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authordgp <dgp@users.sourceforge.net>2014-11-03 20:39:25 (GMT)
committerdgp <dgp@users.sourceforge.net>2014-11-03 20:39:25 (GMT)
commitc40bcd39bfbe1d61ef75fd3cc9a6604b6cd20193 (patch)
treebb8f9550afea449e68a345bf05d0b5a0f8d7f37b
parent75e9bc701fe237f31e8d1467070fadbcc5457a32 (diff)
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[5adc350683] Reworked the management of the EOF states to re-enable the
ability to read beyond EOF. Plenty of assert()s to keep thing from going off track again.
-rw-r--r--generic/tclIO.c182
1 files changed, 139 insertions, 43 deletions
diff --git a/generic/tclIO.c b/generic/tclIO.c
index c55c118..b3af1f5 100644
--- a/generic/tclIO.c
+++ b/generic/tclIO.c
@@ -3977,6 +3977,21 @@ Tcl_GetsObj(
}
/*
+ * If we're sitting ready to read the eofchar, there's no need to
+ * do it.
+ */
+
+ if (GotFlag(statePtr, CHANNEL_STICKY_EOF)) {
+ SetFlag(statePtr, CHANNEL_EOF);
+ assert( statePtr->inputEncodingFlags & TCL_ENCODING_END );
+ assert( !GotFlag(statePtr, CHANNEL_BLOCKED|INPUT_SAW_CR) );
+
+ /* TODO: Do we need this? */
+ UpdateInterest(chanPtr);
+ return -1;
+ }
+
+ /*
* A binary version of Tcl_GetsObj. This could also handle encodings that
* are ascii-7 pure (iso8859, utf-8, ...) with a final encoding conversion
* done on objPtr.
@@ -4194,6 +4209,7 @@ Tcl_GetsObj(
dstEnd = eof;
SetFlag(statePtr, CHANNEL_EOF | CHANNEL_STICKY_EOF);
statePtr->inputEncodingFlags |= TCL_ENCODING_END;
+ ResetFlag(statePtr, CHANNEL_BLOCKED|INPUT_SAW_CR);
}
if (GotFlag(statePtr, CHANNEL_EOF)) {
skip = 0;
@@ -4307,6 +4323,13 @@ Tcl_GetsObj(
*/
done:
+ assert(!GotFlag(statePtr, CHANNEL_EOF)
+ || GotFlag(statePtr, CHANNEL_STICKY_EOF)
+ || Tcl_InputBuffered((Tcl_Channel)chanPtr) == 0);
+
+ assert( !(GotFlag(statePtr, CHANNEL_EOF|CHANNEL_BLOCKED)
+ == (CHANNEL_EOF|CHANNEL_BLOCKED)) );
+
/*
* Regenerate the top channel, in case it was changed due to
* self-modifying reflected transforms.
@@ -4330,6 +4353,11 @@ Tcl_GetsObj(
* end-of-line or end-of-file has been seen. Bytes read from the input
* channel return as a ByteArray obj.
*
+ * WARNING! The notion of "binary" used here is different from
+ * notions of "binary" used in other places. In particular, this
+ * "binary" routine may be called when an -eofchar is set on the
+ * channel.
+ *
* Results:
* Number of characters accumulated in the object or -1 if error,
* blocked, or EOF. If -1, use Tcl_GetErrno() to retrieve the POSIX error
@@ -4416,15 +4444,15 @@ TclGetsObjBinary(
}
} else {
/*
- * There's something already in the buffer. If
- * CHANNEL_STICKY_EOF is set we know that something begins
- * with the eofchar. Otherwise, if CHANNEL_EOF is set, we
- * know some earlier inputproc call returned zero bytes when
- * we were trying to get more bytes to put in the buffer.
- * which means..... ???? Place to probe with tests.
- */
- assert (GotFlag(statePtr, CHANNEL_STICKY_EOF)
- || !GotFlag(statePtr, CHANNEL_EOF) );
+ * Incoming CHANNEL_STICKY_EOF is filtered out on entry.
