/* a fast and simple context switching library */
-/* Copyright (c) 2004 Arnaud Legrand. All rights reserved. */
+/* Copyright (c) 2004 Arnaud Legrand. */
+/* Copyright (c) 2004, 2005 Martin Quinson. */
+/* All rights reserved. */
/* This program is free software; you can redistribute it and/or modify it
* under the terms of the license (GNU LGPL) which comes with this package. */
+#include "portable.h"
#include "context_private.h"
-#include "xbt/error.h"
+#include "xbt/log.h"
#include "xbt/dynar.h"
-#include "gras_config.h"
-XBT_LOG_NEW_DEFAULT_SUBCATEGORY(context, xbt, "Context");
+#include "xbt/xbt_os_thread.h"
+#include "xbt/ex_interface.h"
+XBT_LOG_NEW_DEFAULT_SUBCATEGORY(xbt_ctx, xbt, "Context");
-/************************ GNU LIBC CONTEXTS **************************/
-#if USE_CONTEXT==1
+#define VOIRP(expr) DEBUG1(" {" #expr " = %p }", expr)
-static context_t current_context = NULL;
-static xbt_dynar_t context_to_destroy = NULL;
+static xbt_context_t current_context = NULL;
+static xbt_context_t init_context = NULL;
+static xbt_swag_t context_to_destroy = NULL;
+static xbt_swag_t context_living = NULL;
+#ifdef CONTEXT_THREADS
+static xbt_os_mutex_t creation_mutex;
+static xbt_os_cond_t creation_cond;
+#endif
-void context_init(void)
+static void __context_exit(xbt_context_t context, int value);
+static void __xbt_context_yield(xbt_context_t context)
{
- if(!current_context) {
- current_context = xbt_new0(s_context_t,1);
- context_to_destroy = xbt_dynar_new(sizeof(context_t),xbt_free);
+ xbt_assert0(current_context, "You have to call context_init() first.");
+
+ DEBUG2
+ ("--------- current_context (%p) is yielding to context(%p) ---------",
+ current_context, context);
+
+#ifdef CONTEXT_THREADS
+ if (context) {
+ xbt_context_t self = current_context;
+ DEBUG2("[%p] **** Locking ctx %p ****", self, context);
+ xbt_os_mutex_lock(context->mutex);
+ DEBUG1("[%p] **** Updating current_context ****", self);
+ current_context = context;
+ DEBUG1("[%p] **** Releasing the prisonner ****", self);
+ xbt_os_cond_signal(context->cond);
+ DEBUG3("[%p] **** Going to jail on individual %p/%p ****", self,
+ context->cond, context->mutex);
+ xbt_os_cond_wait(context->cond, context->mutex);
+ DEBUG2("[%p] **** Unlocking individual %p ****", self, context->mutex);
+ xbt_os_mutex_unlock(context->mutex);
+ DEBUG1("[%p] **** Updating current_context ****", self);
+ current_context = self;
}
+#else /* use SUSv2 contexts */
+ VOIRP(current_context);
+ if (current_context)
+ VOIRP(current_context->save);
+
+ VOIRP(context);
+
+ if (context)
+ VOIRP(context->save);
+
+ if (context) {
+
+ 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)
+ __context_exit(current_context, 1);
+
+ return;
}
-void context_empty_trash(void)
+static void xbt_context_free(xbt_context_t context)
{
- xbt_dynar_reset(context_to_destroy);
+ if (!context)
+ return;
+ DEBUG1("Freeing %p", context);
+ free(context->name);
+#ifdef CONTEXT_THREADS
+ /*DEBUG1("\t joining %p",(void *)context->thread->t); */
+ DEBUG1("\t joining %p", (void *) context->thread);
+
+ xbt_os_thread_join(context->thread, NULL);
+
+ DEBUG1("\t mutex_destroy %p", (void *) context->mutex);
+ xbt_os_mutex_destroy(context->mutex);
+ DEBUG1("\t cond_destroy %p", (void *) context->cond);
+ xbt_os_cond_destroy(context->cond);
+
+ context->thread = NULL;
+ context->mutex = NULL;
+ context->cond = NULL;
+#else
+ if (context->exception)
+ free(context->exception);
+#endif
+
+ free(context);
+ return;
}
