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/**
* @file multidepend.c
* @author Ambroz Bizjak <ambrop7@gmail.com>
*
* @section LICENSE
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the author nor the
* names of its contributors may be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* @section DESCRIPTION
*
* This is a compatibility module. It behaves exactly like the depend_scope module,
* except that there is a single global scope for dependency names.
*
* Use depend_scope instead. If you are using multidepend between non-template
* processes, make those processes templates instead and start them via
* process_manager(). For example, instead of this:
*
* process foo {
* multiprovide("FOO");
* }
*
* process bar {
* multidepend({"FOO"});
* }
*
* Use this:
*
* process main {
* depend_scope() scope;
* process_manager() mgr;
* mgr->start("foo", "foo", {});
* mgr->start("bar", "bar", {});
* }
*
* template foo {
* _caller.scope->provide("FOO");
* }
*
* template bar {
* _caller.scope->depend({"FOO"});
* }
*
* Synopsis:
* multiprovide(name)
*
* Synopsis:
* multidepend(list names)
*/
#include <stdlib.h>
#include <string.h>
#include <misc/offset.h>
#include <misc/debug.h>
#include <misc/balloc.h>
#include <structure/LinkedList1.h>
#include <ncd/module_common.h>
#include <generated/blog_channel_ncd_multidepend.h>
struct provide {
NCDModuleInst *i;
NCDValRef name;
LinkedList1Node provides_list_node;
LinkedList1 depends_list;
int dying;
};
struct depend {
NCDModuleInst *i;
NCDValRef names;
LinkedList1Node depends_list_node;
struct provide *provide;
LinkedList1Node provide_depends_list_node;
int provide_collapsing;
};
struct global {
LinkedList1 provides_list;
LinkedList1 depends_list;
};
static struct provide * find_provide (struct global *g, NCDValRef name)
{
for (LinkedList1Node *ln = LinkedList1_GetFirst(&g->provides_list); ln; ln = LinkedList1Node_Next(ln)) {
struct provide *provide = UPPER_OBJECT(ln, struct provide, provides_list_node);
if (NCDVal_Compare(provide->name, name) == 0) {
return provide;
}
}
return NULL;
}
static struct provide * depend_find_best_provide (struct depend *o)
{
struct global *g = ModuleGlobal(o->i);
size_t count = NCDVal_ListCount(o->names);
for (size_t j = 0; j < count; j++) {
NCDValRef name = NCDVal_ListGet(o->names, j);
struct provide *provide = find_provide(g, name);
if (provide && !provide->dying) {
return provide;
}
}
return NULL;
}
static void depend_update (struct depend *o)
{
// if we're collapsing, do nothing
if (o->provide && o->provide_collapsing) {
return;
}
// find best provide
struct provide *best_provide = depend_find_best_provide(o);
ASSERT(!best_provide || !best_provide->dying)
// has anything changed?
if (best_provide == o->provide) {
return;
}
if (o->provide) {
// set collapsing
o->provide_collapsing = 1;
// signal down
NCDModuleInst_Backend_Down(o->i);
} else {
// insert to provide's list
LinkedList1_Append(&best_provide->depends_list, &o->provide_depends_list_node);
// set not collapsing
o->provide_collapsing = 0;
// set provide
o->provide = best_provide;
// signal up
NCDModuleInst_Backend_Up(o->i);
}
}
static int func_globalinit (struct NCDInterpModuleGroup *group, const struct NCDModuleInst_iparams *params)
{
// allocate global state structure
struct global *g = BAlloc(sizeof(*g));
if (!g) {
BLog(BLOG_ERROR, "BAlloc failed");
return 0;
}
// set group state pointer
group->group_state = g;
// init provides list
LinkedList1_Init(&g->provides_list);
// init depends list
LinkedList1_Init(&g->depends_list);
return 1;
}
static void func_globalfree (struct NCDInterpModuleGroup *group)
{
struct global *g = group->group_state;
ASSERT(LinkedList1_IsEmpty(&g->depends_list))
ASSERT(LinkedList1_IsEmpty(&g->provides_list))
// free global state structure
BFree(g);
}
static void provide_func_new (void *vo, NCDModuleInst *i, const struct NCDModuleInst_new_params *params)
{
struct global *g = ModuleGlobal(i);
struct provide *o = vo;
o->i = i;
// read arguments
NCDValRef name_arg;
if (!NCDVal_ListRead(params->args, 1, &name_arg)) {
ModuleLog(i, BLOG_ERROR, "wrong arity");
goto fail0;
}
// remember name
o->name = name_arg;
// check for existing provide with this name
if (find_provide(g, o->name)) {
ModuleLog(o->i, BLOG_ERROR, "a provide with this name already exists");
goto fail0;
}
// insert to provides list
LinkedList1_Append(&g->provides_list, &o->provides_list_node);
// init depends list
LinkedList1_Init(&o->depends_list);
// set not dying
o->dying = 0;
// signal up.
