/* a fast and simple context switching library */
/* Copyright (c) 2004 Arnaud Legrand. */
-/* Copyright (c) 2004 Martin Quinson. */
+/* Copyright (c) 2004, 2005 Martin Quinson. */
/* All rights reserved. */
/* This program is free software; you can redistribute it and/or modify it
#include "xbt/error.h"
#include "xbt/dynar.h"
#include "gras_config.h"
-XBT_LOG_NEW_DEFAULT_SUBCATEGORY(context, xbt, "Context");
-/* #define WARNING(format, ...) (fprintf(stderr, "[%s , %s : %d] ", __FILE__, __FUNCTION__, __LINE__),\ */
-/* fprintf(stderr, format, ## __VA_ARGS__), \ */
-/* fprintf(stderr, "\n")) */
-/* #define VOIRP(expr) WARNING(" {" #expr " = %p }", expr) */
+XBT_LOG_NEW_DEFAULT_SUBCATEGORY(context, xbt, "Context");
-#ifndef HAVE_UCONTEXT_H
-/* 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"
-#endif
+#define VOIRP(expr) DEBUG1(" {" #expr " = %p }", expr)
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;
+#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"
+# endif
+#endif
+
static void __xbt_context_yield(xbt_context_t context)
{
int return_value = 0;
xbt_assert0(current_context,"You have to call context_init() first.");
-/* 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); */
+ 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) {
if(context->save==NULL) {
-/* WARNING("**** Yielding to somebody else ****"); */
-/* WARNING("Saving current_context value (%p) to context(%p)->save",current_context,context); */
+ DEBUG0("**** Yielding to somebody else ****");
+ DEBUG2("Saving current_context value (%p) to context(%p)->save",current_context,context);
context->save = current_context ;
-/* WARNING("current_context becomes context(%p) ",context); */
+ DEBUG1("current_context becomes context(%p) ",context);
current_context = context ;
-/* WARNING("Current position memorized (context->save). Jumping to context (%p)",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");
-/* WARNING("I am (%p). Coming back\n",context); */
+ DEBUG1("I am (%p). Coming back\n",context);
} else {
xbt_context_t old_context = context->save ;
-/* WARNING("**** Back ! ****"); */
-/* WARNING("Setting current_context (%p) to context(%p)->save",current_context,context); */
+ DEBUG0("**** Back ! ****");
+ DEBUG2("Setting current_context (%p) to context(%p)->save",current_context,context);
current_context = context->save ;
-/* WARNING("Setting context(%p)->save to NULL",context); */
+ DEBUG1("Setting context(%p)->save to NULL",context);
context->save = NULL ;
-/* WARNING("Current position memorized (%p). Jumping to context (%p)",context,old_context); */
+ 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");
-/* WARNING("I am (%p). Coming back\n",context); */
+ DEBUG1("I am (%p). Coming back\n",context);
}
}
-
+#endif
return;
}
static void xbt_context_destroy(xbt_context_t context)
{
- xbt_free(context);
-
+#ifdef USE_PTHREADS
+ xbt_free(context->thread);
+ pthread_mutex_destroy(&(context->mutex));
+ pthread_cond_destroy(&(context->cond));
+#endif
+ free(context);
return;
}
+static void *__context_wrapper(void *c)
+{
+ xbt_context_t context = c;
+ int i;
+
+#ifdef USE_PTHREADS
+ DEBUG0("**** Lock ****");
+ pthread_mutex_lock(&(context->mutex));
+ 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));
+#endif
+
+ if(context->startup_func)
+ context->startup_func(context->startup_arg);
+
+ DEBUG0("Calling the main function");
+ (context->code) (context->argc,context->argv);
+
+ for(i=0;i<context->argc; 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_swag_remove(context, context_living);
+ xbt_swag_insert(context, context_to_destroy);
+
+ __xbt_context_yield(context);
+ xbt_assert0(0,"You're cannot be here!");
+ return NULL;
+}
+
/** \name Functions
* \ingroup XBT_context
*/
-/*@{*/
+/* @{ */
/** Context module initialization
*
* \warning It has to be called before using any other function of this module.
xbt_context_destroy(context);
}
-static void *__context_wrapper(void *c)
-{
- xbt_context_t context = c;
- int i;
-
-/* msg_global->current_process = process; */
-
- if(context->startup_func)
- context->startup_func(context->startup_arg);
-
- /* WARNING("Calling the main function"); */
- /* xbt_context_yield(context); */
- (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);
-
- if(context->cleanup_func)
- context->cleanup_func(context->cleanup_arg);
-
- xbt_swag_remove(context, context_living);
- xbt_swag_insert(context, context_to_destroy);
-
- __xbt_context_yield(context);
- xbt_assert0(0,"You're cannot be here!");
- return NULL;
-}
-
/**
* \param context the context to start
*
*/
void xbt_context_start(xbt_context_t context)
{
-/* xbt_fifo_insert(msg_global->process, process); */
-/* xbt_fifo_insert(msg_global->process_to_run, process); */
-
+#ifdef USE_PTHREADS
+ /* Launch the thread */
+ DEBUG0("**** Locking ****");
+ pthread_mutex_lock(&(context->mutex));
+ DEBUG0("**** Pthread create ****");
+ xbt_assert0(!pthread_create(context->thread, NULL, __context_wrapper, context),
+ "Unable to create a thread.");
+ DEBUG0("**** Going to jail ****");
+ pthread_cond_wait(&(context->cond), &(context->mutex));
+ DEBUG0("**** Unlocking ****");
+ pthread_mutex_unlock(&(context->mutex));
+#else
makecontext (&(context->uc), (void (*) (void)) __context_wrapper,
1, context);
+#endif
return;
}
res = xbt_new0(s_xbt_context_t,1);
- xbt_assert0(getcontext(&(res->uc))==0,"Error in context saving.");
-
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->uc.uc_link = NULL;
- res->argc = argc;
- res->argv = argv;
-/* res->uc.uc_link = &(current_context->uc); */
+ /* 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. */
res->uc.uc_stack.ss_sp = res->stack;
res->uc.uc_stack.ss_size = STACK_SIZE;
+#endif
+ res->argc = argc;
+ res->argv = argv;
res->startup_func = startup_func;
res->startup_arg = startup_arg;
res->cleanup_func = cleanup_func;
return res;
}
-
/**
* Calling this function makes the current context yield. The context
* that scheduled it returns from xbt_context_schedule as if nothing
__xbt_context_yield(current_context);
}
-
/**
* \param context the winner
*
xbt_swag_remove(context, context_living);
for(i=0;i<context->argc; i++)
- if(context->argv[i]) xbt_free(context->argv[i]);
- if(context->argv) xbt_free(context->argv);
+ if(context->argv[i]) free(context->argv[i]);
+ if(context->argv) free(context->argv);
if(context->cleanup_func)
context->cleanup_func(context->cleanup_arg);
return;
}
-/*@}*/
+/* @} */