thread.c

这是一个开放源代码的与WINNT/WIN2K/WIN2003兼容的操作系统

/*
 * COPYRIGHT:       See COPYING in the top level directory
 * PROJECT:         ReactOS CSR Sub System
 * FILE:            subsys/csr/csrsrv/thread.c
 * PURPOSE:         CSR Server DLL Thread Implementation
 * PROGRAMMERS:     Alex Ionescu ([e-mail])
 */

/* INCLUDES ******************************************************************/

#include "srv.h"

#define NDEBUG
#include <debug.h>

/* DATA **********************************************************************/

LIST_ENTRY CsrThreadHashTable[256];
SECURITY_QUALITY_OF_SERVICE CsrSecurityQos =
{
    sizeof(SECURITY_QUALITY_OF_SERVICE),
    SecurityImpersonation,
    SECURITY_STATIC_TRACKING,
    FALSE
};

/* PRIVATE FUNCTIONS *********************************************************/

/*++
 * @name CsrAllocateThread
 *
 * The CsrAllocateThread routine allocates a new CSR Thread object.
 *
 * @param CsrProcess
 *        Pointer to the CSR Process which will contain this CSR Thread.
 *
 * @return Pointer to the newly allocated CSR Thread.
 *
 * @remarks None.
 *
 *--*/
PCSR_THREAD
NTAPI
CsrAllocateThread(IN PCSR_PROCESS CsrProcess)
{
    PCSR_THREAD CsrThread;

    /* Allocate the structure */
    CsrThread = RtlAllocateHeap(CsrHeap, HEAP_ZERO_MEMORY, sizeof(CSR_THREAD));
    if (!CsrThread) return(NULL);

    /* Reference the Thread and Process */
    CsrThread->ReferenceCount++;
    CsrProcess->ReferenceCount++;

    /* Set the Parent Process */
    CsrThread->Process = CsrProcess;

    /* Return Thread */
    return CsrThread;
}

/*++
 * @name CsrLocateThreadByClientId
 *
 * The CsrLocateThreadByClientId routine locates the CSR Thread and,
 * optionally, its parent CSR Process, corresponding to a Client ID.
 *
 * @param Process
 *        Optional pointer to a CSR Process pointer which will contain
 *        the CSR Thread's parent.
 *
 * @param ClientId
 *        Pointer to a Client ID structure containing the Unique Thread ID
 *        to look up.
 *
 * @return Pointer to the CSR Thread corresponding to this CID, or NULL if
 *         none was found.
 *
 * @remarks None.
 *
 *--*/
PCSR_THREAD
NTAPI
CsrLocateThreadByClientId(OUT PCSR_PROCESS *Process OPTIONAL,
                          IN PCLIENT_ID ClientId)
{
    ULONG i;
    PLIST_ENTRY ListHead, NextEntry;
    PCSR_THREAD FoundThread;

    /* Hash the Thread */
    i = CsrHashThread(ClientId->UniqueThread);
    
    /* Set the list pointers */
    ListHead = &CsrThreadHashTable[i];
    NextEntry = ListHead->Flink;

    /* Star the loop */
    while (NextEntry != ListHead)
    {
        /* Get the thread */
        FoundThread = CONTAINING_RECORD(NextEntry, CSR_THREAD, HashLinks);

        /* Compare the CID */
        if (FoundThread->ClientId.UniqueThread == ClientId->UniqueThread)
        {
            /* Match found, return the process */
            *Process = FoundThread->Process;

            /* Return thread too */
            return FoundThread;
        }

        /* Next */
        NextEntry = NextEntry->Flink;
    }

    /* Nothing found */
    return NULL;
}

/*++
 * @name CsrLocateThreadInProcess
 *
 * The CsrLocateThreadInProcess routine locates the CSR Thread 
 * corresponding to a Client ID inside a specific CSR Process.
 *
 * @param Process
 *        Optional pointer to the CSR Process which contains the CSR Thread
 *        that will be looked up.
 *
 * @param ClientId
 *        Pointer to a Client ID structure containing the Unique Thread ID
 *        to look up.
 *
 * @return Pointer to the CSR Thread corresponding to this CID, or NULL if
 *         none was found.
 *
 * @remarks If the CsrProcess argument is NULL, the lookup will be done inside
 *          CsrRootProcess.
 *
 *--*/
PCSR_THREAD
NTAPI
CsrLocateThreadInProcess(IN PCSR_PROCESS CsrProcess OPTIONAL,
                         IN PCLIENT_ID Cid)
{
    PLIST_ENTRY ListHead, NextEntry;
    PCSR_THREAD FoundThread = NULL;

    /* Use the Root Process if none was specified */
    if (!CsrProcess) CsrProcess = CsrRootProcess;

    /* Save the List pointers */
    ListHead = &CsrProcess->ThreadList;
    NextEntry = ListHead->Flink;

    /* Start the Loop */
    while (NextEntry != NextEntry)
    {
        /* Get Thread Entry */
        FoundThread = CONTAINING_RECORD(NextEntry, CSR_THREAD, Link);

