/*
* Copyright (C) 1999-2001, 2004, 2007, 2009, 2013, 2014, 2016 Internet Systems Consortium, Inc. ("ISC")
*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/.
*/
/* $Id: app.c,v 1.9 2009/09/02 23:48:03 tbox Exp $ */
#include <config.h>
#include <sys/types.h>
#include <stddef.h>
#include <stdlib.h>
#include <errno.h>
#include <unistd.h>
#include <process.h>
#include <isc/app.h>
#include <isc/boolean.h>
#include <isc/condition.h>
#include <isc/mem.h>
#include <isc/msgs.h>
#include <isc/mutex.h>
#include <isc/event.h>
#include <isc/platform.h>
#include <isc/string.h>
#include <isc/task.h>
#include <isc/time.h>
#include <isc/util.h>
#include <isc/thread.h>
/*%
* For BIND9 internal applications built with threads, we use a single app
* context and let multiple worker, I/O, timer threads do actual jobs.
*/
static isc_thread_t blockedthread;
/*%
* The following are intended for internal use (indicated by "isc__"
* prefix) but are not declared as static, allowing direct access from
* unit tests etc.
*/
isc_result_t isc__app_start(void);
isc_result_t isc__app_ctxstart(isc_appctx_t *ctx);
isc_result_t isc__app_onrun(isc_mem_t *mctx, isc_task_t *task,
isc_taskaction_t action, void *arg);
isc_result_t isc__app_ctxrun(isc_appctx_t *ctx);
isc_result_t isc__app_run(void);
isc_result_t isc__app_ctxshutdown(isc_appctx_t *ctx);
isc_result_t isc__app_shutdown(void);
isc_result_t isc__app_reload(void);
isc_result_t isc__app_ctxsuspend(isc_appctx_t *ctx);
void isc__app_ctxfinish(isc_appctx_t *ctx);
void isc__app_finish(void);
void isc__app_block(void);
void isc__app_unblock(void);
isc_result_t isc__appctx_create(isc_mem_t *mctx, isc_appctx_t **ctxp);
void isc__appctx_destroy(isc_appctx_t **ctxp);
void isc__appctx_settaskmgr(isc_appctx_t *ctx, isc_taskmgr_t *taskmgr);
void isc__appctx_setsocketmgr(isc_appctx_t *ctx, isc_socketmgr_t *socketmgr);
void isc__appctx_settimermgr(isc_appctx_t *ctx, isc_timermgr_t *timermgr);
isc_result_t isc__app_ctxonrun(isc_appctx_t *ctx, isc_mem_t *mctx,
isc_task_t *task, isc_taskaction_t action,
void *arg);
/*
* The application context of this module. This implementation actually
* doesn't use it. (This may change in the future).
*/
#define APPCTX_MAGIC ISC_MAGIC('A', 'p', 'c', 'x')
#define VALID_APPCTX(c) ISC_MAGIC_VALID(c, APPCTX_MAGIC)
/* Events to wait for */
#define NUM_EVENTS 2
enum {
RELOAD_EVENT,
SHUTDOWN_EVENT
};
typedef struct isc__appctx {
isc_appctx_t common;
isc_mem_t *mctx;
isc_eventlist_t on_run;
isc_mutex_t lock;
isc_boolean_t shutdown_requested;
isc_boolean_t running;
/*
* We assume that 'want_shutdown' can be read and written atomically.
*/
isc_boolean_t want_shutdown;
/*
* We assume that 'want_reload' can be read and written atomically.
*/
isc_boolean_t want_reload;
isc_boolean_t blocked;
HANDLE hEvents[NUM_EVENTS];
isc_taskmgr_t *taskmgr;
isc_socketmgr_t *socketmgr;
isc_timermgr_t *timermgr;
} isc__appctx_t;
static isc__appctx_t isc_g_appctx;
static struct {
isc_appmethods_t methods;
/*%
* The following are defined just for avoiding unused static functions.
*/
void *run, *shutdown, *start, *reload, *finish, *block, *unblock;
} appmethods = {
{
isc__appctx_destroy,
isc__app_ctxstart,
isc__app_ctxrun,
isc__app_ctxsuspend,
isc__app_ctxshutdown,
isc__app_ctxfinish,
isc__appctx_settaskmgr,
isc__appctx_setsocketmgr,
isc__appctx_settimermgr,
isc__app_ctxonrun
},
(void *)isc__app_run,
(void *)isc__app_shutdown,
(void *)isc__app_start,
(void *)isc__app_reload,
(void *)isc__app_finish,
(void *)isc__app_block,
(void *)isc__app_unblock
};
/*
* We need to remember which thread is the main thread...
*/
static isc_thread_t main_thread;
isc_result_t
isc__app_ctxstart(isc_appctx_t *ctx0) {
isc__appctx_t *ctx = (isc__appctx_t *)ctx0;
isc_result_t result;
REQUIRE(VALID_APPCTX(ctx));
/*
* Start an ISC library application.
