tor-android/external/badvpn_dns/ncd/modules/dynamic_depend.c

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2015-01-25 11:08:34 +00:00
/**
* @file dynamic_depend.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
*
* Dynamic dependencies module.
*
* Synopsis: dynamic_provide(string name, order_value)
* Synopsis: dynamic_depend(string name)
*/
#include <stdlib.h>
#include <string.h>
#include <misc/offset.h>
#include <misc/debug.h>
#include <misc/compare.h>
#include <misc/strdup.h>
#include <misc/balloc.h>
#include <structure/LinkedList0.h>
#include <structure/BAVL.h>
#include <ncd/NCDModule.h>
#include <generated/blog_channel_ncd_dynamic_depend.h>
#define ModuleLog(i, ...) NCDModuleInst_Backend_Log((i), BLOG_CURRENT_CHANNEL, __VA_ARGS__)
#define ModuleGlobal(i) ((i)->m->group->group_state)
struct provide;
struct name_string {
char *data;
size_t len;
};
struct name {
struct global *g;
struct name_string name;
BAVLNode names_tree_node;
BAVL provides_tree;
LinkedList0 waiting_depends_list;
struct provide *cur_p;
LinkedList0 cur_bound_depends_list;
int cur_resetting;
};
struct provide {
NCDModuleInst *i;
struct name *n;
NCDValRef order_value;
BAVLNode provides_tree_node;
int dying;
};
struct depend {
NCDModuleInst *i;
struct name *n;
int is_bound;
LinkedList0Node depends_list_node;
};
struct global {
BAVL names_tree;
};
static void provide_free (struct provide *o);
static void depend_free (struct depend *o);
static int name_string_comparator (void *user, void *vv1, void *vv2)
{
struct name_string *v1 = vv1;
struct name_string *v2 = vv2;
size_t min_len = (v1->len < v2->len ? v1->len : v2->len);
int cmp = memcmp(v1->data, v2->data, min_len);
if (cmp) {
return B_COMPARE(cmp, 0);
}
return B_COMPARE(v1->len, v2->len);
}
static int val_comparator (void *user, NCDValRef *v1, NCDValRef *v2)
{
return NCDVal_Compare(*v1, *v2);
}
static struct name * find_name (struct global *g, const char *name, size_t name_len)
{
struct name_string ns = {(char *)name, name_len};
BAVLNode *tn = BAVL_LookupExact(&g->names_tree, &ns);
if (!tn) {
return NULL;
}
struct name *n = UPPER_OBJECT(tn, struct name, names_tree_node);
ASSERT(n->name.len == name_len)
ASSERT(!memcmp(n->name.data, name, name_len))
return n;
}
static struct name * name_init (NCDModuleInst *i, struct global *g, const char *name, size_t name_len)
{
ASSERT(!find_name(g, name, name_len))
// allocate structure
struct name *o = malloc(sizeof(*o));
if (!o) {
ModuleLog(i, BLOG_ERROR, "malloc failed");
goto fail0;
}
// set global state
o->g = g;
// copy name
if (!(o->name.data = b_strdup_bin(name, name_len))) {
ModuleLog(i, BLOG_ERROR, "strdup failed");
goto fail1;
}
o->name.len = name_len;
// insert to names tree
ASSERT_EXECUTE(BAVL_Insert(&g->names_tree, &o->names_tree_node, NULL))
// init provides tree
BAVL_Init(&o->provides_tree, OFFSET_DIFF(struct provide, order_value, provides_tree_node), (BAVL_comparator)val_comparator, NULL);
// init waiting depends list
LinkedList0_Init(&o->waiting_depends_list);
// set no current provide
o->cur_p = NULL;
return o;
fail1:
free(o);
fail0:
return NULL;
}
static void name_free (struct name *o)
{
ASSERT(BAVL_IsEmpty(&o->provides_tree))
ASSERT(LinkedList0_IsEmpty(&o->waiting_depends_list))
ASSERT(!o->cur_p)
// remove from names tree
BAVL_Remove(&o->g->names_tree, &o->names_tree_node);
// free name
free(o->name.data);
// free structure
free(o);
}
