diff options
Diffstat (limited to 'ctdb/common/ctdb_fork.c')
| -rw-r--r-- | ctdb/common/ctdb_fork.c | 178 |
1 files changed, 178 insertions, 0 deletions
diff --git a/ctdb/common/ctdb_fork.c b/ctdb/common/ctdb_fork.c new file mode 100644 index 0000000000..d372ae0443 --- /dev/null +++ b/ctdb/common/ctdb_fork.c @@ -0,0 +1,178 @@ +/* + 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; +} + +/* + * 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; + char *process; + + 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) { + ctdb_restore_scheduler(ctdb); + } + ctdb->can_send_controls = false; + + return 0; + } + + if (getpid() != ctdb->ctdbd_pid) { + return pid; + } + + process = talloc_asprintf(ctdb->child_processes, "process:%d", (int)pid); + trbt_insert32(ctdb->child_processes, pid, process); + + 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); +} |