*/
main_thread = GetCurrentThread();
result = isc_mutex_init(&ctx->lock);
if (result != ISC_R_SUCCESS)
return (result);
ctx->shutdown_requested = ISC_FALSE;
ctx->running = ISC_FALSE;
ctx->want_shutdown = ISC_FALSE;
ctx->want_reload = ISC_FALSE;
ctx->blocked = ISC_FALSE;
/* Create the reload event in a non-signaled state */
ctx->hEvents[RELOAD_EVENT] = CreateEvent(NULL, FALSE, FALSE, NULL);
/* Create the shutdown event in a non-signaled state */
ctx->hEvents[SHUTDOWN_EVENT] = CreateEvent(NULL, FALSE, FALSE, NULL);
ISC_LIST_INIT(ctx->on_run);
return (ISC_R_SUCCESS);
}
isc_result_t
isc__app_start(void) {
isc_g_appctx.common.impmagic = APPCTX_MAGIC;
isc_g_appctx.common.magic = ISCAPI_APPCTX_MAGIC;
isc_g_appctx.common.methods = &appmethods.methods;
isc_g_appctx.mctx = NULL;
/* The remaining members will be initialized in ctxstart() */
return (isc__app_ctxstart((isc_appctx_t *)&isc_g_appctx));
}
isc_result_t
isc__app_onrun(isc_mem_t *mctx, isc_task_t *task, isc_taskaction_t action,
void *arg)
{
return (isc__app_ctxonrun((isc_appctx_t *)&isc_g_appctx, mctx,
task, action, arg));
}
isc_result_t
isc__app_ctxonrun(isc_appctx_t *ctx0, isc_mem_t *mctx, isc_task_t *task,
isc_taskaction_t action, void *arg)
{
isc__appctx_t *ctx = (isc__appctx_t *)ctx0;
isc_event_t *event;
isc_task_t *cloned_task = NULL;
isc_result_t result;
LOCK(&ctx->lock);
if (ctx->running) {
result = ISC_R_ALREADYRUNNING;
goto unlock;
}
/*
* Note that we store the task to which we're going to send the event
* in the event's "sender" field.
*/
isc_task_attach(task, &cloned_task);
event = isc_event_allocate(mctx, cloned_task, ISC_APPEVENT_SHUTDOWN,
action, arg, sizeof(*event));
if (event == NULL) {
result = ISC_R_NOMEMORY;
goto unlock;
}
ISC_LINK_INIT(event, ev_link);
ISC_LIST_APPEND(ctx->on_run, event, ev_link);
result = ISC_R_SUCCESS;
unlock:
UNLOCK(&ctx->lock);
return (result);
}
isc_result_t
isc__app_ctxrun(isc_appctx_t *ctx0) {
isc__appctx_t *ctx = (isc__appctx_t *)ctx0;
isc_event_t *event, *next_event;
isc_task_t *task;
HANDLE *pHandles = NULL;
DWORD dwWaitResult;
REQUIRE(VALID_APPCTX(ctx));
REQUIRE(main_thread == GetCurrentThread());
LOCK(&ctx->lock);
if (!ctx->running) {
ctx->running = ISC_TRUE;
/*
* Post any on-run events (in FIFO order).
*/
for (event = ISC_LIST_HEAD(ctx->on_run);
event != NULL;
event = next_event) {
next_event = ISC_LIST_NEXT(event, ev_link);
ISC_LIST_UNLINK(ctx->on_run, event, ev_link);
task = event->ev_sender;
event->ev_sender = NULL;
isc_task_sendanddetach(&task, &event);
}
}
UNLOCK(&ctx->lock);
/*
* There is no danger if isc_app_shutdown() is called before we wait
* for events.