-static void *__context_wrapper(void *c)
+static void __context_exit(xbt_context_t context, int value)
{
- context_t context = c;
int i;
-/* msg_global->current_process = process; */
+ DEBUG1("--------- %p is exiting ---------", context);
+
+ DEBUG0("Calling cleanup functions");
+ if (context->cleanup_func) {
+ DEBUG0("Calling cleanup function");
+ context->cleanup_func(context->cleanup_arg);
+ }
+
+ DEBUG0("Freeing arguments");
+ for (i = 0; i < context->argc; i++)
+ if (context->argv[i])
+ free(context->argv[i]);
+
+ if (context->argv)
+ free(context->argv);
+
+ 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");
+
+ DEBUG0("Yielding");
+
+#ifdef CONTEXT_THREADS
+ DEBUG2("[%p] **** Locking %p ****", context, context->mutex);
+ xbt_os_mutex_lock(context->mutex);
+/* DEBUG1("[%p] **** Updating current_context ****"); */
+/* current_context = context; */
+ DEBUG1("[%p] **** Releasing the prisonner ****", context);
+ xbt_os_cond_signal(context->cond);
+ DEBUG2("[%p] **** Unlocking individual %p ****", context,
+ context->mutex);
+ xbt_os_mutex_unlock(context->mutex);
+ DEBUG1("[%p] **** Exiting ****", context);
+ xbt_os_thread_exit(NULL); // We should provide return value in case other wants it
+#else
+ __xbt_context_yield(context);
+#endif
+ xbt_assert0(0, "You can't be here!");
+}
+
+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();
+
+ DEBUG3("**[ctx:%p;self:%p]** Lock creation_mutex %p ****", context,
+ (void *) xbt_os_thread_self(), creation_mutex);
+ xbt_os_mutex_lock(creation_mutex);
+ xbt_os_mutex_lock(context->mutex);
+
+ DEBUG4
+ ("**[ctx:%p;self:%p]** Releasing the creator (creation_cond %p,%p) ****",
+ context, (void *) xbt_os_thread_self(), creation_cond,
+ creation_mutex);
+ xbt_os_cond_signal(creation_cond);
+ xbt_os_mutex_unlock(creation_mutex);
+
+ DEBUG4("**[ctx:%p;self:%p]** Going to Jail on lock %p and cond %p ****",
+ context, (void *) xbt_os_thread_self(), context->mutex,
+ context->cond);
+ xbt_os_cond_wait(context->cond, context->mutex);
- /* WARNING("Calling the main function"); */
- (context->code) (context->argc,context->argv);
+ DEBUG3("**[ctx:%p;self:%p]** Unlocking individual %p ****",
+ context, (void *) xbt_os_thread_self(), context->mutex);
+ xbt_os_mutex_unlock(context->mutex);
- for(i=0;i<context->argc; i++)
- if(context->argv[i]) xbt_free(context->argv[i]);
- if(context->argv) xbt_free(context->argv);
+#endif
- xbt_dynar_push(context_to_destroy, &context);
+ if (context->startup_func)
+ context->startup_func(context->startup_arg);
- context_yield(context);
+ DEBUG0("Calling the main function");
+ __context_exit(context, (context->code) (context->argc, context->argv));
return NULL;
}
-void context_start(context_t context)
-{
-
-/* TBX_FIFO_insert(msg_global->process, process); */
-/* TBX_FIFO_insert(msg_global->process_to_run, process); */
+#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) {
+ return current_context->exception;
+}
- /* WARNING("Assigning __MSG_process_launcher to context (%p)",context); */
- makecontext (&(context->uc), (void (*) (void)) __context_wrapper,
- 1, context);
+/* callback: termination */
+static void _context_ex_terminate(xbt_ex_t * e) {
+ xbt_ex_display(e);
- return;
+ abort();
+ /* FIXME: there should be a configuration variable to
+ choose to kill everyone or only this one */
+}
+#endif
+
+/** \name Functions
+ * \ingroup XBT_context
+ */
+/* @{ */
+/** Context module initialization
+ *
+ * \warning It has to be called before using any other function of this module.
