/*
* tclWinConsole.c --
*
* This file implements the Windows-specific console functions, and the
* "console" channel driver. Windows 7 or later required.
*
* Copyright © 2022 Ashok P. Nadkarni
*
* See the file "license.terms" for information on usage and redistribution of
* this file, and for a DISCLAIMER OF ALL WARRANTIES.
*/
#ifdef TCL_CONSOLE_DEBUG
#undef NDEBUG /* Enable asserts */
#endif
#include "tclWinInt.h"
#include <assert.h>
#include <ctype.h>
/*
* A general note on the design: The console channel driver differs from
* most other drivers in the following respects:
*
* - There can be at most 3 console handles at any time since Windows does
* support allocation of more than one console (with three handles
* corresponding to stdin, stdout, stderr)
*
* - Consoles are created / inherited at process startup. There is currently
* no way in Tcl to programmatically create a console. Even if these were
* added the above Windows limitation would still apply.
*
* - Unlike files, sockets etc. where there is a one-to-one
* correspondence between Tcl channels and operating system handles,
* std* channels are shared amongst threads which means there can be
* multiple Tcl channels corresponding to a single console handle.
*
* - Even with multiple threads, more than one file event handler is
* unlikely. It does not make sense for multiple threads to register
* handlers for stdin because the input would be randomly fragmented amongst
* the threads.
*
* Various design factors are driven by the above, e.g. use of lists instead
* of hash tables (at most 3 console handles) and use of global instead of
* per thread queues which simplifies lock management particularly because
* thread-console relation is not one-one and is likely more performant as
* well with fewer locks needing to be obtained.
*
* Some additional design notes/reminders for the future:
*
* Aligned, synchronous reads are done directly by interpreter thread.
* Unaligned or asynchronous reads are done through the reader thread.
*
* The reader thread does not read ahead. That is, it will not post a read
* until some interpreter thread is actually requesting a read. This is
* because an interpreter may (for example) turn off echo for passwords and
* the read ahead would come in the way of that.
*
* If multiple threads are reading from stdin, the input is sprayed in
* random fashion. This is not good application design and hence no plan to
* address this (not clear what should be done even in theory)
*
* For output, we do not restrict all output to the console writer threads.
* See ConsoleOutputProc for the conditions.
*
* Locks are never held when calling the ReadConsole/WriteConsole API's
* since they may block.
*/
static int gInitialized = 0;
/*
* INPUT_BUFFER_SIZE is size of buffer passed to ReadConsole in bytes.
* Note that ReadConsole will only allow reading of line lengths up to the
* max of 256 and buffer size passed to it. So dropping this below 512
* means user can type at most 256 chars.
*/
#ifndef INPUT_BUFFER_SIZE
#define INPUT_BUFFER_SIZE 8192 /* In bytes, so 4096 chars */
#endif
/*
* CONSOLE_BUFFER_SIZE is size of storage used in ring buffers.
* In theory, at least sizeof(WCHAR) but note the Tcl channel bug
* https://core.tcl-lang.org/tcl/tktview/b3977d199b08e3979a8da970553d5209b3042e9c
* will cause failures in test suite if close to max input line in the suite.
*/
#ifndef CONSOLE_BUFFER_SIZE
#define CONSOLE_BUFFER_SIZE 8192 /* In bytes */
#endif
/*
* Ring buffer for storing data. Actual data is from bufPtr[start]:bufPtr[size-1]
* and bufPtr[0]:bufPtr[length - (size-start)].
*/
typedef struct RingBuffer {
char *bufPtr; /* Pointer to buffer storage */
Tcl_Size capacity; /* Size of the buffer in RingBufferChar */
Tcl_Size start; /* Start of the data within the buffer. */
Tcl_Size length; /* Number of RingBufferChar*/
} RingBuffer;
#define RingBufferLength(ringPtr_) ((ringPtr_)->length)
#define RingBufferHasFreeSpace(ringPtr_) ((ringPtr_)->length < (ringPtr_)->capacity)
#define RINGBUFFER_ASSERT(ringPtr_) assert(RingBufferCheck(ringPtr_))
/*
* The Win32 console API does not support non-blocking I/O in any form. Thus
* the actual calls are made on a separate thread. Moreover, separate
* threads are needed for each handle because (for example) blocking on user
* input on stdin should not prevent output to stdout when non-blocking i/o
* is configured at the script level.
*
* In the input (e.g. stdin) case, the console stdin thread is the producer
* writing to the buffer ring buffer. The Tcl interpreter threads are the
* consumer. For the output (e.g. stdout/stderr) case, the Tcl interpreter
* are the producers while the console stdout/stderr threads are the
* consumers.
*
* Consoles are identified purely by handles and multiple threads may open
* them (as stdin/stdout/stderr are shared).
*
* Note on reference counting - a ConsoleHandleInfo instance has multiple
* references to it - one each from every channel that is attached to it
* plus one from the console thread itself which also serves as the reference
* from gConsoleHandleInfoList.
*/
typedef struct ConsoleHandleInfo {
struct ConsoleHandleInfo *nextPtr; /* Process-global list of consoles */
HANDLE console; /* Console handle */
HANDLE consoleThread; /* Handle to thread doing actual i/o on the console */
SRWLOCK lock; /* Controls access to this structure.
* Cheaper than CRITICAL_SECTION but note does not
* support recursive locks or Try* style attempts.*/
CONDITION_VARIABLE consoleThreadCV;/* For awakening console thread */
CONDITION_VARIABLE interpThreadCV; /* For awakening interpthread(s) */
RingBuffer buffer; /* Buffer for data transferred between console
* threads and Tcl threads. For input consoles,
* written by the console thread and read by Tcl
* threads. The converse for output threads */
DWORD initMode; /* Initial console mode. */
DWORD lastError; /* An error caused by the last background
* operation. Set to 0 if no error has been
* detected. */
int numRefs; /* See comments above */
int permissions; /* TCL_READABLE for input consoles, TCL_WRITABLE
* for output. Only one or the other can be set. */
int flags;
#define CONSOLE_DATA_AWAITED 0x0001 /* An interpreter is awaiting data */
} ConsoleHandleInfo;
/*
* This structure describes per-instance data for a console based channel.
*
* Note on locking - this structure has no locks because it is accessed
* only from the thread owning channel EXCEPT when a console traverses it
* looking for a channel that is watching for events on the console. Even
* in that case, no locking is required because that access is only under
* the gConsoleLock lock which prevents the channel from being removed from
* the gWatchingChannelList which in turn means it will not be deallocated
* from under the console thread. Access to individual fields does not need
* to be controlled because
* - the console thread does not write to any fields
* - changes to the nextWatchingChannelPtr field
* - changes to other fields do not matter because after being read for
* queueing events, they are verified again when the event is received
* in the interpreter thread (since they could have changed anyways while
* the event was in-flight on the event queue)
*
* Note on reference counting - a structure instance may be referenced from
* three places:
* - the Tcl channel subsystem. This reference is created when on channel
* opening and dropped on channel close. This also covers the reference
* from gWatchingChannelList since queueing / dequeuing from that list
* happens in conjunction with channel operations.
* - the Tcl event queue entries. This reference is added when the event
* is queued and dropped on receipt.
*/
typedef struct ConsoleChannelInfo {
HANDLE handle; /* Console handle */
Tcl_ThreadId threadId; /* Id of owning thread */
struct ConsoleChannelInfo *nextWatchingChannelPtr;
/* Pointer to next channel watching events. */
Tcl_Channel channel; /* Pointer to channel structure. */
DWORD initMode; /* Initial console mode. */
int numRefs; /* See comments above */
int permissions; /* OR'ed combination of TCL_READABLE,
* TCL_WRITABLE, or TCL_EXCEPTION: indicates
* which operations are valid on the file. */
int watchMask; /* OR'ed combination of TCL_READABLE,
* TCL_WRITABLE, or TCL_EXCEPTION: indicates
* which events should be reported. */
int flags; /* State flags */
#define CONSOLE_EVENT_QUEUED 0x0001 /* Notification event already queued */
#define CONSOLE_ASYNC 0x0002 /* Channel is non-blocking. */
#define CONSOLE_READ_OPS 0x0004 /* Channel supports read-related ops. */
} ConsoleChannelInfo;
/*
* The following structure is what is added to the Tcl event queue when
* console events are generated.
*/
typedef struct {
Tcl_Event header; /* Information that is standard for all events. */
ConsoleChannelInfo *chanInfoPtr;
/* Pointer to console info structure. Note
* that we still have to verify that the
* console exists before dereferencing this
* pointer. */
} ConsoleEvent;
/*
* Declarations for functions used only in this file.
