#include #include #include #include #include #include #include #include #include //#define DEBUG_ENABLED #include "gst/gst.h" #include "cothreads.h" #include "gst/gstarch.h" pthread_key_t _cothread_key = -1; cothread_state *cothread_create(cothread_context *ctx) { cothread_state *s; DEBUG("cothread: pthread_self() %ld\n",pthread_self()); //if (pthread_self() == 0) { if (0) { s = (cothread_state *)malloc(sizeof(int) * COTHREAD_STACKSIZE); DEBUG("cothread: new stack at %p\n",s); } else { char *sp = CURRENT_STACK_FRAME; unsigned long *stack_end = (unsigned long *)((unsigned long)sp & ~(STACK_SIZE - 1)); s = (cothread_state *)(stack_end + ((ctx->nthreads - 1) * COTHREAD_STACKSIZE)); if (mmap((char *)s,COTHREAD_STACKSIZE*(sizeof(int)), PROT_READ|PROT_WRITE|PROT_EXEC,MAP_PRIVATE|MAP_ANONYMOUS, -1,0) < 0) { perror("mmap'ing cothread stack space"); return NULL; } } s->ctx = ctx; s->threadnum = ctx->nthreads; s->flags = 0; s->sp = ((int *)s + COTHREAD_STACKSIZE); ctx->threads[ctx->nthreads++] = s; DEBUG("cothread: created cothread at %p %p\n",s, s->sp); return s; } void cothread_setfunc(cothread_state *thread,cothread_func func,int argc,char **argv) { thread->func = func; thread->argc = argc; thread->argv = argv; thread->pc = (int *)func; } cothread_context *cothread_init() { cothread_context *ctx = (cothread_context *)malloc(sizeof(cothread_context)); if (_cothread_key == -1) { if (pthread_key_create(&_cothread_key,NULL) != 0) { perror("pthread_key_create"); return NULL; } } pthread_setspecific(_cothread_key,ctx); memset(ctx->threads,0,sizeof(ctx->threads)); ctx->threads[0] = (cothread_state *)malloc(sizeof(cothread_state)); ctx->threads[0]->ctx = ctx; ctx->threads[0]->threadnum = 0; ctx->threads[0]->func = NULL; ctx->threads[0]->argc = 0; ctx->threads[0]->argv = NULL; ctx->threads[0]->flags = COTHREAD_STARTED; ctx->threads[0]->sp = (int *)CURRENT_STACK_FRAME; ctx->threads[0]->pc = 0; DEBUG("cothread: 0th thread is at %p %p\n",ctx->threads[0], ctx->threads[0]->sp); // we consider the initiating process to be cothread 0 ctx->nthreads = 1; ctx->current = 0; return ctx; } cothread_state *cothread_main(cothread_context *ctx) { // fprintf(stderr,"returning %p, the 0th cothread\n",ctx->threads[0]); return ctx->threads[0]; } void cothread_stub() { cothread_context *ctx = pthread_getspecific(_cothread_key); register cothread_state *thread = ctx->threads[ctx->current]; DEBUG("cothread: cothread_stub() entered\n"); thread->flags |= COTHREAD_STARTED; if (thread->func) thread->func(thread->argc,thread->argv); thread->flags &= ~COTHREAD_STARTED; thread->pc = 0; DEBUG("cothread: cothread_stub() exit\n"); //printf("uh, yeah, we shouldn't be here, but we should deal anyway\n"); } void cothread_switch(cothread_state *thread) { cothread_context *ctx; cothread_state *current; int enter; // int i; if (thread == NULL) return; ctx = thread->ctx; current = ctx->threads[ctx->current]; if (current == NULL) { g_print("cothread: there's no current thread, help!\n"); exit(2); } /* if (current == thread) { g_print("cothread: trying to switch to same thread, legal but not necessary\n"); //return; } */ // find the number of the thread to switch to ctx->current = thread->threadnum; DEBUG("cothread: about to switch to thread #%d\n",ctx->current); /* save the current stack pointer, frame pointer, and pc */ GET_SP(current->sp); enter = setjmp(current->jmp); DEBUG("cothread: after thread #%d %d\n",ctx->current, enter); if (enter != 0) { return; } enter = 1; DEBUG("cothread: set stack to %p\n", thread->sp); /* restore stack pointer and other stuff of new cothread */ if (thread->flags & COTHREAD_STARTED) { DEBUG("cothread: in thread \n"); SET_SP(thread->sp); // switch to it longjmp(thread->jmp,1); } else { SETUP_STACK(thread->sp); SET_SP(thread->sp); // start it //JUMP(cothread_stub); cothread_stub(); DEBUG("cothread: exit thread \n"); } }