+ */
+void xbt_context_init(void)
+{
+ 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);
+#ifdef CONTEXT_THREADS
+ creation_mutex = xbt_os_mutex_init();
+ creation_cond = xbt_os_cond_init();
+#else
+ 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
+ }
}
-context_t context_create(context_function_t code,
- int argc, char *argv[])
+/** 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)
{
- context_t res = NULL;
+ 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);
+}
- res = xbt_new0(s_context_t,1);
+/**
+ * \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
+ /* Launch the thread */
+
+ DEBUG3("**[ctx:%p;self:%p]** Locking creation_mutex %p ****", context,
+ xbt_os_thread_self(), creation_mutex);
+ xbt_os_mutex_lock(creation_mutex);
+
+ DEBUG2("**[ctx:%p;self:%p]** Thread create ****", context,
+ xbt_os_thread_self());
+ context->thread = xbt_os_thread_create(context->name,__context_wrapper, context);
+ DEBUG3("**[ctx:%p;self:%p]** Thread created : %p ****", context,
+ xbt_os_thread_self(), context->thread);
+
+ DEBUG4
+ ("**[ctx:%p;self:%p]** Going to jail on creation_cond/mutex (%p,%p) ****",
+ context, xbt_os_thread_self(), creation_cond, creation_mutex);
+ xbt_os_cond_wait(creation_cond, creation_mutex);
+ DEBUG3("**[ctx:%p;self:%p]** Unlocking creation %p ****", context,
+ xbt_os_thread_self(), creation_mutex);
+ xbt_os_mutex_unlock(creation_mutex);
+#else
+ makecontext(&(context->uc), (void (*)(void)) __context_wrapper, 1,
+ context);
+#endif
+ return;
+}
- /* WARNING("Initializing context (%p)",res); */
+/**
+ * \param code a main function
+ * \param startup_func a function to call when running the context for
+ * the first time and just before the main function \a code
+ * \param startup_arg the argument passed to the previous function (\a startup_func)
+ * \param cleanup_func a function to call when running the context, just after
+ the termination of the main function \a code
+ * \param cleanup_arg the argument passed to the previous function (\a cleanup_func)
+ * \param argc first argument of function \a code
+ * \param argv seconde argument of function \a code
+ */
+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;
- xbt_assert0(getcontext(&(res->uc))==0,"Error in context saving.");
+ res = xbt_new0(s_xbt_context_t, 1);
- /* VOIRP(res->uc); */
res->code = code;
- res->uc.uc_link = &(current_context->uc); /* FIXME LATER */
+ res->name = xbt_strdup(name);
+#ifdef CONTEXT_THREADS
+ res->mutex = xbt_os_mutex_init();
+ res->cond = xbt_os_cond_init();
+#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... May result in bugs later.*/
- res->uc.uc_stack.ss_sp = res->stack;
- res->uc.uc_stack.ss_size = STACK_SIZE;
+ father), is awaken... Theorically, the wrapper should prevent using
+ this feature. */
+ 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;
+
+ xbt_swag_insert(res, context_living);
+
return res;
}
-static void context_destroy(context_t context)
+/**
+ * Calling this function makes the current context yield. The context
+ * that scheduled it returns from xbt_context_schedule as if nothing
+ * had happened.
+ */
+void xbt_context_yield(void)
{
- xbt_free(context);
-
- return;
+ __xbt_context_yield(current_context);
}
-void context_yield(context_t context)
+/**
+ * \param context the winner
+ *
+ * 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.
+ */
+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!");
+ __xbt_context_yield(context);
+}
- xbt_assert0(current_context,"You have to call context_init() first.");
-
- /* __MSG_context_init(); */
- /* fprintf(stderr,"\n"); */
- /* WARNING("--------- current_context (%p) is yielding to context(%p) ---------",current_context,context); */
- /* VOIRP(current_context); */
- /* if(current_context) VOIRP(current_context->save); */
- /* VOIRP(context); */
- /* if(context) VOIRP(context->save); */
+/**
+ * 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;
- if (context) {
-/* m_process_t self = msg_global->current_process; */
- if(context->save==NULL) {
- /* WARNING("**** Yielding to somebody else ****"); */
- /* WARNING("Saving current_context value (%p) to context(%p)->save",current_context,context); */
- context->save = current_context ;
- context->uc.uc_link = &(current_context->uc);
- /* WARNING("current_context becomes context(%p) ",context); */
- current_context = context ;
- /* WARNING("Current position memorized (context->save). Jumping to context (%p)",context); */
- if(!swapcontext (&(context->save->uc), &(context->uc)))
- xbt_assert0(0,"Context swapping failure");
- /* WARNING("I am (%p). Coming back\n",context); */
- } else {
- context_t old_context = context->save ;
- /* WARNING("**** Back ! ****"); */
- /* WARNING("Setting current_context (%p) to context(%p)->save",current_context,context); */
- current_context = context->save ;
- /* WARNING("Setting context(%p)->save to NULL",current_context,context); */
- context->save = NULL ;
- /* WARNING("Current position memorized (%p). Jumping to context (%p)",context,old_context); */
- if(!swapcontext (&(context->uc), &(old_context->uc)) )
- xbt_assert0(0,"Context swapping failure");
- /* WARNING("I am (%p). Coming back\n",context); */
+ xbt_context_empty_trash();
+ while ((context = xbt_swag_extract(context_living))) {
+ if (context != init_context) {
+ xbt_context_kill(context);
}
-/* msg_global->current_process = self; */
}
+#ifdef CONTEXT_THREADS
+ xbt_os_mutex_destroy(creation_mutex);
+ xbt_os_cond_destroy(creation_cond);
+#else
+ free(init_context->exception);
+#endif
+ free(init_context);
+ init_context = current_context = NULL;
+
+ xbt_context_empty_trash();
+ xbt_swag_free(context_to_destroy);
+ xbt_swag_free(context_living);
- return;
}
-#else
-
-/****************************** PTHREADS ***************************/
-/* #if HAVE_LIBPTHREAD==1 */
-#ifdef HAVE_LIBPTHREAD /* Nevermind, let's use pthreads... */
-static void *__MSG_process_launcher(void *p)
+/**
+ * \param context poor victim
+ *
+ * This function simply kills \a context... scarry isn't it ?