*/
static int ConsoleBlockModeProc(void *instanceData, int mode);
static void ConsoleCheckProc(void *clientData, int flags);
static int ConsoleCloseProc(void *instanceData,
Tcl_Interp *interp, int flags);
static int ConsoleEventProc(Tcl_Event *evPtr, int flags);
static void ConsoleExitHandler(void *clientData);
static int ConsoleGetHandleProc(void *instanceData,
int direction, void **handlePtr);
static int ConsoleGetOptionProc(void *instanceData,
Tcl_Interp *interp, const char *optionName,
Tcl_DString *dsPtr);
static void ConsoleInit(void);
static int ConsoleInputProc(void *instanceData, char *buf,
int toRead, int *errorCode);
static int ConsoleOutputProc(void *instanceData,
const char *buf, int toWrite, int *errorCode);
static int ConsoleSetOptionProc(void *instanceData,
Tcl_Interp *interp, const char *optionName,
const char *value);
static void ConsoleSetupProc(void *clientData, int flags);
static void ConsoleWatchProc(void *instanceData, int mask);
static void ProcExitHandler(void *clientData);
static void ConsoleThreadActionProc(void *instanceData, int action);
static DWORD ReadConsoleChars(HANDLE hConsole, WCHAR *lpBuffer,
Tcl_Size nChars, Tcl_Size *nCharsReadPtr);
static DWORD WriteConsoleChars(HANDLE hConsole,
const WCHAR *lpBuffer, Tcl_Size nChars,
Tcl_Size *nCharsWritten);
static void RingBufferInit(RingBuffer *ringPtr, Tcl_Size capacity);
static void RingBufferClear(RingBuffer *ringPtr);
static Tcl_Size RingBufferIn(RingBuffer *ringPtr, const char *srcPtr,
Tcl_Size srcLen, int partialCopyOk);
static Tcl_Size RingBufferOut(RingBuffer *ringPtr, char *dstPtr,
Tcl_Size dstCapacity, int partialCopyOk);
static ConsoleHandleInfo *AllocateConsoleHandleInfo(HANDLE consoleHandle,
int permissions);
static ConsoleHandleInfo *FindConsoleInfo(const ConsoleChannelInfo *);
static DWORD WINAPI ConsoleReaderThread(LPVOID arg);
static DWORD WINAPI ConsoleWriterThread(LPVOID arg);
static void NudgeWatchers(HANDLE consoleHandle);
#ifndef NDEBUG
static int RingBufferCheck(const RingBuffer *ringPtr);
#endif
/*
* Static data.
*/
typedef struct {
/* Currently this struct is only used to detect thread initialization */
int notUsed; /* Dummy field */
} ThreadSpecificData;
static Tcl_ThreadDataKey dataKey;
/*
* All access to static data is controlled through a single process-wide
* lock. A process can have only a single console at a time, with three
* handles for stdin, stdout and stderr. Creation/destruction of consoles is
* a relatively rare event (currently only possible during process start),
* the number of consoles (as opposed to channels) is small (only stdin,
* stdout and stderr), and contention low. More finer-grained locking would
* likely not only complicate implementation but be slower due to multiple
* locks being held. Note console channels also differ from other Tcl
* channel types in that the channel<->OS descriptor mapping is not one-to-one.
*/
SRWLOCK gConsoleLock;
/* Process-wide list of console handles. Access control through gConsoleLock */
static ConsoleHandleInfo *gConsoleHandleInfoList;
/*
* Process-wide list of channels that are listening for events. Again access
* control through gConsoleLock. Common list for all threads is simplifies
* locking and bookkeeping and is workable because in practice multiple
* threads are very unlikely to be all waiting on stdin (not workable
* because input would be randomly distributed to threads)
*/
static ConsoleChannelInfo *gWatchingChannelList;
/*
* This structure describes the channel type structure for command console
* based IO.
*/
static const Tcl_ChannelType consoleChannelType = {
"console", /* Type name. */
TCL_CHANNEL_VERSION_5, /* v5 channel */
NULL, /* Close proc. */
ConsoleInputProc, /* Input proc. */
ConsoleOutputProc, /* Output proc. */
NULL, /* Seek proc. */
ConsoleSetOptionProc, /* Set option proc. */
ConsoleGetOptionProc, /* Get option proc. */
ConsoleWatchProc, /* Set up notifier to watch the channel. */
ConsoleGetHandleProc, /* Get an OS handle from channel. */
ConsoleCloseProc, /* close2proc. */
ConsoleBlockModeProc, /* Set blocking or non-blocking mode. */
NULL, /* Flush proc. */
NULL, /* Handler proc. */
NULL, /* Wide seek proc. */
ConsoleThreadActionProc, /* Thread action proc. */
NULL /* Truncation proc. */
};
/*
*------------------------------------------------------------------------
*
* RingBufferInit --
*
* Initializes the ring buffer to a given size.
*
* Results:
* None.
*
* Side effects:
* Panics on allocation failure.
*
*------------------------------------------------------------------------
*/
static void
RingBufferInit(
RingBuffer *ringPtr,
Tcl_Size capacity)
{
if (capacity <= 0 || capacity > TCL_SIZE_MAX) {
Tcl_Panic("Internal error: invalid ring buffer capacity requested.");
}
ringPtr->bufPtr = (char *)Tcl_Alloc(capacity);
ringPtr->capacity = capacity;
ringPtr->start = 0;
ringPtr->length = 0;
}
/*
*------------------------------------------------------------------------
*
* RingBufferClear
*
* Clears the contents of a ring buffer.
*
* Results:
* None.
*
* Side effects:
* The allocated internal buffer is freed.
*
*------------------------------------------------------------------------
*/
static void
RingBufferClear(
RingBuffer *ringPtr)
{
if (ringPtr->bufPtr) {
Tcl_Free(ringPtr->bufPtr);
ringPtr->bufPtr = NULL;
}
ringPtr->capacity = 0;
ringPtr->start = 0;
ringPtr->length = 0;
}
/*
*------------------------------------------------------------------------
*
* RingBufferIn --
*
* Appends data to the ring buffer.
*
* Results:
* Returns number of bytes copied.
*
* Side effects:
* Internal buffer is updated.
*
*------------------------------------------------------------------------
*/
static Tcl_Size
RingBufferIn(
RingBuffer *ringPtr,
const char *srcPtr, /* Source to be copied */
Tcl_Size srcLen, /* Length of source */
int partialCopyOk) /* If true, partial copy is permitted */
{
Tcl_Size freeSpace;
RINGBUFFER_ASSERT(ringPtr);
freeSpace = ringPtr->capacity - ringPtr->length;
if (freeSpace < srcLen) {
if (!partialCopyOk) {
return 0;
}
/* Copy only as much as free space allows */
srcLen = freeSpace;
}
if (ringPtr->capacity - ringPtr->start > ringPtr->length) {
/* There is room at the back */
Tcl_Size endSpaceStart = ringPtr->start + ringPtr->length;
Tcl_Size endSpace = ringPtr->capacity - endSpaceStart;
if (endSpace >= srcLen) {
/* Everything fits at the back */
memmove(endSpaceStart + ringPtr->bufPtr, srcPtr, srcLen);
} else {
/* srcLen > endSpace */
memmove(endSpaceStart + ringPtr->bufPtr, srcPtr, endSpace);
memmove(ringPtr->bufPtr, endSpace + srcPtr, srcLen - endSpace);
}
} else {
/* No room at the back. Existing data wrap to front. */
Tcl_Size wrapLen =
ringPtr->start + ringPtr->length - ringPtr->capacity;
memmove(wrapLen + ringPtr->bufPtr, srcPtr, srcLen);
}
ringPtr->length += srcLen;
RINGBUFFER_ASSERT(ringPtr);
return srcLen;
}
/*
*------------------------------------------------------------------------
*
* RingBufferOut --
*
* Moves data out of the ring buffer. If dstPtr is NULL, the data
* is simply removed.
*
* Results:
* Returns number of bytes copied or removed.
*
* Side effects:
* Internal buffer is updated.
