Remove long dead "BAD_BLOCKING" support code so it no longer confuses

people reading/editing this code.

1 files changed, 10 insertions, 123 deletions

diff --git a/generic/tclIO.c b/generic/tclIO.c
index b4f1c0c..0f894e4 100644
--- a/generic/tclIO.c
+++ b/generic/tclIO.c
@@ -4873,42 +4873,18 @@ Tcl_ReadRaw(
 		ResetFlag(statePtr, CHANNEL_BLOCKED);
 	    }
 
-#ifdef TCL_IO_TRACK_OS_FOR_DRIVER_WITH_BAD_BLOCKING
 	    /*
-	     * [Bug 943274]. Better emulation of non-blocking channels for
-	     * channels without BlockModeProc, by keeping track of true
-	     * fileevents generated by the OS == Data waiting and reading if
-	     * and only if we are sure to have data.
+	     * Now go to the driver to get as much as is possible to
+	     * fill the remaining request. Do all the error handling by
+	     * ourselves. The code was stolen from 'GetInput' and
+	     * slightly adapted (different return value here).
+	     *
+	     * The case of 'bytesToRead == 0' at this point cannot
+	     * happen.
 	     */
 
-	    if ((statePtr->flags & CHANNEL_NONBLOCKING) &&
-		    (Tcl_ChannelBlockModeProc(chanPtr->typePtr) == NULL) &&
-		    !(statePtr->flags & CHANNEL_HAS_MORE_DATA)) {
-		/*
-		 * We bypass the driver; it would block as no data is
-		 * available.
-		 */
-
-		nread = -1;
-		result = EWOULDBLOCK;
-	    } else {
-#endif /* TCL_IO_TRACK_OS_FOR_DRIVER_WITH_BAD_BLOCKING */
-
-		/*
-		 * Now go to the driver to get as much as is possible to fill
-		 * the remaining request. Do all the error handling by
-		 * ourselves. The code was stolen from 'GetInput' and slightly
-		 * adapted (different return value here).
-		 *
-		 * The case of 'bytesToRead == 0' at this point cannot happen.
-		 */
-
-		nread = ChanRead(chanPtr, bufPtr + copied,
-			bytesToRead - copied, &result);
-
-#ifdef TCL_IO_TRACK_OS_FOR_DRIVER_WITH_BAD_BLOCKING
-	    }
-#endif /* TCL_IO_TRACK_OS_FOR_DRIVER_WITH_BAD_BLOCKING */
+	    nread = ChanRead(chanPtr, bufPtr + copied,
+		    bytesToRead - copied, &result);
 
 	    if (nread > 0) {
 		/*
@@ -4921,18 +4897,6 @@ Tcl_ReadRaw(
 		if (nread < (bytesToRead - copied)) {
 		    SetFlag(statePtr, CHANNEL_BLOCKED);
 		}
-
-#ifdef TCL_IO_TRACK_OS_FOR_DRIVER_WITH_BAD_BLOCKING
-		if (nread <= (bytesToRead - copied)) {
-		    /*
-		     * [Bug 943274] We have read the available data, clear
-		     * flag.
-		     */
-
-		    ResetFlag(statePtr, CHANNEL_HAS_MORE_DATA);
-		}
-#endif /* TCL_IO_TRACK_OS_FOR_DRIVER_WITH_BAD_BLOCKING */
-
 	    } else if (nread == 0) {
 		SetFlag(statePtr, CHANNEL_EOF);
 		statePtr->inputEncodingFlags |= TCL_ENCODING_END;
@@ -6041,32 +6005,7 @@ GetInput(
 	return 0;
     }
 
-#ifdef TCL_IO_TRACK_OS_FOR_DRIVER_WITH_BAD_BLOCKING
-    /*
-     * [SF Tcl Bug 943274]. Better emulation of non-blocking channels for
-     * channels without BlockModeProc, by keeping track of true fileevents
-     * generated by the OS == Data waiting and reading if and only if we are
-     * sure to have data.
-     */
-
-    if ((statePtr->flags & CHANNEL_NONBLOCKING) &&
-	    (Tcl_ChannelBlockModeProc(chanPtr->typePtr) == NULL) &&
-	    !(statePtr->flags & CHANNEL_HAS_MORE_DATA)) {
-	/*
-	 * Bypass the driver, it would block, as no data is available
-	 */
-
-	nread = -1;
-	result = EWOULDBLOCK;
-    } else {
-#endif /* TCL_IO_TRACK_OS_FOR_DRIVER_WITH_BAD_BLOCKING */
-
-	nread = ChanRead(chanPtr, InsertPoint(bufPtr), toRead, &result);
-
-#ifdef TCL_IO_TRACK_OS_FOR_DRIVER_WITH_BAD_BLOCKING
-    }
-#endif /* TCL_IO_TRACK_OS_FOR_DRIVER_WITH_BAD_BLOCKING */
-
+    nread = ChanRead(chanPtr, InsertPoint(bufPtr), toRead, &result);
     if (nread > 0) {
 	bufPtr->nextAdded += nread;
 
