X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/400d76d6ab5e73b056aabdf9ef2842d8a495b500..dfe761f4bc8d35a74c3da5fabe99630c0788001f:/src/xbt/context.c diff --git a/src/xbt/context.c b/src/xbt/context.c index 2091bb7a0e..4f4edcaf46 100644 --- a/src/xbt/context.c +++ b/src/xbt/context.c @@ -13,9 +13,10 @@ #include "context_private.h" #include "xbt/log.h" #include "xbt/dynar.h" -#include "gras_config.h" +#include "xbt/xbt_os_thread.h" +#include "xbt/ex_interface.h" -XBT_LOG_NEW_DEFAULT_SUBCATEGORY(context, xbt, "Context"); +XBT_LOG_NEW_DEFAULT_SUBCATEGORY(xbt_ctx, xbt, "Context"); #define VOIRP(expr) DEBUG1(" {" #expr " = %p }", expr) @@ -24,153 +25,49 @@ static xbt_context_t init_context = NULL; static xbt_swag_t context_to_destroy = NULL; static xbt_swag_t context_living = NULL; -#ifndef USE_PTHREADS /* USE_PTHREADS and USE_CONTEXT are exclusive */ -# ifndef USE_UCONTEXT -/* don't want to play with conditional compilation in automake tonight, sorry. - include directly the c file from here when needed. */ -# include "context_win32.c" -# define USE_WIN_CONTEXT -# endif -#endif - -static void __xbt_context_yield(xbt_context_t context) -{ - xbt_assert0(current_context,"You have to call context_init() first."); - - DEBUG2("--------- current_context (%p) is yielding to context(%p) ---------", - current_context,context); - -#ifdef USE_PTHREADS - if (context) { - xbt_context_t self = current_context; - DEBUG0("**** Locking ****"); - pthread_mutex_lock(&(context->mutex)); - DEBUG0("**** Updating current_context ****"); - current_context = context; - DEBUG0("**** Releasing the prisonner ****"); - pthread_cond_signal(&(context->cond)); - DEBUG0("**** Going to jail ****"); - pthread_cond_wait(&(context->cond), &(context->mutex)); - DEBUG0("**** Unlocking ****"); - pthread_mutex_unlock(&(context->mutex)); - DEBUG0("**** Updating current_context ****"); - current_context = self; - } -#else - if(current_context) - VOIRP(current_context->save); - VOIRP(context); - if(context) VOIRP(context->save); - if (context) { - - int return_value = 0; - - if(context->save==NULL) { - DEBUG0("**** Yielding to somebody else ****"); - DEBUG2("Saving current_context value (%p) to context(%p)->save",current_context,context); - context->save = current_context ; - DEBUG1("current_context becomes context(%p) ",context); - current_context = context ; - DEBUG1("Current position memorized (context->save). Jumping to context (%p)",context); - return_value = swapcontext (&(context->save->uc), &(context->uc)); - xbt_assert0((return_value==0),"Context swapping failure"); - DEBUG1("I am (%p). Coming back\n",context); - } else { - xbt_context_t old_context = context->save ; - DEBUG0("**** Back ! ****"); - DEBUG2("Setting current_context (%p) to context(%p)->save",current_context,context); - current_context = context->save ; - DEBUG1("Setting context(%p)->save to NULL",context); - context->save = NULL ; - DEBUG2("Current position memorized (%p). Jumping to context (%p)",context,old_context); - return_value = swapcontext (&(context->uc), &(old_context->uc)); - xbt_assert0((return_value==0),"Context swapping failure"); - DEBUG1("I am (%p). Coming back\n",context); - } - } -#endif - return; -} -static void xbt_context_destroy(xbt_context_t context) +/********************/ +/* Module init/exit */ +/********************/ +#ifndef CONTEXT_THREADS +/* callback: context fetching (used only with ucontext, os_thread deal with it + for us otherwise) */ +static ex_ctx_t *_context_ex_ctx(void) { -#ifdef USE_PTHREADS - xbt_free(context->thread); - pthread_mutex_destroy(&(context->mutex)); - pthread_cond_destroy(&(context->cond)); -#endif - if(context->exception) free(context->exception); - free(context); - return; + return current_context->exception; } -static void *__context_wrapper(void *c) +/* callback: termination */ +static void _context_ex_terminate(xbt_ex_t * e) { - xbt_context_t context = c; - int i; + xbt_ex_display(e); -#ifdef USE_PTHREADS - DEBUG2("**[%p:%p]** Lock ****",context,(void*)pthread_self()); - pthread_mutex_lock(&(context->mutex)); - DEBUG2("**[%p:%p]** Releasing the prisonner ****",context,(void*)pthread_self()); - pthread_cond_signal(&(context->cond)); - DEBUG2("**[%p:%p]** Going to Jail ****",context,(void*)pthread_self()); - pthread_cond_wait(&(context->cond), &(context->mutex)); - DEBUG2("**[%p:%p]** Unlocking ****",context,(void*)pthread_self()); - pthread_mutex_unlock(&(context->mutex)); + abort(); + /* FIXME: there should be a configuration variable to + choose to kill everyone or only this one */ +} #endif - if(context->startup_func) - context->startup_func(context->startup_arg); - - DEBUG0("Calling the main function"); - (context->code) (context->argc,context->argv); - - DEBUG0("Freeing arguments"); - for(i=0;iargc; i++) - if(context->argv[i]) free(context->argv[i]); - if(context->argv) free(context->argv); - if(context->cleanup_func) { - DEBUG0("Calling cleanup function"); - context->cleanup_func(context->cleanup_arg); - } +static void +schedule(xbt_context_t c); - DEBUG0("Putting context in the to_destroy set"); - xbt_swag_remove(context, context_living); - xbt_swag_insert(context, context_to_destroy); - DEBUG0("Context put in the to_destroy set"); +static void +unschedule(xbt_context_t c); - DEBUG0("Yielding"); -#ifdef USE_PTHREADS - DEBUG0("**** Locking ****"); - pthread_mutex_lock(&(context->mutex)); - DEBUG0("**** Updating current_context ****"); - current_context = context; - DEBUG0("**** Releasing the prisonner ****"); - pthread_cond_signal(&(context->cond)); - DEBUG0("**** Unlocking ****"); - pthread_mutex_unlock(&(context->mutex)); - DEBUG0("**** Exiting ****"); - pthread_exit(0); -#else - __xbt_context_yield(context); -#endif - xbt_assert0(0,"You can't be here!"); - return NULL; -} -/* callback: context fetching */ -static ex_ctx_t *__context_ex_ctx(void) +static void +schedule(xbt_context_t c) { - return current_context->exception; + xbt_os_sem_post(c->begin); + xbt_os_sem_wait(c->end); } -/* callback: termination */ -static void __context_ex_terminate(xbt_ex_t *e) +static void unschedule(xbt_context_t c) { - exit(e->value); + xbt_os_sem_post(c->end); + xbt_os_sem_wait(c->begin); } /** \name Functions @@ -183,58 +80,57 @@ static void __context_ex_terminate(xbt_ex_t *e) */ void xbt_context_init(void) { - if(!current_context) { - current_context = init_context = xbt_new0(s_xbt_context_t,1); - init_context->exception = xbt_new(ex_ctx_t,1); - XBT_CTX_INITIALIZE(init_context->exception); - __xbt_ex_ctx = __context_ex_ctx; - __xbt_ex_terminate = __context_ex_terminate; - context_to_destroy = xbt_swag_new(xbt_swag_offset(*current_context,hookup)); - context_living = xbt_swag_new(xbt_swag_offset(*current_context,hookup)); + if (!current_context) { + current_context = init_context = xbt_new0(s_xbt_context_t, 1); + DEBUG1("Init Context (%p)", init_context); + init_context->iwannadie = 0; /* useless but makes valgrind happy */ + context_to_destroy = + xbt_swag_new(xbt_swag_offset(*current_context, hookup)); + context_living = xbt_swag_new(xbt_swag_offset(*current_context, hookup)); xbt_swag_insert(init_context, context_living); + + #ifndef CONTEXT_THREADS + init_context->exception = xbt_new(ex_ctx_t, 1); + XBT_CTX_INITIALIZE(init_context->exception); + __xbt_ex_ctx = _context_ex_ctx; + __xbt_ex_terminate = _context_ex_terminate; +#endif } } -/** Garbage collection - * - * Should be called some time to time to free the memory allocated for contexts - * that have finished executing their main functions. +/** + * This function kill all existing context and free all the memory + * that has been allocated in this module. */ -void xbt_context_empty_trash(void) +void xbt_context_exit(void) { - xbt_context_t context=NULL; + xbt_context_t context = NULL; - while((context=xbt_swag_extract(context_to_destroy))) - xbt_context_destroy(context); -} + xbt_context_empty_trash(); -/** - * \param context the context to start - * - * Calling this function prepares \a context to be run. It will - however run effectively only when calling #xbt_context_schedule - */ -void xbt_context_start(xbt_context_t context) -{ -#ifdef USE_PTHREADS - /* Launch the thread */ - DEBUG1("**[%p]** Locking ****",context); - pthread_mutex_lock(&(context->mutex)); - DEBUG1("**[%p]** Pthread create ****",context); - xbt_assert0(!pthread_create(context->thread, NULL, __context_wrapper, context), - "Unable to create a thread."); - DEBUG2("**[%p]** Pthread created : %p ****",context,(void*)(*(context->thread))); - DEBUG1("**[%p]** Going