mariadb/server-tools/instance-manager/angel.cc
monty@mysql.com/nosik.monty.fi e53a73e26c Fixed a lot of compiler warnings and errors detected by Forte C++ on Solaris
Faster thr_alarm()
Added 'Opened_files' status variable to track calls to my_open()
Don't give warnings when running mysql_install_db
Added option --source-install to mysql_install_db

I had to do the following renames() as used polymorphism didn't work with Forte compiler on 64 bit systems
index_read()      -> index_read_map()
index_read_idx()  -> index_read_idx_map()
index_read_last() -> index_read_last_map()
2007-08-13 16:11:25 +03:00

407 lines
9.7 KiB
C++

/* Copyright (C) 2003-2006 MySQL AB
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; version 2 of the License.
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, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */
#ifndef __WIN__
#include "angel.h"
#include <sys/wait.h>
/*
sys/wait.h is needed for waitpid(). Unfortunately, there is no MySQL
include file, that can serve for this. Include it before MySQL system
headers so that we can change system defines if needed.
*/
#include "my_global.h"
#include "my_alarm.h"
#include "my_dir.h"
#include "my_sys.h"
/* Include other IM files. */
#include "log.h"
#include "manager.h"
#include "options.h"
#include "priv.h"
/************************************************************************/
enum { CHILD_OK= 0, CHILD_NEED_RESPAWN, CHILD_EXIT_ANGEL };
static int log_fd;
static volatile sig_atomic_t child_status= CHILD_OK;
static volatile sig_atomic_t child_exit_code= 0;
static volatile sig_atomic_t shutdown_request_signo= 0;
/************************************************************************/
/**
Open log file.
@return
TRUE on error;
FALSE on success.
*************************************************************************/
static bool open_log_file()
{
log_info("Angel: opening log file '%s'...",
(const char *) Options::Daemon::log_file_name);
log_fd= open(Options::Daemon::log_file_name,
O_WRONLY | O_CREAT | O_APPEND | O_NOCTTY,
S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP);
if (log_fd < 0)
{
log_error("Can not open log file '%s': %s.",
(const char *) Options::Daemon::log_file_name,
(const char *) strerror(errno));
return TRUE;
}
return FALSE;
}
/************************************************************************/
/**
Detach the process from controlling tty.
@return
TRUE on error;
FALSE on success.
*************************************************************************/
static bool detach_process()
{
/*
Become a session leader (the goal is not to have a controlling tty).
setsid() must succeed because child is guaranteed not to be a process
group leader (it belongs to the process group of the parent).
NOTE: if we now don't have a controlling tty we will not receive
tty-related signals - no need to ignore them.
*/
if (setsid() < 0)
{
log_error("setsid() failed: %s.", (const char *) strerror(errno));
return -1;
}
/* Close STDIN. */
log_info("Angel: preparing standard streams.");
if (close(STDIN_FILENO) < 0)
{
log_error("Warning: can not close stdin (%s)."
"Trying to continue...",
(const char *) strerror(errno));
}
/* Dup STDOUT and STDERR to the log file. */
if (dup2(log_fd, STDOUT_FILENO) < 0 ||
dup2(log_fd, STDERR_FILENO) < 0)
{
log_error("Can not redirect stdout and stderr to the log file: %s.",
(const char *) strerror(errno));
return TRUE;
}
if (log_fd != STDOUT_FILENO && log_fd != STDERR_FILENO)
{
if (close(log_fd) < 0)
{
log_error("Can not close original log file handler (%d): %s. "
"Trying to continue...",
(int) log_fd,
(const char *) strerror(errno));
}
}
return FALSE;
}
/************************************************************************/
/**
Create PID file.
@return
TRUE on error;
FALSE on success.
*************************************************************************/
static bool create_pid_file()
{
if (create_pid_file(Options::Daemon::angel_pid_file_name, getpid()))
{
log_error("Angel: can not create pid file (%s).",
(const char *) Options::Daemon::angel_pid_file_name);
return TRUE;
}
log_info("Angel: pid file (%s) created.",
(const char *) Options::Daemon::angel_pid_file_name);
return FALSE;
}
/************************************************************************/
/**
SIGCHLD handler.
Reap child, analyze child exit code, and set child_status
appropriately.
*************************************************************************/
extern "C" void reap_child(int);
void reap_child(int __attribute__((unused)) signo)
{
