diff options
Diffstat (limited to 'generic/tclIO.c')
-rw-r--r-- | generic/tclIO.c | 176 |
1 files changed, 97 insertions, 79 deletions
diff --git a/generic/tclIO.c b/generic/tclIO.c index 8ca01ca..41f555b 100644 --- a/generic/tclIO.c +++ b/generic/tclIO.c @@ -12,6 +12,7 @@ * this file, and for a DISCLAIMER OF ALL WARRANTIES. */ +#undef NDEBUG #include "tclInt.h" #include "tclIO.h" #include <assert.h> @@ -167,6 +168,7 @@ static void PreserveChannelBuffer(ChannelBuffer *bufPtr); static void ReleaseChannelBuffer(ChannelBuffer *bufPtr); static int IsShared(ChannelBuffer *bufPtr); static void ChannelTimerProc(ClientData clientData); +static int ChanRead(Channel *chanPtr, char *dst, int dstSize); static int CheckChannelErrors(ChannelState *statePtr, int direction); static int CheckForDeadChannel(Tcl_Interp *interp, @@ -345,22 +347,73 @@ static Tcl_ObjType chanObjType = { #define MAX_CHANNEL_BUFFER_SIZE (1024*1024) /* - * ChanRead, dropped here by a time traveler, see 8.6 + *--------------------------------------------------------------------------- + * + * ChanRead -- + * + * Read up to dstSize bytes using the inputProc of chanPtr, store + * them at dst, and return the number of bytes stored. + * + * Results: + * The return value of the driver inputProc, + * - number of bytes stored at dst, ot + * - -1 on error, with a Posix error code available to the + * caller by calling Tcl_GetErrno(). + * + * Side effects: + * The CHANNEL_BLOCKED and CHANNEL_EOF flags of the channel state are + * set as appropriate. + * On EOF, the inputEncodingFlags are set to perform ending operations + * on decoding. + * TODO - Is this really the right place for that? + * + *--------------------------------------------------------------------------- */ -static inline int +static int ChanRead( Channel *chanPtr, char *dst, - int dstSize, - int *errnoPtr) + int dstSize) { + int bytesRead, result; + + /* + * If the caller asked for zero bytes, we'd force the inputProc + * to return zero bytes, and then misinterpret that as EOF. + */ + assert(dstSize > 0); + if (WillRead(chanPtr) < 0) { - *errnoPtr = Tcl_GetErrno(); return -1; } - return chanPtr->typePtr->inputProc(chanPtr->instanceData, dst, dstSize, - errnoPtr); + bytesRead = chanPtr->typePtr->inputProc(chanPtr->instanceData, + dst, dstSize, &result); + + /* Stop any flag leakage through stacked channel levels */ + ResetFlag(chanPtr->state, CHANNEL_BLOCKED | CHANNEL_EOF); + if (bytesRead > 0) { + /* + * If we get a short read, signal up that we may be BLOCKED. + * We should avoid calling the driver because on some + * platforms we will block in the low level reading code even + * though the channel is set into nonblocking mode. + */ + + if (bytesRead < dstSize) { + SetFlag(chanPtr->state, CHANNEL_BLOCKED); + } + } else if (bytesRead == 0) { + SetFlag(chanPtr->state, CHANNEL_EOF); + chanPtr->state->inputEncodingFlags |= TCL_ENCODING_END; + } else if (bytesRead < 0) { + if ((result == EWOULDBLOCK) || (result == EAGAIN)) { + SetFlag(chanPtr->state, CHANNEL_BLOCKED); + result = EAGAIN; + } + Tcl_SetErrno(result); + } + return bytesRead; } static inline Tcl_WideInt @@ -4932,7 +4985,7 @@ Tcl_ReadRaw( Channel *chanPtr = (Channel *) chan; ChannelState *statePtr = chanPtr->state; /* State info for channel */ - int nread, result, copied, copiedNow; + int nread, copied, copiedNow; /* * The check below does too much because it will reject a call to this @@ -4962,11 +5015,11 @@ Tcl_ReadRaw( bytesToRead - copied); if (copiedNow == 0) { if (GotFlag(statePtr, CHANNEL_EOF)) { - goto done; + break; } if (GotFlag(statePtr, CHANNEL_BLOCKED)) { if (GotFlag(statePtr, CHANNEL_NONBLOCKING)) { - goto