IGlobalStopListeningProvider::DrainRequestsGracefully Method

 

Indicates whether IIS will gracefully close any currently pending requests.

Syntax

virtual BOOL DrainRequestsGracefully(  
   VOID  
) const = 0;  

Parameters

This method takes no parameters.

Return Value

true if IIS will close current requests gracefully; otherwise, false.

Remarks

The DrainRequestsGracefully method retrieves information about how IIS is going to close any pending requests when a worker process is shutting down. For example, if IIS is restarted, the DrainRequestsGracefully method will return false because all pending requests will be terminated. However, if an application pool is recycled, the DrainRequestsGracefully method will return true because all pending requests on the worker process that is shutting down will be closed gracefully.

Example

The following code example demonstrates how to create an HTTP module that performs the following tasks:

1. Registers for the GL_STOP_LISTENING notification.

2. Creates a CGlobalModule class that contains an OnGlobalStopListening method. This method performs the following tasks:

   1. Retrieves the status that IIS will use to close current requests by using the DrainRequestsGracefully method.

   2. Formats a string that contains the status information.

   3. Writes the string as an event to the application log of the Event Viewer.

3. Removes the CGlobalModule class from memory and then exits.

#define _WINSOCKAPI_
#include <windows.h>
#include <sal.h>
#include <httpserv.h>

// Create the module's global class.
class MyGlobalModule : public CGlobalModule
{
public:

    // Process a GL_STOP_LISTENING notification.
    GLOBAL_NOTIFICATION_STATUS
    OnGlobalStopListening(
        IN IGlobalStopListeningProvider * pProvider
    )
    {
        UNREFERENCED_PARAMETER( pProvider );
        // Create a string buffer.
        char szBuffer[256] = "";
        // Retrieve the Boolean value and format the string.
        sprintf_s(szBuffer,255,"Drain Requests Gracefully: %s",
            (TRUE==pProvider->DrainRequestsGracefully())?"Yes":"No");
        // Write the string to the event viewer.
        WriteEventViewerLog(szBuffer);
        // Continue processing.
        return GL_NOTIFICATION_CONTINUE;
    }

    VOID Terminate()
    {
        // Remove the class from memory.
        delete this;
    }

    MyGlobalModule()
    {
        // Open a handle to the Event Viewer.
        m_hEventLog = RegisterEventSource( NULL,"IISADMIN" );
    }

    ~MyGlobalModule()
    {
        // Test whether the handle for the Event Viewer is open.
        if (NULL != m_hEventLog)
        {
            // Close the handle to the Event Viewer.
            DeregisterEventSource( m_hEventLog );
            m_hEventLog = NULL;
        }
    }

private:

    // Create a handle for the event viewer.
    HANDLE m_hEventLog;

    // Define a method that writes to the Event Viewer.
    BOOL WriteEventViewerLog(LPCSTR szNotification)
    {
        // Test whether the handle for the Event Viewer is open.
        if (NULL != m_hEventLog)
        {
            // Write any strings to the Event Viewer and return.
            return ReportEvent(
                m_hEventLog, EVENTLOG_INFORMATION_TYPE, 0, 0,
                NULL, 1, 0, &szNotification, NULL );
        }
        return FALSE;
    }
};

// Create the module's exported registration function.
HRESULT
__stdcall
RegisterModule(
    DWORD dwServerVersion,
    IHttpModuleRegistrationInfo * pModuleInfo,
    IHttpServer * pGlobalInfo
)
{
    UNREFERENCED_PARAMETER( dwServerVersion );
    UNREFERENCED_PARAMETER( pGlobalInfo );

    // Create an instance of the global module class.
    MyGlobalModule * pGlobalModule = new MyGlobalModule;
    // Test for an error.
    if (NULL == pGlobalModule)
    {
        return HRESULT_FROM_WIN32(ERROR_NOT_ENOUGH_MEMORY);
    }
    // Set the global notifications and exit.
    return pModuleInfo->SetGlobalNotifications(
        pGlobalModule, GL_STOP_LISTENING );
}

Your module must export the RegisterModule function. You can export this function by creating a module definition (.def) file for your project, or you can compile the module by using the /EXPORT:RegisterModule switch. For more information, see Walkthrough: Creating a Request-Level HTTP Module By Using Native Code.

You can optionally compile the code by using the __stdcall (/Gz) calling convention instead of explicitly declaring the calling convention for each function.

Requirements

Type	Description
Client	- IIS 7.0 on Windows Vista - IIS 7.5 on Windows 7 - IIS 8.0 on Windows 8 - IIS 10.0 on Windows 10
Server	- IIS 7.0 on Windows Server 2008 - IIS 7.5 on Windows Server 2008 R2 - IIS 8.0 on Windows Server 2012 - IIS 8.5 on Windows Server 2012 R2 - IIS 10.0 on Windows Server 2016 Technical Preview
Product	- IIS 7.0, IIS 7.5, IIS 8.0, IIS 8.5, IIS 10.0 - IIS Express 7.5, IIS Express 8.0, IIS Express 10.0
Header	Httpserv.h

See Also

IGlobalStopListeningProvider Interface