static struct provide * name_get_first_provide (struct name *o)
{
BAVLNode *tn = BAVL_GetFirst(&o->provides_tree);
if (!tn) {
return NULL;
}
struct provide *p = UPPER_OBJECT(tn, struct provide, provides_tree_node);
ASSERT(p->n == o)
return p;
}
static void name_new_current (struct name *o)
{
ASSERT(!o->cur_p)
ASSERT(!BAVL_IsEmpty(&o->provides_tree))
// set current provide
o->cur_p = name_get_first_provide(o);
// init bound depends list
LinkedList0_Init(&o->cur_bound_depends_list);
// set not resetting
o->cur_resetting = 0;
// bind waiting depends
while (!LinkedList0_IsEmpty(&o->waiting_depends_list)) {
struct depend *d = UPPER_OBJECT(LinkedList0_GetFirst(&o->waiting_depends_list), struct depend, depends_list_node);
ASSERT(d->n == o)
ASSERT(!d->is_bound)
// remove from waiting depends list
LinkedList0_Remove(&o->waiting_depends_list, &d->depends_list_node);
// set bound
d->is_bound = 1;
// add to bound depends list
LinkedList0_Prepend(&o->cur_bound_depends_list, &d->depends_list_node);
// signal up
NCDModuleInst_Backend_Up(d->i);
}
}
static void name_free_if_unused (struct name *o)
{
if (BAVL_IsEmpty(&o->provides_tree) && LinkedList0_IsEmpty(&o->waiting_depends_list)) {
name_free(o);
}
}
static void name_continue_resetting (struct name *o)
{
ASSERT(o->cur_p)
ASSERT(o->cur_resetting)
// still have bound depends?
if (!LinkedList0_IsEmpty(&o->cur_bound_depends_list)) {
return;
}
struct provide *old_p = o->cur_p;
// set no current provide
o->cur_p = NULL;
// free old current provide if it's dying
if (old_p->dying) {
provide_free(old_p);
}
if (!BAVL_IsEmpty(&o->provides_tree)) {
// get new current provide
name_new_current(o);
} else {
// free name if unused
name_free_if_unused(o);
}
}
static void name_start_resetting (struct name *o)
{
ASSERT(o->cur_p)
ASSERT(!o->cur_resetting)
// set resetting
o->cur_resetting = 1;
// signal bound depends down
for (LinkedList0Node *ln = LinkedList0_GetFirst(&o->cur_bound_depends_list); ln; ln = LinkedList0Node_Next(ln)) {
struct depend *d = UPPER_OBJECT(ln, struct depend, depends_list_node);
ASSERT(d->n == o)
ASSERT(d->is_bound)
NCDModuleInst_Backend_Down(d->i);
}
// if there were no bound depends, continue right away
name_continue_resetting(o);
}
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 names tree
BAVL_Init(&g->names_tree, OFFSET_DIFF(struct name, name, names_tree_node), name_string_comparator, NULL);
return 1;
}
static void func_globalfree (struct NCDInterpModuleGroup *group)
{
struct global *g = group->group_state;
ASSERT(BAVL_IsEmpty(&g->names_tree))
// 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, 2, &name_arg, &o->order_value)) {
ModuleLog(i, BLOG_ERROR, "wrong arity");
goto fail0;
}
if (!NCDVal_IsString(name_arg)) {
ModuleLog(i, BLOG_ERROR, "wrong type");
goto fail0;
}
const char *name_str = NCDVal_StringData(name_arg);
size_t name_len = NCDVal_StringLength(name_arg);
// find name, create new if needed
struct name *n = find_name(g, name_str, name_len);
if (!n && !(n = name_init(i, g, name_str, name_len))) {
goto fail0;
}
// set name
o->n = n;
// check for order value conflict
if (BAVL_LookupExact(&n->provides_tree, &o->order_value)) {
ModuleLog(i, BLOG_ERROR, "order value already exists");
goto fail0;
}
// add to name's provides tree
ASSERT_EXECUTE(BAVL_Insert(&n->provides_tree, &o->provides_tree_node, NULL))
// set not dying
o->dying = 0;
// signal up
NCDModuleInst_Backend_Up(i);
// should this be the current provide?