done; + break; } ResetFlag(statePtr, CHANNEL_BLOCKED); } @@ -4982,49 +5035,22 @@ Tcl_ReadRaw( */ nread = ChanRead(chanPtr, bufPtr + copied, - bytesToRead - copied, &result); - - if (nread > 0) { - /* - * If we get a short read, signal up that we may be BLOCKED. - * We should avoid calling the driver because on some - * platforms we will block in the low level reading code even - * though the channel is set into nonblocking mode. - */ - - if (nread < (bytesToRead - copied)) { - SetFlag(statePtr, CHANNEL_BLOCKED); - } - } else if (nread == 0) { - SetFlag(statePtr, CHANNEL_EOF); - statePtr->inputEncodingFlags |= TCL_ENCODING_END; - - } else if (nread < 0) { - if ((result == EWOULDBLOCK) || (result == EAGAIN)) { - if (copied > 0) { - /* - * Information that was copied earlier has precedence - * over EAGAIN/WOULDBLOCK handling. - */ - - goto done; - } + bytesToRead - copied); - SetFlag(statePtr, CHANNEL_BLOCKED); - result = EAGAIN; + if (nread < 0) { + if (GotFlag(statePtr, CHANNEL_BLOCKED) && copied > 0) { +/* TODO: comment out? */ +// ResetFlag(statePtr, CHANNEL_BLOCKED); + } else { + copied = -1; } - - Tcl_SetErrno(result); - copied = -1; - goto done; + } else { + copied += nread; } - - copied += nread; - goto done; + break; } } - done: Tcl_Release(chanPtr); return copied; } @@ -5201,11 +5227,10 @@ DoReadChars( Tcl_Preserve(chanPtr); } if (result != 0) { - if (result == EAGAIN) { - break; + if (!GotFlag(statePtr, CHANNEL_BLOCKED)) { + copied = -1; } - copied = -1; - goto done; + break; } } else { copied += copiedNow; @@ -5213,14 +5238,15 @@ DoReadChars( } } - ResetFlag(statePtr, CHANNEL_BLOCKED); - /* - * Update the notifier state so we don't block while there is still data - * in the buffers. + * Failure to fill a channel buffer may have left channel reporting + * a "blocked" state, but so long as we fulfilled the request here, + * the caller does not consider us blocked. */ + if (toRead == 0) { + ResetFlag(statePtr, CHANNEL_BLOCKED); + } - done: /* * Regenerate the top channel, in case it was changed due to * self-modifying reflected transforms. @@ -5230,6 +5256,11 @@ DoReadChars( chanPtr = statePtr->topChanPtr; Tcl_Preserve(chanPtr); } + + /* + * Update the notifier state so we don't block while there is still data + * in the buffers. + */ UpdateInterest(chanPtr); Tcl_Release(chanPtr); return copied; @@ -6108,32 +6139,15 @@ GetInput( } PreserveChannelBuffer(bufPtr); - nread = ChanRead(chanPtr, InsertPoint(bufPtr), toRead, &result); - if (nread > 0) { - result = 0; - bufPtr->nextAdded += nread; + nread = ChanRead(chanPtr, InsertPoint(bufPtr), toRead); - /* - * If we get a short read, signal up that we may be BLOCKED. We should - * avoid calling the driver because on some platforms we will block in - * the low level reading code even though the channel is set into - * nonblocking mode. - */ - - if (nread < toRead) { - SetFlag(statePtr, CHANNEL_BLOCKED); - } - } else if (nread == 0) { + if (nread < 0) { + result = Tcl_GetErrno(); + } else { result = 0; - SetFlag(statePtr, CHANNEL_EOF); - statePtr->inputEncodingFlags |= TCL_ENCODING_END; - } else if (nread < 0) { - if ((result == EWOULDBLOCK) || (result == EAGAIN)) { - SetFlag(statePtr, CHANNEL_BLOCKED); - result = EAGAIN; - } - Tcl_SetErrno(result); + bufPtr->nextAdded += nread; } + ReleaseChannelBuffer(bufPtr); return result; } @@ -8805,6 +8819,7 @@ DoRead( ResetFlag(statePtr, CHANNEL_BLOCKED); moreData: + code = GetInput(chanPtr); bufPtr = statePtr->inQueueHead; @@ -8912,6 +8927,9 @@ DoRead( break; } } + if (bytesToRead == 0) { + ResetFlag(statePtr, CHANNEL_BLOCKED); + } Tcl_Release(chanPtr); return (int)(p - dst); |