From 19bd4e211da6d428a2390f6306578117c7f04948 Mon Sep 17 00:00:00 2001 From: Pekka Riikonen Date: Sun, 24 Jun 2001 13:05:41 +0000 Subject: [PATCH] updates. --- lib/silcutil/win32/silcwin32schedule.c | 127 ++++++++++++++++++------- 1 file changed, 90 insertions(+), 37 deletions(-) diff --git a/lib/silcutil/win32/silcwin32schedule.c b/lib/silcutil/win32/silcwin32schedule.c index 62571b77..2b53bc48 100644 --- a/lib/silcutil/win32/silcwin32schedule.c +++ b/lib/silcutil/win32/silcwin32schedule.c @@ -21,80 +21,133 @@ #include "silcincludes.h" -/* Our "select()" for WIN32. This actually is not the select() and does - not call Winsock's select() (since it cannot be used for our purposes) - but mimics the functions of select(). +/* Our "select()" for WIN32. This mimics the behaviour of select() system + call. It does not call the Winsock's select() though. Its functions + are derived from GLib's g_poll() and from some old Xemacs's sys_select(). - This is taken from the GLib and is the g_poll function in the Glib. - It has been *heavily* modified to be select() like and fit for SILC. */ + This makes following assumptions, which I don't know whether they + are correct or not: + + o writefds are ignored, if set this will return immediately. + o exceptfds are ignored totally + o If all arguments except timeout are NULL then this will register + a timeout with SetTimer and will wait just for Windows messages + with WaitMessage. + o MsgWaitForMultipleObjects is used to wait all kind of events, this + includes SOCKETs and Windows messages. + o All Windows messages are dispatched from this function. + o The Operating System has Winsock 2. + + MSDN References: + + o http://msdn.microsoft.com/library/default.asp? + url=/library/en-us/winui/hh/winui/messques_77zk.asp + +*/ int silc_select(int n, fd_set *readfds, fd_set *writefds, fd_set *exceptfds, struct timeval *timeout) { HANDLE handles[MAXIMUM_WAIT_OBJECTS]; - DWORD ready; - int nhandles = 0; - int timeo, i; - - /* Check fd sets (ignoring the exceptfds for now) */ + DWORD ready, curtime, timeo; + int nhandles = 0, i; + MSG msg; + /* Check fd sets (ignoring the exceptfds) */ if (readfds) { for (i = 0; i < n - 1; i++) if (FD_ISSET(i, readfds)) handles[nhandles++] = (HANDLE)i; + + FD_ZERO(readfds); } + /* If writefds is set then return immediately */ if (writefds) { - /* If write fd is set then we just return */ for (i = 0; i < n - 1; i++) if (FD_ISSET(i, writefds)) return 1; } - if (!timeout) - timeo = INFINITE; - else - timeo = (timeout.tv_sec * 1000) + (timeout.tv_usec / 1000); + timeo = (timeout ? (timeout.tv_sec * 1000) + (timeout.tv_usec / 1000) : + INFINITE); + + /* If we have nothing to wait and timeout is set then register a timeout + and wait just for windows messages. */ + if (nhandles == 0 && timeout) { + UINT timer = SetTimer(NULL, 0, timeo, NULL); + if (timer) { + WaitMessage(); + KillTimer(NULL, timer); + + while (PeekMessage(&msg, NULL, 0, 0, PM_REMOVE)) { + TranslateMessage(&msg); + DispatchMessage(&msg); + } + + return 0; + } + } retry: - if (nhandles == 0) - return -1; - else - ready = WaitForMultipleObjects(nhandles, handles, FALSE, timeo, - QS_ALLINPUT); + curtime = GetTickCount(); + ready = MsgWaitForMultipleObjects(nhandles, handles, FALSE, timeo, + QS_ALLINPUT); if (ready == WAIT_FAILED) { + /* Wait failed with error */ SILC_LOG_WARNING(("WaitForMultipleObjects() failed")); return -1; + + } else if (ready >= WAIT_ABANDONED_0 && + ready < WAIT_ABANDONED_0 + nhandles) { + /* Signal abandoned */ + SILC_LOG_WARNING(("WaitForMultipleObjects() failed (ABANDONED)")); + return -1; } else if (ready == WAIT_TIMEOUT) { + /* Timeout */ return 0; } else if (ready == WAIT_OBJECT_0 + nhandles) { - /* For Windows messages. The MSDN online says that if the application + /* Windows messages. The MSDN online says that if the application creates a window then its main loop (and we're assuming that it is our SILC Scheduler) must handle the Windows messages, so do - it here as the MSDN suggests. -Pekka */ - /* For reference: http://msdn.microsoft.com/library/default.asp? - url=/library/en-us/winui/hh/winui/messques_77zk.asp */ - MSG msg; - + it here as the MSDN suggests. */ while (PeekMessage(&msg, NULL, 0, 0, PM_REMOVE)) { TranslateMessage(&msg); DispatchMessage(&msg); } - /* Bad thing is that I don't know what to return, since actually - nothing for us happened. So, make another try with the waiting - and do not return. This of course may fuck up the timeouts! */ - goto retry; - } else if (ready >= WAIT_OBJECT_0 && ready < WAIT_OBJECT_0 + nhandles && - readfds) { - for (i = 0; i < n - 1; i++) { - if (ready - WAIT_OBJECT_0 != i) - FD_CLR(i, readfds); + /* If timeout is set then we must update the timeout since we won't + return and we will give the wait another try. */ + if (timeo != INFINITE) { + timeo -= GetTickCount() - curtime; + if (timeo < 0) + timeo = 0; } - /* Always one entry in the fd set. */ - return 1; + /* Give the wait another try */ + goto retry; + } else if (ready >= WAIT_OBJECT_0 && ready < WAIT_OBJECT_0 + nhandles && + readfds) { + /* Some other event, like SOCKET or something. */ + + /* Go through all fds even though only one was set. This is to avoid + starvation of high numbered fds. */ + ready -= WAIT_OBJECT_0; + i = 0; + do { + /* Set the handle to fd set */ + FD_SET(handle[ready], readfds); + i++; + + /* Check the status of the next handle and set it's fd to the fd + set if data is available. */ + while (++ready < n) + if (WaitForSingleObject(handle[ready], 0) == WAIT_OBJECT_0) + break; + } while (ready < n); + + return i; } return -1; -- 2.43.0