1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18#include <common.h>
19#include <exports.h>
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41#define MAX_THREADS 8
42
43#define CTX_SIZE 512
44#define STK_SIZE 8*1024
45
46#define STATE_EMPTY 0
47#define STATE_RUNNABLE 1
48#define STATE_STOPPED 2
49#define STATE_TERMINATED 2
50
51#define MASTER_THREAD 0
52
53#define RC_FAILURE (-1)
54#define RC_SUCCESS (0)
55
56typedef vu_char *jmp_ctx;
57unsigned long setctxsp (vu_char *sp);
58int ppc_setjmp(jmp_ctx env);
59void ppc_longjmp(jmp_ctx env, int val);
60#define setjmp ppc_setjmp
61#define longjmp ppc_longjmp
62
63struct lthread {
64 int state;
65 int retval;
66 char stack[STK_SIZE];
67 uchar context[CTX_SIZE];
68 int (*func) (void *);
69 void *arg;
70};
71static volatile struct lthread lthreads[MAX_THREADS];
72static volatile int current_tid = MASTER_THREAD;
73
74
75static uchar dbg = 0;
76
77#define PDEBUG(fmt, args...) { \
78 if(dbg != 0) { \
79 printf("[%s %d %s]: ",__FILE__,__LINE__,__FUNCTION__);\
80 printf(fmt, ##args); \
81 printf("\n"); \
82 } \
83}
84
85static int testthread (void *);
86static void sched_init (void);
87static int thread_create (int (*func) (void *), void *arg);
88static int thread_start (int id);
89static void thread_yield (void);
90static int thread_delete (int id);
91static int thread_join (int *ret);
92
93#if 0
94static int thread_stop (int id);
95#endif
96
97
98
99#define NUMTHREADS 7
100int sched (int ac, char *av[])
101{
102 int i, j;
103 int tid[NUMTHREADS];
104 int names[NUMTHREADS];
105
106 app_startup(av);
107
108 sched_init ();
109
110 for (i = 0; i < NUMTHREADS; i++) {
111 names[i] = i;
112 j = thread_create (testthread, (void *) &names[i]);
113 if (j == RC_FAILURE)
114 printf ("schedtest: Failed to create thread %d\n", i);
115 if (j > 0) {
116 printf ("schedtest: Created thread with id %d, name %d\n",
117 j, i);
118 tid[i] = j;
119 }
120 }
121 printf ("schedtest: Threads created\n");
122
123 printf ("sched_test: function=0x%08x\n", (unsigned)testthread);
124 for (i = 0; i < NUMTHREADS; i++) {
125 printf ("schedtest: Setting thread %d runnable\n", tid[i]);
126 thread_start (tid[i]);
127 thread_yield ();
128 }
129 printf ("schedtest: Started %d threads\n", NUMTHREADS);
130
131 while (1) {
132 printf ("schedtest: Waiting for threads to complete\n");
133 if (tstc () && getc () == 0x3) {
134 printf ("schedtest: Aborting threads...\n");
135 for (i = 0; i < NUMTHREADS; i++) {
136 printf ("schedtest: Deleting thread %d\n", tid[i]);
137 thread_delete (tid[i]);
138 }
139 return RC_SUCCESS;
140 }
141 j = -1;
142 i = thread_join (&j);
143 if (i == RC_FAILURE) {
144 printf ("schedtest: No threads pending, "
145 "exiting schedular test\n");
146 return RC_SUCCESS;
147 }
148 printf ("schedtest: thread is %d returned %d\n", i, j);
149 thread_yield ();
150 }
151
152 return RC_SUCCESS;
153}
154
155static int testthread (void *name)
156{
157 int i;
158
159 printf ("testthread: Begin executing thread, myname %d, &i=0x%08x\n",
160 *(int *) name, (unsigned)&i);
161
162 printf ("Thread %02d, i=%d\n", *(int *) name, i);
163
164 for (i = 0; i < 0xffff * (*(int *) name + 1); i++) {
165 if (tstc () && getc () == 0x3) {
166 printf ("testthread: myname %d terminating.\n",
167 *(int *) name);
168 return *(int *) name + 1;
169 }
170
171 if (i % 100 == 0)
172 thread_yield ();
173 }
174
175 printf ("testthread: returning %d, i=0x%x\n",
176 *(int *) name + 1, i);
177
178 return *(int *) name + 1;
179}
180
181
182static void sched_init (void)
183{
184 int i;
185
186 for (i = MASTER_THREAD + 1; i < MAX_THREADS; i++)
187 lthreads[i].state = STATE_EMPTY;
188
189 current_tid = MASTER_THREAD;
190 lthreads[current_tid].state = STATE_RUNNABLE;
191 PDEBUG ("sched_init: master context = 0x%08x",
192 (unsigned)lthreads[current_tid].context);
193 return;
194}
195
196static void thread_yield (void)
197{
198 static int i;
199
200 PDEBUG ("thread_yield: current tid=%d", current_tid);
201