+ */
+void xbt_context_kill(xbt_context_t context)
{
- m_process_t process = (m_process_t) p;
- sim_data_process_t sim_data = process->simdata;
- context_t context = NULL;
- int i;
- msg_global->current_process = process;
- TBX_FIFO_insert(msg_global->process, process);
-
- TBX_FIFO_insert(msg_global->process_to_run, process);
-/* pthread_mutex_lock(&(sim_data->context->mutex)); */
- __MSG_context_yield(sim_data->context);
-
- (*sim_data->context->code) (sim_data->argc,sim_data->argv);
+ DEBUG1("Killing %p", context);
- TBX_FIFO_remove(msg_global->process, process);
- TBX_FIFO_remove(msg_global->process_to_run, process);
+ context->iwannadie = 1;
+ DEBUG1("Scheduling %p", context);
+ __xbt_context_yield(context);
+ DEBUG1("End of Scheduling %p", context);
- /* Free blocked process if any */
-/* pthread_mutex_lock(&(sim_data->context->mutex)); */
-/* pthread_cond_signal(&(sim_data->context->cond)); */
-/* pthread_mutex_unlock(&(sim_data->context->mutex)); */
-
- context = sim_data->context;
-
- for(i=0;i<sim_data->argc; i++)
- if(sim_data->argv[i]) FREE(sim_data->argv[i]);
- if(sim_data->argv) FREE(sim_data->argv);
- if(process->name) FREE(process->name);
- FREE(sim_data);
- FREE(process);
+ return;
+}
- TBX_FIFO_insert(msg_global->context_to_destroy,context);
- __MSG_context_yield(context);
-/* __MSG_context_destroy(&context); */
+/* @} */
+/* Stub of the stuff to interact with JAVA threads; not used in native lib */
+void xbt_context_set_jprocess(xbt_context_t context, void *jp)
+{
+}
+void *xbt_context_get_jprocess(xbt_context_t context)
+{
return NULL;
}
-MSG_error_t __MSG_context_start(m_process_t process)
+void xbt_context_set_jmutex(xbt_context_t context, void *jm)
{
- sim_data_process_t sim_data = NULL;
-
- sim_data = process->simdata;
-
- pthread_mutex_lock(&(sim_data->context->mutex));
-
- /* Launch the thread */
- if (pthread_create(sim_data->context->thread, NULL, __MSG_process_launcher,
- process) != 0) {
- WARNING("Unable to create a thread.");
- return MSG_FATAL;
- }
- pthread_cond_wait(&(sim_data->context->cond), &(sim_data->context->mutex));
- pthread_mutex_unlock(&(sim_data->context->mutex));
-/* __MSG_context_yield(sim_data->context); */
-
- return MSG_OK;
}
-
-context_t __MSG_context_create(m_process_code_t code)
+void *xbt_context_get_jmutex(xbt_context_t context)
{
- context_t res = NULL;
-
- res = CALLOC(1, sizeof(struct s_context));
-
- res->code = code;
- res->thread = CALLOC(1, sizeof(pthread_t));
- if (pthread_mutex_init(&(res->mutex), NULL) != 0)
- FAILURE("Mutex initialization error");
- if (pthread_cond_init(&(res->cond), NULL) != 0)
- FAILURE("Condition initialization error");
-
- return res;
+ return NULL;
}
-MSG_error_t __MSG_context_destroy(context_t * context)
+void xbt_context_set_jcond(xbt_context_t context, void *jc)
{
- ASSERT(((context != NULL) && (*context != NULL)), "Invalid parameters");
-
- FREE((*context)->thread);
- pthread_mutex_destroy(&((*context)->mutex));
- pthread_cond_destroy(&((*context)->cond));
-
- FREE(*context);
- *context = NULL;
-
- return MSG_OK;
+}
+void *xbt_context_get_jcond(xbt_context_t context)
+{
+ return NULL;
}
-MSG_error_t __MSG_context_yield(context_t context)
+void xbt_context_set_jenv(xbt_context_t context, void *je)
{
- if (context) {
- m_process_t self = msg_global->current_process;
- pthread_mutex_lock(&(context->mutex));
- pthread_cond_signal(&context->cond);
- pthread_cond_wait(&context->cond, &context->mutex);
- pthread_mutex_unlock(&(context->mutex));
- msg_global->current_process = self;
- }
- return MSG_OK;
}
-#endif /* HAVE_LIBPTHREAD */
-#endif /* USE_CONTEXT */
+void *xbt_context_get_jenv(xbt_context_t context)
+{
+ return NULL;
+}