--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/nspr/pr/src/misc/prcountr.c	Mon Jul 28 10:47:06 2014 +0200
@@ -0,0 +1,474 @@
+/* -*- 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() */