RName: %s %p\n\t",
         qName, qnp, rName, rnp ));
     return((PRCounterHandle)rnp);
 } /*  end PR_CreateCounter() */
 /*
 **
 */
 PR_IMPLEMENT(void)
 	PR_DestroyCounter(
 		PRCounterHandle handle
 )
 {
     RName   *rnp = (RName *)handle;
     QName   *qnp = rnp->qName;
     PR_LOG( lm, PR_LOG_DEBUG, ("PR_Counter: Deleting: QName: %s, RName: %s",
         qnp->name, rnp->name));
     /* Lock the Facility */
     PR_Lock( counterLock );
     /*
     ** Remove RName from the list of RNames in QName
     ** and free RName
     */
     PR_LOG( lm, PR_LOG_DEBUG, ("PR_Counter: Deleting RName: %s, %p",
         rnp->name, rnp));
     PR_REMOVE_LINK( &rnp->link );
     PR_Free( rnp->lock );
     PR_DELETE( rnp );
     /*
     ** If this is the last RName within QName
     **   remove QName from the qNameList and free it
     */
     if ( PR_CLIST_IS_EMPTY( &qnp->rNameList ) )
     {
         PR_LOG( lm, PR_LOG_DEBUG, ("PR_Counter: Deleting unused QName: %s, %p",
             qnp->name, qnp));
         PR_REMOVE_LINK( &qnp->link );
         PR_DELETE( qnp );
     }
     /* Unlock the Facility */
     PR_Unlock( counterLock );
     return;
 } /*  end PR_DestroyCounter() */
 /*
 **
 */
 PR_IMPLEMENT(PRCounterHandle)
 	PR_GetCounterHandleFromName(
     	const char *qName,
     	const char *rName
 )
 {
     const char    *qn, *rn, *desc;
     PRCounterHandle     qh, rh = NULL;
     RName   *rnp = NULL;
     PR_LOG( lm, PR_LOG_DEBUG, ("PR_Counter: GetCounterHandleFromName:\n\t"
         "QName: %s, RName: %s", qName, rName ));
     qh = PR_FindNextCounterQname( NULL );
     while (qh != NULL)
     {
         rh = PR_FindNextCounterRname( NULL, qh );
         while ( rh != NULL )
         {
             PR_GetCounterNameFromHandle( rh, &qn, &rn, &desc );
             if ( (strcmp( qName, qn ) == 0)
                 && (strcmp( rName, rn ) == 0 ))
             {
                 rnp = (RName *)rh;
                 goto foundIt;
             }
             rh = PR_FindNextCounterRname( rh, qh );
         }
         qh = PR_FindNextCounterQname( NULL );
     }
 foundIt:
     PR_LOG( lm, PR_LOG_DEBUG, ("PR_Counter: GetConterHandleFromName: %p", rnp ));
     return(rh);
 } /*  end PR_GetCounterHandleFromName() */
 /*
 **
 */
 PR_IMPLEMENT(void)
 	PR_GetCounterNameFromHandle(
     	PRCounterHandle handle,
 	    const char **qName,
 	    const char **rName,
 		const char **description
 )
 {
     RName   *rnp = (RName *)handle;
     QName   *qnp = rnp->qName;
     *qName = qnp->name;
     *rName = rnp->name;
     *description = rnp->desc;
     PR_LOG( lm, PR_LOG_DEBUG, ("PR_Counter: GetConterNameFromHandle: "
         "QNp: %p, RNp: %p,\n\tQName: %s, RName: %s, Desc: %s",
         qnp, rnp, qnp->name, rnp->name, rnp->desc ));
     return;
 } /*  end PR_GetCounterNameFromHandle() */
 /*
 **
 */
 PR_IMPLEMENT(void)
 	PR_IncrementCounter(
 		PRCounterHandle handle
 )
 {
     PR_Lock(((RName *)handle)->lock);
     ((RName *)handle)->counter++;
     PR_Unlock(((RName *)handle)->lock);
     PR_LOG( lm, PR_LOG_DEBUG, ("PR_Counter: Increment: %p, %ld",
         handle, ((RName *)handle)->counter ));
     return;
 } /*  end PR_IncrementCounter() */
 /*
 **
 */
