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

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2015-01-25 11:08:34 +00:00
/**
* @file imperative.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
*
* Imperative statement.
*
* Synopsis:
* imperative(string init_template, list init_args, string deinit_template, list deinit_args, string deinit_timeout)
*
* Description:
* Does the following, in order:
* 1. Starts a template process from (init_template, init_args) and waits for it to
* initialize completely.
* 2. Initiates termination of the process and wait for it to terminate.
* 3. Puts the statement UP, then waits for a statement termination request (which may
* already have been received).
* 4. Starts a template process from (deinit_template, deinit_args) and waits for it
* to initialize completely, or for the timeout to elapse.
* 5. Initiates termination of the process and wait for it to terminate.
* 6. Terminates the statement.
*
* If init_template="<none>", steps (1-2) are skipped.
* If deinit_template="<none>", steps (4-5) are skipped.
*/
#include <stdlib.h>
#include <string.h>
#include <misc/string_begins_with.h>
#include <misc/offset.h>
#include <ncd/NCDModule.h>
#include <ncd/static_strings.h>
#include <ncd/extra/value_utils.h>
#include <generated/blog_channel_ncd_imperative.h>
#define ModuleLog(i, ...) NCDModuleInst_Backend_Log((i), BLOG_CURRENT_CHANNEL, __VA_ARGS__)
#define STATE_INIT_WORKING 1
#define STATE_INIT_CLEANING 2
#define STATE_UP 3
#define STATE_DEINIT_WORKING 4
#define STATE_DEINIT_CLEANING 5
struct instance {
NCDModuleInst *i;
NCDValRef deinit_template;
NCDValRef deinit_args;
BTimer deinit_timer;
NCDModuleProcess process;
int state;
int dying;
};
static int start_process (struct instance *o, NCDValRef template_name, NCDValRef args, NCDModuleProcess_handler_event handler);
static void go_deinit (struct instance *o);
static void init_process_handler_event (NCDModuleProcess *process, int event);
static void deinit_process_handler_event (NCDModuleProcess *process, int event);
static int process_func_getspecialobj (NCDModuleProcess *process, NCD_string_id_t name, NCDObject *out_object);
static int process_caller_object_func_getobj (const NCDObject *obj, NCD_string_id_t name, NCDObject *out_object);
static void deinit_timer_handler (struct instance *o);
static void instance_free (struct instance *o);
static int start_process (struct instance *o, NCDValRef template_name, NCDValRef args, NCDModuleProcess_handler_event handler)
{
ASSERT(NCDVal_IsString(template_name))
ASSERT(NCDVal_IsList(args))
// create process
if (!NCDModuleProcess_InitValue(&o->process, o->i, template_name, args, handler)) {
ModuleLog(o->i, BLOG_ERROR, "NCDModuleProcess_Init failed");
return 0;
}
// set special functions
NCDModuleProcess_SetSpecialFuncs(&o->process, process_func_getspecialobj);
return 1;
}
static void go_deinit (struct instance *o)
{
ASSERT(o->dying)
// deinit is no-op?
if (ncd_is_none(o->deinit_template)) {
instance_free(o);
return;
}
// start deinit process
if (!start_process(o, o->deinit_template, o->deinit_args, deinit_process_handler_event)) {
instance_free(o);
return;
}
// start timer
BReactor_SetTimer(o->i->params->iparams->reactor, &o->deinit_timer);
// set state deinit working
o->state = STATE_DEINIT_WORKING;
}
static void init_process_handler_event (NCDModuleProcess *process, int event)
{
struct instance *o = UPPER_OBJECT(process, struct instance, process);
switch (event) {
case NCDMODULEPROCESS_EVENT_UP: {
ASSERT(o->state == STATE_INIT_WORKING)
// start terminating
NCDModuleProcess_Terminate(&o->process);
// set state init cleaning
o->state = STATE_INIT_CLEANING;
} break;
case NCDMODULEPROCESS_EVENT_TERMINATED: {
ASSERT(o->state == STATE_INIT_CLEANING)
// free process
NCDModuleProcess_Free(&o->process);
// were we requested to die aleady?
