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.
 
 
 
 
 
 

432 lines
8.9 KiB

/*++
Copyright (c) 1998 Microsoft Corporation
Module Name:
blocklst.cxx
Abstract:
Contains WinInet async support to allow blocking of unknown threads, on auto-proxy events.
Contents:
BlockThreadOnEvent
SignalThreadOnEvent
AcquireBlockedRequestQueue
ReleaseBlockedRequestQueue
(DestroyBlockedThreadEvent)
Author:
Arthur L Bierer (arthurbi) 15-Feb-1998
Environment:
Win32 user-mode DLL
Revision History:
15-Feb-1998 arthurbi
Created
--*/
#include <wininetp.h>
#include <perfdiag.hxx>
//
// private data
//
//
// BlockedRequestQueue - when threads need to block on an event they get
// placed in here until their event is signaled. This is needed so threads
// can block on internally kept events without having to be tied
// to keeping track of event handles.
//
// Blocked threads must not be also waiting for a socket to become unblocked
//
GLOBAL SERIALIZED_LIST BlockedRequestQueue = {0};
//
// ARB - information common to all asynchronous blocked events
//
typedef struct {
//
// List - requests are queued on doubly-linked list. N.B. Code that deals
// in ARBs implicitly assumes that List is at offset zero in the ARB. Move
// this and pick up the pieces...
//
LIST_ENTRY List;
//
// hEvent - handle to Event that we are blocked on.
//
HANDLE hEvent;
//
// dwBlockedOnEvent - contains the event this ARB may be blocked
// on. This allows a FIBER to block itself on an Internally kept
// event. When the event is signalled, it will wakeup, and moved
// to the Active Pool of fibers.
//
// A ZERO value means there is NO event that is being blocked on.
//
DWORD_PTR dwBlockedOnEvent;
//
// dwBlockedOnEventReturnCode - contains error code returned from
// fiber or main thread that is doing the unblocking.
//
DWORD dwBlockedOnEventReturnCode;
#if INET_DEBUG
//
// dwSignature - in the debug version, we maintain a signature in the ARB
// for sanity checking
//
DWORD dwSignature;
#endif // INET_DEBUG
} ARB, * LPARB;
//
// functions...
//
PRIVATE
VOID
DestroyBlockedThreadEvent(
IN LPARB lpArb
)
/*++
Routine Description:
Removes lpArb from the blocked request queue if its still there, and
destroys it
Arguments:
lpArb - pointer to AR_SYNC_EVENT ARB
Return Value:
None.
--*/
{
DEBUG_ENTER((DBG_ASYNC,
None,
"DestroyBlockedThreadEvent",
"%#x",
lpArb
));
AcquireBlockedRequestQueue();
if (lpArb->hEvent != NULL) {
CloseHandle(lpArb->hEvent);
}
if (IsOnSerializedList(&BlockedRequestQueue, &lpArb->List)) {
RemoveFromSerializedList(&BlockedRequestQueue, &lpArb->List);
}
ReleaseBlockedRequestQueue();
DEBUG_LEAVE(0);
}
DWORD
BlockThreadOnEvent(
IN DWORD_PTR dwEventId,
IN DWORD dwTimeout,
IN BOOL bReleaseLock
)
/*++
Routine Description:
Waits for an async event if called in the context of a fiber, else waits for
an event if called in the context of a sync request
Arguments:
dwEventId - event id to wait on
dwTimeout - amount of time to wait
bReleaseLock - TRUE if we need to release the blocked request queue
Return Value:
DWORD
Success - ERROR_SUCCESS
The request/wait completed successfully
Failure - ERROR_INTERNET_TIMEOUT
The request timed out
ERROR_INTERNET_INTERNAL_ERROR
We couldn't get the INTERNET_THREAD_INFO
--*/
{
DEBUG_ENTER((DBG_ASYNC,
Dword,
"BlockThreadOnEvent",
"%#x, %d, %B",
dwEventId,
dwTimeout,
bReleaseLock
));
DWORD error;
ARB Arb;
ZeroMemory(&Arb, sizeof(Arb));
//
// set up the remaining fields in the ARB - initialize the list pointer,