*
*------------------------------------------------------------------------
*/
static Tcl_Size
RingBufferOut(
RingBuffer *ringPtr,
char *dstPtr, /* Buffer for output data. May be NULL */
Tcl_Size dstCapacity, /* Size of buffer */
int partialCopyOk) /* If true, return what's available */
{
Tcl_Size leadLen;
RINGBUFFER_ASSERT(ringPtr);
if (dstCapacity > ringPtr->length) {
if (dstPtr && !partialCopyOk) {
return 0;
}
dstCapacity = ringPtr->length;
}
if (ringPtr->start <= (ringPtr->capacity - ringPtr->length)) {
/* No content wrap around. So leadLen is entire content */
leadLen = ringPtr->length;
} else {
/* Content wraps around so lead segment stretches to end of buffer */
leadLen = ringPtr->capacity - ringPtr->start;
}
if (leadLen >= dstCapacity) {
if (dstPtr) {
memmove(dstPtr, ringPtr->start + ringPtr->bufPtr, dstCapacity);
}
ringPtr->start += dstCapacity;
} else {
Tcl_Size wrapLen = dstCapacity - leadLen;
if (dstPtr) {
memmove(dstPtr,
ringPtr->start + ringPtr->bufPtr,
leadLen);
memmove(
leadLen + dstPtr, ringPtr->bufPtr, wrapLen);
}
ringPtr->start = wrapLen;
}
ringPtr->length -= dstCapacity;
if (ringPtr->start == ringPtr->capacity || ringPtr->length == 0) {
ringPtr->start = 0;
}
RINGBUFFER_ASSERT(ringPtr);
return dstCapacity;
}
#ifndef NDEBUG
static int
RingBufferCheck(
const RingBuffer *ringPtr)
{
return (ringPtr->bufPtr != NULL && ringPtr->capacity == CONSOLE_BUFFER_SIZE
&& ringPtr->start < ringPtr->capacity
&& ringPtr->length <= ringPtr->capacity);
}
#endif
/*
*------------------------------------------------------------------------
*
* ReadConsoleChars --
*
* Wrapper for ReadConsoleW.
*
* Results:
* Returns 0 on success, else Windows error code.
*
* Side effects:
* On success the number of characters (not bytes) read is stored in
* *nCharsReadPtr. This will be 0 if the operation was interrupted by
* a Ctrl-C or a CancelIo call.
*
*------------------------------------------------------------------------
*/
static DWORD
ReadConsoleChars(
HANDLE hConsole,
WCHAR *lpBuffer,
Tcl_Size nChars,
Tcl_Size *nCharsReadPtr)
{
DWORD nRead;
BOOL result;
/*
* If user types a Ctrl-Break or Ctrl-C, ReadConsole will return success
* with ntchars == 0 and GetLastError() will be ERROR_OPERATION_ABORTED.
* If no Ctrl signal handlers have been established, the default signal
* OS handler in a separate thread will terminate the program. If a Ctrl
* signal handler has been established (through an extension for
* example), it will run and take whatever action it deems appropriate.
*
* If one thread closes its channel, it calls CancelSynchronousIo on the
* console handle which results again in success being returned and
* GetLastError() being ERROR_OPERATION_ABORTED but ntchars in
* unmodified.
*
* In both cases above we will return success but with nbytesread as 0.
* This allows caller to check for thread termination etc.
*
* See https://bugs.python.org/issue30237
* or https://github.com/microsoft/terminal/issues/12143
*/
nRead = (DWORD)-1;
result = ReadConsoleW(hConsole, lpBuffer, nChars, &nRead, NULL);
if (result) {
if ((nRead == 0 || nRead == (DWORD)-1)
&& GetLastError() == ERROR_OPERATION_ABORTED) {
nRead = 0;
}
*nCharsReadPtr = nRead;
return 0;
} else {
return GetLastError();
}
}
/*
*------------------------------------------------------------------------
*
* WriteConsoleChars --
*
* Wrapper for WriteConsoleW.
*
* Results:
* Returns 0 on success, Windows error code on failure.
*
* Side effects:
* On success the number of characters (not bytes) written is stored in
* *nCharsWrittenPtr. This will be 0 if the operation was interrupted by
* a Ctrl-C or a CancelIo call.
*
*------------------------------------------------------------------------
*/
static DWORD
WriteConsoleChars(
HANDLE hConsole,
const WCHAR *lpBuffer,
Tcl_Size nChars,
Tcl_Size *nCharsWrittenPtr)
{
DWORD nCharsWritten;
BOOL result;
/* See comments in ReadConsoleChars, not sure that applies here */
nCharsWritten = (DWORD)-1;
result = WriteConsoleW(hConsole, lpBuffer, nChars, &nCharsWritten, NULL);
if (result) {
if (nCharsWritten == (DWORD) -1) {
nCharsWritten = 0;
}
*nCharsWrittenPtr = nCharsWritten;
return 0;
} else {
return GetLastError();
}
}
/*
*----------------------------------------------------------------------
*
* ConsoleInit --
*
* This function initializes the static variables for this file.
*
* Results:
* None.
*
* Side effects:
* Creates a new event source.
*
*----------------------------------------------------------------------
*/
static void
ConsoleInit(void)
{
/*
* Check the initialized flag first, then check again in the mutex. This
* is a speed enhancement.
*/
if (!gInitialized) {
AcquireSRWLockExclusive(&gConsoleLock);
if (!gInitialized) {
gInitialized = 1;
Tcl_CreateExitHandler(ProcExitHandler, NULL);
}
ReleaseSRWLockExclusive(&gConsoleLock);
}
if (TclThreadDataKeyGet(&dataKey) == NULL) {
ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);
tsdPtr->notUsed = 0;
Tcl_CreateEventSource(ConsoleSetupProc, ConsoleCheckProc, NULL);
Tcl_CreateThreadExitHandler(ConsoleExitHandler, NULL);
}
}
/*
*----------------------------------------------------------------------
*
* ConsoleExitHandler --
*
* This function is called to cleanup the console module before Tcl is
* unloaded.
*
* Results:
* None.
*
* Side effects:
* Removes the console event source.
*
*----------------------------------------------------------------------
*/
static void
ConsoleExitHandler(
TCL_UNUSED(void *))
{
Tcl_DeleteEventSource(ConsoleSetupProc, ConsoleCheckProc, NULL);
}
/*
*----------------------------------------------------------------------
*
* ProcExitHandler --
*
* This function is called to cleanup the process list before Tcl is
* unloaded.
*
* Results:
* None.
*
* Side effects:
* Resets the process list.
*
*----------------------------------------------------------------------
*/
static void
ProcExitHandler(
TCL_UNUSED(void *))
{
AcquireSRWLockExclusive(&gConsoleLock);
gInitialized = 0;
ReleaseSRWLockExclusive(&gConsoleLock);
}
/*
*------------------------------------------------------------------------
*
* NudgeWatchers --
*
* Wakes up all threads which have file event watchers on the passed
* console handle.
*
* The function locks and releases gConsoleLock.
* Caller must not be holding locks that will violate lock hierarchy.
*
* Results:
* None.
*
* Side effects:
* As above.
*------------------------------------------------------------------------
*/
static void
NudgeWatchers(
HANDLE consoleHandle)
{
ConsoleChannelInfo *chanInfoPtr;
AcquireSRWLockShared(&gConsoleLock); /* Shared-read lock */
for (chanInfoPtr = gWatchingChannelList; chanInfoPtr;
chanInfoPtr = chanInfoPtr->nextWatchingChannelPtr) {
/*
* Notify channels interested in our handle AND that have
* a thread attached.
* No lock needed for chanInfoPtr. See ConsoleChannelInfo.
*/
if (chanInfoPtr->handle == consoleHandle
&& chanInfoPtr->threadId != NULL) {
Tcl_ThreadAlert(chanInfoPtr->threadId);
}
}
ReleaseSRWLockShared(&gConsoleLock);
}
/*
*----------------------------------------------------------------------
*
* ConsoleSetupProc --
*
* This procedure is invoked before Tcl_DoOneEvent blocks waiting for an
* event. It walks the channel list and if any input channel has data
* available or output channel has space for data, sets the event loop
* blocking time to 0 so that it will poll immediately.
*
* Results:
* None.
*
* Side effects:
* Adjusts the block time if needed.
*
*----------------------------------------------------------------------
*/
void
ConsoleSetupProc(
TCL_UNUSED(void *),
int flags) /* Event flags as passed to Tcl_DoOneEvent. */
{
ConsoleChannelInfo *chanInfoPtr;
Tcl_Time blockTime = { 0, 0 };
int block = 1;
if (!(flags & TCL_FILE_EVENTS)) {
return;
}
/*
* Walk the list of channels. See general comments for struct
* ConsoleChannelInfo with regard to locking and field access.