        /* Check for TID Match */
        if (FoundThread->ClientId.UniqueThread == Cid->UniqueThread) break;

        /* Next entry */
        NextEntry = NextEntry->Flink;
    }

    /* Return what we found */
    return FoundThread;
}

/*++
 * @name CsrInsertThread
 *
 * The CsrInsertThread routine inserts a CSR Thread into its parent's
 * Thread List and into the Thread Hash Table.
 *
 * @param Process
 *        Pointer to the CSR Process containing this CSR Thread.
 *
 * @param Thread
 *        Pointer to the CSR Thread to be inserted.
 *
 * @return None.
 *
 * @remarks None.
 *
 *--*/
VOID
NTAPI
CsrInsertThread(IN PCSR_PROCESS Process,
                IN PCSR_THREAD Thread)
{
    ULONG i;

    /* Insert it into the Regular List */
    InsertTailList(&Process->ThreadList, &Thread->Link);

    /* Increase Thread Count */
    Process->ThreadCount++;

    /* Hash the Thread */
    i = CsrHashThread(Thread->ClientId.UniqueThread);

    /* Insert it there too */
    InsertHeadList(&CsrThreadHashTable[i], &Thread->HashLinks);
}

/*++
 * @name CsrDeallocateThread
 *
 * The CsrDeallocateThread frees the memory associated with a CSR Thread.
 *
 * @param CsrThread
 *        Pointer to the CSR Thread to be freed.
 *
 * @return None.
 *
 * @remarks Do not call this routine. It is reserved for the internal
 *          thread management routines when a CSR Thread has been cleanly
 *          dereferenced and killed.
 *
 *--*/
VOID
NTAPI
CsrDeallocateThread(IN PCSR_THREAD CsrThread)
{
    /* Free the process object from the heap */
    RtlFreeHeap(CsrHeap, 0, CsrThread);
}

/*++
 * @name CsrLockedDereferenceThread
 *
 * The CsrLockedDereferenceThread derefences a CSR Thread while the
 * Process Lock is already being held.
 *
 * @param CsrThread
 *        Pointer to the CSR Thread to be dereferenced.
 *
 * @return None.
 *
 * @remarks This routine will return with the Process Lock held.
 *
 *--*/
VOID
NTAPI
CsrLockedDereferenceThread(PCSR_THREAD CsrThread)
{
    /* Decrease reference count */
    if (!(--CsrThread->ReferenceCount))
    {
        /* Call the generic cleanup code */
        CsrThreadRefcountZero(CsrThread);
        CsrAcquireProcessLock();
    }
}

/*++
 * @name CsrRemoveThread
 *
 * The CsrRemoveThread function undoes a CsrInsertThread operation and
 * removes the CSR Thread from the the Hash Table and Thread List.
 *
 * @param CsrThread
 *        Pointer to the CSR Thread to remove.  
 *
 * @return None.
 *
 * @remarks If this CSR Thread is the last one inside a CSR Process, the
 *          parent will be dereferenced and the CsrProcessLastThreadTerminated
 *          flag will be set.
 *
 *          After executing this routine, the CSR Thread will have the
 *          CsrThreadInTermination flag set.
 *
 *--*/
VOID
NTAPI
CsrRemoveThread(IN PCSR_THREAD CsrThread)
{
    /* Remove it from the List */
    RemoveEntryList(&CsrThread->Link);

    /* Decreate the thread count of the process */
    CsrThread->Process->ThreadCount--;

    /* Remove it from the Hash List as well */
    if (CsrThread->HashLinks.Flink) RemoveEntryList(&CsrThread->HashLinks);

    /* Check if this is the last Thread */
    if (!CsrThread->Process->ThreadCount)
    {
        /* Check if it's not already been marked for deletion */
        if (!(CsrThread->Process->Flags & CsrProcessLastThreadTerminated))
        {
            /* Let everyone know this process is about to lose the thread */
            CsrThread->Process->Flags |= CsrProcessLastThreadTerminated;

            /* Reference the Process */
            CsrLockedDereferenceProcess(CsrThread->Process);
        }
    }

    /* Mark the thread for deletion */
    CsrThread->Flags |= CsrThreadInTermination;
}

/*++
 * @name CsrThreadRefcountZero
 *
 * The CsrThreadRefcountZero routine is executed when a CSR Thread has lost
 * all its active references. It removes and de-allocates the CSR Thread.
 *
 * @param CsrThread
 *        Pointer to the CSR Thread that is to be deleted.
 *
 * @return None.
 *
 * @remarks Do not call this routine. It is reserved for the internal
 *          thread management routines when a CSR Thread has lost all
 *          its references.
 *
 *          This routine is called with the Process Lock held.
 *
 *--*/
VOID
NTAPI
CsrThreadRefcountZero(IN PCSR_THREAD CsrThread)
{
    PCSR_PROCESS CsrProcess = CsrThread->Process;