/* NOTE: As we have only one child, no need to cycle waitpid(). */
int exit_code;
if (waitpid(0, &exit_code, WNOHANG) > 0)
{
child_exit_code= exit_code;
child_status= exit_code ? CHILD_NEED_RESPAWN : CHILD_EXIT_ANGEL;
}
}
/************************************************************************/
/**
SIGTERM, SIGHUP, SIGINT handler.
Set termination status and return.
*************************************************************************/
extern "C" void terminate(int signo);
void terminate(int signo)
{
shutdown_request_signo= signo;
}
/************************************************************************/
/**
Angel main loop.
@return
The function returns exit status for global main():
0 -- program completed successfully;
!0 -- error occurred.
*************************************************************************/
static int angel_main_loop()
{
/*
Install signal handlers.
NOTE: Although signal handlers are needed only for parent process
(IM-angel), we should install them before fork() in order to avoid race
condition (i.e. to be sure, that IM-angel will receive SIGCHLD in any
case).
*/
sigset_t wait_for_signals_mask;
struct sigaction sa_chld;
struct sigaction sa_term;
struct sigaction sa_chld_orig;
struct sigaction sa_term_orig;
struct sigaction sa_int_orig;
struct sigaction sa_hup_orig;
log_info("Angel: setting necessary signal actions...");
sigemptyset(&wait_for_signals_mask);
sigemptyset(&sa_chld.sa_mask);
sa_chld.sa_handler= reap_child;
sa_chld.sa_flags= SA_NOCLDSTOP;
sigemptyset(&sa_term.sa_mask);
sa_term.sa_handler= terminate;
sa_term.sa_flags= 0;
/* NOTE: sigaction() fails only if arguments are wrong. */
sigaction(SIGCHLD, &sa_chld, &sa_chld_orig);
sigaction(SIGTERM, &sa_term, &sa_term_orig);
sigaction(SIGINT, &sa_term, &sa_int_orig);
sigaction(SIGHUP, &sa_term, &sa_hup_orig);
/* The main Angel loop. */
while (true)
{
/* Spawn a new Manager. */
log_info("Angel: forking Manager process...");
switch (fork()) {
case -1:
log_error("Angel: can not fork IM-main: %s.",
(const char *) strerror(errno));
return -1;
case 0:
/*
We are in child process, which will be IM-main:
- Restore default signal actions to let the IM-main work with
signals as he wishes;
- Call Manager::main();
*/
log_info("Angel: Manager process created successfully.");
/* NOTE: sigaction() fails only if arguments are wrong. */
sigaction(SIGCHLD, &sa_chld_orig, NULL);
sigaction(SIGTERM, &sa_term_orig, NULL);
sigaction(SIGINT, &sa_int_orig, NULL);
sigaction(SIGHUP, &sa_hup_orig, NULL);
log_info("Angel: executing Manager...");
return Manager::main();
}
/* Wait for signals. */
log_info("Angel: waiting for signals...");
while (child_status == CHILD_OK && shutdown_request_signo == 0)
sigsuspend(&wait_for_signals_mask);
/* Exit if one of shutdown signals has been caught. */
if (shutdown_request_signo)
{
log_info("Angel: received shutdown signal (%d). Exiting...",
(int) shutdown_request_signo);
return 0;
}
/* Manager process died. Respawn it if it was a failure. */
if (child_status == CHILD_NEED_RESPAWN)
{
child_status= CHILD_OK;
log_error("Angel: Manager exited abnormally (exit code: %d).",
(int) child_exit_code);
log_info("Angel: sleeping 1 second...");
sleep(1); /* don't respawn too fast */
log_info("Angel: respawning Manager...");
continue;
}
/* Delete IM-angel PID file. */
my_delete(Options::Daemon::angel_pid_file_name, MYF(0));
/* IM-angel finished. */
log_info("Angel: Manager exited normally. Exiting...");
return 0;
}
}
/************************************************************************/
/**
Angel main function.
@return
The function returns exit status for global main():
0 -- program completed successfully;
!0 -- error occurred.
*************************************************************************/
int Angel::main()
{
log_info("Angel: started.");
/* Open log file. */
if (open_log_file())
return -1;
/* Fork a new process. */
log_info("Angel: daemonizing...");
switch (fork()) {
case -1:
/*
This is the main Instance Manager process, fork() failed.
Log an error and bail out with error code.
*/
log_error("fork() failed: %s.", (const char *) strerror(errno));
return -1;
case 0:
/* We are in child process. Continue Angel::main() execution. */
break;
default:
/*
We are in the parent process. Return 0 so that parent exits
successfully.
*/
log_info("Angel: exiting from the original process...");
return 0;
}
/* Detach child from controlling tty. */
if (detach_process())
return -1;
/* Create PID file. */
if (create_pid_file())
return -1;
/* Start Angel main loop. */
return angel_main_loop();
}
#endif // __WIN__