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/*
functions to track and manage processes
Copyright (C) Ronnie Sahlberg 2012
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, see <http://www.gnu.org/licenses/>.
*/
#include "includes.h"
#include "system/wait.h"
#include "../include/ctdb_client.h"
#include "../include/ctdb_private.h"
#include "../common/rb_tree.h"
static bool is_child = false;
void ctdb_set_child_info(TALLOC_CTX *mem_ctx, const char *child_name_fmt, ...)
{
is_child = true;
if (child_name_fmt != NULL) {
va_list ap;
char *t;
va_start(ap, child_name_fmt);
t = talloc_vasprintf(mem_ctx, child_name_fmt, ap);
debug_extra = talloc_asprintf(mem_ctx, "%s:", t);
talloc_free(t);
va_end(ap);
}
}
bool ctdb_is_child_process(void)
{
return is_child;
}
void ctdb_track_child(struct ctdb_context *ctdb, pid_t pid)
{
char *process;
/* Only CTDB main daemon should track child processes */
if (getpid() != ctdb->ctdbd_pid) {
return;
}
process = talloc_asprintf(ctdb->child_processes, "process:%d", (int)pid);
trbt_insert32(ctdb->child_processes, pid, process);
}
/*
* This function forks a child process and drops the realtime
* scheduler for the child process.
*/
pid_t ctdb_fork_no_free_ringbuffer(struct ctdb_context *ctdb)
{
pid_t pid;
pid = fork();
if (pid == -1) {
return -1;
}
if (pid == 0) {
ctdb_set_child_info(ctdb, NULL);
/* Close the Unix Domain socket and the TCP socket.
* This ensures that none of the child processes will
* look like the main daemon when it is not running.
* tevent needs to be stopped before closing sockets.
*/
if (ctdb->ev != NULL) {
talloc_free(ctdb->ev);
ctdb->ev = NULL;
}
if (ctdb->daemon.sd != -1) {
close(ctdb->daemon.sd);
ctdb->daemon.sd = -1;
}
if (ctdb->methods != NULL) {
ctdb->methods->shutdown(ctdb);
}
/* The child does not need to be realtime */
if (ctdb->do_setsched) {
reset_scheduler();
}
ctdb->can_send_controls = false;
return 0;
}
ctdb_track_child(ctdb, pid);
return pid;
}
pid_t ctdb_fork(struct ctdb_context *ctdb)
{
pid_t pid;
pid = ctdb_fork_no_free_ringbuffer(ctdb);
if (pid == 0) {
ctdb_log_ringbuffer_free();
}
return pid;
}
static void ctdb_sigchld_handler(struct tevent_context *ev,
struct tevent_signal *te, int signum, int count,
void *dont_care,
void *private_data)
{
struct ctdb_context *ctdb = talloc_get_type(private_data, struct ctdb_context);
int status;
pid_t pid = -1;
while (pid != 0) {
pid = waitpid(-1, &status, WNOHANG);
if (pid == -1) {
DEBUG(DEBUG_ERR, (__location__ " waitpid() returned error. errno:%d\n", errno));
return;
}
if (pid > 0) {
char *process;
if (getpid() != ctdb->ctdbd_pid) {
continue;
}
process = trbt_lookup32(ctdb->child_processes, pid);
if (process == NULL) {
DEBUG(DEBUG_ERR,("Got SIGCHLD from pid:%d we didn not spawn with ctdb_fork\n", pid));
}
DEBUG(DEBUG_DEBUG, ("SIGCHLD from %d %s\n", (int)pid, process));
talloc_free(process);
}
}
}
struct tevent_signal *
ctdb_init_sigchld(struct ctdb_context *ctdb)
{
struct tevent_signal *se;
ctdb->child_processes = trbt_create(ctdb, 0);
se = tevent_add_signal(ctdb->ev, ctdb, SIGCHLD, 0, ctdb_sigchld_handler, ctdb);
return se;
}
int
ctdb_kill(struct ctdb_context *ctdb, pid_t pid, int signum)
{
char *process;
if (signum == 0) {
return kill(pid, signum);
}
if (getpid() != ctdb->ctdbd_pid) {
return kill(pid, signum);
}
process = trbt_lookup32(ctdb->child_processes, pid);
if (process == NULL) {
DEBUG(DEBUG_ERR,("ctdb_kill: trying to kill(%d, %d) a process that does not exist\n", pid, signum));
return 0;
}
return kill(pid, signum);
}
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