/* 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/. */

/*
 * nssilock.c - NSS lock instrumentation wrapper functions
 *
 * NOTE - These are not public interfaces
 *
 * Implementation Notes:
 * I've tried to make the instrumentation relatively non-intrusive.
 * To do this, I have used a single PR_LOG() call in each
 * instrumented function. There's room for improvement.
 *
 *
 */

#include "prinit.h"
#include "prerror.h"
#include "prlock.h"
#include "prmem.h"
#include "prenv.h"
#include "prcvar.h"
#include "prio.h"

#if defined(NEED_NSS_ILOCK)
#include "prlog.h"
#include "nssilock.h"

/*
** Declare the instrumented PZLock 
*/
struct pzlock_s {
    PRLock *lock;  /* the PZLock to be instrumented */
    PRIntervalTime time; /* timestamp when the lock was aquired */
    nssILockType ltype;
};

/*
** Declare the instrumented PZMonitor 
*/
struct pzmonitor_s {
    PRMonitor *mon;   /* the PZMonitor to be instrumented */
    PRIntervalTime time; /* timestamp when the monitor was aquired */
    nssILockType ltype;
};

/*
** Declare the instrumented PZCondVar
*/
struct pzcondvar_s  {
    PRCondVar   *cvar;  /* the PZCondVar to be instrumented */
    nssILockType ltype;
};


/*
** Define a CallOnce type to ensure serialized self-initialization
*/
static PRCallOnceType coNssILock;     /* CallOnce type */
static PRIntn  nssILockInitialized;   /* initialization done when 1 */
static PRLogModuleInfo *nssILog;      /* Log instrumentation to this handle */


#define NUM_TT_ENTRIES 6000000
static PRInt32  traceIndex = -1;      /* index into trace table */
static struct pzTrace_s *tt;          /* pointer to trace table */
static PRInt32  ttBufSize = (NUM_TT_ENTRIES * sizeof(struct pzTrace_s ));
static PRCondVar *ttCVar;
static PRLock    *ttLock;
static PRFileDesc *ttfd;              /* trace table file */

/*
** Vtrace() -- Trace events, write events to external media
**
** Vtrace() records traced events in an in-memory trace table
** when the trace table fills, Vtrace writes the entire table
** to a file.
**
** data can be lost!
**
*/
static void Vtrace(
    nssILockOp      op,
    nssILockType    ltype,
    PRIntervalTime  callTime,
    PRIntervalTime  heldTime,
    void            *lock,
    PRIntn          line,
    char            *file
)  {
    PRInt32 idx;
    struct pzTrace_s *tp;

RetryTrace:
    idx = PR_ATOMIC_INCREMENT( &traceIndex );
    while( NUM_TT_ENTRIES <= idx || op == FlushTT ) {
        if( NUM_TT_ENTRIES == idx  || op == FlushTT )  {
            int writeSize = idx * sizeof(struct pzTrace_s);
            PR_Lock(ttLock);
            PR_Write( ttfd, tt, writeSize );
            traceIndex = -1;
            PR_NotifyAllCondVar( ttCVar );
            PR_Unlock(ttLock);
            goto RetryTrace;
        } else {
            PR_Lock(ttLock);
            while( NUM_TT_ENTRIES < idx )
                PR_WaitCondVar(ttCVar, PR_INTERVAL_NO_WAIT);
            PR_Unlock(ttLock);
            goto RetryTrace;
        }
    } /* end while() */

    /* create the trace entry */
    tp = tt + idx;
    tp->threadID = PR_GetThreadID(PR_GetCurrentThread());
    tp->op = op;
    tp->ltype = ltype;
    tp->callTime = callTime;
    tp->heldTime = heldTime;
    tp->lock = lock;
    tp ->line = line;
    strcpy(tp->file, file );
    return;
} /* --- end Vtrace() --- */

/*
** pz_TraceFlush() -- Force trace table write to file
**
*/
extern void pz_TraceFlush( void )
{
    Vtrace( FlushTT, nssILockSelfServ, 0, 0, NULL, 0, "" );
    return;
} /* --- end pz_TraceFlush() --- */

/*
** nssILockInit() -- Initialization for nssilock
**
** This function is called from the CallOnce mechanism.
*/
static PRStatus
    nssILockInit( void ) 
{   
    int i;
    nssILockInitialized = 1;

    /* new log module */
    nssILog = PR_NewLogModule("nssilock");
    if ( NULL == nssILog )  {
        return(PR_FAILURE);
    }

    tt = PR_Calloc( NUM_TT_ENTRIES, sizeof(struct pzTrace_s));
    if (NULL == tt ) {
        fprintf(stderr, "nssilock: can't allocate trace table\n");
        exit(1);
    }

    ttfd = PR_Open( "xxxTTLog", PR_CREATE_FILE | PR_WRONLY, 0666 );
    if ( NULL == ttfd )  {
        fprintf( stderr, "Oh Drat! Can't open 'xxxTTLog'\n");
        exit(1);
    }

    ttLock = PR_NewLock();
    ttCVar = PR_NewCondVar(ttLock);

    return(PR_SUCCESS);
} /* --- end nssILockInit() --- */

extern PZLock * pz_NewLock( 
    nssILockType ltype,
    char *file,  
    PRIntn line )
{
    PRStatus rc;
    PZLock  *lock;
    
