restart_monitor_win.cc File Reference

#include "restart_monitor_win.h"
#include <assert.h>
#include <windows.h>
#include <memory>
#include <vector>
#include <shellapi.h>
#include "my_sys.h"
#include "mysqld.h"
#include "sql/log.h"
#include "sql/message.h"
#include "sql/sql_const.h"

Functions
static int	monitor_mysqld (LPSTR cmdline)
	Spawn mysqld process. More...
static bool	initialize_events (void)
	Initialize event handles in monitor process. More...
bool	initialize_monitor_log ()
	Initialize the monitor log. More...
void	deinitialize_monitor_log ()
	Deinitialize the monitor log. More...
static WORD	get_event_type (Monitor_log_msg_type type)
	Map monitor msg type to corresponding event log type. More...
static void	log_in_eventlog (WORD type, LPCSTR msg)
	Log a message to the event log. More...
void	monitor_log_msg (Monitor_log_msg_type type, LPCTSTR format,...)
	Log an msg. More...
static void	signal_thr_open_event (const char *event_name)
	Signal an named event by the event name. More...
const char *	get_monitor_pid ()
	Get char representation corresponding to MYSQLD_PARENT_PID. More...
void	signal_event (Signal_type signal_type)
	Signal an event of type Signal_type. More...
static HANDLE	get_service_status_pipe_in_mysqld ()
	Get handle to service status pipe. More...
void	close_service_status_pipe_in_mysqld ()
	Close mysqld service status pipe. More...
static bool	setup_service_status_pipe_in_monitor ()
	Setup service status pipe. More...
static void	close_service_status_pipe_in_monitor ()
	Close service status pipe. More...
bool	send_service_status (const Service_status_msg &msg)
	Send service status message to the monitor. More...
static bool	get_and_set_service_status ()
	Get the service status command from the mysqld process and process it and set the status in the SCM. More...
static void	quote_arg (const std::string &arg, std::string *cmd_line)
	Add an argument to a command line adding quotes and backlashes for paths as necessary. More...
static std::string	construct_cmd_line (const std::vector< std::string > &args)
	Construct the command line that is to be passed to the spawned mysqld process. More...
static bool	is_early_short_option (const char ch)
	Check if the char representing is an early option. More...
static bool	is_early_option (const char *cur_arg)
	Check if the option specified is an early option. More...
bool	is_early_option (int argc, char **argv)
	Check if option is an early type or –gdb, –no-monitor. More...
bool	initialize_mysqld_monitor ()
	Initialize the mysqld monitor. More...
bool	is_monitor_win_service ()
	Check if the monitor is started under a windows service. More...
void	deinitialize_mysqld_monitor ()
	Deinitialize the monitor. More...
bool	is_mysqld_monitor ()
	Check if we are monitor process. More...
static void	set_event_names ()
	This function assigns names to the shutdown event, service status command event, service status command processed event and the name of service status pipe. More...
bool	setup_service_status_cmd_processed_handle ()
	Create an event handle to indicate service status command has been processed from the mysqld monitor parent to the mysqld child. More...
void	close_service_status_cmd_processed_handle ()
	Close the Service Status Cmd Processed handle. More...
int	start_monitor ()
	Start the monitor if we are called in parent (monitor) context. More...

Variables
static DWORD	my_monitor_pid
static bool	mysqld_monitor_process
static HANDLE	service_status_cmd_event
static HANDLE	service_status_pipe
static HANDLE	client_service_status_pipe = nullptr
static HANDLE	service_status_cmd_processed_handle = nullptr
static HANDLE	event_log_handle = nullptr
static const int	NUM_WAIT_HANDLES = 2
static const int	MYSQLD_HANDLE = 0
static const int	SERVICE_STATUS_CMD_HANDLE = 1
static const int	EVENT_NAME_LEN = 32
static char	service_status_cmd_processed_event_name [EVENT_NAME_LEN]
static char	shutdown_event_name [EVENT_NAME_LEN]
static char	service_status_pipe_name [EVENT_NAME_LEN]
static char	service_status_cmd_event_name [EVENT_NAME_LEN]

Function Documentation

close_service_status_cmd_processed_handle()

void close_service_status_cmd_processed_handle

(

)

Close the Service Status Cmd Processed handle.

close_service_status_pipe_in_monitor()

static void close_service_status_pipe_in_monitor ( )

static

Close service status pipe.

