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Version 3.15

    1: /*
    2:  * iperf, Copyright (c) 2014, The Regents of the University of
    3:  * California, through Lawrence Berkeley National Laboratory (subject
    4:  * to receipt of any required approvals from the U.S. Dept. of
    5:  * Energy).  All rights reserved.
    6:  *
    7:  * If you have questions about your rights to use or distribute this
    8:  * software, please contact Berkeley Lab's Technology Transfer
    9:  * Department at TTD@lbl.gov.
   10:  *
   11:  * NOTICE.  This software is owned by the U.S. Department of Energy.
   12:  * As such, the U.S. Government has been granted for itself and others
   13:  * acting on its behalf a paid-up, nonexclusive, irrevocable,
   14:  * worldwide license in the Software to reproduce, prepare derivative
   15:  * works, and perform publicly and display publicly.  Beginning five
   16:  * (5) years after the date permission to assert copyright is obtained
   17:  * from the U.S. Department of Energy, and subject to any subsequent
   18:  * five (5) year renewals, the U.S. Government is granted for itself
   19:  * and others acting on its behalf a paid-up, nonexclusive,
   20:  * irrevocable, worldwide license in the Software to reproduce,
   21:  * prepare derivative works, distribute copies to the public, perform
   22:  * publicly and display publicly, and to permit others to do so.
   23:  *
   24:  * This code is distributed under a BSD style license, see the LICENSE
   25:  * file for complete information.
   26:  *
   27:  * Based on timers.c by Jef Poskanzer. Used with permission.
   28:  */
   29: 
   30: #include <sys/types.h>
   31: #include <stdlib.h>
   32: 
   33: #include "timer.h"
   34: #include "iperf_time.h"
   35: 
   36: static Timer* timers = NULL;
   37: static Timer* free_timers = NULL;
   38: 
   39: TimerClientData JunkClientData;
   40: 
   41: 
   42: 
   43: /* This is an efficiency tweak.  All the routines that need to know the
   44: ** current time get passed a pointer to a struct iperf_time.  If it's non-NULL
   45: ** it gets used, otherwise we do our own iperf_time_now() to fill it in.
   46: ** This lets the caller avoid extraneous iperf_time_now()s when efficiency
   47: ** is needed, and not bother with the extra code when efficiency doesn't
   48: ** matter too much.
   49: */
   50: static void
   51: getnow( struct iperf_time* nowP, struct iperf_time* nowP2 )
   52: {
   53:     if ( nowP != NULL )
   54: 	*nowP2 = *nowP;
   55:     else
   56: 	iperf_time_now(nowP2);
   57: }
   58: 
   59: 
   60: static void
   61: list_add( Timer* t )
   62: {
   63:     Timer* t2;
   64:     Timer* t2prev;
   65: 
   66:     if ( timers == NULL ) {
   67: 	/* The list is empty. */
   68: 	timers = t;
   69: 	t->prev = t->next = NULL;
   70:     } else {
   71: 	if (iperf_time_compare(&t->time, &timers->time) < 0) {
   72: 	    /* The new timer goes at the head of the list. */
   73: 	    t->prev = NULL;
   74: 	    t->next = timers;
   75: 	    timers->prev = t;
   76: 	    timers = t;
   77: 	} else {
   78: 	    /* Walk the list to find the insertion point. */
   79: 	    for ( t2prev = timers, t2 = timers->next; t2 != NULL;
   80: 		  t2prev = t2, t2 = t2->next ) {
   81: 		if (iperf_time_compare(&t->time, &t2->time) < 0) {
   82: 		    /* Found it. */
   83: 		    t2prev->next = t;
   84: 		    t->prev = t2prev;
   85: 		    t->next = t2;
   86: 		    t2->prev = t;
   87: 		    return;
   88: 		}
   89: 	    }
   90: 	    /* Oops, got to the end of the list.  Add to tail. */
   91: 	    t2prev->next = t;
   92: 	    t->prev = t2prev;
   93: 	    t->next = NULL;
   94: 	}
   95:     }
   96: }
   97: 
   98: 
   99: static void