+ * A new CHANNEL_STICKY_EOF set in this routine leads to
+ * return before coming back here. When we are not dealing
+ * with CHANNEL_STICKY_EOF, a CHANNEL_EOF implies an
+ * empty buffer. Here the buffer is non-empty so we know
+ * we're a non-EOF */
+
+ assert ( !GotFlag(statePtr, CHANNEL_STICKY_EOF) );
+ assert ( !GotFlag(statePtr, CHANNEL_EOF) );
}
dst = (unsigned char *) RemovePoint(bufPtr);
@@ -4466,6 +4494,7 @@ TclGetsObjBinary(
SetFlag(statePtr, CHANNEL_EOF | CHANNEL_STICKY_EOF);
statePtr->inputEncodingFlags |= TCL_ENCODING_END;
+ ResetFlag(statePtr, CHANNEL_BLOCKED|INPUT_SAW_CR);
}
if (GotFlag(statePtr, CHANNEL_EOF)) {
skip = 0;
@@ -4575,6 +4604,11 @@ TclGetsObjBinary(
*/
done:
+ assert(!GotFlag(statePtr, CHANNEL_EOF)
+ || GotFlag(statePtr, CHANNEL_STICKY_EOF)
+ || Tcl_InputBuffered((Tcl_Channel)chanPtr) == 0);
+ assert( !(GotFlag(statePtr, CHANNEL_EOF|CHANNEL_BLOCKED)
+ == (CHANNEL_EOF|CHANNEL_BLOCKED)) );
UpdateInterest(chanPtr);
TclChannelRelease((Tcl_Channel)chanPtr);
return copiedTotal;
@@ -4706,8 +4740,16 @@ FilterInputBytes(
return -1;
}
} else {
- assert( GotFlag(statePtr, CHANNEL_STICKY_EOF)
- || !GotFlag(statePtr, CHANNEL_EOF) );
+ /*
+ * Incoming CHANNEL_STICKY_EOF is filtered out on entry.
+ * A new CHANNEL_STICKY_EOF set in this routine leads to
+ * return before coming back here. When we are not dealing
+ * with CHANNEL_STICKY_EOF, a CHANNEL_EOF implies an
+ * empty buffer. Here the buffer is non-empty so we know
+ * we're a non-EOF */
+
+ assert ( !GotFlag(statePtr, CHANNEL_STICKY_EOF) );
+ assert ( !GotFlag(statePtr, CHANNEL_EOF) );
}
/*
@@ -5201,19 +5243,11 @@ DoReadChars(
ChannelState *statePtr = chanPtr->state;
/* State info for channel */
ChannelBuffer *bufPtr;
- int factor, copied, copiedNow, result;
- Tcl_Encoding encoding;
+ int copied, copiedNow, result;
+ Tcl_Encoding encoding = statePtr->encoding;
int binaryMode;
#define UTF_EXPANSION_FACTOR 1024
-
- /*
- * This operation should occur at the top of a channel stack.
- */
-
- chanPtr = statePtr->topChanPtr;
- encoding = statePtr->encoding;
- factor = UTF_EXPANSION_FACTOR;
- TclChannelPreserve((Tcl_Channel)chanPtr);
+ int factor = UTF_EXPANSION_FACTOR;
binaryMode = (encoding == NULL)
&& (statePtr->inputTranslation == TCL_TRANSLATE_LF)
@@ -5237,6 +5271,36 @@ DoReadChars(
}
}
+ /*
+ * Early out when next read will see eofchar.
+ *
+ * NOTE: See DoRead for argument that it's a bug (one we're keeping)
+ * to have this escape before the one for zero-char read request.
+ */
+
+ if (GotFlag(statePtr, CHANNEL_STICKY_EOF)) {
+ SetFlag(statePtr, CHANNEL_EOF);
+ assert( statePtr->inputEncodingFlags & TCL_ENCODING_END );
+ assert( !GotFlag(statePtr, CHANNEL_BLOCKED|INPUT_SAW_CR) );
+
+ UpdateInterest(chanPtr);
+ return 0;
+ }
+
+ /* Special handling for zero-char read request. */
+ if (toRead == 0) {
+ ResetFlag(statePtr, CHANNEL_BLOCKED|CHANNEL_EOF);
+ UpdateInterest(chanPtr);
+ return 0;
+ }
+
+ /*
+ * This operation should occur at the top of a channel stack.
+ */
+
+ chanPtr = statePtr->topChanPtr;
+ TclChannelPreserve((Tcl_Channel)chanPtr);
+
/* Must clear the BLOCKED flag here since we check before reading */
ResetFlag(statePtr, CHANNEL_BLOCKED|CHANNEL_EOF);
for (copied = 0; (unsigned) toRead > 0; ) {
@@ -5314,6 +5378,11 @@ DoReadChars(
* Update the notifier state so we don't block while there is still data
* in the buffers.
*/
+ assert(!GotFlag(statePtr, CHANNEL_EOF)
+ || GotFlag(statePtr, CHANNEL_STICKY_EOF)
+ || Tcl_InputBuffered((Tcl_Channel)chanPtr) == 0);
+ assert( !(GotFlag(statePtr, CHANNEL_EOF|CHANNEL_BLOCKED)
+ == (CHANNEL_EOF|CHANNEL_BLOCKED)) );
UpdateInterest(chanPtr);
TclChannelRelease((Tcl_Channel)chanPtr);
return copied;
@@ -5922,7 +5991,7 @@ TranslateInputEOL(
SetFlag(statePtr, CHANNEL_EOF | CHANNEL_STICKY_EOF);
statePtr->inputEncodingFlags |= TCL_ENCODING_END;
- ResetFlag(statePtr, INPUT_SAW_CR);
+ ResetFlag(statePtr, CHANNEL_BLOCKED|INPUT_SAW_CR);
}
}
@@ -6132,6 +6201,14 @@ GetInput(
ChannelState *statePtr = chanPtr->state;
/* State info for channel */
+ /*
+ * Verify that all callers know better than to call us when
+ * it's recorded that the next char waiting to be read is the
+ * eofchar.