This handle is closed in context of the monitor process.

close_service_status_pipe_in_mysqld()

void close_service_status_pipe_in_mysqld

(

)

Close mysqld service status pipe.

Close the service status pipe.

This call shall made in context of the mysqld process.

construct_cmd_line()

static std::string construct_cmd_line ( const std::vector< std::string > &  args )

static

Construct the command line that is to be passed to the spawned mysqld process.

Parameters

args	reference to vector of string arguments.

Returns

string representing the cmd line.

deinitialize_monitor_log()

void deinitialize_monitor_log

(

)

Deinitialize the monitor log.

This method deregisters the event log.

deinitialize_mysqld_monitor()

void deinitialize_mysqld_monitor

(

)

Deinitialize the monitor.

This method essentially closes any handles opened during initialization.

get_and_set_service_status()

static bool get_and_set_service_status ( )

static

Get the service status command from the mysqld process and process it and set the status in the SCM.

Returns

bool true if the call is successful else false.

get_event_type()

static WORD get_event_type ( Monitor_log_msg_type  type )

static

Map monitor msg type to corresponding event log type.

Parameters

type	Type of the message.

Returns

a DWORD indicating event log type.

get_monitor_pid()

const char * get_monitor_pid

(

)

Get char representation corresponding to MYSQLD_PARENT_PID.

Returns

Pointer to string representing pid of the monitor.

get_service_status_pipe_in_mysqld()

static HANDLE get_service_status_pipe_in_mysqld ( )

static

Get handle to service status pipe.

This call will be in the context of mysqld process.

Returns

handle to the service status pipe.

initialize_events()

static bool initialize_events ( void  )

static

Initialize event handles in monitor process.

initialize_monitor_log()

bool initialize_monitor_log

(

)

Initialize the monitor log.

In case mysqld is spawned from windows service, we use event log for logging error messages. (stderr/stdout is not available when started as as a service.)

initialize_mysqld_monitor()

bool initialize_mysqld_monitor

(

)

Initialize the mysqld monitor.

This method is called from both the monitor and mysqld. It sets the variable that distinguishes the monitor and the mysqld. It also initialize the monitor logging subsystem if the process under which it is called is monitor.

is_early_option() [1/2]

static bool is_early_option ( const char *  cur_arg )

inlinestatic

Check if the option specified is an early option.

Parameters

cur_arg

string representing an early option.

Returns

true if string is an early option else false.

is_early_option() [2/2]

bool is_early_option	(	int	argc,
		char **	argv
	)

Check if option is an early type or –gdb, –no-monitor.

The early type options are verbose, help, initialize, version and initialize-insecure. These options print and do certain activities and allow the server to exit. In addition there are options like gdb, no-monitor where we do not spawn a monitor process.

Parameters

argc	Count of arguments.
argv	Vector of arguments.

Returns

true if we are early option else false.

is_early_short_option()

static bool is_early_short_option ( const char  ch )

inlinestatic

Check if the char representing is an early option.

Parameters

ch	charactering representing an short option.

Returns

true if the option char is an early short option else false.

is_monitor_win_service()

bool is_monitor_win_service

(

)

Check if the monitor is started under a windows service.

Returns

true if the monitor is started as a windows service.

is_mysqld_monitor()

bool is_mysqld_monitor

(

)

Check if we are monitor process.

Returns

true if the current process is monitor else false.

log_in_eventlog()

static void log_in_eventlog ( WORD  type, LPCSTR  msg  )

inlinestatic

Log a message to the event log.

