354 lines
11 KiB
C
354 lines
11 KiB
C
|
/**
|
||
|
|
* @file blocker.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
|
||
|
|
*
|
||
|
|
* Blocker module. Provides a statement that blocks when initialized, and which can be blocked
|
||
|
|
* and unblocked from outside.
|
||
|
|
*
|
||
|
|
* Synopsis: blocker()
|
||
|
|
* Description: provides blocking operations. Initially the blocking state is down (but this statement
|
||
|
|
* does not block). On deinitialization, waits for all corresponding use() statements
|
||
|
|
* to die before dying itself.
|
||
|
|
*
|
||
|
|
* Synopsis: blocker::up()
|
||
|
|
* Description: sets the blocking state to up.
|
||
|
|
* The immediate effects of corresponding use() statements going up are processed before
|
||
|
|
* this statement goes up; but this statement statement still goes up immediately,
|
||
|
|
* assuming the effects mentioned haven't resulted in the intepreter scheduling this
|
||
|
|
* very statement for destruction.
|
||
|
|
*
|
||
|
|
* Synopsis: blocker::down()
|
||
|
|
* Description: sets the blocking state to down.
|
||
|
|
* The immediate effects of corresponding use() statements going up are processed before
|
||
|
|
* this statement goes up; but this statement statement still goes up immediately,
|
||
|
|
* assuming the effects mentioned haven't resulted in the intepreter scheduling this
|
||
|
|
* very statement for destruction.
|
||
|
|
*
|
||
|
|
* Synopsis: blocker::downup()
|
||
|
|
* Description: atomically sets the blocker to down state (if it was up), then (back) to up state.
|
||
|
|
* Note that this is not equivalent to calling down() and immediately up(); in that case,
|
||
|
|
* the interpreter will first handle the immediate effects of any use() statements
|
||
|
|
* going down as a result of having called down() and will only later execute the up()
|
||
|
|
* statement. In fact, it is possible that the effects of down() will prevent up() from
|
||
|
|
* executing, which may leave the program in an undesirable state.
|
||
|
|
*
|
||
|
|
* Synopsis: blocker::rdownup()
|
||
|
|
* Description: on deinitialization, atomically sets the blocker to down state (if it was up), then
|
||
|
|
* (back) to up state.
|
||
|
|
* The immediate effects of corresponding use() statements changing state are processed
|
||
|
|
* *after* the immediate effects of this statement dying (in contrast to downup()).
|
||
|
|
*
|
||
|
|
* Synopsis: blocker::use()
|
||
|
|
* Description: blocks on the blocker. This module is in up state if and only if the blocking state of
|
||
|
|
* the blocker is up. Multiple use statements may be used with the same blocker.
|
||
|
|
*/
|
||
|
|
|
||
|
|
#include <stdlib.h>
|
||
|
|
#include <string.h>
|
||
|
|
|
||
|
|
#include <misc/offset.h>
|
||
|
|