// This comes above the loop which follows, so that effects on related depend statements are
// computed before this process advances, avoiding problems like failed variable resolutions.
NCDModuleInst_Backend_Up(o->i);
// update depends
for (LinkedList1Node *ln = LinkedList1_GetFirst(&g->depends_list); ln; ln = LinkedList1Node_Next(ln)) {
struct depend *depend = UPPER_OBJECT(ln, struct depend, depends_list_node);
depend_update(depend);
}
return;
fail0:
NCDModuleInst_Backend_DeadError(i);
}
static void provide_free (struct provide *o)
{
struct global *g = ModuleGlobal(o->i);
ASSERT(LinkedList1_IsEmpty(&o->depends_list))
// remove from provides list
LinkedList1_Remove(&g->provides_list, &o->provides_list_node);
NCDModuleInst_Backend_Dead(o->i);
}
static void provide_func_die (void *vo)
{
struct provide *o = vo;
ASSERT(!o->dying)
// if we have no depends, die immediately
if (LinkedList1_IsEmpty(&o->depends_list)) {
provide_free(o);
return;
}
// set dying
o->dying = 1;
// start collapsing our depends
for (LinkedList1Node *ln = LinkedList1_GetFirst(&o->depends_list); ln; ln = LinkedList1Node_Next(ln)) {
struct depend *depend = UPPER_OBJECT(ln, struct depend, provide_depends_list_node);
ASSERT(depend->provide == o)
// update depend to make sure it is collapsing
depend_update(depend);
}
}
static void depend_func_new (void *vo, NCDModuleInst *i, const struct NCDModuleInst_new_params *params)
{
struct global *g = ModuleGlobal(i);
struct depend *o = vo;
o->i = i;
// read arguments
NCDValRef names_arg;
if (!NCDVal_ListRead(params->args, 1, &names_arg)) {
ModuleLog(i, BLOG_ERROR, "wrong arity");
goto fail0;
}
if (!NCDVal_IsList(names_arg)) {
ModuleLog(o->i, BLOG_ERROR, "wrong type");
goto fail0;
}
// remember names
o->names = names_arg;
// insert to depends list
LinkedList1_Append(&g->depends_list, &o->depends_list_node);
// set no provide
o->provide = NULL;
// update
depend_update(o);
return;
fail0:
NCDModuleInst_Backend_DeadError(i);
}
static void depend_func_die (void *vo)
{
struct depend *o = vo;
struct global *g = ModuleGlobal(o->i);
if (o->provide) {
// remove from provide's list
LinkedList1_Remove(&o->provide->depends_list, &o->provide_depends_list_node);
// if provide is dying and is empty, let it die
if (o->provide->dying && LinkedList1_IsEmpty(&o->provide->depends_list)) {
provide_free(o->provide);
}
}
// remove from depends list
LinkedList1_Remove(&g->depends_list, &o->depends_list_node);
NCDModuleInst_Backend_Dead(o->i);
}
static void depend_func_clean (void *vo)
{
struct depend *o = vo;
if (!(o->provide && o->provide_collapsing)) {
return;
}
// save provide
struct provide *provide = o->provide;
// remove from provide's list
LinkedList1_Remove(&provide->depends_list, &o->provide_depends_list_node);
// set no provide
o->provide = NULL;
// update
depend_update(o);
// if provide is dying and is empty, let it die
if (provide->dying && LinkedList1_IsEmpty(&provide->depends_list)) {
provide_free(provide);
}
}
static int depend_func_getobj (void *vo, NCD_string_id_t objname, NCDObject *out_object)
{
struct depend *o = vo;
if (!o->provide) {
return 0;
}
return NCDModuleInst_Backend_GetObj(o->provide->i, objname, out_object);
}
static struct NCDModule modules[] = {
{
.type = "multiprovide",
.func_new2 = provide_func_new,
.func_die = provide_func_die,
.alloc_size = sizeof(struct provide)
}, {
.type = "multidepend",
.func_new2 = depend_func_new,
.func_die = depend_func_die,
.func_clean = depend_func_clean,
.func_getobj = depend_func_getobj,
.flags = NCDMODULE_FLAG_CAN_RESOLVE_WHEN_DOWN,
.alloc_size = sizeof(struct depend)
}, {
.type = NULL
}
};
const struct NCDModuleGroup ncdmodule_multidepend = {
.func_globalinit = func_globalinit,
.func_globalfree = func_globalfree,
.modules = modules
};