*/
AcquireSRWLockShared(&gConsoleLock); /* READ lock - no data modification */
for (chanInfoPtr = gWatchingChannelList; block && chanInfoPtr != NULL;
chanInfoPtr = chanInfoPtr->nextWatchingChannelPtr) {
ConsoleHandleInfo *handleInfoPtr;
handleInfoPtr = FindConsoleInfo(chanInfoPtr);
if (handleInfoPtr != NULL) {
AcquireSRWLockShared(&handleInfoPtr->lock);
/* Remember at most one of READABLE, WRITABLE set */
if (chanInfoPtr->watchMask & TCL_READABLE) {
if (RingBufferLength(&handleInfoPtr->buffer) > 0
|| handleInfoPtr->lastError != ERROR_SUCCESS) {
block = 0; /* Input data available */
}
} else if (chanInfoPtr->watchMask & TCL_WRITABLE) {
if (RingBufferHasFreeSpace(&handleInfoPtr->buffer)) {
/* TCL_WRITABLE */
block = 0; /* Output space available */
}
}
ReleaseSRWLockShared(&handleInfoPtr->lock);
}
}
ReleaseSRWLockShared(&gConsoleLock);
if (!block) {
/* At least one channel is readable/writable. Set block time to 0 */
Tcl_SetMaxBlockTime(&blockTime);
}
}
/*
*----------------------------------------------------------------------
*
* ConsoleCheckProc --
*
* This procedure is called by Tcl_DoOneEvent to check the console event
* source for events.
*
* Results:
* None.
*
* Side effects:
* May queue an event.
*
*----------------------------------------------------------------------
*/
static void
ConsoleCheckProc(
TCL_UNUSED(void *),
int flags) /* Event flags as passed to Tcl_DoOneEvent. */
{
ConsoleChannelInfo *chanInfoPtr;
Tcl_ThreadId me;
int needEvent;
if (!(flags & TCL_FILE_EVENTS)) {
return;
}
me = Tcl_GetCurrentThread();
/*
* Acquire a shared lock. Note this is ok even though we potentially
* modify the chanInfoPtr->flags because chanInfoPtr is only modified
* when it belongs to this thread and no other thread will write to it.
* THe shared lock is intended to protect the global gWatchingChannelList
* as we traverse it.
*/
AcquireSRWLockShared(&gConsoleLock);
for (chanInfoPtr = gWatchingChannelList; chanInfoPtr != NULL;
chanInfoPtr = chanInfoPtr->nextWatchingChannelPtr) {
ConsoleHandleInfo *handleInfoPtr;
if (chanInfoPtr->threadId != me) {
/* Some other thread owns the channel */
continue;
}
if (chanInfoPtr->flags & CONSOLE_EVENT_QUEUED) {
/* A notification event already queued. No point in another. */
continue;
}
handleInfoPtr = FindConsoleInfo(chanInfoPtr);
/* Pointer is safe to access as we are holding gConsoleLock */
if (handleInfoPtr == NULL) {
/* Stale event */
continue;
}
needEvent = 0;
AcquireSRWLockShared(&handleInfoPtr->lock);
/* Rememeber channel is read or write, never both */
if (chanInfoPtr->watchMask & TCL_READABLE) {
if (RingBufferLength(&handleInfoPtr->buffer) > 0
|| handleInfoPtr->lastError != ERROR_SUCCESS) {
needEvent = 1; /* Input data available or error/EOF */
}
/*
* TCL_READABLE watch means someone is looking out for data being
* available, let reader thread know. Note channel need not be
* ASYNC! (Bug [baa51423c2])
*/
handleInfoPtr->flags |= CONSOLE_DATA_AWAITED;
WakeConditionVariable(&handleInfoPtr->consoleThreadCV);
} else if (chanInfoPtr->watchMask & TCL_WRITABLE) {
if (RingBufferHasFreeSpace(&handleInfoPtr->buffer)) {
needEvent = 1; /* Output space available */
}
}
ReleaseSRWLockShared(&handleInfoPtr->lock);
if (needEvent) {
ConsoleEvent *evPtr = (ConsoleEvent *)Tcl_Alloc(sizeof(ConsoleEvent));
/* See note above loop why this can be accessed without locks */
chanInfoPtr->flags |= CONSOLE_EVENT_QUEUED;
chanInfoPtr->numRefs += 1; /* So it does not go away while event
is in queue */
evPtr->header.proc = ConsoleEventProc;
evPtr->chanInfoPtr = chanInfoPtr;
Tcl_QueueEvent((Tcl_Event *) evPtr, TCL_QUEUE_TAIL);
}
}
ReleaseSRWLockShared(&gConsoleLock);
}
/*
*----------------------------------------------------------------------
*
* ConsoleBlockModeProc --
*
* Set blocking or non-blocking mode on channel.
*
* Results:
* 0 if successful, errno when failed.
*
* Side effects:
* Sets the device into blocking or non-blocking mode.
*
*----------------------------------------------------------------------
*/
static int
ConsoleBlockModeProc(
void *instanceData, /* Instance data for channel. */
int mode) /* TCL_MODE_BLOCKING or
* TCL_MODE_NONBLOCKING. */
{
ConsoleChannelInfo *chanInfoPtr = (ConsoleChannelInfo *)instanceData;
/*
* Consoles on Windows can not be switched between blocking and
* nonblocking, hence we have to emulate the behavior. This is done in the
* input function by checking against a bit in the state. We set or unset
* the bit here to cause the input function to emulate the correct
* behavior.
*/
if (mode == TCL_MODE_NONBLOCKING) {
chanInfoPtr->flags |= CONSOLE_ASYNC;
} else {
chanInfoPtr->flags &= ~CONSOLE_ASYNC;
}
return 0;
}
/*
*----------------------------------------------------------------------
*
* ConsoleCloseProc --
*
* Closes a console based IO channel.
*
* Results:
* 0 on success, errno otherwise.
*
* Side effects:
* Closes the physical channel.
*
*----------------------------------------------------------------------
*/
static int
ConsoleCloseProc(
void *instanceData, /* Pointer to ConsoleChannelInfo structure. */
TCL_UNUSED(Tcl_Interp *),
int flags)
{
ConsoleChannelInfo *chanInfoPtr = (ConsoleChannelInfo *)instanceData;
ConsoleHandleInfo *handleInfoPtr;
int errorCode = 0;
ConsoleChannelInfo **nextPtrPtr;
int closeHandle;
if ((flags & (TCL_CLOSE_READ | TCL_CLOSE_WRITE)) != 0) {
return EINVAL;
}
/*
* Don't close the Win32 handle if the handle is a standard channel
* during the thread exit process. Otherwise, one thread may kill the
* stdio of another while exiting. Note an explicit close in script will
* still close the handle. That's historical behavior on all platforms.
*/
if (!TclInThreadExit()
|| ( (GetStdHandle(STD_INPUT_HANDLE) != chanInfoPtr->handle)
&& (GetStdHandle(STD_OUTPUT_HANDLE) != chanInfoPtr->handle)
&& (GetStdHandle(STD_ERROR_HANDLE) != chanInfoPtr->handle))) {
closeHandle = 1;
} else {
closeHandle = 0;
}
AcquireSRWLockExclusive(&gConsoleLock);
/* Remove channel from watchers' list */
for (nextPtrPtr = &gWatchingChannelList; *nextPtrPtr != NULL;
nextPtrPtr = &(*nextPtrPtr)->nextWatchingChannelPtr) {
if (*nextPtrPtr == (ConsoleChannelInfo *) chanInfoPtr) {
*nextPtrPtr = (*nextPtrPtr)->nextWatchingChannelPtr;
break;
}
}
handleInfoPtr = FindConsoleInfo(chanInfoPtr);
if (handleInfoPtr) {
/*
* Console thread may be blocked either waiting for console i/o
* or waiting on the condition variable for buffer empty/full
*/
AcquireSRWLockShared(&handleInfoPtr->lock);
if (closeHandle) {
handleInfoPtr->console = INVALID_HANDLE_VALUE;
}
/* Break the thread out of blocking console i/o */
handleInfoPtr->numRefs -= 1; /* Remove reference from this channel */
if (handleInfoPtr->numRefs == 1) {
/*
* Abort the i/o if no other threads are listening on it.
* Note without this check, an input line will be skipped on
* the cancel.
*/
CancelSynchronousIo(handleInfoPtr->consoleThread);
}
/*
* Wake up the console handling thread. Note we do not explicitly
* tell it handle is closed (below). It will find out on next access
*/
WakeConditionVariable(&handleInfoPtr->consoleThreadCV);
ReleaseSRWLockShared(&handleInfoPtr->lock);
}
ReleaseSRWLockExclusive(&gConsoleLock);
chanInfoPtr->channel = NULL;
chanInfoPtr->watchMask = 0;
chanInfoPtr->permissions = 0;
if (closeHandle && chanInfoPtr->handle != INVALID_HANDLE_VALUE) {
if (CloseHandle(chanInfoPtr->handle) == FALSE) {
Tcl_WinConvertError(GetLastError());
errorCode = errno;
}
chanInfoPtr->handle = INVALID_HANDLE_VALUE;
}
/*
* Note, we can check and manipulate numRefs without a lock because
* we have removed it from the watch queue so the console thread cannot
* get at it.
