2 * This program is free software; you can redistribute it and/or
3 * modify it under the terms of the GNU General Public License as
4 * published by the Free Software Foundation; either version 2 of
5 * the License, or (at your option) any later version.
7 * This program is distributed in the hope that it will be useful,
8 * but WITHOUT ANY WARRANTY; without even the implied warranty of
9 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
10 * GNU General Public License for more details.
12 * You should have received a copy of the GNU General Public License
13 * along with this program; if not, write to the Free Software
14 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
22 * Author: Arun Dharankar <ADharankar@ATTBI.Com>
24 * A very simple thread/schedular model:
25 * - only one master thread, and no parent child relation maintained
26 * - parent thread cannot be stopped or deleted
27 * - no permissions or credentials
28 * - no elaborate safety checks
29 * - cooperative multi threading
30 * - Simple round-robin scheduleing with no priorities
31 * - no metering/statistics collection
33 * Basic idea of implementing this is to allow more than one tests to
34 * execute "simultaneously".
36 * This may be modified such thread_yield may be called in syscalls, and
44 #define STK_SIZE 8*1024
47 #define STATE_RUNNABLE 1
48 #define STATE_STOPPED 2
49 #define STATE_TERMINATED 2
51 #define MASTER_THREAD 0
53 #define RC_FAILURE (-1)
54 #define RC_SUCCESS (0)
56 typedef vu_char *jmp_ctx;
57 unsigned long setctxsp (vu_char *sp);
58 int ppc_setjmp(jmp_ctx env);
59 void ppc_longjmp(jmp_ctx env, int val);
60 #define setjmp ppc_setjmp
61 #define longjmp ppc_longjmp
67 uchar context[CTX_SIZE];
71 static volatile struct lthread lthreads[MAX_THREADS];
72 static volatile int current_tid = MASTER_THREAD;
77 #define PDEBUG(fmt, args...) { \
79 printf("[%s %d %s]: ",__FILE__,__LINE__,__FUNCTION__);\
80 printf(fmt, ##args); \
85 static int testthread (void *);
86 static void sched_init (void);
87 static int thread_create (int (*func) (void *), void *arg);
88 static int thread_start (int id);
89 static void thread_yield (void);
90 static int thread_delete (int id);
91 static int thread_join (int *ret);
93 #if 0 /* not used yet */
94 static int thread_stop (int id);
95 #endif /* not used yet */
97 /* An example of schedular test */
100 int sched (int ac, char *av[])
104 int names[NUMTHREADS];
110 for (i = 0; i < NUMTHREADS; i++) {
112 j = thread_create (testthread, (void *) &names[i]);
114 printf ("schedtest: Failed to create thread %d\n", i);
116 printf ("schedtest: Created thread with id %d, name %d\n",
121 printf ("schedtest: Threads created\n");
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]);
129 printf ("schedtest: Started %d threads\n", NUMTHREADS);
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]);
142 i = thread_join (&j);
143 if (i == RC_FAILURE) {
144 printf ("schedtest: No threads pending, "
145 "exiting schedular test\n");
148 printf ("schedtest: thread is %d returned %d\n", i, j);
155 static int testthread (void *name)
159 printf ("testthread: Begin executing thread, myname %d, &i=0x%08x\n",
160 *(int *) name, (unsigned)&i);
162 printf ("Thread %02d, i=%d\n", *(int *) name, i);
164 for (i = 0; i < 0xffff * (*(int *) name + 1); i++) {
165 if (tstc () && getc () == 0x3) {
166 printf ("testthread: myname %d terminating.\n",
168 return *(int *) name + 1;
175 printf ("testthread: returning %d, i=0x%x\n",
176 *(int *) name + 1, i);
178 return *(int *) name + 1;
182 static void sched_init (void)
186 for (i = MASTER_THREAD + 1; i < MAX_THREADS; i++)
187 lthreads[i].state = STATE_EMPTY;
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);
196 static void thread_yield (void)
200 PDEBUG ("thread_yield: current tid=%d", current_tid);
202 #define SWITCH(new) \
203 if(lthreads[new].state == STATE_RUNNABLE) { \
204 PDEBUG("thread_yield: %d match, ctx=0x%08x", \
206 (unsigned)lthreads[current_tid].context); \
207 if(setjmp(lthreads[current_tid].context) == 0) { \
209 PDEBUG("thread_yield: tid %d returns 0", \
211 longjmp(lthreads[new].context, 1); \
213 PDEBUG("thread_yield: tid %d returns 1", \
219 for (i = current_tid + 1; i < MAX_THREADS; i++) {
223 if (current_tid != 0) {
224 for (i = 0; i <= current_tid; i++) {
229 PDEBUG ("thread_yield: returning from thread_yield");
233 static int thread_create (int (*func) (void *), void *arg)
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);
247 PDEBUG ("thread_create: returns failure");
251 static int thread_delete (int id)
253 if (id <= MASTER_THREAD || id > MAX_THREADS)
256 if (current_tid == id)
259 lthreads[id].state = STATE_EMPTY;
263 static void thread_launcher (void)
265 PDEBUG ("thread_launcher: invoking func=0x%08x",
266 (unsigned)lthreads[current_tid].func);
268 lthreads[current_tid].retval =
269 lthreads[current_tid].func (lthreads[current_tid].arg);
271 PDEBUG ("thread_launcher: tid %d terminated", current_tid);
273 lthreads[current_tid].state = STATE_TERMINATED;
275 printf ("thread_launcher: should NEVER get here!\n");
280 static int thread_start (int id)
282 PDEBUG ("thread_start: id=%d", id);
283 if (id <= MASTER_THREAD || id > MAX_THREADS) {
287 if (lthreads[id].state != STATE_STOPPED)
290 if (setjmp (lthreads[current_tid].context) == 0) {
291 lthreads[id].state = STATE_RUNNABLE;
293 PDEBUG ("thread_start: to be stack=0%08x",
294 (unsigned)lthreads[id].stack);
295 setctxsp ((vu_char *)<hreads[id].stack[STK_SIZE]);
299 PDEBUG ("thread_start: Thread id=%d started, parent returns", id);
304 #if 0 /* not used so far */
305 static int thread_stop (int id)
307 if (id <= MASTER_THREAD || id >= MAX_THREADS)
310 if (current_tid == id)
313 lthreads[id].state = STATE_STOPPED;
316 #endif /* not used so far */
318 static int thread_join (int *ret)
322 PDEBUG ("thread_join: *ret = %d", *ret);
324 if (!(*ret == -1 || *ret > MASTER_THREAD || *ret < MAX_THREADS)) {
325 PDEBUG ("thread_join: invalid tid %d", *ret);
330 PDEBUG ("Checking for tid = -1");
332 /* PDEBUG("thread_join: start while-loopn"); */
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 /* PDEBUG("thread_join: returning retval %d of tid %d",
343 if (lthreads[i].state != STATE_EMPTY) {
344 PDEBUG ("thread_join: %d used slots tid %d state=%d",
345 j, i, lthreads[i].state);
350 PDEBUG ("thread_join: all slots empty!");
353 /* PDEBUG("thread_join: yielding"); */
355 /* PDEBUG("thread_join: back from yield"); */
359 if (lthreads[*ret].state == STATE_TERMINATED) {
361 *ret = lthreads[*ret].retval;
362 lthreads[*ret].state = STATE_EMPTY;
363 PDEBUG ("thread_join: returing %d for tid %d", *ret, i);
367 PDEBUG ("thread_join: thread %d is not terminated!", *ret);