    /* Self Initialize the nssILock feature */
    if (!nssILockInitialized)  {
        rc = PR_CallOnce( &coNssILock, nssILockInit );
        if ( PR_FAILURE == rc ) {
            PR_SetError( PR_UNKNOWN_ERROR, 0 );
            return( NULL );
        }
    }

    lock = PR_NEWZAP( PZLock );
    if ( NULL != lock )  {
        lock->ltype = ltype;
        lock->lock = PR_NewLock();
        if ( NULL == lock->lock )  {
            PR_DELETE( lock );
            PORT_SetError(SEC_ERROR_NO_MEMORY);
        }
    } else {
            PORT_SetError(SEC_ERROR_NO_MEMORY);
    }

    Vtrace( NewLock, ltype, 0, 0, lock, line, file );
    return(lock);
} /* --- end pz_NewLock() --- */

extern void
    pz_Lock(
        PZLock *lock,
        char *file,
        PRIntn line
    )
{            
    PRIntervalTime callTime;

    callTime = PR_IntervalNow();
    PR_Lock( lock->lock );
    lock->time = PR_IntervalNow();
    callTime = lock->time - callTime;

    Vtrace( Lock, lock->ltype, callTime, 0, lock, line, file );
    return;
} /* --- end  pz_Lock() --- */

extern PRStatus
    pz_Unlock(
        PZLock *lock,
        char *file,
        PRIntn line
    ) 
{
    PRStatus rc;
    PRIntervalTime callTime, now, heldTime;

    callTime = PR_IntervalNow();
    rc = PR_Unlock( lock->lock );
    now = PR_IntervalNow(); 
    callTime = now - callTime;
    heldTime = now - lock->time;
    Vtrace( Unlock, lock->ltype, callTime, heldTime, lock, line, file );
    return( rc );
} /* --- end  pz_Unlock() --- */

extern void
    pz_DestroyLock(
        PZLock *lock,
        char *file,
        PRIntn line
    )
{
    Vtrace( DestroyLock, lock->ltype, 0, 0, lock, line, file );
    PR_DestroyLock( lock->lock );
    PR_DELETE( lock );
    return;
} /* --- end  pz_DestroyLock() --- */


extern PZCondVar *
    pz_NewCondVar(
        PZLock *lock,
        char *file,
        PRIntn line
    )
{
    PZCondVar *cvar;

    cvar = PR_NEWZAP( PZCondVar );
    if ( NULL == cvar ) {
        PORT_SetError(SEC_ERROR_NO_MEMORY);
    } else {
        cvar->ltype = lock->ltype; 
        cvar->cvar = PR_NewCondVar( lock->lock );
        if ( NULL == cvar->cvar )  {
            PR_DELETE( cvar );
            PORT_SetError(SEC_ERROR_NO_MEMORY);
        }

    }
    Vtrace( NewCondVar, lock->ltype, 0, 0, cvar, line, file );
    return( cvar );
} /* --- end  pz_NewCondVar() --- */

extern void
    pz_DestroyCondVar(
        PZCondVar *cvar,
        char *file,
        PRIntn line
    )
{
    Vtrace( DestroyCondVar, cvar->ltype, 0, 0, cvar, line, file );
    PR_DestroyCondVar( cvar->cvar );
    PR_DELETE( cvar );
} /* --- end  pz_DestroyCondVar() --- */

extern PRStatus
    pz_WaitCondVar(
        PZCondVar *cvar,
        PRIntervalTime timeout,
        char *file,
        PRIntn line
    )
{
    PRStatus    rc;
    PRIntervalTime callTime;

    callTime = PR_IntervalNow();
    rc = PR_WaitCondVar( cvar->cvar, timeout );
    callTime = PR_IntervalNow() - callTime;
    
    Vtrace( WaitCondVar, cvar->ltype, callTime, 0, cvar, line, file );
    return(rc);
} /* --- end  pz_WaitCondVar() --- */

extern PRStatus
    pz_NotifyCondVar(
        PZCondVar *cvar,
        char *file,
        PRIntn line
    )
{
    PRStatus    rc;
    
    rc = PR_NotifyCondVar( cvar->cvar );
    
    Vtrace( NotifyCondVar, cvar->ltype, 0, 0, cvar, line, file );
    return(rc);
} /* --- end  pz_NotifyCondVar() --- */

extern PRStatus
    pz_NotifyAllCondVar(
        PZCondVar *cvar,
        char *file,
        PRIntn line
    )
{
    PRStatus    rc;
    
    rc = PR_NotifyAllCondVar( cvar->cvar );
    