*/
if (chanInfoPtr->numRefs > 1) {
/* There may be references already on the event queue */
chanInfoPtr->numRefs -= 1;
} else {
Tcl_Free(chanInfoPtr);
}
return errorCode;
}
/*
*----------------------------------------------------------------------
*
* ConsoleInputProc --
*
* Reads input from the IO channel into the buffer given. Returns count
* of how many bytes were actually read, and an error indication.
*
* Results:
* A count of how many bytes were read is returned and an error
* indication is returned in an output argument.
*
* Side effects:
* Reads input from the actual channel.
*
*----------------------------------------------------------------------
*/
static int
ConsoleInputProc(
void *instanceData, /* Console state. */
char *bufPtr, /* Where to store data read. */
int bufSize, /* How much space is available in the
* buffer? */
int *errorCode) /* Where to store error code. */
{
ConsoleChannelInfo *chanInfoPtr = (ConsoleChannelInfo *)instanceData;
ConsoleHandleInfo *handleInfoPtr;
Tcl_Size numRead;
if (chanInfoPtr->handle == INVALID_HANDLE_VALUE) {
return 0; /* EOF */
}
*errorCode = 0;
AcquireSRWLockShared(&gConsoleLock);
handleInfoPtr = FindConsoleInfo(chanInfoPtr);
if (handleInfoPtr == NULL) {
/* Really shouldn't happen since channel is holding a reference */
ReleaseSRWLockShared(&gConsoleLock);
return 0; /* EOF */
}
AcquireSRWLockExclusive(&handleInfoPtr->lock);
ReleaseSRWLockShared(&gConsoleLock); /* AFTER acquiring handleInfoPtr->lock */
while (1) {
numRead = RingBufferOut(&handleInfoPtr->buffer, bufPtr, bufSize, 1);
/*
* Note: even if channel is closed or has an error, as long there is
* buffered data, we will pass it up.
*/
if (numRead != 0) {
break;
}
/*
* No data available.
* - If an error was recorded, generate that and reset it.
* - If EOF, indicate as much. It is up to the application to close
* the channel.
* - Otherwise, if non-blocking return EAGAIN or wait for more data.
*/
if (handleInfoPtr->lastError != 0) {
if (handleInfoPtr->lastError == ERROR_INVALID_HANDLE) {
numRead = 0; /* Treat as EOF */
} else {
Tcl_WinConvertError(handleInfoPtr->lastError);
handleInfoPtr->lastError = 0;
*errorCode = Tcl_GetErrno();
numRead = -1;
}
break;
}
if (handleInfoPtr->console == INVALID_HANDLE_VALUE) {
/* EOF - break with numRead == 0 */
chanInfoPtr->handle = INVALID_HANDLE_VALUE;
break;
}
/* For async, tell caller we are blocked */
if (chanInfoPtr->flags & CONSOLE_ASYNC) {
*errorCode = EWOULDBLOCK;
numRead = -1;
break;
}
/*
* Blocking read. Just get data from directly from console. There
* is a small complication in that
* 1. The destination buffer should be WCHAR aligned.
* 2. We can only read even number of bytes (wide-character API).
* 3. Caller has large enough buffer (else length of line user can
* enter will be limited)
* If any condition is not met, we defer to the
* reader thread which handles these cases rather than dealing with
* them here (which is a little trickier than it might sound.)
*
* TODO - not clear this block is a useful optimization. bufSize by
* default is 4K which is < INPUT_BUFFER_SIZE and will rarely be
* increased on stdin.
*/
if ((1 & (size_t)bufPtr) == 0 /* aligned buffer */
&& (1 & bufSize) == 0 /* Even number of bytes */
&& bufSize > INPUT_BUFFER_SIZE) {
DWORD lastError;
Tcl_Size numChars;
ReleaseSRWLockExclusive(&handleInfoPtr->lock);
lastError = ReadConsoleChars(chanInfoPtr->handle,
(WCHAR *)bufPtr, bufSize / sizeof(WCHAR), &numChars);
/* NOTE lock released so DON'T break. Return instead */
if (lastError != ERROR_SUCCESS) {
Tcl_WinConvertError(lastError);
*errorCode = Tcl_GetErrno();
return -1;
} else if (numChars > 0) {
/* Successfully read something. */
return numChars * sizeof(WCHAR);
} else {
/*
* Ctrl-C/Ctrl-Brk interrupt. Loop around to retry.
* We have to reacquire the lock. No worried about handleInfoPtr
* having gone away since the channel holds a reference.
*/
AcquireSRWLockExclusive(&handleInfoPtr->lock);
continue;
}
}
/*
* Deferring blocking read to reader thread.
* Release the lock and sleep. Note that because the channel
* holds a reference count on handleInfoPtr, it will not
* be deallocated while the lock is released.
*/
handleInfoPtr->flags |= CONSOLE_DATA_AWAITED;
WakeConditionVariable(&handleInfoPtr->consoleThreadCV);
if (!SleepConditionVariableSRW(&handleInfoPtr->interpThreadCV,
&handleInfoPtr->lock, INFINITE, 0)) {
Tcl_WinConvertError(GetLastError());
*errorCode = Tcl_GetErrno();
numRead = -1;
break;
}
/* Lock is reacquired, loop back to try again */
}
/* We read data. Ask for more if either async or watching for reads */
if ((chanInfoPtr->flags & CONSOLE_ASYNC)
|| (chanInfoPtr->watchMask & TCL_READABLE)) {
handleInfoPtr->flags |= CONSOLE_DATA_AWAITED;
WakeConditionVariable(&handleInfoPtr->consoleThreadCV);
}
ReleaseSRWLockExclusive(&handleInfoPtr->lock);
return numRead;
}
/*
*----------------------------------------------------------------------
*
* ConsoleOutputProc --
*
* Writes the given output on the IO channel. Returns count of how many
* characters were actually written, and an error indication.
*
* Results:
* A count of how many characters were written is returned and an error
* indication is returned in an output argument.
*
* Side effects:
* Writes output on the actual channel.
*
*----------------------------------------------------------------------
*/
static int
ConsoleOutputProc(
void *instanceData, /* Console state. */
const char *buf, /* The data buffer. */
int toWrite, /* How many bytes to write? */
int *errorCode) /* Where to store error code. */
{
ConsoleChannelInfo *chanInfoPtr = (ConsoleChannelInfo *)instanceData;
ConsoleHandleInfo *handleInfoPtr;
Tcl_Size numWritten;
*errorCode = 0;
if (chanInfoPtr->handle == INVALID_HANDLE_VALUE) {
/* Some other thread would have *previously* closed the stdio handle */
*errorCode = EPIPE;
return -1;
}
AcquireSRWLockShared(&gConsoleLock);
handleInfoPtr = FindConsoleInfo(chanInfoPtr);
if (handleInfoPtr == NULL) {
/* Really shouldn't happen since channel is holding a reference */
*errorCode = EPIPE;
ReleaseSRWLockShared(&gConsoleLock);
return -1;
}
AcquireSRWLockExclusive(&handleInfoPtr->lock);
ReleaseSRWLockShared(&gConsoleLock); /* AFTER acquiring handleInfoPtr->lock */
/* Keep looping until all written. Break out for async and errors */
numWritten = 0;
while (1) {
/* Check for error and closing on every loop. */
if (handleInfoPtr->lastError != 0) {
Tcl_WinConvertError(handleInfoPtr->lastError);
*errorCode = Tcl_GetErrno();
numWritten = -1;
break;
}
if (handleInfoPtr->console == INVALID_HANDLE_VALUE) {
*errorCode = EPIPE;
chanInfoPtr->handle = INVALID_HANDLE_VALUE;
numWritten = -1;
break;
}
/*
* We can either write directly or through the console thread's
* ring buffer. We have to do the latter when
* (1) the operation is async since WriteConsoleChars is always blocking
* (2) when there is already data in the ring buffer because we don't
* want to reorder output from within a thread
* (3) when there are an odd number of bytes since WriteConsole
* takes whole WCHARs
* (4) when the pointer is not aligned on WCHAR
* The ring buffer deals with cases (3) and (4). It would be harder
* to duplicate that here.