#include <misc/debug.h>
|
||
|
|
#include <structure/LinkedList1.h>
|
||
|
|
#include <structure/LinkedList0.h>
|
||
|
|
#include <ncd/NCDModule.h>
|
||
|
|
|
||
|
|
#include <generated/blog_channel_ncd_blocker.h>
|
||
|
|
|
||
|
|
#define ModuleLog(i, ...) NCDModuleInst_Backend_Log((i), BLOG_CURRENT_CHANNEL, __VA_ARGS__)
|
||
|
|
|
||
|
|
struct instance {
|
||
|
|
NCDModuleInst *i;
|
||
|
|
LinkedList1 users;
|
||
|
|
LinkedList0 rdownups_list;
|
||
|
|
int up;
|
||
|
|
int dying;
|
||
|
|
};
|
||
|
|
|
||
|
|
struct rdownup_instance {
|
||
|
|
NCDModuleInst *i;
|
||
|
|
struct instance *blocker;
|
||
|
|
LinkedList0Node rdownups_list_node;
|
||
|
|
};
|
||
|
|
|
||
|
|
struct use_instance {
|
||
|
|
NCDModuleInst *i;
|
||
|
|
struct instance *blocker;
|
||
|
|
LinkedList1Node blocker_node;
|
||
|
|
};
|
||
|
|
|
||
|
|
static void func_new (void *vo, NCDModuleInst *i, const struct NCDModuleInst_new_params *params)
|
||
|
|
{
|
||
|
|
struct instance *o = vo;
|
||
|
|
o->i = i;
|
||
|
|
|
||
|
|
// check arguments
|
||
|
|
if (!NCDVal_ListRead(params->args, 0)) {
|
||
|
|
ModuleLog(o->i, BLOG_ERROR, "wrong arity");
|
||
|
|
goto fail0;
|
||
|
|
}
|
||
|
|
|
||
|
|
// init users list
|
||
|
|
LinkedList1_Init(&o->users);
|
||
|
|
|
||
|
|
// init rdownups list
|
||
|
|
LinkedList0_Init(&o->rdownups_list);
|
||
|
|
|
||
|
|
// set not up
|
||
|
|
o->up = 0;
|
||
|
|
|
||
|
|
// set not dying
|
||
|
|
o->dying = 0;
|
||
|
|
|
||
|
|
// signal up
|
||
|
|
NCDModuleInst_Backend_Up(o->i);
|
||
|
|
return;
|
||
|
|
|
||
|
|
fail0:
|
||
|
|
NCDModuleInst_Backend_DeadError(i);
|
||
|
|
}
|
||
|
|
|
||
|
|
static void instance_free (struct instance *o)
|
||
|
|
{
|
||
|
|
ASSERT(LinkedList1_IsEmpty(&o->users))
|
||
|
|
|
||
|
|
// break any rdownups
|
||
|
|
LinkedList0Node *ln;
|
||
|
|
while (ln = LinkedList0_GetFirst(&o->rdownups_list)) {
|
||
|
|
struct rdownup_instance *rdu = UPPER_OBJECT(ln, struct rdownup_instance, rdownups_list_node);
|
||
|
|
ASSERT(rdu->blocker == o)
|
||
|
|
LinkedList0_Remove(&o->rdownups_list, &rdu->rdownups_list_node);
|
||
|
|
rdu->blocker = NULL;
|
||
|
|
}
|
||
|
|
|
||
|
|
NCDModuleInst_Backend_Dead(o->i);
|
||
|
|
}
|
||
|
|
|
||
|
|
static void func_die (void *vo)
|
||
|
|
{
|
||
|
|
struct instance *o = vo;
|
||
|
|
ASSERT(!o->dying)
|
||
|
|
|
||
|
|
// if we have no users, die right away, else wait for users
|
||
|
|
if (LinkedList1_IsEmpty(&o->users)) {
|
||
|
|
instance_free(o);
|
||
|
|
return;
|
||
|
|
}
|
||
|
|
|
||
|
|
// set dying
|
||
|
|
o->dying = 1;
|
||
|
|
}
|
||
|
|
|
||
|
|
static void updown_func_new_templ (NCDModuleInst *i, const struct NCDModuleInst_new_params *params, int up, int first_down)
|
||
|
|
{
|
||
|
|
ASSERT(!first_down || up)
|
||
|
|
|
||
|
|
// check arguments
|
||
|
|
if (!NCDVal_ListRead(params->args, 0)) {
