Leaked source code of windows server 2003
You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
 
 
 
 
 
 

323 lines
9.6 KiB

/* Copyright 1999 American Power Conversion, All Rights Reserved
*
* Description:
* The file implements the Notifier. The Notifier is reponsible
* for broadcasting power-related and shutdown messages to the
* local machine.
*
*
* Revision History:
* sberard 30Mar1999 initial revision.
* mholly 27Apr1999 create and recycle a single thread for repeat
* notifications - use two separate events to signal
* either pause or resume of the thread state
* mholly 27Apr1999 make sure to clear the pause event when resuming
* and to clear the resume event when pausing
* mholly 28May1999 send all messages in _theNotifierThread, also
* have this thread do any delaying for the callee,
* and keep track of whether a power out message
* was sent, so we know when to send a power restored
* v-stebe 17Dec2001 added check to ensure the SetEvent and ResetEvent are not
* called with NULL.
*/
#include "notifier.h"
#include "service.h"
#include "upsmsg.h"
//
// Function prototypes
//
static void sendSingleNotification(DWORD aMsgId);
static void sendRepeatingNotification(void);
static void setupNotifierThread(void);
//
// Globals
//
static HANDLE _theNotifierThread = NULL;
static HANDLE _theNotificationPause = NULL;
static HANDLE _theNotificationResume = NULL;
static DWORD _theMessageId;
static DWORD _theNotificationInterval;
static DWORD _theMessageDelay;
static DWORD _theLastMessageSent = 0;
//
// Constats
//
static const int kMilliSeconds = 1000; // Used to convert seconds to milliseconds
/**
* SendNotification
*
* Description:
* This function sends a broadcast message to the local machine. The
* message is specified by aMsgId. The parameter anInterval specifies
* the amount of time to wait between consecutive messages. If this
* value is zero the message is only sent once, otherwise the message
* will repeat until SendNotification(..) or CancelNotification() is
* called. aDelay specifies that the message should be send aDelay
* seconds in the future - note that this method will not block for aDelay
* seconds, it returns immediately and sends the message on a separate
* thread. Any current previously executing periodic notifications
* are canceled as a result of this call.
*
* This method also keeps track of whether the power out message had
* been sent to users. This is done in order to squelch a power return
* message if a power out message had not already been sent.
*
* Parameters:
* aMsgId - the message to send
* anInterval - the amount of time, in seconds, between messages
* aDelay - the amount of time, in seconds to wait to send message
*
* Returns:
* nothing
*/
void SendNotification(DWORD aMsgId, DWORD anInterval, DWORD aDelay)
{
//
// Cancel any current periodic notifications
//
CancelNotification();
//
// only sent the power back message if
// the power out message had already
// been broadcast to the users
//
if ((APE2_UPS_POWER_BACK == aMsgId) &&
(APE2_UPS_POWER_OUT != _theLastMessageSent)) {
//
// the last message sent was not power out
// so simply return
//
return;
}
//
// Set the message parameters for _theNotifierThread
//
_theMessageId = aMsgId;
_theNotificationInterval = anInterval;
_theMessageDelay = aDelay;
//
// setup the thread events and thread
//
setupNotifierThread();
//
// tell _theNotificationThread to run by
// signalling the resume event - must make
// sure to clear the pause event before
// signalling the resume
//
if (_theNotificationPause) {
ResetEvent(_theNotificationPause);
}
if (_theNotificationResume){
SetEvent(_theNotificationResume);
}
}
/**
* CancelNotification
*
* Description:
* This function cancels the periodic messaging initiated through a call
* to the SendNotification(..) function.
*
* Parameters:
* none
*
* Returns:
* nothing
*/
void CancelNotification()
{
//
// tell _theNotificationThread to pause
// by signalling the pause event - must make
// sure to clear the resume event before
// signalling the pause event
//
if (_theNotificationResume) {
