/*++ Copyright (c) 1991 Microsoft Corporation Module Name: threads.c Abstract: This file contains routines that manage access to a database of worker thread handles and a database containing the current messenger status (used to report status to the Service Controller). Access to these two databases is controled via a Critical Section. Functions for managing worker threads: MsgThreadManagerInit MsgThreadCloseAll Routines for managing _access to the status information and reporting: MsgStatusInit MsgBeginForcedShutdown MsgStatusUpdate GetMsgrState Author: Dan Lafferty (danl) 17-Jul-1991 Environment: User Mode -Win32 Notes: These functions must be used carefully in order to be effective in shutting the messenger threads down nicely if the shutdown happens to occur during Messenger Initialization. This note explains when each function is to be called. MsgThreadManagerInit This function must be called early on in the initialization process. It should be called before NetRegisterCtrlDispatcher. This way, it is impossible for an UNINSTALL request to be received prior to initializing the Critical Section and the Messenger State. Revision History: 15-Dec-1998 jschwart Eliminated MsgThreadManagerEnd. The DLL is no longer unloaded by services.exe, so deleting the critical section can create a race condition (stop service, new service starts and calls init, first thread deletes critsec, first thread tries to enter critsec and AVs) 03-Nov-1992 Danl Changed status reporting so that we only accept STOP controls if the service is in the RUNNING state. 18-Feb-1992 RitaW Convert to Win32 service control APIs. 02-Oct-1991 JohnRo Work toward UNICODE. 17-Jul-1991 danl created --*/ // // Includes // #include "msrv.h" #include // strlen #include // SERVICE_STATUS #include // UNUSED Macro #include "msgdbg.h" // MSG_LOG #include "msgdata.h" // // Global Data // RTL_RESOURCE g_StateResource; SERVICE_STATUS MsgrStatus; DWORD HintCount; DWORD MsgrUninstallCode; // reason for uninstalling BOOL g_fResourceCreated; DWORD MsgrState; DWORD MsgThreadManagerInit( VOID ) /*++ Routine Description: Initializes the critical section that is used to guard access to the thread and status database. Note that this critsec is created and never deleted (OK since the DLL is never unloaded by services.exe) to fix synchronization problems with stopping/restarting the service. Arguments: none Return Value: NO_ERROR on success, ERROR_NOT_ENOUGH_MEMORY if the init fails Note: --*/ { DWORD dwError = NO_ERROR; NTSTATUS status; if (!g_fResourceCreated) { status = MsgInitResource(&g_StateResource); if (NT_SUCCESS(status)) { g_fResourceCreated = TRUE; } else { MSG_LOG1(ERROR, "MsgThreadManagerInit: MsgInitResource failed %#x\n", status); dwError = ERROR_NOT_ENOUGH_MEMORY; } } return dwError; } VOID MsgThreadCloseAll( VOID ) /*++ Routine Description: Closes all handles stored in the table of worker thread handles. Arguments: none Return Value: none Note: --*/ { RtlAcquireResourceExclusive(&g_StateResource, TRUE); MsgrState = STOPPING; RtlReleaseResource(&g_StateResource); } VOID MsgStatusInit(VOID) /*++ Routine Description: Initializes the status database. Arguments: none. Return Value: none. Note: --*/ { RtlAcquireResourceExclusive(&g_StateResource, TRUE); MsgrState = STARTING; HintCount = 1; MsgrUninstallCode = 0; MsgrStatus.dwServiceType = SERVICE_WIN32; MsgrStatus.dwCurrentState = SERVICE_START_PENDING; MsgrStatus.dwControlsAccepted = 0; MsgrStatus.dwCheckPoint = HintCount; MsgrStatus.dwWaitHint = 20000; // 20 seconds SET_SERVICE_EXITCODE( NO_ERROR, MsgrStatus.dwWin32ExitCode, MsgrStatus.dwServiceSpecificExitCode ); RtlReleaseResource(&g_StateResource); return; } DWORD MsgBeginForcedShutdown( IN BOOL PendingCode, IN DWORD ExitCode ) /*++ Routine Description: This function is called to set the appropriate status when a shutdown is to occur due to an error in the Messenger. NOTE: if a shutdown is based on a request from the Service Controller, MsgStatusUpdate is called instead. On a PENDING call, this routine will also wake up all messenger threads so that they will also shut down. Arguments: PendingCode - Indicates if the Shutdown is immediate or pending. If PENDING, the shutdown will take some time, so a pending status is sent to the ServiceController. ExitCode - Indicates the reason for the shutdown. Return Value: CurrentState - Contains the current state that the messenger is in upon exit from this routine. In this case it will be STOPPED if the PendingCode is PENDING, or STOPPING if the PendingCode is IMMEDIATE. Note: --*/ { NET_API_STATUS status; RtlAcquireResourceExclusive(&g_StateResource, TRUE); // // See if the messenger is already stopping for some reason. // It could be that the ControlHandler thread received a control to // stop the messenger just as we decided to stop ourselves. // if ((MsgrState != STOPPING) && (MsgrState != STOPPED)) { if (PendingCode == PENDING) { MsgrStatus.dwCurrentState = SERVICE_STOP_PENDING; MsgrState = STOPPING; } else { // // The shutdown is to take immediate effect. // MsgrStatus.dwCurrentState = SERVICE_STOPPED; MsgrStatus.dwControlsAccepted = 0; MsgrStatus.dwCheckPoint = 0; MsgrStatus.dwWaitHint = 0; MsgrState = STOPPED; } MsgrUninstallCode = ExitCode; SET_SERVICE_EXITCODE( ExitCode, MsgrStatus.dwWin32ExitCode, MsgrStatus.dwServiceSpecificExitCode ); } // // Send the new status to the service controller. // if (MsgrStatusHandle == (SERVICE_STATUS_HANDLE) NULL) { MSG_LOG(ERROR, "MsgBeginForcedShutdown, no handle to call SetServiceStatus\n", 0); } else if (! SetServiceStatus( MsgrStatusHandle, &MsgrStatus )) { status = GetLastError(); if (status != NERR_Success) { MSG_LOG(ERROR, "MsgBeginForcedShutdown,SetServiceStatus Failed %X\n", status); } } status = MsgrState; RtlReleaseResource(&g_StateResource); return status; } DWORD MsgStatusUpdate( IN DWORD NewState ) /*++ Routine Description: Sends a status to the Service Controller via SetServiceStatus. The contents of the status message is controlled by this routine. The caller simply passes in the desired state, and this routine does the rest. For instance, if the Messenger passes in a STARTING state, This routine will update the hint count that it maintains, and send the appropriate information in the SetServiceStatus call. This routine uses transitions in state to send determine which status to send. For instance if the status was STARTING, and has changed to RUNNING, this routine sends out an INSTALLED to the Service Controller. Arguments: NewState - Can be any of the state flags: UPDATE_ONLY - Simply send out the current status STARTING - The Messenger is in the process of initializing RUNNING - The Messenger has finished with initialization STOPPING - The Messenger is in the process of shutting down STOPPED - The Messenger has completed the shutdown. Return Value: CurrentState - This may not be the same as the NewState that was passed in. It could be that the main thread is sending in a new install state just after the Control Handler set the state to STOPPING. In this case, the STOPPING state will be returned so as to inform the main thread that a shut-down is in process. Note: --*/ { DWORD status; BOOL inhibit = FALSE; // Used to inhibit sending the status // to the service controller. RtlAcquireResourceExclusive(&g_StateResource, TRUE); if (NewState == STOPPED) { if (MsgrState == STOPPED) { // // It was already stopped, don't send another SetServiceStatus. // inhibit = TRUE; } else { // // The shut down is complete, indicate that the messenger // has stopped. // MsgrStatus.dwCurrentState = SERVICE_STOPPED; MsgrStatus.dwControlsAccepted = 0; MsgrStatus.dwCheckPoint = 0; MsgrStatus.dwWaitHint = 0; SET_SERVICE_EXITCODE( MsgrUninstallCode, MsgrStatus.dwWin32ExitCode, MsgrStatus.dwServiceSpecificExitCode ); } MsgrState = NewState; } else { // // We are not being asked to change to the STOPPED state. // switch(MsgrState) { case STARTING: if (NewState == STOPPING) { MsgrStatus.dwCurrentState = SERVICE_STOP_PENDING; MsgrStatus.dwControlsAccepted = 0; MsgrStatus.dwCheckPoint = HintCount++; MsgrStatus.dwWaitHint = 20000; // 20 seconds MsgrState = NewState; } else if (NewState == RUNNING) { // // The Messenger Service has completed installation. // MsgrStatus.dwCurrentState = SERVICE_RUNNING; MsgrStatus.dwControlsAccepted = SERVICE_ACCEPT_STOP | SERVICE_ACCEPT_SHUTDOWN; MsgrStatus.dwCheckPoint = 0; MsgrStatus.dwWaitHint = 0; MsgrState = NewState; } else { // // The NewState must be STARTING. So update the pending // count // MsgrStatus.dwCurrentState = SERVICE_START_PENDING; MsgrStatus.dwControlsAccepted = 0; MsgrStatus.dwCheckPoint = HintCount++; MsgrStatus.dwWaitHint = 20000; // 20 seconds } break; case RUNNING: if (NewState == STOPPING) { MsgrStatus.dwCurrentState = SERVICE_STOP_PENDING; MsgrStatus.dwControlsAccepted = 0; MsgrStatus.dwCheckPoint = HintCount++; MsgrStatus.dwWaitHint = 20000; // 20 seconds MsgrState = NewState; } break; case STOPPING: // // No matter what else was passed in, force the status to // indicate that a shutdown is pending. // MsgrStatus.dwCurrentState = SERVICE_STOP_PENDING; MsgrStatus.dwControlsAccepted = 0; MsgrStatus.dwCheckPoint = HintCount++; MsgrStatus.dwWaitHint = 20000; // 20 seconds break; case STOPPED: // // We're already stopped. Therefore, an uninstalled status // as already been sent. Do nothing. // inhibit = TRUE; break; } } if (!inhibit) { if (MsgrStatusHandle == (SERVICE_STATUS_HANDLE) NULL) { MSG_LOG(ERROR, "MsgStatusUpdate, no handle to call SetServiceStatus\n", 0); } else if (! SetServiceStatus( MsgrStatusHandle, &MsgrStatus )) { status = GetLastError(); if (status != NERR_Success) { MSG_LOG(ERROR, "MsgStatusUpdate, SetServiceStatus Failed %d\n", status); } } } status = MsgrState; RtlReleaseResource(&g_StateResource); return status; } DWORD GetMsgrState ( VOID ) /*++ Routine Description: Obtains the state of the Messenger Service. This state information is protected as a critical section such that only one thread can modify or read it at a time. Arguments: none Return Value: The Messenger State is returned as the return value. --*/ { DWORD status; RtlAcquireResourceShared(&g_StateResource, TRUE); status = MsgrState; RtlReleaseResource(&g_StateResource); return status; } VOID MsgrBlockStateChange( VOID ) { RtlAcquireResourceShared(&g_StateResource, TRUE); } VOID MsgrUnblockStateChange( VOID ) { RtlReleaseResource(&g_StateResource); }