to jail ****",context); - pthread_cond_wait(&(context->cond), &(context->mutex)); - DEBUG1("**[%p]** Unlocking ****",context); - pthread_mutex_unlock(&(context->mutex)); -#else - makecontext (&(context->uc), (void (*) (void)) __context_wrapper, - 1, context); + while ((context = xbt_swag_extract(context_living))) { + if (context != init_context) { + xbt_context_kill(context); + } + } + +#ifndef CONTEXT_THREADS + free(init_context->exception); #endif - return; + + free(init_context); + init_context = current_context = NULL; + + xbt_context_empty_trash(); + xbt_swag_free(context_to_destroy); + xbt_swag_free(context_living); + } + +/*******************************/ +/* Object creation/destruction */ +/*******************************/ /** * \param code a main function * \param startup_func a function to call when running the context for @@ -246,51 +142,314 @@ void xbt_context_start(xbt_context_t context) * \param argc first argument of function \a code * \param argv seconde argument of function \a code */ -xbt_context_t xbt_context_new(xbt_context_function_t code, - void_f_pvoid_t startup_func, void *startup_arg, - void_f_pvoid_t cleanup_func, void *cleanup_arg, - int argc, char *argv[]) +xbt_context_t +xbt_context_new(const char *name, + xbt_main_func_t code, + void_f_pvoid_t startup_func, + void *startup_arg, + void_f_pvoid_t cleanup_func, + void *cleanup_arg, int argc, char *argv[] + ) { xbt_context_t res = NULL; - res = xbt_new0(s_xbt_context_t,1); + res = xbt_new0(s_xbt_context_t, 1); res->code = code; -#ifdef USE_PTHREADS - res->thread = xbt_new0(pthread_t,1); - xbt_assert0(!pthread_mutex_init(&(res->mutex), NULL), "Mutex initialization error"); - xbt_assert0(!pthread_cond_init(&(res->cond), NULL), "Condition initialization error"); -#else - /* FIXME: strerror is not thread safe */ - xbt_assert2(getcontext(&(res->uc))==0,"Error in context saving: %d (%s)", errno, strerror(errno)); + res->name = xbt_strdup(name); + +#ifdef CONTEXT_THREADS + /* + * initialize the semaphores used to schedule/unschedule + * the process associated to the newly created context + */ + res->begin = xbt_os_sem_init(0,0); + res->end = xbt_os_sem_init(0,0); +#else + + xbt_assert2(getcontext(&(res->uc)) == 0, + "Error in context saving: %d (%s)", errno, strerror(errno)); res->uc.uc_link = NULL; /* res->uc.uc_link = &(current_context->uc); */ /* WARNING : when this context is over, the current_context (i.e. the father), is awaken... Theorically, the wrapper should prevent using this feature. */ -# ifndef USE_WIN_CONTEXT - res->uc.uc_stack.ss_sp = pth_skaddr_makecontext(res->stack,STACK_SIZE); - res->uc.uc_stack.ss_size = pth_sksize_makecontext(res->stack,STACK_SIZE); -# endif /* USE_WIN_CONTEXT */ -#endif /* USE_PTHREADS or not */ + res->uc.uc_stack.ss_sp = pth_skaddr_makecontext(res->stack, STACK_SIZE); + res->uc.uc_stack.ss_size = pth_sksize_makecontext(res->stack, STACK_SIZE); + + res->exception = xbt_new(ex_ctx_t, 1); + XBT_CTX_INITIALIZE(res->exception); +#endif /* CONTEXT_THREADS or not */ + + res->iwannadie = 0; /* useless but makes valgrind happy */ + res->argc = argc; res->argv = argv; res->startup_func = startup_func; res->startup_arg = startup_arg; res->cleanup_func = cleanup_func; res->cleanup_arg = cleanup_arg; - res->exception = xbt_new(ex_ctx_t,1); - XBT_CTX_INITIALIZE(res->exception); xbt_swag_insert(res, context_living); return res; } +/* Scenario for the end of a context: + * + * CASE 1: death after end of function + * __context_wrapper, called by os thread, calls xbt_context_stop after user code stops + * xbt_context_stop calls user cleanup_func if any (in context settings), + * add current to trashbin + * yields back to maestro (destroy os thread on need) + * From time to time, maestro calls xbt_context_empty_trash, + * which maps xbt_context_free on the content + * xbt_context_free frees some more memory, + * joins os thread + * + * CASE 2: brutal death + * xbt_context_kill (from any context) + * set context->wannadie to 1 + * yields to the context + * the context is awaken in the middle of __yield. + * At the end of it, it checks that wannadie == 1, and call xbt_context_stop + * (same than first case afterward) + */ + + +/* Argument must be stopped first -- runs in