gonzui

    1: /*
    2:  *----------------------------------------------------------------------
    3:  *    T-Kernel 2.0 Software Package
    4:  *
    5:  *    Copyright 2011 by Ken Sakamura.
    6:  *    This software is distributed under the latest version of T-License 2.x.
    7:  *----------------------------------------------------------------------
    8:  *
    9:  *    Released by T-Engine Forum(http://www.t-engine.org/) at 2011/05/17.
   10:  *    Modified by T-Engine Forum at 2014/09/10.
   11:  *    Modified by TRON Forum(http://www.tron.org/) at 2015/06/01.
   12:  *
   13:  *----------------------------------------------------------------------
   14:  */
   15: 
   16: /*
   17:  *      @(#)fastlock.c (libtk)
   18:  *
   19:  *      High-speed exclusive control lock
   20:  */
   21: 
   22: #include <basic.h>
   23: #include <tk/tkernel.h>
   24: #include <tk/util.h>
   25: #include <libstr.h>
   26: 
   27: /* ------------------------------------------------------------------------ */
   28: /*
   29:  *      Inc  Increment cnt, in result if cnt >  0, returns positive value.
   30:  *              If cnt <= 0, returns 0 or negative value.
   31:  *      Dec  Decrement cnt, in result if cnt >= 0, returns positive value.
   32:  *              If cnt <  0, returns 0 or negative value.
   33:  *      Increment/Decrement and evaluation of the associated result must
   34:  *      be executed exclusively.
   35:  */
   36: 
   37: Inline INT Inc( FastLock *lock )
   38: {
   39:         UINT   imask;
   40:         INT    c;
   41:         DI(imask);
   42:         c = ++lock->cnt;
   43:         EI(imask);
   44:         return c;
   45: }
   46: Inline INT Dec( FastLock *lock )
   47: {
   48:         UINT   imask;
   49:         INT    c;
   50:         DI(imask);
   51:         c = lock->cnt--;
   52:         EI(imask);
   53:         return c;
   54: }
   55: 
   56: /* ------------------------------------------------------------------------ */
   57: 
   58: /*
   59:  * Lock
   60:  */
   61: EXPORT void Lock( FastLock *lock )
   62: {
   63:         if ( Inc(lock) > 0 ) {
   64:                 tk_wai_sem(lock->id, 1, TMO_FEVR);
   65:         }
   66: }
   67: 
   68: /*
   69:  * Lock release
   70:  */
   71: EXPORT void Unlock( FastLock *lock )
   72: {
   73:         if ( Dec(lock) > 0 ) {
   74:                 tk_sig_sem(lock->id, 1);
   75:         }
   76: }
   77: 
   78: /*
   79:  * Create high-speed lock
   80:  */
   81: EXPORT ER CreateLock( FastLock *lock, CONST UB *name )
   82: {
   83:         T_CSEM csem;
   84:         ER     ercd;
   85: 
   86:         if ( name == NULL ) {
   87:                 csem.exinf = NULL;
   88:         } else {
   89:                 STRNCPY((char*)&csem.exinf, (char*)name, sizeof(csem.exinf));
   90:         }
   91:         csem.sematr  = TA_TPRI | TA_NODISWAI;
   92:         csem.isemcnt = 0;
   93:         csem.maxsem  = 1;
   94: 
   95:         ercd = tk_cre_sem(&csem);
   96:         if ( ercd < E_OK ) {
   97:                 return ercd;
   98:         }
   99: 
  100:         lock->id = ercd;
  101:         lock->cnt = -1;
  102: 
  103:         return E_OK;
  104: }
  105: 
  106: /*
  107:  * Delete high-speed lock
  108:  */
  109: EXPORT void DeleteLock( FastLock *lock )
  110: {
  111:         if ( lock->id > 0 ) {
  112:                 tk_del_sem(lock->id);
  113:         }
  114:         lock->id = 0;
  115: }