*/
if ((chanInfoPtr->flags & CONSOLE_ASYNC) /* Case (1) */
|| RingBufferLength(&handleInfoPtr->buffer) != 0 /* Case (2) */
|| (toWrite & 1) != 0 /* Case (3) */
|| (PTR2INT(buf) & 1) != 0) { /* Case (4) */
numWritten += RingBufferIn(&handleInfoPtr->buffer,
numWritten + buf, toWrite - numWritten, 1);
if (numWritten == toWrite || chanInfoPtr->flags & CONSOLE_ASYNC) {
/* All done or async, just accept whatever was written */
break;
}
/*
* Release the lock and sleep. Note that because the channel
* holds a reference count on handleInfoPtr, it will not
* be deallocated while the lock is released.
*/
WakeConditionVariable(&handleInfoPtr->consoleThreadCV);
if (!SleepConditionVariableSRW(&handleInfoPtr->interpThreadCV,
&handleInfoPtr->lock, INFINITE, 0)) {
/* Report the error */
Tcl_WinConvertError(GetLastError());
*errorCode = Tcl_GetErrno();
numWritten = -1;
break;
}
} else {
/* Direct output */
DWORD winStatus;
HANDLE consoleHandle = handleInfoPtr->console;
/* Unlock before blocking in WriteConsole */
ReleaseSRWLockExclusive(&handleInfoPtr->lock);
/* UNLOCKED so return, DON'T break out of loop as it will unlock
* again! */
winStatus = WriteConsoleChars(consoleHandle,
(WCHAR *)buf, toWrite / sizeof(WCHAR), &numWritten);
if (winStatus == ERROR_SUCCESS) {
return numWritten * sizeof(WCHAR);
} else {
Tcl_WinConvertError(winStatus);
*errorCode = Tcl_GetErrno();
return -1;
}
}
/* Lock must have been reacquired before continuing loop */
}
WakeConditionVariable(&handleInfoPtr->consoleThreadCV);
ReleaseSRWLockExclusive(&handleInfoPtr->lock);
return numWritten;
}
/*
*----------------------------------------------------------------------
*
* ConsoleEventProc --
*
* This function is invoked by Tcl_ServiceEvent when a file event reaches
* the front of the event queue. This procedure invokes Tcl_NotifyChannel
* on the console.
*
* Results:
* Returns 1 if the event was handled, meaning it should be removed from
* the queue. Returns 0 if the event was not handled, meaning it should
* stay on the queue. The only time the event isn't handled is if the
* TCL_FILE_EVENTS flag bit isn't set.
*
* Side effects:
* Whatever the notifier callback does.
*
*----------------------------------------------------------------------
*/
static int
ConsoleEventProc(
Tcl_Event *evPtr, /* Event to service. */
int flags) /* Flags that indicate what events to handle,
* such as TCL_FILE_EVENTS. */
{
ConsoleEvent *consoleEvPtr = (ConsoleEvent *) evPtr;
ConsoleChannelInfo *chanInfoPtr;
int freeChannel;
int mask = 0;
if (!(flags & TCL_FILE_EVENTS)) {
return 0;
}
chanInfoPtr = consoleEvPtr->chanInfoPtr;
/*
* We know chanInfoPtr is valid because its reference count would have
* been incremented when the event was queued. The corresponding release
* happens in this function.
*/
/*
* Global lock used for chanInfoPtr. A read (shared) lock suffices
* because all access is within the channel owning thread with the
* exception of watchers which is a read-only access. See comments
* to ConsoleChannelInfo.
*/
AcquireSRWLockShared(&gConsoleLock);
chanInfoPtr->flags &= ~CONSOLE_EVENT_QUEUED;
/*
* Only handle the event if the Tcl channel has not gone away AND is
* still owned by this thread AND is still watching events.
*/
if (chanInfoPtr->channel && chanInfoPtr->threadId == Tcl_GetCurrentThread()
&& (chanInfoPtr->watchMask & (TCL_READABLE|TCL_WRITABLE))) {
ConsoleHandleInfo *handleInfoPtr = FindConsoleInfo(chanInfoPtr);
if (handleInfoPtr == NULL) {
/* Console was closed. EOF->read event only (not write) */
if (chanInfoPtr->watchMask & TCL_READABLE) {
mask = TCL_READABLE;
}
} else {
AcquireSRWLockShared(&handleInfoPtr->lock);
/* Remember at most one of READABLE, WRITABLE set */
if ((chanInfoPtr->watchMask & TCL_READABLE)
&& RingBufferLength(&handleInfoPtr->buffer)) {
mask = TCL_READABLE;
} else if ((chanInfoPtr->watchMask & TCL_WRITABLE)
&& RingBufferHasFreeSpace(&handleInfoPtr->buffer)) {
/* Generate write event space available */
mask = TCL_WRITABLE;
}
ReleaseSRWLockShared(&handleInfoPtr->lock);
}
}
/*
* Tcl_NotifyChannel can recurse through the file event callback so need
* to release locks first. Our reference still holds so no danger of
* chanInfoPtr being deallocated if the callback closes the channel.
*/
ReleaseSRWLockShared(&gConsoleLock);
if (mask) {
Tcl_NotifyChannel(chanInfoPtr->channel, mask);
/* Note: chanInfoPtr ref count may have changed */
}
/* No need to lock - see comments earlier */
/* Remove the reference to the channel from event record */
if (chanInfoPtr->numRefs > 1) {
chanInfoPtr->numRefs -= 1;
freeChannel = 0;
} else {
assert(chanInfoPtr->channel == NULL);
freeChannel = 1;
}
if (freeChannel) {
Tcl_Free(chanInfoPtr);
}
return 1;
}
/*
*----------------------------------------------------------------------
*
* ConsoleWatchProc --
*
* Called by the notifier to set up to watch for events on this channel.
*
* Results:
* None.
*
* Side effects:
* None.
*
*----------------------------------------------------------------------
*/
static void
ConsoleWatchProc(
void *instanceData, /* Console state. */
int newMask) /* What events to watch for, one of
* of TCL_READABLE, TCL_WRITABLE */
{
ConsoleChannelInfo **nextPtrPtr, *ptr;
ConsoleChannelInfo *chanInfoPtr = (ConsoleChannelInfo *)instanceData;
int oldMask = chanInfoPtr->watchMask;
/*
* Since most of the work is handled by the background threads, we just
* need to update the watchMask and then force the notifier to poll once.
*/
chanInfoPtr->watchMask = newMask & chanInfoPtr->permissions;
if (chanInfoPtr->watchMask) {
Tcl_Time blockTime = { 0, 0 };
if (!oldMask) {
AcquireSRWLockExclusive(&gConsoleLock);
/* Add to list of watched channels */
chanInfoPtr->nextWatchingChannelPtr = gWatchingChannelList;
gWatchingChannelList = chanInfoPtr;
/*
* For read channels, need to tell the console reader thread
* that we are looking for data since it will not do reads until
* it knows someone is awaiting.
*/
ConsoleHandleInfo *handleInfoPtr = FindConsoleInfo(chanInfoPtr);
if (handleInfoPtr) {
AcquireSRWLockExclusive(&handleInfoPtr->lock);
handleInfoPtr->flags |= CONSOLE_DATA_AWAITED;
WakeConditionVariable(&handleInfoPtr->consoleThreadCV);
ReleaseSRWLockExclusive(&handleInfoPtr->lock);
}
ReleaseSRWLockExclusive(&gConsoleLock);
}
Tcl_SetMaxBlockTime(&blockTime);
} else if (oldMask) {
/* Remove from list of watched channels */
AcquireSRWLockExclusive(&gConsoleLock);
for (nextPtrPtr = &gWatchingChannelList, ptr = *nextPtrPtr;
ptr != NULL;
nextPtrPtr = &ptr->nextWatchingChannelPtr, ptr = *nextPtrPtr) {
if (chanInfoPtr == ptr) {
*nextPtrPtr = ptr->nextWatchingChannelPtr;
break;
}
}
ReleaseSRWLockExclusive(&gConsoleLock);
}
}
/*
*----------------------------------------------------------------------
*
* ConsoleGetHandleProc --
*
* Called from Tcl_GetChannelHandle to retrieve OS handles from inside a
* command consoleline based channel.
*
* Results:
* Returns TCL_OK with the fd in handlePtr, or TCL_ERROR if there is no
* handle for the specified direction.
*
* Side effects:
* None.
*
*----------------------------------------------------------------------
*/
static int
ConsoleGetHandleProc(
void *instanceData, /* The console state. */
TCL_UNUSED(int) /*direction*/,
void **handlePtr) /* Where to store the handle. */
{
ConsoleChannelInfo *chanInfoPtr = (ConsoleChannelInfo *)instanceData;
if (chanInfoPtr->handle == INVALID_HANDLE_VALUE) {
return TCL_ERROR;
} else {
*handlePtr = chanInfoPtr->handle;
return TCL_OK;
}
}
/*
*------------------------------------------------------------------------
*
* ConsoleDataAvailable --
*
* Checks if there is data in the console input queue.