  100: list_remove( Timer* t )
  101: {
  102:     if ( t->prev == NULL )
  103: 	timers = t->next;
  104:     else
  105: 	t->prev->next = t->next;
  106:     if ( t->next != NULL )
  107: 	t->next->prev = t->prev;
  108: }
  109: 
  110: 
  111: static void
  112: list_resort( Timer* t )
  113: {
  114:     /* Remove the timer from the list. */
  115:     list_remove( t );
  116:     /* And add it back in, sorted correctly. */
  117:     list_add( t );
  118: }
  119: 
  120: 
  121: Timer*
  122: tmr_create(
  123:     struct iperf_time* nowP, TimerProc* timer_proc, TimerClientData client_data,
  124:     int64_t usecs, int periodic )
  125: {
  126:     struct iperf_time now;
  127:     Timer* t;
  128: 
  129:     getnow( nowP, &now );
  130: 
  131:     if ( free_timers != NULL ) {
  132: 	t = free_timers;
  133: 	free_timers = t->next;
  134:     } else {
  135: 	t = (Timer*) malloc( sizeof(Timer) );
  136: 	if ( t == NULL )
  137: 	    return NULL;
  138:     }
  139: 
  140:     t->timer_proc = timer_proc;
  141:     t->client_data = client_data;
  142:     t->usecs = usecs;
  143:     t->periodic = periodic;
  144:     t->time = now;
  145:     iperf_time_add_usecs(&t->time, usecs);
  146:     /* Add the new timer to the active list. */
  147:     list_add( t );
  148: 
  149:     return t;
  150: }
  151: 
  152: 
  153: struct timeval*
  154: tmr_timeout( struct iperf_time* nowP )
  155: {
  156:     struct iperf_time now, diff;
  157:     int64_t usecs;
  158:     int past;
  159:     static struct timeval timeout;
  160: 
  161:     getnow( nowP, &now );
  162:     /* Since the list is sorted, we only need to look at the first timer. */
  163:     if ( timers == NULL )
  164: 	return NULL;
  165:     past = iperf_time_diff(&timers->time, &now, &diff);
  166:     if (past)
  167:         usecs = 0;
  168:     else
  169:         usecs = iperf_time_in_usecs(&diff);
  170:     timeout.tv_sec = usecs / 1000000LL;
  171:     timeout.tv_usec = usecs % 1000000LL;
  172:     return &timeout;
  173: }
  174: 
  175: 
  176: void
  177: tmr_run( struct iperf_time* nowP )
  178: {
  179:     struct iperf_time now;
  180:     Timer* t;
  181:     Timer* next;
  182: 
  183:     getnow( nowP, &now );
  184:     for ( t = timers; t != NULL; t = next ) {
  185: 	next = t->next;
  186: 	/* Since the list is sorted, as soon as we find a timer
  187: 	** that isn't ready yet, we are done.
  188: 	*/
  189: 	if (iperf_time_compare(&t->time, &now) > 0)
  190: 	    break;
  191: 	(t->timer_proc)( t->client_data, &now );
  192: 	if ( t->periodic ) {
  193: 	    /* Reschedule. */
  194: 	    iperf_time_add_usecs(&t->time, t->usecs);
  195: 	    list_resort( t );
  196: 	} else
  197: 	    tmr_cancel( t );
  198:     }
  199: }
  200: 
  201: 
  202: void
  203: tmr_reset( struct iperf_time* nowP, Timer* t )
  204: {
  205:     struct iperf_time now;
  206: 
  207:     getnow( nowP, &now );
  208:     t->time = now;
  209:     iperf_time_add_usecs( &t->time, t->usecs );
  210:     list_resort( t );
  211: }
  212: 
  213: 
  214: void
  215: tmr_cancel( Timer* t )
  216: {
  217:     /* Remove it from the active list. */
  218:     list_remove( t );
  219:     /* And put it on the free list. */
  220:     t->next = free_timers;
  221:     free_timers = t;
  222:     t->prev = NULL;
  223: }
  224: 
  225: 
  226: void
  227: tmr_cleanup( void )
  228: {
  229:     Timer* t;
  230: 
  231:     while ( free_timers != NULL ) {
  232: 	t = free_timers;
  233: 	free_timers = t->next;
  234: 	free( (void*) t );
  235:     }
  236: }
  237: 
  238: 
  239: void
  240: tmr_destroy( void )
  241: {
  242:     while ( timers != NULL )
  243: 	tmr_cancel( timers );
  244:     tmr_cleanup();
  245: }