    Vtrace( NotifyAllCondVar, cvar->ltype, 0, 0, cvar, line, file );
    return(rc);
} /* --- end  pz_NotifyAllCondVar() --- */

extern PZMonitor *
    pz_NewMonitor( 
        nssILockType ltype,
        char *file,
        PRIntn line
    )
{
    PRStatus rc;
    PZMonitor   *mon;

    /* Self Initialize the nssILock feature */
    if (!nssILockInitialized)  {
        rc = PR_CallOnce( &coNssILock, nssILockInit );
        if ( PR_FAILURE == rc ) {
            PR_SetError( PR_UNKNOWN_ERROR, 0 );
            return( NULL );
        }
    }

    mon = PR_NEWZAP( PZMonitor );
    if ( NULL != mon )  {
        mon->ltype = ltype;
        mon->mon = PR_NewMonitor();
        if ( NULL == mon->mon )  {
            PR_DELETE( mon );
            PORT_SetError(SEC_ERROR_NO_MEMORY);
        }
    } else {
        PORT_SetError(SEC_ERROR_NO_MEMORY);
    }

    Vtrace( NewMonitor, ltype, 0, 0, mon, line, file );
    return(mon);
} /* --- end  pz_NewMonitor() --- */

extern void
    pz_DestroyMonitor(
        PZMonitor *mon,
        char *file,
        PRIntn line
    )
{
    Vtrace( DestroyMonitor, mon->ltype, 0, 0, mon, line, file );
    PR_DestroyMonitor( mon->mon );
    PR_DELETE( mon );
    return;                
} /* --- end  pz_DestroyMonitor() --- */

extern void
    pz_EnterMonitor(
        PZMonitor *mon,
        char *file,
        PRIntn line
    )
{
    PRIntervalTime callTime, now;

    callTime = PR_IntervalNow();
    PR_EnterMonitor( mon->mon );
    now = PR_IntervalNow();
    callTime = now - callTime;
    if ( PR_GetMonitorEntryCount(mon->mon) == 1 )  {
        mon->time = now;
    }
    Vtrace( EnterMonitor, mon->ltype, callTime, 0, mon, line, file );
    return;
} /* --- end  pz_EnterMonitor() --- */

extern PRStatus
    pz_ExitMonitor(
        PZMonitor *mon,
        char *file,
        PRIntn line
    )
{
    PRStatus rc;
    PRIntervalTime callTime, now, heldTime;
    PRIntn  mec = PR_GetMonitorEntryCount( mon->mon );
   
    heldTime = (PRIntervalTime)-1; 
    callTime = PR_IntervalNow();
    rc = PR_ExitMonitor( mon->mon );
    now = PR_IntervalNow();
    callTime = now - callTime;
    if ( mec == 1 )
        heldTime = now - mon->time;
    Vtrace( ExitMonitor, mon->ltype, callTime, heldTime, mon, line, file );
    return( rc );
} /* --- end  pz_ExitMonitor() --- */

extern PRIntn
    pz_GetMonitorEntryCount(
        PZMonitor *mon,
        char *file,
        PRIntn line
    )
{
    return( PR_GetMonitorEntryCount(mon->mon));
} /* --- end pz_GetMonitorEntryCount() --- */


extern PRStatus
    pz_Wait(
        PZMonitor *mon,
        PRIntervalTime ticks,
        char *file,
        PRIntn line
    )
{
    PRStatus rc;
    PRIntervalTime callTime;

    callTime = PR_IntervalNow();
    rc = PR_Wait( mon->mon, ticks );
    callTime = PR_IntervalNow() - callTime;
    Vtrace( Wait, mon->ltype, callTime, 0, mon, line, file );
    return( rc );
} /* --- end  pz_Wait() --- */

extern PRStatus
    pz_Notify(
        PZMonitor *mon,
        char *file,
        PRIntn line
    )
{
    PRStatus rc;
    PRIntervalTime callTime;

    callTime = PR_IntervalNow();
    rc = PR_Notify( mon->mon );
    callTime = PR_IntervalNow() - callTime;
    Vtrace( Notify, mon->ltype, callTime, 0, mon, line, file );
    return( rc );
} /* --- end  pz_Notify() --- */

extern PRStatus
    pz_NotifyAll(
        PZMonitor *mon,
        char *file,
        PRIntn line
    )
{
    PRStatus rc;
    PRIntervalTime callTime;

    callTime = PR_IntervalNow();
    rc = PR_NotifyAll( mon->mon );
    callTime = PR_IntervalNow() - callTime;
    Vtrace( NotifyAll, mon->ltype, callTime, 0, mon, line, file );
    return( rc );
} /* --- end  pz_NotifyAll() --- */

#endif /* NEED_NSS_ILOCK */
/* --- end nssilock.c --------------------------------- */