--- /dev/null
+/* $Id$ */
+
+/* a fast and simple context switching library */
+
+/* Copyright (c) 2004 Arnaud Legrand. 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 "context_private.h"
+#include "xbt/error.h"
+#include "xbt/dynar.h"
+#include "gras_config.h"
+XBT_LOG_NEW_DEFAULT_SUBCATEGORY(context, xbt, "Context");
+
+
+/************************ GNU LIBC CONTEXTS **************************/
+#if USE_CONTEXT==1
+
+static context_t current_context = NULL;
+static xbt_dynar_t context_to_destroy = NULL;
+
+void context_init(void)
+{
+ if(!current_context) {
+ current_context = xbt_new0(s_context_t,1);
+ context_to_destroy = xbt_dynar_new(sizeof(context_t),xbt_free);
+ }
+}
+
+void context_empty_trash(void)
+{
+ xbt_dynar_reset(context_to_destroy);
+}
+
+static void *__context_wrapper(void *c)
+{
+ context_t context = c;
+ int i;
+
+/* msg_global->current_process = process; */
+
+ /* WARNING("Calling the main function"); */
+ (context->code) (context->argc,context->argv);
+
+ for(i=0;i<context->argc; i++)
+ if(context->argv[i]) xbt_free(context->argv[i]);
+ if(context->argv) xbt_free(context->argv);
+
+ xbt_dynar_push(context_to_destroy, &context);
+
+ context_yield(context);
+
+ return NULL;
+}
+
+void context_start(context_t context)
+{
+
+/* TBX_FIFO_insert(msg_global->process, process); */
+/* TBX_FIFO_insert(msg_global->process_to_run, process); */
+
+ /* WARNING("Assigning __MSG_process_launcher to context (%p)",context); */
+ makecontext (&(context->uc), (void (*) (void)) __context_wrapper,
+ 1, context);
+
+ return;
+}
+
+context_t context_create(context_function_t code,
+ int argc, char *argv[])
+{
+ context_t res = NULL;
+
+ res = xbt_new0(s_context_t,1);
+
+ /* WARNING("Initializing context (%p)",res); */
+
+ xbt_assert0(getcontext(&(res->uc))==0,"Error in context saving.");
+
+ /* VOIRP(res->uc); */
+ res->code = code;
+ res->uc.uc_link = &(current_context->uc); /* FIXME LATER */
+ /* 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;
+ return res;
+}
+
+static void context_destroy(context_t context)
+{
+ xbt_free(context);
+
+ return;
+}
+
+void context_yield(context_t 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); */
+
+ 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); */
+ }
+/* msg_global->current_process = self; */
+ }
+
+ return;
+}
+#else
+
+/****************************** PTHREADS ***************************/
+/* #if HAVE_LIBPTHREAD==1 */
+#ifdef HAVE_LIBPTHREAD /* Nevermind, let's use pthreads... */
+
+static void *__MSG_process_launcher(void *p)
+{
+ 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);
+
+ TBX_FIFO_remove(msg_global->process, process);
+ TBX_FIFO_remove(msg_global->process_to_run, process);
+
+ /* 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);
+
+ TBX_FIFO_insert(msg_global->context_to_destroy,context);
+ __MSG_context_yield(context);
+/* __MSG_context_destroy(&context); */
+
+ return NULL;
+}
+
+MSG_error_t __MSG_context_start(m_process_t process)
+{
+ 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)
+{
+ 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;
+}
+
+MSG_error_t __MSG_context_destroy(context_t * context)
+{
+ 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;
+}
+
+MSG_error_t __MSG_context_yield(context_t context)
+{
+ 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 */