if (o == name_get_first_provide(n)) {
if (!n->cur_p) {
name_new_current(n);
}
else if (!n->cur_resetting) {
name_start_resetting(n);
}
}
return;
fail0:
NCDModuleInst_Backend_DeadError(i);
}
static void provide_free (struct provide *o)
{
struct name *n = o->n;
ASSERT(o->dying)
ASSERT(o != n->cur_p)
// remove from name's provides tree
BAVL_Remove(&n->provides_tree, &o->provides_tree_node);
NCDModuleInst_Backend_Dead(o->i);
}
static void provide_func_die (void *vo)
{
struct provide *o = vo;
struct name *n = o->n;
ASSERT(!o->dying)
// set dying
o->dying = 1;
// if this is not the current provide, die right away
if (o != n->cur_p) {
// free provide
provide_free(o);
// free name if unused
name_free_if_unused(n);
return;
}
ASSERT(!n->cur_resetting)
// start resetting
name_start_resetting(n);
}
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 name_arg;
if (!NCDVal_ListRead(params->args, 1, &name_arg)) {
ModuleLog(i, BLOG_ERROR, "wrong arity");
goto fail0;
}
if (!NCDVal_IsString(name_arg)) {
ModuleLog(i, BLOG_ERROR, "wrong type");
goto fail0;
}
const char *name_str = NCDVal_StringData(name_arg);
size_t name_len = NCDVal_StringLength(name_arg);
// find name, create new if needed
struct name *n = find_name(g, name_str, name_len);
if (!n && !(n = name_init(i, g, name_str, name_len))) {
goto fail0;
}
// set name
o->n = n;
if (n->cur_p && !n->cur_resetting) {
// set bound
o->is_bound = 1;
// add to bound depends list
LinkedList0_Prepend(&n->cur_bound_depends_list, &o->depends_list_node);
// signal up
NCDModuleInst_Backend_Up(i);
} else {
// set not bound
o->is_bound = 0;
// add to waiting depends list
LinkedList0_Prepend(&n->waiting_depends_list, &o->depends_list_node);
}
return;
fail0:
NCDModuleInst_Backend_DeadError(i);
}
static void depend_func_die (void *vo)
{
struct depend *o = vo;
struct name *n = o->n;
if (o->is_bound) {
ASSERT(n->cur_p)
// remove from bound depends list
LinkedList0_Remove(&n->cur_bound_depends_list, &o->depends_list_node);
// continue resetting
if (n->cur_resetting) {
name_continue_resetting(n);
}
} else {
// remove from waiting depends list
LinkedList0_Remove(&n->waiting_depends_list, &o->depends_list_node);
// free name if unused
name_free_if_unused(n);
}
NCDModuleInst_Backend_Dead(o->i);
}
static void depend_func_clean (void *vo)
{
struct depend *o = vo;
struct name *n = o->n;
ASSERT(!o->is_bound || n->cur_p)
if (!(o->is_bound && n->cur_resetting)) {
return;
}
// remove from bound depends list
LinkedList0_Remove(&n->cur_bound_depends_list, &o->depends_list_node);
// set not bound
o->is_bound = 0;
// add to waiting depends list
LinkedList0_Prepend(&n->waiting_depends_list, &o->depends_list_node);
// continue resetting
name_continue_resetting(n);
}
static int depend_func_getobj (void *vo, NCD_string_id_t objname, NCDObject *out_object)
{
struct depend *o = vo;
struct name *n = o->n;
ASSERT(!o->is_bound || n->cur_p)
if (!o->is_bound) {
return 0;
}
return NCDModuleInst_Backend_GetObj(n->cur_p->i, objname, out_object);
}
static struct NCDModule modules[] = {
{
.type = "dynamic_provide",
.func_new2 = provide_func_new,
.func_die = provide_func_die,
.alloc_size = sizeof(struct provide)
}, {
.type = "dynamic_depend",
.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_dynamic_depend = {
.func_globalinit = func_globalinit,
.func_globalfree = func_globalfree,
.modules = modules
};