/* ***** BEGIN LICENSE BLOCK *****
 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is the Netscape security libraries.
 *
 * The Initial Developer of the Original Code is
 * Netscape Communications Corporation.
 * Portions created by the Initial Developer are Copyright (C) 1994-2000
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *
 * Alternatively, the contents of this file may be used under the terms of
 * either the GNU General Public License Version 2 or later (the "GPL"), or
 * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
 * of those above. If you wish to allow use of your version of this file only
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 * the provisions above, a recipient may use your version of this file under
 * the terms of any one of the MPL, the GPL or the LGPL.
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 * ***** END LICENSE BLOCK ***** */

#ifdef DEBUG
static const char CVS_ID[] = "@(#) $RCSfile: mutex.c,v $ $Revision: 1.7 $ $Date: 2005/08/25 20:08:26 $";
#endif /* DEBUG */

/*
 * mutex.c
 *
 * This file implements a mutual-exclusion locking facility for Modules
 * using the NSS Cryptoki Framework.
 */

#ifndef CK_T
#include "ck.h"
#endif /* CK_T */

/*
 * NSSCKFWMutex
 *
 *  NSSCKFWMutex_Destroy
 *  NSSCKFWMutex_Lock
 *  NSSCKFWMutex_Unlock
 *
 *  nssCKFWMutex_Create
 *  nssCKFWMutex_Destroy
 *  nssCKFWMutex_Lock
 *  nssCKFWMutex_Unlock
 *
 *  -- debugging versions only --
 *  nssCKFWMutex_verifyPointer
 *
 */

struct NSSCKFWMutexStr {
  PRLock *lock;
};

#ifdef DEBUG
/*
 * But first, the pointer-tracking stuff.
 *
 * NOTE: the pointer-tracking support in NSS/base currently relies
 * upon NSPR's CallOnce support.  That, however, relies upon NSPR's
 * locking, which is tied into the runtime.  We need a pointer-tracker
 * implementation that uses the locks supplied through C_Initialize.
 * That support, however, can be filled in later.  So for now, I'll
 * just do this routines as no-ops.
 */

static CK_RV
mutex_add_pointer
(
  const NSSCKFWMutex *fwMutex
)
{
  return CKR_OK;
}

static CK_RV
mutex_remove_pointer
(
  const NSSCKFWMutex *fwMutex
)
{
  return CKR_OK;
}

NSS_IMPLEMENT CK_RV
nssCKFWMutex_verifyPointer
(
  const NSSCKFWMutex *fwMutex
)
{
  return CKR_OK;
}

#endif /* DEBUG */

static CK_RV
mutex_noop
(
  CK_VOID_PTR pMutex
)
{
  return CKR_OK;
}

/*
 * nssCKFWMutex_Create
 *
 */
NSS_EXTERN NSSCKFWMutex *
nssCKFWMutex_Create
(
  CK_C_INITIALIZE_ARGS_PTR pInitArgs,
  CryptokiLockingState LockingState,
  NSSArena *arena,
  CK_RV *pError
)
{
  NSSCKFWMutex *mutex;
  
  mutex = nss_ZNEW(arena, NSSCKFWMutex);
  if( (NSSCKFWMutex *)NULL == mutex ) {
    *pError = CKR_HOST_MEMORY;
    return (NSSCKFWMutex *)NULL;
  }
  *pError = CKR_OK;
  mutex->lock = NULL;
  if (LockingState == MultiThreaded) {
    mutex->lock = PR_NewLock();
    if (!mutex->lock) {
      *pError = CKR_HOST_MEMORY; /* we couldn't get the resource */
    }
  }
    
  if( CKR_OK != *pError ) {
    (void)nss_ZFreeIf(mutex);
    return (NSSCKFWMutex *)NULL;
  }

#ifdef DEBUG
  *pError = mutex_add_pointer(mutex);
  if( CKR_OK != *pError ) {
    if (mutex->lock) {
      PR_DestroyLock(mutex->lock);
    }
    (void)nss_ZFreeIf(mutex);
    return (NSSCKFWMutex *)NULL;
  }
#endif /* DEBUG */

  return mutex;
}  

/*
 * nssCKFWMutex_Destroy
 *
 */
NSS_EXTERN CK_RV
nssCKFWMutex_Destroy
(
  NSSCKFWMutex *mutex
)
{
  CK_RV rv = CKR_OK;

#ifdef NSSDEBUG
  rv = nssCKFWMutex_verifyPointer(mutex);
  if( CKR_OK != rv ) {
    return rv;
  }
#endif /* NSSDEBUG */
 
  if (mutex->lock) {
    PR_DestroyLock(mutex->lock);
  } 

#ifdef DEBUG
  (void)mutex_remove_pointer(mutex);
#endif /* DEBUG */

  (void)nss_ZFreeIf(mutex);
  return rv;
}

/*
 * nssCKFWMutex_Lock
 *
 */
NSS_EXTERN CK_RV
nssCKFWMutex_Lock
(
  NSSCKFWMutex *mutex
)
{
#ifdef NSSDEBUG
  CK_RV rv = nssCKFWMutex_verifyPointer(mutex);
  if( CKR_OK != rv ) {
    return rv;
  }
#endif /* NSSDEBUG */
  if (mutex->lock) {
    PR_Lock(mutex->lock);
  }
  
  return CKR_OK;
}

/*
 * nssCKFWMutex_Unlock
 *
 */
NSS_EXTERN CK_RV
nssCKFWMutex_Unlock
(
  NSSCKFWMutex *mutex
)
{
  PRStatus nrv;
#ifdef NSSDEBUG
  CK_RV rv = nssCKFWMutex_verifyPointer(mutex);

  if( CKR_OK != rv ) {
    return rv;
  }
#endif /* NSSDEBUG */

  if (!mutex->lock) 
    return CKR_OK;

  nrv =  PR_Unlock(mutex->lock);

  /* if unlock fails, either we have a programming error, or we have
   * some sort of hardware failure... in either case return CKR_DEVICE_ERROR.
   */
  return nrv == PR_SUCCESS ? CKR_OK : CKR_DEVICE_ERROR;
}

/*
 * NSSCKFWMutex_Destroy
 *
 */
NSS_EXTERN CK_RV
NSSCKFWMutex_Destroy
(
  NSSCKFWMutex *mutex
)
{
#ifdef DEBUG
  CK_RV rv = nssCKFWMutex_verifyPointer(mutex);
  if( CKR_OK != rv ) {
    return rv;
  }
#endif /* DEBUG */
  
  return nssCKFWMutex_Destroy(mutex);
}

/*
 * NSSCKFWMutex_Lock
 *
 */
NSS_EXTERN CK_RV
NSSCKFWMutex_Lock
(
  NSSCKFWMutex *mutex
)
{
#ifdef DEBUG
  CK_RV rv = nssCKFWMutex_verifyPointer(mutex);
  if( CKR_OK != rv ) {
    return rv;
  }
#endif /* DEBUG */
  
  return nssCKFWMutex_Lock(mutex);
}

/*
 * NSSCKFWMutex_Unlock
 *
 */
NSS_EXTERN CK_RV
NSSCKFWMutex_Unlock
(
  NSSCKFWMutex *mutex
)
{
#ifdef DEBUG
  CK_RV rv = nssCKFWMutex_verifyPointer(mutex);
  if( CKR_OK != rv ) {
    return rv;
  }
#endif /* DEBUG */

  return nssCKFWMutex_Unlock(mutex);
}