*
* Results:
* Returns 1 if the input queue has data, -1 on error else 0 if empty.
*
* Side effects:
* None.
*
*------------------------------------------------------------------------
*/
static int
ConsoleDataAvailable(
HANDLE consoleHandle)
{
INPUT_RECORD input[10];
DWORD count;
DWORD i;
/*
* Need at least one keyboard event.
*/
if (PeekConsoleInputW(consoleHandle, input,
sizeof(input) / sizeof(input[0]), &count) == FALSE) {
return -1;
}
/*
* Even if windows size and mouse events are disabled, can still have
* events other than keyboard, like focus events. Look for at least one
* keydown event because a trailing LF keyup is always present from the
* last input. However, if our buffer is full, assume there is a key
* down somewhere in the unread buffer. I suppose we could expand the
* buffer but not worth...
*/
if (count == (sizeof(input)/sizeof(input[0]))) {
return 1;
}
for (i = 0; i < count; ++i) {
if (input[i].EventType == KEY_EVENT
&& input[i].Event.KeyEvent.bKeyDown) {
return 1;
}
}
return 0;
}
/*
*----------------------------------------------------------------------
*
* ConsoleReaderThread --
*
* This function runs in a separate thread and waits for input to become
* available on a console.
*
* Results:
* Always 0.
*
* Side effects:
* Signals the main thread when input become available.
*
*----------------------------------------------------------------------
*/
static DWORD WINAPI
ConsoleReaderThread(
LPVOID arg)
{
ConsoleHandleInfo *handleInfoPtr = (ConsoleHandleInfo *) arg;
ConsoleHandleInfo **iterator;
Tcl_Size inputLen = 0;
Tcl_Size inputOffset = 0;
Tcl_Size lastReadSize = 0;
DWORD sleepTime;
char inputChars[INPUT_BUFFER_SIZE];
/*
* Keep looping until one of the following happens.
* - there are no more channels listening on the console
* - the console handle has been closed
*/
/* This thread is holding a reference so pointer is safe */
AcquireSRWLockExclusive(&handleInfoPtr->lock);
while (1) {
if (handleInfoPtr->numRefs == 1) {
/*
* Sole reference. That's this thread. Exit since no clients
* and no way for a thread to attach to a console after process
* start.
*/
break;
}
/*
* Shared buffer has no data. If we have some in our private buffer
* copy that. Else check if there has been an error. In both cases
* notify the interp threads.
*/
if (inputLen > 0 || handleInfoPtr->lastError != 0) {
HANDLE consoleHandle;
if (inputLen > 0) {
/* Private buffer has data. Copy it over. */
Tcl_Size nStored;
assert((inputLen - inputOffset) > 0);
nStored = RingBufferIn(&handleInfoPtr->buffer,
inputOffset + inputChars, inputLen - inputOffset,
1);
inputOffset += nStored;
if (inputOffset == inputLen) {
/* Temp buffer now empty */
inputOffset = 0;
inputLen = 0;
}
} else {
/*
* On error, nothing but inform caller and wait
* We do not want to exit until there are no client interps.
*/
}
/*
* Wake up any threads waiting either synchronously or
* asynchronously. Since we are providing data, turn off the
* AWAITED flag. If the data provided is not sufficient the
* clients will request again. Note we have to wake up ALL
* awaiting threads, not just one, so they can all reissue
* requests if needed. (In a properly designed app, at most one
* thread should be reading standard input but...)
*/
handleInfoPtr->flags &= ~CONSOLE_DATA_AWAITED;
/* Wake synchronous channels */
WakeAllConditionVariable(&handleInfoPtr->interpThreadCV);
/*
* Wake up async channels registered for file events. Note in
* order to follow the locking hierarchy, we need to release
* handleInfoPtr->lock before calling NudgeWatchers.
*/
consoleHandle = handleInfoPtr->console;
ReleaseSRWLockExclusive(&handleInfoPtr->lock);
NudgeWatchers(consoleHandle);
AcquireSRWLockExclusive(&handleInfoPtr->lock);
/*
* Loop back to recheck for exit conditions changes while the
* the lock was not held.
*/
continue;
}
assert(inputLen == 0);
/*
* Read more data in two cases:
* 1. The previous read filled the buffer and there could be more
* data in the console internal *text* buffer. Note
* ConsolePendingInput (checked in ConsoleDataAvailable) will NOT
* show this. It holds input events not yet translated to text.
* 2. Tcl threads want more data AND there is data in the
* ConsolePendingInput buffer. The latter check necessary because
* we do not want to read ahead because the interp thread might
* change the read mode, e.g. turning off echo for password
* input. So only do so if at least one interpreter has requested
* data.
*/
if (lastReadSize == sizeof(inputChars)
|| ((handleInfoPtr->flags & CONSOLE_DATA_AWAITED)
&& ConsoleDataAvailable(handleInfoPtr->console))) {
DWORD error;
/* Do not hold the lock while blocked in console */
ReleaseSRWLockExclusive(&handleInfoPtr->lock);
error = ReadConsoleChars(handleInfoPtr->console,
(WCHAR *)inputChars, sizeof(inputChars) / sizeof(WCHAR),
&inputLen);
AcquireSRWLockExclusive(&handleInfoPtr->lock);
if (error == 0) {
inputLen *= sizeof(WCHAR);
lastReadSize = inputLen;
} else {
/*
* We only store the last error. It is up to channel
* handlers whether to close or not in case of errors.
*/
lastReadSize = 0;
handleInfoPtr->lastError = error;
if (handleInfoPtr->lastError == ERROR_INVALID_HANDLE) {
handleInfoPtr->console = INVALID_HANDLE_VALUE;
}
}
} else {
/*
* Either no one was asking for data, or no data was available.
* In the former case, wait until someone wakes us asking for
* data. In the latter case, there is no alternative but to
* poll since ReadConsole does not support async operation.
* So sleep for a short while and loop back to retry.
*/
sleepTime =
handleInfoPtr->flags & CONSOLE_DATA_AWAITED ? 50 : INFINITE;
SleepConditionVariableSRW(&handleInfoPtr->consoleThreadCV,
&handleInfoPtr->lock, sleepTime, 0);
}
/* Loop again to check for exit or wait for readers to wake us */
}
/*
* Exiting:
* - remove the console from global list
* - close the handle if still valid
* - release the structure
* Note there is not need to check for any watchers because we only
* exit when there are no channels open to this console.
*/
ReleaseSRWLockExclusive(&handleInfoPtr->lock);
AcquireSRWLockExclusive(&gConsoleLock); /* Modifying - exclusive lock */
for (iterator = &gConsoleHandleInfoList; *iterator;
iterator = &(*iterator)->nextPtr) {
if (*iterator == handleInfoPtr) {
*iterator = handleInfoPtr->nextPtr;
break;
}
}
ReleaseSRWLockExclusive(&gConsoleLock);
/* No need for relocking - no other thread should have access to it now */
RingBufferClear(&handleInfoPtr->buffer);
if (handleInfoPtr->console != INVALID_HANDLE_VALUE
&& handleInfoPtr->lastError != ERROR_INVALID_HANDLE) {
SetConsoleMode(handleInfoPtr->console, handleInfoPtr->initMode);
/*
* NOTE: we do not call CloseHandle(handleInfoPtr->console) here.
* As per the GetStdHandle documentation, it need not be closed.
* Other components may be directly using it. Note however that
* an explicit chan close script command does close the handle
* for all threads.
*/
}
Tcl_Free(handleInfoPtr);
return 0;
}
/*
*----------------------------------------------------------------------
*
* ConsoleWriterThread --
*
* This function runs in a separate thread and writes data onto a
* console.
*
* Results:
* Always returns 0.
*
* Side effects:
* Signals the main thread when an output operation is completed.
*
*----------------------------------------------------------------------
*/
static DWORD WINAPI
ConsoleWriterThread(
LPVOID arg)
{
ConsoleHandleInfo *handleInfoPtr = (ConsoleHandleInfo *) arg;
ConsoleHandleInfo **iterator;
BOOL success;
Tcl_Size numBytes;
/*
* This buffer size has no relation really with the size of the shared
* buffer. Could be bigger or smaller. Make larger as multiple threads
* could potentially be writing to it.
*/
char buffer[2*CONSOLE_BUFFER_SIZE];
/*
* Keep looping until one of the following happens.