    /* Remove this thread */
    CsrRemoveThread(CsrThread);

    /* Release the Process Lock */
    CsrReleaseProcessLock();

    /* Close the NT Thread Handle */
    NtClose(CsrThread->ThreadHandle);
    
    /* De-allocate the CSR Thread Object */
    CsrDeallocateThread(CsrThread);

    /* Remove a reference from the process */
    CsrDereferenceProcess(CsrProcess);
}

/* PUBLIC FUNCTIONS ***********************************************************/

/*++
 * @name CsrAddStaticServerThread
 * @implemented NT4
 *
 * The CsrAddStaticServerThread routine adds a new CSR Thread to the
 * CSR Server Process (CsrRootProcess).
 *
 * @param hThread
 *        Handle to an existing NT Thread to which to associate this
 *        CSR Thread.
 *
 * @param ClientId
 *        Pointer to the Client ID structure of the NT Thread to associate
 *        with this CSR Thread.
 *
 * @param ThreadFlags
 *        Initial CSR Thread Flags to associate to this CSR Thread. Usually
 *        CsrThreadIsServerThread.
 *
 * @return Pointer to the newly allocated CSR Thread.
 *
 * @remarks None.
 *
 *--*/
PCSR_THREAD
NTAPI
CsrAddStaticServerThread(IN HANDLE hThread,
                         IN PCLIENT_ID ClientId,
                         IN ULONG ThreadFlags)
{
    PCSR_THREAD CsrThread;

    /* Get the Lock */
    CsrAcquireProcessLock();

    /* Allocate the Server Thread */
    if ((CsrThread = CsrAllocateThread(CsrRootProcess)))
    {
        /* Setup the Object */
        CsrThread->ThreadHandle = hThread;
        CsrThread->ClientId = *ClientId;
        CsrThread->Flags = ThreadFlags;

        /* Insert it into the Thread List */
        InsertTailList(&CsrRootProcess->ThreadList, &CsrThread->Link);

        /* Increment the thread count */
        CsrRootProcess->ThreadCount++;
    }

    /* Release the Process Lock and return */
    CsrReleaseProcessLock();
    return CsrThread;
}

/*++
 * @name CsrCreateRemoteThread
 * @implemented NT4
 *
 * The CsrCreateRemoteThread routine creates a CSR Thread object for
 * an NT Thread which is not part of the current NT Process.
 *
 * @param hThread
 *        Handle to an existing NT Thread to which to associate this
 *        CSR Thread.
 *
 * @param ClientId
 *        Pointer to the Client ID structure of the NT Thread to associate
 *        with this CSR Thread.  
 *
 * @return STATUS_SUCCESS in case of success, STATUS_UNSUCCESSFUL
 *         othwerwise.
 *
 * @remarks None.
 *
 *--*/
NTSTATUS
NTAPI
CsrCreateRemoteThread(IN HANDLE hThread,
                      IN PCLIENT_ID ClientId)
{
    NTSTATUS Status;
    HANDLE ThreadHandle;
    PCSR_THREAD CsrThread;
    PCSR_PROCESS CsrProcess;
    KERNEL_USER_TIMES KernelTimes;

    DPRINT("CSRSRV: %s called\n", __FUNCTION__);

    /* Get the Thread Create Time */
    Status = NtQueryInformationThread(hThread,
                                      ThreadTimes,
                                      (PVOID)&KernelTimes,
                                      sizeof(KernelTimes),
                                      NULL);

    /* Lock the Owner Process */
    Status = CsrLockProcessByClientId(&ClientId->UniqueProcess,
                                      &CsrProcess);

    /* Make sure the thread didn't terminate */
    if (KernelTimes.ExitTime.QuadPart)
    {
        /* Unlock the process and return */
        CsrUnlockProcess(CsrProcess);
        return STATUS_THREAD_IS_TERMINATING;
    }

    /* Allocate a CSR Thread Structure */
    if (!(CsrThread = CsrAllocateThread(CsrProcess)))
    {
        DPRINT1("CSRSRV:%s: out of memory!\n", __FUNCTION__);
        CsrUnlockProcess(CsrProcess);
        return STATUS_NO_MEMORY;
    }

    /* Duplicate the Thread Handle */
    Status = NtDuplicateObject(NtCurrentProcess(),
                               hThread,
                               NtCurrentProcess(),
                               &ThreadHandle,
                               0,
                               0,
                               DUPLICATE_SAME_ACCESS);
    /* Allow failure */
    if (!NT_SUCCESS(Status)) ThreadHandle = hThread;

    /* Save the data we have */
    CsrThread->CreateTime = KernelTimes.CreateTime;
    CsrThread->ClientId = *ClientId;
    CsrThread->ThreadHandle = ThreadHandle;
    CsrThread->Flags = 0;

    /* Insert the Thread into the Process */
    CsrInsertThread(CsrProcess, CsrThread);

    /* Release the lock and return */
    CsrUnlockProcess(CsrProcess);
    return STATUS_SUCCESS;
}

/*++