*/
while (!ctx->want_shutdown) {
dwWaitResult = WaitForMultipleObjects(NUM_EVENTS, ctx->hEvents,
FALSE, INFINITE);
/* See why we returned */
if (WaitSucceeded(dwWaitResult, NUM_EVENTS)) {
/*
* The return was due to one of the events
* being signaled
*/
switch (WaitSucceededIndex(dwWaitResult)) {
case RELOAD_EVENT:
ctx->want_reload = ISC_TRUE;
break;
case SHUTDOWN_EVENT:
ctx->want_shutdown = ISC_TRUE;
break;
}
}
if (ctx->want_reload) {
ctx->want_reload = ISC_FALSE;
return (ISC_R_RELOAD);
}
if (ctx->want_shutdown && ctx->blocked)
exit(-1);
}
return (ISC_R_SUCCESS);
}
isc_result_t
isc__app_run(void) {
return (isc__app_ctxrun((isc_appctx_t *)&isc_g_appctx));
}
isc_result_t
isc__app_ctxshutdown(isc_appctx_t *ctx0) {
isc__appctx_t *ctx = (isc__appctx_t *)ctx0;
isc_boolean_t want_kill = ISC_TRUE;
REQUIRE(VALID_APPCTX(ctx));
LOCK(&ctx->lock);
REQUIRE(ctx->running);
if (ctx->shutdown_requested)
want_kill = ISC_FALSE; /* We're only signaling once */
else
ctx->shutdown_requested = ISC_TRUE;
UNLOCK(&ctx->lock);
if (want_kill)
SetEvent(ctx->hEvents[SHUTDOWN_EVENT]);
return (ISC_R_SUCCESS);
}
isc_result_t
isc__app_shutdown(void) {
return (isc__app_ctxshutdown((isc_appctx_t *)&isc_g_appctx));
}
isc_result_t
isc__app_ctxsuspend(isc_appctx_t *ctx0) {
isc__appctx_t *ctx = (isc__appctx_t *)ctx0;
isc_boolean_t want_kill = ISC_TRUE;
REQUIRE(VALID_APPCTX(ctx));
LOCK(&ctx->lock);
REQUIRE(ctx->running);
/*
* Don't send the reload signal if we're shutting down.
*/
if (ctx->shutdown_requested)
want_kill = ISC_FALSE;
UNLOCK(&ctx->lock);
if (want_kill)
SetEvent(ctx->hEvents[RELOAD_EVENT]);
return (ISC_R_SUCCESS);
}
isc_result_t
isc__app_reload(void) {
return (isc__app_ctxsuspend((isc_appctx_t *)&isc_g_appctx));
}
void
isc__app_ctxfinish(isc_appctx_t *ctx0) {
isc__appctx_t *ctx = (isc__appctx_t *)ctx0;
REQUIRE(VALID_APPCTX(ctx));
DESTROYLOCK(&ctx->lock);
}
void
isc__app_finish(void) {
isc__app_ctxfinish((isc_appctx_t *)&isc_g_appctx);
}
void
isc__app_block(void) {
REQUIRE(isc_g_appctx.running);
REQUIRE(!isc_g_appctx.blocked);
isc_g_appctx.blocked = ISC_TRUE;
blockedthread = GetCurrentThread();
}
void
isc__app_unblock(void) {
REQUIRE(isc_g_appctx.running);
REQUIRE(isc_g_appctx.blocked);
isc_g_appctx.blocked = ISC_FALSE;
REQUIRE(blockedthread == GetCurrentThread());
}
isc_result_t
isc__appctx_create(isc_mem_t *mctx, isc_appctx_t **ctxp) {
isc__appctx_t *ctx;
REQUIRE(mctx != NULL);
REQUIRE(ctxp != NULL && *ctxp == NULL);
ctx = isc_mem_get(mctx, sizeof(*ctx));
if (ctx == NULL)
return (ISC_R_NOMEMORY);
ctx->common.impmagic = APPCTX_MAGIC;
ctx->common.magic = ISCAPI_APPCTX_MAGIC;
ctx->common.methods = &appmethods.methods;
ctx->mctx = NULL;
isc_mem_attach(mctx, &ctx->mctx);
ctx->taskmgr = NULL;
ctx->socketmgr = NULL;
ctx->timermgr = NULL;
*ctxp = (isc_appctx_t *)ctx;
return (ISC_R_SUCCESS);
}
void
isc__appctx_destroy(isc_appctx_t **ctxp) {
isc__appctx_t *ctx;
REQUIRE(ctxp != NULL);
ctx = (isc__appctx_t *)*ctxp;
REQUIRE(VALID_APPCTX(ctx));
isc_mem_putanddetach(&ctx->mctx, ctx, sizeof(*ctx));
*ctxp = NULL;
}
void
isc__appctx_settaskmgr(isc_appctx_t *ctx0, isc_taskmgr_t *taskmgr) {
isc__appctx_t *ctx = (isc__appctx_t *)ctx0;
REQUIRE(VALID_APPCTX(ctx));
ctx->taskmgr = taskmgr;
}
void
isc__appctx_setsocketmgr(isc_appctx_t *ctx0, isc_socketmgr_t *socketmgr) {
isc__appctx_t *ctx = (isc__appctx_t *)ctx0;
REQUIRE(VALID_APPCTX(ctx));
ctx->socketmgr = socketmgr;
}
void
isc__appctx_settimermgr(isc_appctx_t *ctx0, isc_timermgr_t *timermgr) {
isc__appctx_t *ctx = (isc__appctx_t *)ctx0;
REQUIRE(VALID_APPCTX(ctx));
ctx->timermgr = timermgr;
}
isc_result_t
isc__app_register(void) {
return (isc_app_register(isc__appctx_create));
}
#include "../app_api.c"