|
||
|
|
ModuleLog(i, BLOG_ERROR, "wrong arity");
|
||
|
|
goto fail0;
|
||
|
|
}
|
||
|
|
|
||
|
|
// signal up
|
||
|
|
NCDModuleInst_Backend_Up(i);
|
||
|
|
|
||
|
|
// get method object
|
||
|
|
struct instance *mo = NCDModuleInst_Backend_GetUser((NCDModuleInst *)params->method_user);
|
||
|
|
|
||
|
|
if (first_down || mo->up != up) {
|
||
|
|
// signal users
|
||
|
|
for (LinkedList1Node *node = LinkedList1_GetFirst(&mo->users); node; node = LinkedList1Node_Next(node)) {
|
||
|
|
struct use_instance *user = UPPER_OBJECT(node, struct use_instance, blocker_node);
|
||
|
|
ASSERT(user->blocker == mo)
|
||
|
|
if (first_down && mo->up) {
|
||
|
|
NCDModuleInst_Backend_Down(user->i);
|
||
|
|
}
|
||
|
|
if (up) {
|
||
|
|
NCDModuleInst_Backend_Up(user->i);
|
||
|
|
} else {
|
||
|
|
NCDModuleInst_Backend_Down(user->i);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
// change up state
|
||
|
|
mo->up = up;
|
||
|
|
}
|
||
|
|
|
||
|
|
return;
|
||
|
|
|
||
|
|
fail0:
|
||
|
|
NCDModuleInst_Backend_DeadError(i);
|
||
|
|
}
|
||
|
|
|
||
|
|
static void up_func_new (void *unused, NCDModuleInst *i, const struct NCDModuleInst_new_params *params)
|
||
|
|
{
|
||
|
|
updown_func_new_templ(i, params, 1, 0);
|
||
|
|
}
|
||
|
|
|
||
|
|
static void down_func_new (void *unused, NCDModuleInst *i, const struct NCDModuleInst_new_params *params)
|
||
|
|
{
|
||
|
|
updown_func_new_templ(i, params, 0, 0);
|
||
|
|
}
|
||
|
|
|
||
|
|
static void downup_func_new (void *unused, NCDModuleInst *i, const struct NCDModuleInst_new_params *params)
|
||
|
|
{
|
||
|
|
updown_func_new_templ(i, params, 1, 1);
|
||
|
|
}
|
||
|
|
|
||
|
|
static void rdownup_func_new (void *vo, NCDModuleInst *i, const struct NCDModuleInst_new_params *params)
|
||
|
|
{
|
||
|
|
struct rdownup_instance *o = vo;
|
||
|
|
o->i = i;
|
||
|
|
|
||
|
|
// check arguments
|
||
|
|
if (!NCDVal_ListRead(params->args, 0)) {
|
||
|
|
ModuleLog(i, BLOG_ERROR, "wrong arity");
|
||
|
|
goto fail0;
|
||
|
|
}
|
||
|
|
|
||
|
|
// get blocker
|
||
|
|
struct instance *blk = NCDModuleInst_Backend_GetUser((NCDModuleInst *)params->method_user);
|
||
|
|
|
||
|
|
// set blocker
|
||
|
|
o->blocker = blk;
|
||
|
|
|
||
|
|
// insert to rdownups list
|
||
|
|
LinkedList0_Prepend(&blk->rdownups_list, &o->rdownups_list_node);
|
||
|
|
|
||
|
|
// signal up
|
||
|
|
NCDModuleInst_Backend_Up(i);
|
||
|
|
return;
|
||
|
|
|
||
|
|
fail0:
|
||
|
|
NCDModuleInst_Backend_DeadError(i);
|
||
|
|
}
|
||
|
|
|
||
|
|
static void rdownup_func_die (void *vo)
|
||
|
|
{
|
||
|
|
struct rdownup_instance *o = vo;
|
||
|
|
|
||
|
|
struct instance *blk = o->blocker;
|
||
|
|
|
||
|
|
if (blk) {
|
||
|
|
// remove from rdownups list
|
||
|
|
LinkedList0_Remove(&blk->rdownups_list, &o->rdownups_list_node);