Parameters

type	Event log type.
msg	Pointer to the message string.

monitor_log_msg()

void monitor_log_msg	(	Monitor_log_msg_type	type,
		LPCTSTR	format,
			...
	)

Log an msg.

If the monitor is started as a windows service, then log it to the event log using apporirate type.

Parameters

type	Type of message indicating whether it is information, warning, error.
format	format string.

monitor_mysqld()

static int monitor_mysqld ( LPSTR  cmdline )

static

Spawn mysqld process.

Wait on spawned process handle for mysqld exit. On exit, retrieve exit code to check for restart and shutdown or abort exit. If we exit using MYSQLD_RESTART_EXIT code then we respawn this child process. In addition, if the mysqld process is instantiated as a windows service, then we create a named pipe. The pipe allows for communication from mysqld to send service status code. This service status code can then be relayed to the Service Control Manager using the service status handle. This is used to relay the service running status and set slow status timeout value.

quote_arg()

static void quote_arg ( const std::string &  arg, std::string *  cmd_line  )

static

Add an argument to a command line adding quotes and backlashes for paths as necessary.

Parameters

	arg	string representing the argument.
[in,out]	cmd_line	command line to which the string should be appended with necessary quoting.

send_service_status()

bool send_service_status

(

const Service_status_msg &

msg

)

Send service status message to the monitor.

This method is used by mysqld to send service status like running and setting the slow timeout value.

set_event_names()

static void set_event_names ( )

static

This function assigns names to the shutdown event, service status command event, service status command processed event and the name of service status pipe.

setup_service_status_cmd_processed_handle()

bool setup_service_status_cmd_processed_handle

(

)

Create an event handle to indicate service status command has been processed from the mysqld monitor parent to the mysqld child.

Setup the service status command processed handle.

Returns

true if service status command processed handle could not be setup else false.

setup_service_status_pipe_in_monitor()

static bool setup_service_status_pipe_in_monitor ( )

static

Setup service status pipe.

Returns

true if service status pipe is setup successfully else false.

signal_event()

void signal_event

(

Signal_type

signal

)

Signal an event of type Signal_type.

Parameters

signal

type of the event.

signal_thr_open_event()

static void signal_thr_open_event ( const char *  event_name )

static

Signal an named event by the event name.

Parameters

event_name

pointer to char string representing the event.

start_monitor()

int start_monitor

(

)

Start the monitor if we are called in parent (monitor) context.

In child context, set the event names and get the monitor process pid and return -1.

Returns

-1 if we are in child context else exit code of the mysqld process.

Variable Documentation

client_service_status_pipe

HANDLE client_service_status_pipe = nullptr

static

event_log_handle

HANDLE event_log_handle = nullptr

static

EVENT_NAME_LEN

const int EVENT_NAME_LEN = 32

static

my_monitor_pid

DWORD my_monitor_pid

static

MYSQLD_HANDLE

const int MYSQLD_HANDLE = 0

static

mysqld_monitor_process

bool mysqld_monitor_process

static

NUM_WAIT_HANDLES

const int NUM_WAIT_HANDLES = 2

static

service_status_cmd_event

HANDLE service_status_cmd_event

static

service_status_cmd_event_name

char service_status_cmd_event_name[EVENT_NAME_LEN]

static

SERVICE_STATUS_CMD_HANDLE

const int SERVICE_STATUS_CMD_HANDLE = 1

static

service_status_cmd_processed_event_name

char service_status_cmd_processed_event_name[EVENT_NAME_LEN]

static

service_status_cmd_processed_handle

HANDLE service_status_cmd_processed_handle = nullptr

static

service_status_pipe

HANDLE service_status_pipe

static

service_status_pipe_name

char service_status_pipe_name[EVENT_NAME_LEN]

static

shutdown_event_name

char shutdown_event_name[EVENT_NAME_LEN]

static