@@ -6080,18 +6019,6 @@ GetInput(
 	if (nread < toRead) {
 	    SetFlag(statePtr, CHANNEL_BLOCKED);
 	}
-
-#ifdef TCL_IO_TRACK_OS_FOR_DRIVER_WITH_BAD_BLOCKING
-	if (nread <= toRead) {
-	    /*
-	     * [SF Tcl Bug 943274] We have read the available data, clear
-	     * flag.
-	     */
-
-	    ResetFlag(statePtr, CHANNEL_HAS_MORE_DATA);
-	}
-#endif /* TCL_IO_TRACK_OS_FOR_DRIVER_WITH_BAD_BLOCKING */
-
     } else if (nread == 0) {
 	SetFlag(statePtr, CHANNEL_EOF);
 	statePtr->inputEncodingFlags |= TCL_ENCODING_END;
@@ -7548,21 +7475,6 @@ Tcl_NotifyChannel(
     Channel *upChanPtr;
     const Tcl_ChannelType *upTypePtr;
 
-#ifdef TCL_IO_TRACK_OS_FOR_DRIVER_WITH_BAD_BLOCKING
-    /*
-     * [SF Tcl Bug 943274] For a non-blocking channel without blockmodeproc we
-     * keep track of actual input coming from the OS so that we can do a
-     * credible imitation of non-blocking behaviour.
-     */
-
-    if ((mask & TCL_READABLE) &&
-	    (statePtr->flags & CHANNEL_NONBLOCKING) &&
-	    (Tcl_ChannelBlockModeProc(chanPtr->typePtr) == NULL) &&
-	    !(statePtr->flags & CHANNEL_TIMER_FEV)) {
-	SetFlag(statePtr, CHANNEL_HAS_MORE_DATA);
-    }
-#endif /* TCL_IO_TRACK_OS_FOR_DRIVER_WITH_BAD_BLOCKING */
-
     /*
      * In contrast to the other API functions this procedure walks towards the
      * top of a stack and not down from it.
@@ -7797,29 +7709,8 @@ ChannelTimerProc(
 	 */
 
 	statePtr->timer = Tcl_CreateTimerHandler(0, ChannelTimerProc,chanPtr);
-
-#ifdef TCL_IO_TRACK_OS_FOR_DRIVER_WITH_BAD_BLOCKING
-	/*
-	 * Set the TIMER flag to notify the higher levels that the driver
-	 * might have no data for us. We do this only if we are in
-	 * non-blocking mode and the driver has no BlockModeProc because only
-	 * then we really don't know if the driver will block or not. A
-	 * similar test is done in "PeekAhead".
-	 */
-
-	if ((statePtr->flags & CHANNEL_NONBLOCKING) &&
-	    (Tcl_ChannelBlockModeProc(chanPtr->typePtr) == NULL)) {
-	    SetFlag(statePtr, CHANNEL_TIMER_FEV);
-	}
-#endif /* TCL_IO_TRACK_OS_FOR_DRIVER_WITH_BAD_BLOCKING */
-
 	Tcl_Preserve(statePtr);
 	Tcl_NotifyChannel((Tcl_Channel)chanPtr, TCL_READABLE);
-
-#ifdef TCL_IO_TRACK_OS_FOR_DRIVER_WITH_BAD_BLOCKING
-	ResetFlag(statePtr, CHANNEL_TIMER_FEV);
-#endif /* TCL_IO_TRACK_OS_FOR_DRIVER_WITH_BAD_BLOCKING */
-
 	Tcl_Release(statePtr);
     } else {
 	statePtr->timer = NULL;
@@ -10381,10 +10272,6 @@ DumpFlags(
     ChanFlag('/', INPUT_SAW_CR);
     ChanFlag('D', CHANNEL_DEAD);
     ChanFlag('R', CHANNEL_RAW_MODE);
-#ifdef TCL_IO_TRACK_OS_FOR_DRIVER_WITH_BAD_BLOCKING
-    ChanFlag('T', CHANNEL_TIMER_FEV);
-    ChanFlag('H', CHANNEL_HAS_MORE_DATA);
-#endif /* TCL_IO_TRACK_OS_FOR_DRIVER_WITH_BAD_BLOCKING */
     ChanFlag('x', CHANNEL_INCLOSE);
 
     buf[i] ='\0';