ResetEvent(_theNotificationResume);
}
if (_theNotificationPause) {
SetEvent(_theNotificationPause);
}
}
/**
* setupNotifierThread
*
* Description:
* Creates the thread on which the notifications will
* actually be sent. It also creates the events that
* are used to signal the start and end of notifications
*
* Parameters:
* none
*
* Returns:
* nothing
*/
void setupNotifierThread(void)
{
if (!_theNotificationPause) {
//
// Create the pause event
//
_theNotificationPause = CreateEvent(NULL, FALSE, FALSE, NULL);
}
if (!_theNotificationResume) {
//
// create the resume event
//
_theNotificationResume = CreateEvent(NULL, FALSE, FALSE, NULL);
}
if (!_theNotifierThread) {
//
// create the notification thread
//
_theNotifierThread = CreateThread(NULL, // no security attributes
0, // default stack
(LPTHREAD_START_ROUTINE)
sendRepeatingNotification,
NULL,
0,
NULL);
}
}
/**
* sendSingleNotification
*
* Description:
* This function sends a single broadcast message to the local machine.
* The message is specified by aMsgId.
*
* Parameters:
* aMsgId - the message to send
*
* Returns:
* nothing
*/
static void sendSingleNotification(DWORD aMsgId)
{
DWORD status;
TCHAR computer_name[MAX_COMPUTERNAME_LENGTH + 1];
DWORD computer_name_len = MAX_COMPUTERNAME_LENGTH + 1;
LPTSTR msg_buf, additional_args[1];
DWORD buf_len;
// Get the computer name and pass it as additional
// information for the message
GetComputerName(computer_name, &computer_name_len);
additional_args[0] = computer_name;
buf_len = FormatMessage(FORMAT_MESSAGE_ALLOCATE_BUFFER |
FORMAT_MESSAGE_ARGUMENT_ARRAY |
FORMAT_MESSAGE_FROM_SYSTEM ,
NULL, // NULL means get message from system
aMsgId,
MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
(LPTSTR) &msg_buf,
0, // buffer size
(va_list *)additional_args); // additional arguements
if (buf_len > 0) {
_theLastMessageSent = aMsgId;
// Display the message
status = NetMessageBufferSend(NULL,
computer_name,
computer_name,
(LPBYTE) msg_buf,
buf_len * 2); // multiply by 2 because the string is Unicodeh
// Free the memory allocated by FormatMessage
LocalFree(msg_buf);
}
}
/**
* sendRepeatingNotification
*
* Description:
* This function sends notifications repeatedly to the local machine.
* This function calls sendSingleNotification(..) to perform the actual
* notification. The message will be sent after _theMessageDelay seconds
* has elapsed after _theNotificationResume event is signaled. If
* _theMessageDelay is zero, a message is sent immediately. Messages are
* repeated, if _theNotificationInterval is not zero, until the Event
* _theNotificationPause is signaled. The message Id and the notification
* interval are specified by the global variables _theMessageId and
* _theNotificationInterval.
*
* To restart notifications using this thread signal _theNotificationResume
* event. This thread will remain idle until this event is signalled
*
* Parameters:
* none
*
* Returns:
* nothing
*/
static void sendRepeatingNotification(void)
{
//
// wait for _theNotificationResume to become signaled
// this becomes signaled when a notification should be sent
//
while (WAIT_OBJECT_0 ==
WaitForSingleObject(_theNotificationResume, INFINITE)) {
//
// Send the initial message after the message delay
// seconds has elapsed - if _theNotificationPause becomes
// signaled before the delay seconds has elapsed then
// this notification has been cancelled
//
if (WAIT_TIMEOUT == WaitForSingleObject(_theNotificationPause,
_theMessageDelay * kMilliSeconds)) {
//
// send the message that was requested
//
sendSingleNotification(_theMessageId);
//
// now send repeating notifications
// if necessary - if _theNotificationInterval
// is set to zero, then only send the single
// message above
//
if (0 != _theNotificationInterval) {
//
// wait for either _theNotificationPause to become
// signalled or until it is time to notify again
//
DWORD interval = _theNotificationInterval * kMilliSeconds;
while (WAIT_TIMEOUT ==
WaitForSingleObject(_theNotificationPause, interval)) {
sendSingleNotification(_theMessageId);
}
}
}
}
}