202#define SWITCH(new) \
203 if(lthreads[new].state == STATE_RUNNABLE) { \
204 PDEBUG("thread_yield: %d match, ctx=0x%08x", \
205 new, \
206 (unsigned)lthreads[current_tid].context); \
207 if(setjmp(lthreads[current_tid].context) == 0) { \
208 current_tid = new; \
209 PDEBUG("thread_yield: tid %d returns 0", \
210 new); \
211 longjmp(lthreads[new].context, 1); \
212 } else { \
213 PDEBUG("thread_yield: tid %d returns 1", \
214 new); \
215 return; \
216 } \
217 }
218
219 for (i = current_tid + 1; i < MAX_THREADS; i++) {
220 SWITCH (i);
221 }
222
223 if (current_tid != 0) {
224 for (i = 0; i <= current_tid; i++) {
225 SWITCH (i);
226 }
227 }
228
229 PDEBUG ("thread_yield: returning from thread_yield");
230 return;
231}
232
233static int thread_create (int (*func) (void *), void *arg)
234{
235 int i;
236
237 for (i = MASTER_THREAD + 1; i < MAX_THREADS; i++) {
238 if (lthreads[i].state == STATE_EMPTY) {
239 lthreads[i].state = STATE_STOPPED;
240 lthreads[i].func = func;
241 lthreads[i].arg = arg;
242 PDEBUG ("thread_create: returns new tid %d", i);
243 return i;
244 }
245 }
246
247 PDEBUG ("thread_create: returns failure");
248 return RC_FAILURE;
249}
250
251static int thread_delete (int id)
252{
253 if (id <= MASTER_THREAD || id > MAX_THREADS)
254 return RC_FAILURE;
255
256 if (current_tid == id)
257 return RC_FAILURE;
258
259 lthreads[id].state = STATE_EMPTY;
260 return RC_SUCCESS;
261}
262
263static void thread_launcher (void)
264{
265 PDEBUG ("thread_launcher: invoking func=0x%08x",
266 (unsigned)lthreads[current_tid].func);
267
268 lthreads[current_tid].retval =
269 lthreads[current_tid].func (lthreads[current_tid].arg);
270
271 PDEBUG ("thread_launcher: tid %d terminated", current_tid);
272
273 lthreads[current_tid].state = STATE_TERMINATED;
274 thread_yield ();
275 printf ("thread_launcher: should NEVER get here!\n");
276
277 return;
278}
279
280static int thread_start (int id)
281{
282 PDEBUG ("thread_start: id=%d", id);
283 if (id <= MASTER_THREAD || id > MAX_THREADS) {
284 return RC_FAILURE;
285 }
286
287 if (lthreads[id].state != STATE_STOPPED)
288 return RC_FAILURE;
289
290 if (setjmp (lthreads[current_tid].context) == 0) {
291 lthreads[id].state = STATE_RUNNABLE;
292 current_tid = id;
293 PDEBUG ("thread_start: to be stack=0%08x",
294 (unsigned)lthreads[id].stack);
295 setctxsp ((vu_char *)<hreads[id].stack[STK_SIZE]);
296 thread_launcher ();
297 }
298
299 PDEBUG ("thread_start: Thread id=%d started, parent returns", id);
300
301 return RC_SUCCESS;
302}
303
304#if 0
305static int thread_stop (int id)
306{
307 if (id <= MASTER_THREAD || id >= MAX_THREADS)
308 return RC_FAILURE;
309
310 if (current_tid == id)
311 return RC_FAILURE;
312
313 lthreads[id].state = STATE_STOPPED;
314 return RC_SUCCESS;
315}
316#endif
317
318static int thread_join (int *ret)
319{
320 int i, j = 0;
321
322 PDEBUG ("thread_join: *ret = %d", *ret);
323
324 if (!(*ret == -1 || *ret > MASTER_THREAD || *ret < MAX_THREADS)) {
325 PDEBUG ("thread_join: invalid tid %d", *ret);
326 return RC_FAILURE;
327 }
328
329 if (*ret == -1) {
330 PDEBUG ("Checking for tid = -1");
331 while (1) {
332
333 j = 0;
334 for (i = MASTER_THREAD + 1; i < MAX_THREADS; i++) {
335 if (lthreads[i].state == STATE_TERMINATED) {
336 *ret = lthreads[i].retval;
337 lthreads[i].state = STATE_EMPTY;
338
339
340 return RC_SUCCESS;
341 }
342
343 if (lthreads[i].state != STATE_EMPTY) {
344 PDEBUG ("thread_join: %d used slots tid %d state=%d",
345 j, i, lthreads[i].state);
346 j++;
347 }
348 }
349 if (j == 0) {
350 PDEBUG ("thread_join: all slots empty!");
351 return RC_FAILURE;
352 }
353
354 thread_yield ();
355
356 }
357 }
358
359 if (lthreads[*ret].state == STATE_TERMINATED) {
360 i = *ret;
361 *ret = lthreads[*ret].retval;
362 lthreads[*ret].state = STATE_EMPTY;
363 PDEBUG ("thread_join: returing %d for tid %d", *ret, i);
364 return RC_SUCCESS;
365 }
366
367 PDEBUG ("thread_join: thread %d is not terminated!", *ret);
368 return RC_FAILURE;
369}
370
