+++ /dev/null
-/* module - module handling, along with module dependencies and local state */
-
-/* Copyright (c) 2006, 2007, 2009, 2010. The SimGrid Team.
- * 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 "xbt.h"
-#include "gras/module.h"
-#include "virtu_private.h"
-
-XBT_LOG_NEW_DEFAULT_SUBCATEGORY(gras_modules, gras,
- "Module and moddata handling");
-
-/* IMPLEMENTATION NOTE
-
-The goal of this module is quite difficult. We want to have several modules,
-each of them having globals which have to be initialized in any unix
-process. Let's call them world-wide globals. An example may be the messages
-dictionnary, which is world-wide to detect definition discrepencies when
-running in SG.
-
-And then, the module may want to have some globals specific to a gras process,
-just like userdata stuff allows to have per-process globals. Let's call them
-process-wide globals. An example may be the list of attached callbacks.
-
-That is why we have 4 functions per module: the join function is called by any
-process, and is in charge of creating the process-wide globals. If it is the
-first time a process uses the module, it also calls the init function, in
-charge of initializing the world-wide globals. We have the symmetric functions
-leave, called by any process not using the module anymore, and exit, in charge
-of freeing the world-wide globals when no process use it anymore.
-
-One can see this as a factory of factories. the init function is a factory
-creating the module, which contains a factory (the join function) able to
-create process-wide globals. The fact that indeed the calling sequence goes
-from join to init and not the other side is just an implementation bias ;)
-
-Then again, we want these functionalities to be quick. We want to access
-the process-wide globals by providing their rank in a dynar, we don't want to
-search them in a dictionary. This is especially true in the module
-implementation, where each functions is likely to require them to work. The
-position could be a stored in a global variable only visible from the module
-implementation.
-
-The need for an array in which to store the globals does not hold for
-world-wide globals: only one instance of them can exist in the same unix naming
-space. Thus, there is no need to put them in an array, we can actually declare
-them as regular C globals.
-
-The next trick comes from the fact that the user may (and will) mess up and not
-get all modules initialized in the same order in every process. So, the rank of
-module data cannot be the order in which a process called the join
-function. This has to be a world-wide global instead.
-
-And finally, if we want to get the ability to destroy modules (one day, they
-will load their code in as plugin), we want to give the module handling library
-(ie, this file) to modify the variable containing the rank of module in the
-tables. This is why we have the ID field in the module structure: it points
-exactly to the implementation side global.
-
-Yeah, I know. All this is not that clear. But at least, writing this helped me
-to design that crap ;)
-
-*/
-
-typedef struct s_gras_module {
- XBT_SET_HEADERS;
-
- unsigned int datasize;
- int refcount; /* Number of processes using this module */
- /* FIXME: we should keep a count of references within a given process to
- allow modules initializing other modules while tracking dependencies
- properly and leave() only when needed. This would allow dynamic module
- loading/unloading */
-
- int *p_id; /* where the module stores the libdata ID (a global somewhere), to tweak it on need */
- void_f_void_t init_f; /* First time the module is referenced. */
- void_f_void_t exit_f; /* When last process referencing it stops doing so. */
- void_f_pvoid_t join_f; /* Called by each process in initialization phase (init_f called once for all processes) */
- void_f_pvoid_t leave_f; /* Called by each process in finalization phase. Should free moddata passed */
-} s_gras_module_t, *gras_module_t;
-
-static xbt_set_t _gras_modules = NULL; /* content: s_gras_module_t */
-
-static void gras_module_freep(void *p)
-{
- free(((gras_module_t) p)->name);
- free(p);
-}
-
-
-/**
- * @brief Declaring a new GRAS module
- * @param name: name of the module, of course (beware of dupplicates!)
- * @param datasize: the size of your data, ie of the state this module has on each process
- * @param ID: address of a global you use as parameter to gras_module_data_by_id
- * @param init_f: function called the first time a module gets by a process of the naming space.
- * A classical use is to declare some messages the module uses, as well as the initialization
- * of module constants (accross processes boundaries in SG).
- * @param exit_f: function called when the last process of this naming space unref this module.
- * @param join_f: function called each time a process references the module.
- * It is passed the moddata already malloced, and should initialize the fields as it wants.
- * It can also attach some callbacks to the module messages.
- * @param leave_f: function called each time a process unrefs the module.
- * It is passed the moddata, and should free any memory allocated by init_f.
- * It should alse disconnect any attached callbacks.
