1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
|
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <unistd.h>
#include <assert.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
/* Include gettid() */
#include <sys/types.h>
/* Include threading support. */
#include <pthread.h>
/* Include the LITMUS^RT API.*/
#include "litmus.h"
/* Catch errors.
*/
#define CALL( exp ) do { \
int ret; \
ret = exp; \
if (ret != 0) \
fprintf(stderr, "%s failed: %m\n", #exp);\
else \
fprintf(stderr, "%s ok.\n", #exp); \
} while (0)
#define TH_CALL( exp ) do { \
int ret; \
ret = exp; \
if (ret != 0) \
fprintf(stderr, "[%d] %s failed: %m\n", ctx->id, #exp); \
else \
fprintf(stderr, "[%d] %s ok.\n", ctx->id, #exp); \
} while (0)
#define TH_SAFE_CALL( exp ) do { \
int ret; \
fprintf(stderr, "[%d] calling %s...\n", ctx->id, #exp); \
ret = exp; \
if (ret != 0) \
fprintf(stderr, "\t...[%d] %s failed: %m\n", ctx->id, #exp); \
else \
fprintf(stderr, "\t...[%d] %s ok.\n", ctx->id, #exp); \
} while (0)
#define NUM_CPUS 4
//#define NUM_THREADS 3
int NUM_THREADS=3;
/* NEST_DEPTH may not be greater than NUM_SEMS. */
//#define NUM_SEMS 10
int NUM_SEMS=10;
int SLEEP_BETWEEN_JOBS = 1;
int USE_PRIOQ = 0;
#define MAX_SEMS 1000
//#define NEST_DEPTH 5
int NEST_DEPTH=5;
#define EXEC_COST 1000*1
#define PERIOD 1000*10
/* The information passed to each thread. Could be anything. */
struct thread_context {
int id;
int fd;
int od[MAX_SEMS];
int count;
unsigned int rand;
};
void* rt_thread(void* _ctx);
int nested_job(struct thread_context* ctx, int *count, int *next);
int job(struct thread_context*);
#define OPTSTR "t:s:d:fq"
int main(int argc, char** argv)
{
int i;
struct thread_context* ctx; //[NUM_THREADS];
pthread_t* task; //[NUM_THREADS];
int fd;
int opt;
while((opt = getopt(argc, argv, OPTSTR)) != -1) {
switch(opt) {
case 't':
NUM_THREADS = atoi(optarg);
break;
case 's':
NUM_SEMS = atoi(optarg);
assert(NUM_SEMS <= MAX_SEMS);
break;
case 'd':
NEST_DEPTH = atoi(optarg);
break;
case 'f':
SLEEP_BETWEEN_JOBS = 0;
break;
case 'q':
USE_PRIOQ = 1;
break;
default:
fprintf(stderr, "Unknown option: %c\n", opt);
exit(-1);
break;
}
}
ctx = (struct thread_context*) calloc(NUM_THREADS, sizeof(struct thread_context));
task = (pthread_t*) calloc(NUM_THREADS, sizeof(pthread_t));
srand(0); /* something repeatable for now */
fd = open("semaphores", O_RDONLY | O_CREAT, S_IRUSR | S_IWUSR);
CALL( init_litmus() );
for (i = 0; i < NUM_THREADS; i++) {
ctx[i].id = i;
ctx[i].fd = fd;
ctx[i].rand = rand();
CALL( pthread_create(task + i, NULL, rt_thread, ctx + i) );
}
for (i = 0; i < NUM_THREADS; i++)
pthread_join(task[i], NULL);
return 0;
}
void* rt_thread(void* _ctx)
{
int i;
int do_exit = 0;
struct rt_task param;
struct thread_context *ctx = (struct thread_context*)_ctx;
init_rt_task_param(¶m);
param.exec_cost = EXEC_COST;
param.period = PERIOD + 10*ctx->id;
param.cls = RT_CLASS_SOFT;
/* Make presence visible. */
//printf("RT Thread %d active.\n", ctx->id);
TH_CALL( init_rt_thread() );
TH_CALL( set_rt_task_param(gettid(), ¶m) );
for (i = 0; i < NUM_SEMS; i++) {
if (!USE_PRIOQ) {
ctx->od[i] = open_fifo_sem(ctx->fd, i);
if(ctx->od[i] < 0)
perror("open_fifo_sem");
}
else {
ctx->od[i] = open_prioq_sem(ctx->fd, i);
if(ctx->od[i] < 0)
perror("open_prioq_sem");
}
//printf("[%d] ctx->od[%d]: %d\n", ctx->id, i, ctx->od[i]);
}
TH_CALL( task_mode(LITMUS_RT_TASK) );
printf("[%d] Waiting for TS release.\n ", ctx->id);
wait_for_ts_release();
ctx->count = 0;
do {
int first = (int)(NUM_SEMS * (rand_r(&(ctx->rand)) / (RAND_MAX + 1.0)));
int count = NEST_DEPTH;
do_exit = nested_job(ctx, &count, &first);
if(SLEEP_BETWEEN_JOBS && !do_exit) {
sleep_next_period();
}
} while(!do_exit);
/*****
* 4) Transition to background mode.
*/
TH_CALL( task_mode(BACKGROUND_TASK) );
return NULL;
}
int nested_job(struct thread_context* ctx, int *count, int *next)
{
int ret;
if(*count == 0 || *next == NUM_SEMS) /* base case */
{
ret = job(ctx);
}
else
{
int which_sem = ctx->od[*next];
++(*next);
--(*count);
printf("[%d]: trying to get semaphore %d.\n", ctx->id, which_sem);
fflush(stdout);
TH_SAFE_CALL ( litmus_lock(which_sem) );
printf("[%d] got semaphore %d.\n", ctx->id, which_sem);
fflush(stdout);
ret = nested_job(ctx, count, next);
TH_SAFE_CALL ( litmus_unlock(which_sem) );
fflush(stdout);
}
return(ret);
}
void dirty_kb(int kb)
{
int32_t one_kb[256];
int32_t sum = 0;
int32_t i;
for (i = 0; i < 256; i++)
sum += one_kb[i];
kb--;
/* prevent tail recursion */
if (kb)
dirty_kb(kb);
for (i = 0; i < 256; i++)
sum += one_kb[i];
}
int job(struct thread_context* ctx)
{
/* Do real-time calculation. */
dirty_kb(8);
/* Don't exit. */
//return ctx->count++ > 100;
//return ctx->count++ > 12000;
//return ctx->count++ > 120000;
return ctx->count++ > 30000;
}
|