+ */
+
+ assert( !GotFlag(statePtr, CHANNEL_STICKY_EOF) );
+
/*
* Prevent reading from a dead channel -- a channel that has been closed
* but not yet deallocated, which can happen if the exit handler for
@@ -6143,21 +6220,6 @@ GetInput(
return EINVAL;
}
- /*
- * Strangely named "STICKY_EOF" really means we've seen the
- * eofchar for this channel, and nothing since has reset it.
- * (changed the eofchar, [seek]ed to a new offset, etc.) So,
- * we know we're still poised to read that eofchar again, and
- * there's no need to actually do it.
- */
-
- if (GotFlag(statePtr, CHANNEL_STICKY_EOF)) {
- assert(statePtr->inEofChar);
- assert(statePtr->inQueueHead);
- assert(RemovePoint(statePtr->inQueueHead)[0] == statePtr->inEofChar);
- return 0;
- }
-
/*
* WARNING: There was once a comment here claiming that it was
* a bad idea to make another call to the inputproc of a channel
@@ -6185,6 +6247,7 @@ GetInput(
if (chanPtr->inQueueHead != NULL) {
+ /* TODO: Tests to cover this. */
assert(statePtr->inQueueHead == NULL);
statePtr->inQueueHead = chanPtr->inQueueHead;
@@ -6215,6 +6278,7 @@ GetInput(
* Check the actual buffersize against the requested buffersize.
* Saved buffers of the wrong size are squashed. This is done
* to honor dynamic changes of the buffersize made by the user.
+ * TODO: Tests to cover this.
*/
if ((bufPtr != NULL)
@@ -6758,9 +6822,7 @@ Tcl_Eof(
ChannelState *statePtr = ((Channel *) chan)->state;
/* State of real channel structure. */
- return (GotFlag(statePtr, CHANNEL_STICKY_EOF) ||
- (GotFlag(statePtr, CHANNEL_EOF) &&
- (Tcl_InputBuffered(chan) == 0))) ? 1 : 0;
+ return GotFlag(statePtr, CHANNEL_EOF) ? 1 : 0;
}
/*
@@ -8882,6 +8944,36 @@ DoRead(
ChannelState *statePtr = chanPtr->state;
char *p = dst;
+ assert (bytesToRead >= 0);
+
+ /*
+ * Early out when we know a read will get the eofchar.
+ *
+ * NOTE: This seems to be a bug. The special handling for
+ * a zero-char read request ought to come first. As coded
+ * the EOF due to eofchar has distinguishing behavior from
+ * the EOF due to reported EOF on the underlying device, and
+ * that seems undesirable. However recent history indicates
+ * that new inconsistent behavior in a patchlevel has problems
+ * too. Keep on keeping on for now.
+ */
+
+ if (GotFlag(statePtr, CHANNEL_STICKY_EOF)) {
+ SetFlag(statePtr, CHANNEL_EOF);
+ assert( statePtr->inputEncodingFlags & TCL_ENCODING_END );
+ assert( !GotFlag(statePtr, CHANNEL_BLOCKED|INPUT_SAW_CR) );
+
+ UpdateInterest(chanPtr);
+ return 0;
+ }
+
+ /* Special handling for zero-char read request. */
+ if (bytesToRead == 0) {
+ ResetFlag(statePtr, CHANNEL_BLOCKED|CHANNEL_EOF);
+ UpdateInterest(chanPtr);
+ return 0;
+ }
+
TclChannelPreserve((Tcl_Channel)chanPtr);
while (bytesToRead) {
/*
@@ -8952,8 +9044,7 @@ DoRead(
* 1) We're @EOF because we saw eof char.
*/
- if (statePtr->inEofChar
- && RemovePoint(bufPtr)[0] == statePtr->inEofChar) {
+ if (GotFlag(statePtr, CHANNEL_STICKY_EOF)) {
UpdateInterest(chanPtr);
break;
}
@@ -9026,6 +9117,11 @@ DoRead(
ResetFlag(statePtr, CHANNEL_BLOCKED);
}
+ assert(!GotFlag(statePtr, CHANNEL_EOF)
+ || GotFlag(statePtr, CHANNEL_STICKY_EOF)
+ || Tcl_InputBuffered((Tcl_Channel)chanPtr) == 0);
+ assert( !(GotFlag(statePtr, CHANNEL_EOF|CHANNEL_BLOCKED)
+ == (CHANNEL_EOF|CHANNEL_BLOCKED)) );
TclChannelRelease((Tcl_Channel)chanPtr);
return (int)(p - dst);
}