From 3d0e0863c3cb661e0e0b03a84f6227bc3b5a0d20 Mon Sep 17 00:00:00 2001 From: oehhar Date: Thu, 6 Mar 2014 10:37:13 +0000 Subject: Terminate async connect synchronously by any blocking operation --- win/tclWinSock.c | 116 +++++++++++++++++++++++++++++++++++++++++++++++++------ 1 file changed, 104 insertions(+), 12 deletions(-) diff --git a/win/tclWinSock.c b/win/tclWinSock.c index 162cbd4..263ef9a 100644 --- a/win/tclWinSock.c +++ b/win/tclWinSock.c @@ -47,7 +47,7 @@ #include "tclWinInt.h" -#define DEBUGGING +//#define DEBUGGING #ifdef DEBUGGING #define DEBUG(x) fprintf(stderr, ">>> %p %s(%d): %s<<<\n", \ infoPtr, __FUNCTION__, __LINE__, x) @@ -207,6 +207,9 @@ typedef struct { #define SOCKET_ASYNC_CONNECT (1<<2) /* This socket uses async connect. */ #define SOCKET_PENDING (1<<3) /* A message has been sent for this * socket */ +#define SOCKET_REENTER_PENDING (1<<4) /* The reentering after a received + * FD_CONNECT to CreateClientSocket + * is pending */ typedef struct { HWND hwnd; /* Handle to window for socket messages. */ @@ -236,6 +239,7 @@ static LRESULT CALLBACK SocketProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam); static int SocketsEnabled(void); static void TcpAccept(TcpFdList *fds, SOCKET newSocket, address addr); +static int WaitForAsyncConnect(SocketInfo *infoPtr, int *errorCodePtr); static int WaitForSocketEvent(SocketInfo *infoPtr, int events, int *errorCodePtr); static DWORD WINAPI SocketThread(LPVOID arg); @@ -763,11 +767,12 @@ SocketEventProc( infoPtr->flags &= ~SOCKET_PENDING; - if (infoPtr->readyEvents & FD_CONNECT) { + /* Continue async connect if pending and ready */ + if ( (infoPtr->flags & SOCKET_REENTER_PENDING) + && (infoPtr->readyEvents & FD_CONNECT) ) { DEBUG("FD_CONNECT"); SetEvent(tsdPtr->socketListLock); CreateClientSocket(NULL, infoPtr); - infoPtr->readyEvents &= ~(FD_CONNECT); return 1; } @@ -1173,15 +1178,22 @@ CreateClientSocket( SocketInfo *infoPtr) { u_long flag = 1; /* Indicates nonblocking mode. */ - int async = infoPtr->flags & SOCKET_ASYNC_CONNECT; + /* + * We are started with async connect and the connect notification + * was not jet received + */ + int async_connect = infoPtr->flags & SOCKET_ASYNC_CONNECT; + /* We were called by the event procedure and continue our loop */ int async_callback = infoPtr->sockets->fd != INVALID_SOCKET; ThreadSpecificData *tsdPtr; DWORD error; - DEBUG(async ? "async" : "sync"); + DEBUG(async_connect ? "async connect" : "sync connect"); if (async_callback) { DEBUG("subsequent call"); + /* Clear this pending reenter case */ + infoPtr->flags &= ~(SOCKET_REENTER_PENDING); goto reenter; } else { DEBUG("first call"); @@ -1257,7 +1269,7 @@ CreateClientSocket( * Set the socket into nonblocking mode if the connect should * be done in the background. */ - if (async) { + if (async_connect) { ThreadSpecificData *tsdPtr = TclThreadDataKeyGet(&dataKey); infoPtr->selectEvents |= FD_CONNECT; @@ -1280,6 +1292,8 @@ CreateClientSocket( #endif if (error == WSAEWOULDBLOCK) { DEBUG("WSAEWOULDBLOCK"); + /* Jump out and remember that we want to get back in */ + infoPtr->flags |= SOCKET_REENTER_PENDING; return TCL_OK; reenter: Tcl_SetErrno(infoPtr->lastError); @@ -1299,6 +1313,8 @@ out: DEBUG("connected or finally failed"); if (Tcl_GetErrno() != 0 && interp != NULL) { DEBUG("ERRNO"); + /* Clear async flag so if a read is done it does not block */ + infoPtr->flags &= ~(SOCKET_ASYNC_CONNECT); if (interp != NULL) { Tcl_SetObjResult(interp, Tcl_ObjPrintf( "couldn't open socket: %s", Tcl_PosixError(interp))); @@ -1329,6 +1345,82 @@ out: /* *---------------------------------------------------------------------- * + * WaitForAsyncConnect -- + * + * Terminate an asyncroneous connect syncroneously. + * This routine should only be called if flag ASYNC_CONNECT is set. + * + * Results: + * Returns 1 on success or 0 on failure, with an error code in + * errorCodePtr. + * + * Side effects: + * Processes socket events off the system queue. + * + *---------------------------------------------------------------------- + */ + +static int +WaitForAsyncConnect( + SocketInfo *infoPtr, /* Information about this socket. */ + int *errorCodePtr) /* Where to store errors? */ +{ + int result = 1; + int oldMode; + ThreadSpecificData *tsdPtr = TclThreadDataKeyGet(&dataKey); + /* + * A non blocking socket waiting for an asyncronous connect + * returns directly an error + */ + if (infoPtr->flags & SOCKET_ASYNC) { + *errorCodePtr = EWOULDBLOCK; + return 0; + } + + /* + * Be sure to disable event servicing so we are truly modal. + */ + + oldMode = Tcl_SetServiceMode(TCL_SERVICE_NONE); + + /* + * Disable async connect as we continue now synchoneously + */ + + /* ToDo: need thread protection * */ + infoPtr->flags &= ~(SOCKET_ASYNC_CONNECT); + + /* + * Reset WSAAsyncSelect so we have a fresh set of events pending. + */ + + SendMessage(tsdPtr->hwnd, SOCKET_SELECT, (WPARAM) UNSELECT, + (LPARAM) infoPtr); + SendMessage(tsdPtr->hwnd, SOCKET_SELECT, (WPARAM) SELECT, + (LPARAM) infoPtr); + + while (1) { + /* Check for connect event */ + if (infoPtr->readyEvents & FD_CONNECT) { + /* continue async connect syncroneously */ + result = CreateClientSocket(NULL, infoPtr); + (void) Tcl_SetServiceMode(oldMode); + /* Todo: find adequate error code */ + *errorCodePtr = EFAULT; + return (result == TCL_OK); + } + + /* + * Wait until something happens. + */ + + WaitForSingleObject(tsdPtr->readyEvent, INFINITE); + } +} + +/* + *---------------------------------------------------------------------- + * * WaitForSocketEvent -- * * Waits until one of the specified events occurs on a socket. @@ -1865,11 +1957,11 @@ TcpInputProc( } /* - * Check to see if the socket is connected before trying to read. + * Check if there is an async connect to terminate */ - if ((infoPtr->flags & SOCKET_ASYNC_CONNECT) - && !WaitForSocketEvent(infoPtr, FD_CONNECT, errorCodePtr)) { + if ( (infoPtr->flags & SOCKET_REENTER_PENDING) + && !WaitForAsyncConnect(infoPtr, errorCodePtr)) { return -1; } @@ -1993,11 +2085,11 @@ TcpOutputProc( } /* - * Check to see if the socket is connected before trying to write. + * Check if there is an async connect to terminate */ - if ((infoPtr->flags & SOCKET_ASYNC_CONNECT) - && !WaitForSocketEvent(infoPtr, FD_CONNECT, errorCodePtr)) { + if ( (infoPtr->flags & SOCKET_REENTER_PENDING) + && !WaitForAsyncConnect(infoPtr, errorCodePtr)) { return -1; } -- cgit v0.12