// set the priority (to default), and the event id
//
Arb.hEvent = CreateEvent(NULL, FALSE, FALSE, NULL);
if (Arb.hEvent == NULL) {
error = GetLastError();
// IE6 BUG #25117
// if we acquired the blocked request queue before calling this function
// then we need to release it
//
if (bReleaseLock) {
ReleaseBlockedRequestQueue();
}
goto quit;
}
Arb.dwBlockedOnEvent = dwEventId;
//
// add the request to the blocked request queue
//
InsertAtTailOfSerializedList(&BlockedRequestQueue, &Arb.List);
//
// if we acquired the blocked request queue before calling this function
// then we need to release it
//
if (bReleaseLock) {
ReleaseBlockedRequestQueue();
}
//
// now wait here for the event to become signalled
//
error = PERF_WaitForSingleObject(Arb.hEvent,
dwTimeout
);
//
// if we timed out then we will remove and destroy the ARB, else the thread
// which signalled the request will have done so
//
if (error == WAIT_TIMEOUT) {
error = ERROR_INTERNET_TIMEOUT;
} else {
error = Arb.dwBlockedOnEventReturnCode;
}
quit:
//
// remove the request from the blocked request queue and destroy it
//
DestroyBlockedThreadEvent(&Arb);
DEBUG_LEAVE(error);
return error;
}
DWORD
SignalThreadOnEvent(
IN DWORD_PTR dwEventId,
IN DWORD dwNumberOfWaiters,
IN DWORD dwReturnCode
)
/*++
Routine Description:
Unblocks a number of fibers that may be waiting for an event to be signalled.
When the fibers unblock they will be rescheduled to the Active Request Queue.
The 'event' is reset automatically back to unsignalled state.
If called outside of the worker thread, this function also handles
interupting the blocked worked thread so it can resume requests.
Arguments:
dwEventId - Event ID to wake up on.
dwNumberOfWaiters - number of waiters to unblock. Choose a large number
to mean 'all'
dwReturnCode - Upon waking up fibers, their blocked called will return
with this error code.
Return Value:
DWORD
Number of waiters unblocked
--*/
{
DEBUG_ENTER((DBG_ASYNC,
Int,
"SignalThreadOnEvent",
"%#x, %d, %d (%s)",
dwEventId,
dwNumberOfWaiters,
dwReturnCode,
InternetMapError(dwReturnCode)
));
INET_ASSERT(dwNumberOfWaiters > 0);
DWORD dwUnblocked = 0;
AcquireBlockedRequestQueue();
LPARB lpArb = (LPARB)HeadOfSerializedList(&BlockedRequestQueue);
LPARB lpArbPrevious = (LPARB)SlSelf(&BlockedRequestQueue);
while (lpArb != (LPARB)SlSelf(&BlockedRequestQueue)) {
if (lpArb->dwBlockedOnEvent == dwEventId) {
lpArb->dwBlockedOnEventReturnCode = dwReturnCode;
//
// if the ARB is really an async request then add it to the end of
// the async request queue else if it is a sync request then just
// signal the event. The waiter will free the ARB
//
SetEvent(lpArb->hEvent);
DEBUG_PRINT(ASYNC,
INFO,
("signalled sync request %#x, on %#x\n",
lpArb,
lpArb->dwBlockedOnEvent
));
//
// if we've hit the number of waiters we were to unblock then
// quit
//
++dwUnblocked;
if (dwUnblocked == dwNumberOfWaiters) {
break;
}
//
// we moved the ARB
//
lpArb = lpArbPrevious;
}
lpArbPrevious = lpArb;
lpArb = (LPARB)lpArb->List.Flink;
}
ReleaseBlockedRequestQueue();
DEBUG_LEAVE(dwUnblocked);
return dwUnblocked;
}
VOID
AcquireBlockedRequestQueue(
VOID
)
/*++
Routine Description:
Synchronizes access to the blocked request queue
Arguments:
None.
Return Value:
None.
--*/
{
LockSerializedList(&BlockedRequestQueue);
}
VOID
ReleaseBlockedRequestQueue(
VOID
)
/*++
Routine Description:
Releases the lock acquired with AcquireBlockedRequestQueue
Arguments:
None.
Return Value:
None.
--*/
{
UnlockSerializedList(&BlockedRequestQueue);
}