maestro context */ +static void xbt_context_free(xbt_context_t context) +{ + int i; + + if (!context) + return; + + DEBUG1("Freeing %p", context); + free(context->name); + + DEBUG0("Freeing arguments"); + + for (i = 0; i < context->argc; i++) + if (context->argv[i]) + free(context->argv[i]); + + if (context->argv) + free(context->argv); + +#ifdef CONTEXT_THREADS + DEBUG1("\t joining %p", (void *) context->thread); + + xbt_os_thread_join(context->thread, NULL); + + /* destroy the semaphore used to schedule/unshedule the process */ + xbt_os_sem_destroy(context->begin); + xbt_os_sem_destroy(context->end); + + context->thread = NULL; + context->begin = NULL; + context->end = NULL; +#else + if (context->exception) + free(context->exception); +#endif + + free(context); +} + +/************************/ +/* Start/stop a context */ +/************************/ +static void xbt_context_stop(int retvalue); +static void __xbt_context_yield(xbt_context_t context); + +static void *__context_wrapper(void *c) +{ + xbt_context_t context = current_context; + +#ifdef CONTEXT_THREADS + context = (xbt_context_t) c; + /*context->thread = xbt_os_thread_self();*/ + + /* signal its starting to the maestro and wait to start its job*/ + unschedule(context); + +#endif + + if (context->startup_func) + context->startup_func(context->startup_arg); + + DEBUG0("Calling the main function"); + + xbt_context_stop((context->code) (context->argc, context->argv)); + return NULL; +} +/** + * \param context the context to start + * + * Calling this function prepares \a context to be run. It will + however run effectively only when calling #xbt_context_schedule + */ +void xbt_context_start(xbt_context_t context) +{ +#ifdef CONTEXT_THREADS + /* create the process and start it */ + context->thread = xbt_os_thread_create(context->name,__context_wrapper, context); + + /* wait the starting of the newly created process */ + xbt_os_sem_wait(context->end); +#else + makecontext(&(context->uc), (void (*)(void)) __context_wrapper, 1, context); +#endif +} + +/* Stops current context: calls user's cleanup function, kills os thread, and yields back to maestro */ +static void xbt_context_stop(int retvalue) +{ + DEBUG1("--------- %p is exiting ---------", current_context); + + if (current_context->cleanup_func) { + DEBUG0("Calling cleanup function"); + current_context->cleanup_func(current_context->cleanup_arg); + } + + DEBUG0("Putting context in the to_destroy set"); + xbt_swag_remove(current_context, context_living); + xbt_swag_insert(current_context, context_to_destroy); + + DEBUG0("Yielding"); + +#ifdef CONTEXT_THREADS + /* signal to the maestro that it has finished */ + xbt_os_sem_post(current_context->end); + /* exit*/ + xbt_os_thread_exit(NULL); /* We should provide return value in case other wants it */ +#else + __xbt_context_yield(current_context); +#endif + THROW_IMPOSSIBLE; +} + + + +/** Garbage collection + * + * Should be called some time to time to free the memory allocated for contexts + * that have finished executing their main functions. + */ +void xbt_context_empty_trash(void) +{ + xbt_context_t context = NULL; + + DEBUG1("Emptying trashbin (%d contexts to free)", + xbt_swag_size(context_to_destroy)); + + while ((context = xbt_swag_extract(context_to_destroy))) + xbt_context_free(context); +} + +/*********************/ +/* context switching */ +/*********************/ + +static void __xbt_context_yield(xbt_context_t context) +{ + xbt_assert0(current_context, "You have to call context_init() first."); + xbt_assert0(context, "Invalid argument"); + + if (current_context == context) { + DEBUG1 + ("--------- current_context (%p) is yielding back to maestro ---------", + context); + } else { + DEBUG2 + ("--------- current_context (%p) is yielding to context(%p) ---------", + current_context, context); + } + +#ifdef CONTEXT_THREADS + + if(current_context != init_context && !context->iwannadie) + {/* it's a process and it doesn't wants to die (xbt_context_yield()) */ + + /* save the current context */ + xbt_context_t self = current_context; + + /* update the current context to this context */ + current_context = context; + + /* yield itself */ + unschedule(context); + + /* restore the current context to the previously saved