|
||
|
|
|
||
|
|
// downup users
|
||
|
|
for (LinkedList1Node *ln = LinkedList1_GetFirst(&blk->users); ln; ln = LinkedList1Node_Next(ln)) {
|
||
|
|
struct use_instance *user = UPPER_OBJECT(ln, struct use_instance, blocker_node);
|
||
|
|
ASSERT(user->blocker == blk)
|
||
|
|
if (blk->up) {
|
||
|
|
NCDModuleInst_Backend_Down(user->i);
|
||
|
|
}
|
||
|
|
NCDModuleInst_Backend_Up(user->i);
|
||
|
|
}
|
||
|
|
|
||
|
|
// set up
|
||
|
|
blk->up = 1;
|
||
|
|
}
|
||
|
|
|
||
|
|
NCDModuleInst_Backend_Dead(o->i);
|
||
|
|
}
|
||
|
|
|
||
|
|
static void use_func_new (void *vo, NCDModuleInst *i, const struct NCDModuleInst_new_params *params)
|
||
|
|
{
|
||
|
|
struct use_instance *o = vo;
|
||
|
|
o->i = i;
|
||
|
|
|
||
|
|
// check arguments
|
||
|
|
if (!NCDVal_ListRead(params->args, 0)) {
|
||
|
|
ModuleLog(o->i, BLOG_ERROR, "wrong arity");
|
||
|
|
goto fail0;
|
||
|
|
}
|
||
|
|
|
||
|
|
// set blocker
|
||
|
|
o->blocker = NCDModuleInst_Backend_GetUser((NCDModuleInst *)params->method_user);
|
||
|
|
|
||
|
|
// add to blocker's list
|
||
|
|
LinkedList1_Append(&o->blocker->users, &o->blocker_node);
|
||
|
|
|
||
|
|
// signal up if needed
|
||
|
|
if (o->blocker->up) {
|
||
|
|
NCDModuleInst_Backend_Up(o->i);
|
||
|
|
}
|
||
|
|
|
||
|
|
return;
|
||
|
|
|
||
|
|
fail0:
|
||
|
|
NCDModuleInst_Backend_DeadError(i);
|
||
|
|
}
|
||
|
|
|
||
|
|
static void use_func_die (void *vo)
|
||
|
|
{
|
||
|
|
struct use_instance *o = vo;
|
||
|
|
|
||
|
|
// remove from blocker's list
|
||
|
|
LinkedList1_Remove(&o->blocker->users, &o->blocker_node);
|
||
|
|
|
||
|
|
// make the blocker die if needed
|
||
|
|
if (o->blocker->dying && LinkedList1_IsEmpty(&o->blocker->users)) {
|
||
|
|
instance_free(o->blocker);
|
||
|
|
}
|
||
|
|
|
||
|
|
NCDModuleInst_Backend_Dead(o->i);
|
||
|
|
}
|
||
|
|
|
||
|
|
static struct NCDModule modules[] = {
|
||
|
|
{
|
||
|
|
.type = "blocker",
|
||
|
|
.func_new2 = func_new,
|
||
|
|
.func_die = func_die,
|
||
|
|
.alloc_size = sizeof(struct instance)
|
||
|
|
}, {
|
||
|
|
.type = "blocker::up",
|
||
|
|
.func_new2 = up_func_new
|
||
|
|
}, {
|
||
|
|
.type = "blocker::down",
|
||
|
|
.func_new2 = down_func_new
|
||
|
|
}, {
|
||
|
|
.type = "blocker::downup",
|
||
|
|
.func_new2 = downup_func_new
|
||
|
|
}, {
|
||
|
|
.type = "blocker::rdownup",
|
||
|
|
.func_new2 = rdownup_func_new,
|
||
|
|
.func_die = rdownup_func_die,
|
||
|
|
.alloc_size = sizeof(struct rdownup_instance)
|
||
|
|
}, {
|
||
|
|
.type = "blocker::use",
|
||
|
|
.func_new2 = use_func_new,
|
||
|
|
.func_die = use_func_die,
|
||
|
|
.alloc_size = sizeof(struct use_instance)
|
||
|
|
}, {
|
||
|
|
.type = NULL
|
||
|
|
}
|
||
|
|
};
|
||
|
|
|
||
|
|
const struct NCDModuleGroup ncdmodule_blocker = {
|
||
|
|
.modules = modules
|
||
|
|
};
|