 PR_IMPLEMENT(void)
 	PR_DecrementCounter(
 		PRCounterHandle handle
 )
 {
     PR_Lock(((RName *)handle)->lock);
     ((RName *)handle)->counter--;
     PR_Unlock(((RName *)handle)->lock);
     PR_LOG( lm, PR_LOG_DEBUG, ("PR_Counter: Decrement: %p, %ld",
         handle, ((RName *)handle)->counter ));
     return;
 } /*  end PR_DecrementCounter()  */
 /*
 **
 */
 PR_IMPLEMENT(void)
 	PR_AddToCounter(
     	PRCounterHandle handle,
 	    PRUint32 value
 )
 {
     PR_Lock(((RName *)handle)->lock);
     ((RName *)handle)->counter += value;
     PR_Unlock(((RName *)handle)->lock);
     PR_LOG( lm, PR_LOG_DEBUG, ("PR_Counter: AddToCounter: %p, %ld",
         handle, ((RName *)handle)->counter ));
     return;
 } /*  end PR_AddToCounter() */
 /*
 **
 */
 PR_IMPLEMENT(void)
 	PR_SubtractFromCounter(
     	PRCounterHandle handle,
 	    PRUint32 value
 )
 {
     PR_Lock(((RName *)handle)->lock);
     ((RName *)handle)->counter -= value;
     PR_Unlock(((RName *)handle)->lock);
     PR_LOG( lm, PR_LOG_DEBUG, ("PR_Counter: SubtractFromCounter: %p, %ld",
         handle, ((RName *)handle)->counter ));
     return;
 } /*  end  PR_SubtractFromCounter() */
 /*
 **
 */
 PR_IMPLEMENT(PRUint32)
 	PR_GetCounter(
 		PRCounterHandle handle
 )
 {
     PR_LOG( lm, PR_LOG_DEBUG, ("PR_Counter: GetCounter: %p, %ld",
         handle, ((RName *)handle)->counter ));
     return(((RName *)handle)->counter);
 } /*  end  PR_GetCounter() */
 /*
 **
 */
 PR_IMPLEMENT(void)
 	PR_SetCounter(
 		PRCounterHandle handle,
 		PRUint32 value
 )
 {
     ((RName *)handle)->counter = value;
     PR_LOG( lm, PR_LOG_DEBUG, ("PR_Counter: SetCounter: %p, %ld",
         handle, ((RName *)handle)->counter ));
     return;
 } /*  end  PR_SetCounter() */
 /*
 **
 */
 PR_IMPLEMENT(PRCounterHandle)
 	PR_FindNextCounterQname(
         PRCounterHandle handle
 )
 {
     QName *qnp = (QName *)handle;
     if ( PR_CLIST_IS_EMPTY( &qNameList ))
             qnp = NULL;
     else if ( qnp == NULL )
         qnp = (QName *)PR_LIST_HEAD( &qNameList );
     else if ( PR_NEXT_LINK( &qnp->link ) ==  &qNameList )
         qnp = NULL;
     else
         qnp = (QName *)PR_NEXT_LINK( &qnp->link );
     PR_LOG( lm, PR_LOG_DEBUG, ("PR_Counter: FindNextQname: Handle: %p, Returns: %p",
         handle, qnp ));
     return((PRCounterHandle)qnp);
 } /*  end  PR_FindNextCounterQname() */
 /*
 **
 */
 PR_IMPLEMENT(PRCounterHandle)
 	PR_FindNextCounterRname(
         PRCounterHandle rhandle,
         PRCounterHandle qhandle
 )
 {
     RName *rnp = (RName *)rhandle;
     QName *qnp = (QName *)qhandle;
     if ( PR_CLIST_IS_EMPTY( &qnp->rNameList ))
         rnp = NULL;
     else if ( rnp == NULL )
         rnp = (RName *)PR_LIST_HEAD( &qnp->rNameList );
     else if ( PR_NEXT_LINK( &rnp->link ) ==  &qnp->rNameList )
         rnp = NULL;
     else
         rnp = (RName *)PR_NEXT_LINK( &rnp->link );
     PR_LOG( lm, PR_LOG_DEBUG, ("PR_Counter: FindNextRname: Rhandle: %p, QHandle: %p, Returns: %p",
         rhandle, qhandle, rnp ));
     return((PRCounterHandle)rnp);
 } /*  end PR_FindNextCounterRname() */

The Tor Browser / annotate

nsprpub/pr/src/misc/prcountr.c@6474c204b198 (annotated)

nsprpub/pr/src/misc/prcountr.c