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 (at) 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 } 246