- */
-
-void gras_module_add(const char *name, unsigned int datasize, int *ID,
- void_f_void_t init_f, void_f_void_t exit_f,
- void_f_pvoid_t join_f, void_f_pvoid_t leave_f)
-{
- gras_module_t mod = NULL;
- xbt_ex_t e;
- volatile int found = 0;
-
- if (!_gras_modules)
- _gras_modules = xbt_set_new();
-
- TRY {
- mod = (gras_module_t) xbt_set_get_by_name(_gras_modules, name);
- found = 1;
- }
- CATCH(e) {
- if (e.category != not_found_error)
- RETHROW;
- xbt_ex_free(e);
- }
-
- if (found) {
- xbt_assert(mod->init_f == init_f,
- "Module %s reregistered with a different init_f!", name);
- xbt_assert(mod->exit_f == exit_f,
- "Module %s reregistered with a different exit_f!", name);
- xbt_assert(mod->join_f == join_f,
- "Module %s reregistered with a different join_f!", name);
- xbt_assert(mod->leave_f == leave_f,
- "Module %s reregistered with a different leave_f!", name);
- xbt_assert(mod->datasize == datasize,
- "Module %s reregistered with a different datasize!", name);
- xbt_assert(mod->p_id == ID,
- "Module %s reregistered with a different p_id field!",
- name);
-
- XBT_DEBUG("Module %s already registered. Ignoring re-registration", name);
- return;
- }
-
- XBT_VERB("Register module %s", name);
- mod = xbt_new(s_gras_module_t, 1);
- mod->name = xbt_strdup(name);
- mod->name_len = strlen(name);
-
- mod->datasize = datasize;
- mod->p_id = ID;
- mod->init_f = init_f;
- mod->exit_f = exit_f;
- mod->join_f = join_f;
- mod->leave_f = leave_f;
- mod->refcount = 0;
-
- *mod->p_id = xbt_set_length(_gras_modules);
-
- xbt_set_add(_gras_modules, (void *) mod, gras_module_freep);
-}
-
-/* shutdown the module mechanism (world-wide cleanups) */
-void gras_moddata_exit(void)
-{
- xbt_set_free(&_gras_modules);
-}
-
-/* frees the moddata on this host (process-wide cleanups) */
-void gras_moddata_leave(void)
-{
- gras_procdata_t *pd = gras_procdata_get();
-
- xbt_dynar_free(&pd->moddata);
-}
-
-/* Removes & frees a given moddata from the current host */
-static void moddata_freep(void *p)
-{
- gras_procdata_t *pd = gras_procdata_get();
- int id = xbt_dynar_search(pd->moddata, p);
- gras_module_t mod = (gras_module_t) xbt_set_get_by_id(_gras_modules, id);
-
- mod->leave_f(gras_moddata_by_id(id));
-}
-
-void gras_module_join(const char *name)
-{
- gras_procdata_t *pd;
- void *moddata;
- gras_module_t mod =
- (gras_module_t) xbt_set_get_by_name(_gras_modules, name);
-
- XBT_VERB("Join to module %s (%p)", name, mod);
-
- /* NEW */
- if (mod->refcount == 0) {
- XBT_VERB("Init module %s", name);
- mod->name = xbt_strdup(name);
-
- mod->init_f();
- } else {
- XBT_DEBUG("Module %s already inited. Refcount=%d ID=%d",
- mod->name, mod->refcount, *(mod->p_id));
- }
- mod->refcount++;
-
- /* JOIN */
- pd = gras_procdata_get();
-
- if (!pd->moddata) /* Damn. I must be the first module on this process. Scary ;) */
- pd->moddata = xbt_dynar_new(sizeof(gras_module_t), &moddata_freep);
-
- moddata = xbt_malloc(mod->datasize);
-
- xbt_dynar_set(pd->moddata, *(mod->p_id), &moddata);
-
- mod->join_f(moddata);
-
- XBT_DEBUG("Module %s joined successfully (ID=%d)", name, *(mod->p_id));
-}
-
-void gras_module_leave(const char *name)
-{
- void *moddata;
- gras_module_t mod =
- (gras_module_t) xbt_set_get_by_name(_gras_modules, name);
-
- XBT_VERB("Leave module %s", name);
-
- /* LEAVE */
- moddata = gras_moddata_by_id(*(mod->p_id));
- mod->leave_f(moddata);
-
- /* EXIT */
- mod->refcount--;
- if (!mod->refcount) {
- XBT_VERB("Exit module %s", name);
-
- mod->exit_f();
-
- /* Don't remove the module for real, sets don't allow to
-
- free(mod->name);
- free(mod);
- */
- }
-}
-
-
-void *gras_moddata_by_id(unsigned int ID)
-{
- gras_procdata_t *pd = gras_procdata_get();
- void *p;
-
- xbt_dynar_get_cpy(pd->moddata, ID, &p);
- return p;
-}