if (o->dying) {
go_deinit(o);
return;
}
// signal up
NCDModuleInst_Backend_Up(o->i);
// set state up
o->state = STATE_UP;
} break;
default: ASSERT(0);
}
}
static void deinit_process_handler_event (NCDModuleProcess *process, int event)
{
struct instance *o = UPPER_OBJECT(process, struct instance, process);
ASSERT(o->dying)
switch (event) {
case NCDMODULEPROCESS_EVENT_UP: {
ASSERT(o->state == STATE_DEINIT_WORKING)
// stop timer
BReactor_RemoveTimer(o->i->params->iparams->reactor, &o->deinit_timer);
// start terminating
NCDModuleProcess_Terminate(&o->process);
// set state deinit cleaning
o->state = STATE_DEINIT_CLEANING;
} break;
case NCDMODULEPROCESS_EVENT_TERMINATED: {
ASSERT(o->state == STATE_DEINIT_CLEANING)
// free process
NCDModuleProcess_Free(&o->process);
// die
instance_free(o);
return;
} break;
default: ASSERT(0);
}
}
static int process_func_getspecialobj (NCDModuleProcess *process, NCD_string_id_t name, NCDObject *out_object)
{
struct instance *o = UPPER_OBJECT(process, struct instance, process);
ASSERT(o->state != STATE_UP)
if (name == NCD_STRING_CALLER) {
*out_object = NCDObject_Build(-1, o, NCDObject_no_getvar, process_caller_object_func_getobj);
return 1;
}
return 0;
}
static int process_caller_object_func_getobj (const NCDObject *obj, NCD_string_id_t name, NCDObject *out_object)
{
struct instance *o = NCDObject_DataPtr(obj);
ASSERT(o->state != STATE_UP)
return NCDModuleInst_Backend_GetObj(o->i, name, out_object);
}
static void deinit_timer_handler (struct instance *o)
{
ASSERT(o->state == STATE_DEINIT_WORKING)
ModuleLog(o->i, BLOG_ERROR, "imperative deinit timeout elapsed");
// start terminating
NCDModuleProcess_Terminate(&o->process);
// set state deinit cleaning
o->state = STATE_DEINIT_CLEANING;
}
static void func_new (void *vo, NCDModuleInst *i, const struct NCDModuleInst_new_params *params)
{
struct instance *o = vo;
o->i = i;
// check arguments
NCDValRef init_template_arg;
NCDValRef init_args;
NCDValRef deinit_template_arg;
NCDValRef deinit_timeout_arg;
if (!NCDVal_ListRead(params->args, 5, &init_template_arg, &init_args, &deinit_template_arg, &o->deinit_args, &deinit_timeout_arg)) {
ModuleLog(i, BLOG_ERROR, "wrong arity");
goto fail0;
}
if (!NCDVal_IsString(init_template_arg) || !NCDVal_IsList(init_args) ||
!NCDVal_IsString(deinit_template_arg) || !NCDVal_IsList(o->deinit_args) ||
!NCDVal_IsString(deinit_timeout_arg)) {
ModuleLog(i, BLOG_ERROR, "wrong type");
goto fail0;
}
o->deinit_template = deinit_template_arg;
// read timeout
uintmax_t timeout;
if (!ncd_read_uintmax(deinit_timeout_arg, &timeout) || timeout > UINT64_MAX){
ModuleLog(i, BLOG_ERROR, "wrong timeout");
goto fail0;
}
// init timer
BTimer_Init(&o->deinit_timer, timeout, (BTimer_handler)deinit_timer_handler, o);
if (ncd_is_none(init_template_arg)) {
// signal up
NCDModuleInst_Backend_Up(i);
// set state up
o->state = STATE_UP;
} else {
// start init process
if (!start_process(o, init_template_arg, init_args, init_process_handler_event)) {
goto fail0;
}
// set state init working
o->state = STATE_INIT_WORKING;
}
// set not dying
o->dying = 0;
return;
fail0:
NCDModuleInst_Backend_DeadError(i);
}
static void instance_free (struct instance *o)
{
NCDModuleInst_Backend_Dead(o->i);
}
static void func_die (void *vo)
{
struct instance *o = vo;
ASSERT(!o->dying)
// set dying
o->dying = 1;
if (o->state == STATE_UP) {
go_deinit(o);
return;
}
}
static struct NCDModule modules[] = {
{
.type = "imperative",
.func_new2 = func_new,
.func_die = func_die,
.alloc_size = sizeof(struct instance)
}, {
.type = NULL
}
};
const struct NCDModuleGroup ncdmodule_imperative = {
.modules = modules
};