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
getnow(struct iperf_time * nowP,struct iperf_time * nowP2)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
list_add(Timer * t)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
list_remove(Timer * t)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
list_resort(Timer * t)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*
tmr_create(struct iperf_time * nowP,TimerProc * timer_proc,TimerClientData client_data,int64_t usecs,int periodic)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*
tmr_timeout(struct iperf_time * nowP)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
tmr_run(struct iperf_time * nowP)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
tmr_reset(struct iperf_time * nowP,Timer * t)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
tmr_cancel(Timer * t)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
tmr_cleanup(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
tmr_destroy(void)240 tmr_destroy( void )
241 {
242 while ( timers != NULL )
243 tmr_cancel( timers );
244 tmr_cleanup();
245 }
246