context */ + current_context = self; + } + else + { /* maestro wants to schedule a process or a process wants to die (xbt_context_schedule() or xbt_context_kill())*/ + + /* save the current context */ + xbt_context_t self = current_context; + + /* update the current context */ + current_context = context; + + /* schedule the process associated with this context */ + schedule(context); + + /* restore the current context to the previously saved context */ + current_context = self; + } + +#else /* use SUSv2 contexts */ + VOIRP(current_context); + VOIRP(current_context->save); + + VOIRP(context); + VOIRP(context->save); + + int return_value = 0; + + if (context->save == NULL) { + DEBUG1("[%p] **** Yielding to somebody else ****", current_context); + DEBUG2("Saving current_context value (%p) to context(%p)->save", + current_context, context); + context->save = current_context; + DEBUG1("current_context becomes context(%p) ", context); + current_context = context; + DEBUG1 + ("Current position memorized (context->save). Jumping to context (%p)", + context); + return_value = swapcontext(&(context->save->uc), &(context->uc)); + xbt_assert0((return_value == 0), "Context swapping failure"); + DEBUG1("I am (%p). Coming back\n", context); + } else { + xbt_context_t old_context = context->save; + + DEBUG1("[%p] **** Back ! ****", context); + DEBUG2("Setting current_context (%p) to context(%p)->save", + current_context, context); + current_context = context->save; + DEBUG1("Setting context(%p)->save to NULL", context); + context->save = NULL; + DEBUG2("Current position memorized (%p). Jumping to context (%p)", + context, old_context); + return_value = swapcontext(&(context->uc), &(old_context->uc)); + xbt_assert0((return_value == 0), "Context swapping failure"); + DEBUG1("I am (%p). Coming back\n", context); + } +#endif + + if (current_context->iwannadie) + xbt_context_stop(1); +} + /** * Calling this function makes the current context yield. The context * that scheduled it returns from xbt_context_schedule as if nothing * had happened. + * + * Only the processes can call this function, giving back the control + * to the maestro */ void xbt_context_yield(void) { @@ -303,51 +462,38 @@ void xbt_context_yield(void) * Calling this function blocks the current context and schedule \a context. * When \a context will call xbt_context_yield, it will return * to this function as if nothing had happened. + * + * Only the maestro can call this function to run a given process. */ void xbt_context_schedule(xbt_context_t context) { - DEBUG1("Scheduling %p",context); - xbt_assert0((current_context==init_context), - "You are not supposed to run this function here!"); + DEBUG1("Scheduling %p", context); + xbt_assert0((current_context == init_context), + "You are not supposed to run this function here!"); __xbt_context_yield(context); } -/** - * This function kill all existing context and free all the memory - * that has been allocated in this module. - */ -void xbt_context_exit(void) { - xbt_context_t context=NULL; - - xbt_context_empty_trash(); - xbt_swag_free(context_to_destroy); - - while((context=xbt_swag_extract(context_living))) - xbt_context_free(context); - - xbt_swag_free(context_living); - - init_context = current_context = NULL ; -} /** * \param context poor victim * * This function simply kills \a context... scarry isn't it ? */ -void xbt_context_free(xbt_context_t context) +void xbt_context_kill(xbt_context_t context) { - int i ; - - xbt_swag_remove(context, context_living); - for(i=0;iargc; i++) - if(context->argv[i]) free(context->argv[i]); - if(context->argv) free(context->argv); - - if(context->cleanup_func) - context->cleanup_func(context->cleanup_arg); - xbt_context_destroy(context); - - return; + DEBUG1("Killing %p", context); + + context->iwannadie = 1; + + DEBUG1("Scheduling %p", context); + __xbt_context_yield(context); + DEBUG1("End of Scheduling %p", context); } + +/* Java cruft I'm gonna kill in the next cleanup round */ +void xbt_context_set_jprocess(xbt_context_t context, void *jp){} +void* xbt_context_get_jprocess(xbt_context_t context){return NULL;} +void xbt_context_set_jenv(xbt_context_t context,void* je){} +void* xbt_context_get_jenv(xbt_context_t context){return NULL;} + /* @} */