*
* - there are not more channels listening on the console
* - the console handle has been closed
*
* On each iteration,
* - if the channel buffer is empty, wait for some channel writer to write
* - if there is data in our buffer, write it to the console
*/
/* This thread is holding a reference so pointer is safe */
AcquireSRWLockExclusive(&handleInfoPtr->lock);
while (1) {
/* handleInfoPtr->lock must be held on entry to loop */
int offset;
HANDLE consoleHandle;
/*
* Sadly, we need to do another copy because do not want to hold
* a lock on handleInfoPtr->buffer while calling WriteConsole as that
* might block. Also, we only want to copy an integral number of
* WCHAR's, i.e. even number of chars so do some length checks up
* front.
*/
numBytes = RingBufferLength(&handleInfoPtr->buffer);
numBytes &= ~1; /* Copy integral number of WCHARs -> even number of bytes */
if (numBytes == 0) {
/* No data to write */
if (handleInfoPtr->numRefs == 1) {
/*
* Sole reference. That's this thread. Exit since no clients
* and no buffered output.
*/
break;
}
/* Wake up any threads waiting synchronously. */
WakeConditionVariable(&handleInfoPtr->interpThreadCV);
success = SleepConditionVariableSRW(&handleInfoPtr->consoleThreadCV,
&handleInfoPtr->lock, INFINITE, 0);
/* Note: lock has been acquired again! */
if (!success && GetLastError() != ERROR_TIMEOUT) {
/* TODO - what can be done? Should not happen */
/* For now keep going */
}
continue;
}
/* We have data to write */
if ((size_t)numBytes > (sizeof(buffer) / sizeof(buffer[0]))) {
numBytes = sizeof(buffer);
}
/* No need to check result, we already checked length bytes available */
RingBufferOut(&handleInfoPtr->buffer, buffer, numBytes, 0);
consoleHandle = handleInfoPtr->console;
WakeConditionVariable(&handleInfoPtr->interpThreadCV);
ReleaseSRWLockExclusive(&handleInfoPtr->lock);
offset = 0;
while (numBytes > 0) {
Tcl_Size numWChars = numBytes / sizeof(WCHAR);
DWORD status;
status = WriteConsoleChars(handleInfoPtr->console,
(WCHAR *)(offset + buffer), numWChars, &numWChars);
if (status != 0) {
/* Only overwrite if no previous error */
if (handleInfoPtr->lastError == 0) {
handleInfoPtr->lastError = status;
}
if (status == ERROR_INVALID_HANDLE) {
handleInfoPtr->console = INVALID_HANDLE_VALUE;
}
/* Assume this write is done but keep looping in case
* it is a transient error. Not sure just closing handle
* and exiting thread is a good idea until all references
* from interp threads are gone.
*/
break;
}
numBytes -= numWChars * sizeof(WCHAR);
offset += numWChars * sizeof(WCHAR);
}
/* Wake up any threads waiting synchronously. */
WakeConditionVariable(&handleInfoPtr->interpThreadCV);
/*
* Wake up all channels registered for file events. Note in
* order to follow the locking hierarchy, we cannot hold any locks
* when calling NudgeWatchers.
*/
NudgeWatchers(consoleHandle);
AcquireSRWLockExclusive(&handleInfoPtr->lock);
}
/*
* Exiting:
* - remove the console from global list
* - release the structure
* NOTE: we do not call CloseHandle(handleInfoPtr->console) here.
* As per the GetStdHandle documentation, it need not be closed.
* Other components may be directly using it. Note however that
* an explicit chan close script command does close the handle
* for all threads.
*/
ReleaseSRWLockExclusive(&handleInfoPtr->lock);
AcquireSRWLockExclusive(&gConsoleLock); /* Modifying - exclusive lock */
for (iterator = &gConsoleHandleInfoList; *iterator;
iterator = &(*iterator)->nextPtr) {
if (*iterator == handleInfoPtr) {
*iterator = handleInfoPtr->nextPtr;
break;
}
}
ReleaseSRWLockExclusive(&gConsoleLock);
RingBufferClear(&handleInfoPtr->buffer);
Tcl_Free(handleInfoPtr);
return 0;
}
/*
*------------------------------------------------------------------------
*
* AllocateConsoleHandleInfo --
*
* Allocates a ConsoleHandleInfo for the passed console handle. As
* a side effect starts a console thread to handle i/o on the handle.
*
* Important: Caller must be holding an EXCLUSIVE lock on gConsoleLock
* when calling this function. The lock continues to be held on return.
*
* Results:
* Pointer to an unlocked ConsoleHandleInfo structure. The reference
* count on the structure is 1. This corresponds to the common reference
* from the console thread and the gConsoleHandleInfoList. Returns NULL
* on error.
*
* Side effects:
* A console reader or writer thread is started. The returned structure
* is placed on the active console handler list gConsoleHandleInfoList.
*
*------------------------------------------------------------------------
*/
static ConsoleHandleInfo *
AllocateConsoleHandleInfo(
HANDLE consoleHandle,
int permissions) /* TCL_READABLE or TCL_WRITABLE */
{
ConsoleHandleInfo *handleInfoPtr;
DWORD consoleMode;
handleInfoPtr = (ConsoleHandleInfo *)Tcl_Alloc(sizeof(*handleInfoPtr));
memset(handleInfoPtr, 0, sizeof(*handleInfoPtr));
handleInfoPtr->console = consoleHandle;
InitializeSRWLock(&handleInfoPtr->lock);
InitializeConditionVariable(&handleInfoPtr->consoleThreadCV);
InitializeConditionVariable(&handleInfoPtr->interpThreadCV);
RingBufferInit(&handleInfoPtr->buffer, CONSOLE_BUFFER_SIZE);
handleInfoPtr->lastError = 0;
handleInfoPtr->permissions = permissions;
handleInfoPtr->numRefs = 1; /* See function header */
if (permissions == TCL_READABLE) {
GetConsoleMode(consoleHandle, &handleInfoPtr->initMode);
consoleMode = handleInfoPtr->initMode;
consoleMode &= ~(ENABLE_WINDOW_INPUT | ENABLE_MOUSE_INPUT);
consoleMode |= ENABLE_LINE_INPUT;
SetConsoleMode(consoleHandle, consoleMode);
}
handleInfoPtr->consoleThread = CreateThread(
NULL, /* default security descriptor */
2*CONSOLE_BUFFER_SIZE, /* Stack size - gets rounded up to granularity */
permissions == TCL_READABLE ? ConsoleReaderThread : ConsoleWriterThread,
handleInfoPtr, /* Pass to thread */
0, /* Flags - no special cases */
NULL); /* Don't care about thread id */
if (handleInfoPtr->consoleThread == NULL) {
/* Note - SRWLock and condition variables do not need finalization */
RingBufferClear(&handleInfoPtr->buffer);
Tcl_Free(handleInfoPtr);
return NULL;
}
/* Chain onto global list */
handleInfoPtr->nextPtr = gConsoleHandleInfoList;
gConsoleHandleInfoList = handleInfoPtr;
return handleInfoPtr;
}
/*
*------------------------------------------------------------------------
*
* FindConsoleInfo --
*
* Finds the ConsoleHandleInfo record for a given ConsoleChannelInfo.
* The found record must match the console handle. It is the caller's
* responsibility to check the permissions (read/write) in the returned
* ConsoleHandleInfo match permissions in chanInfoPtr. This function does
* not check that.
*
* Important: Caller must be holding an shared or exclusive lock on
* gConsoleMutex. That ensures the returned pointer stays valid on
* return without risk of deallocation by other threads.
*
* Results:
* Pointer to the found ConsoleHandleInfo or NULL if not found
*
* Side effects:
* None.
*
*------------------------------------------------------------------------
*/
static ConsoleHandleInfo *
FindConsoleInfo(const ConsoleChannelInfo *chanInfoPtr)
{
ConsoleHandleInfo *handleInfoPtr;
for (handleInfoPtr = gConsoleHandleInfoList; handleInfoPtr; handleInfoPtr = handleInfoPtr->nextPtr) {
if (handleInfoPtr->console == chanInfoPtr->handle) {
return handleInfoPtr;
}
}
return NULL;
}
/*
*----------------------------------------------------------------------
*
* TclWinOpenConsoleChannel --
*
* Constructs a Console channel for the specified standard OS handle.
* This is a helper function to break up the construction of channels
* into File, Console, or Serial.
*
* Results:
* Returns the new channel, or NULL.
*
* Side effects:
* May open the channel.
*
*----------------------------------------------------------------------
*/
Tcl_Channel
TclWinOpenConsoleChannel(
HANDLE handle,
char *channelName,
int permissions)
{
ConsoleChannelInfo *chanInfoPtr;
ConsoleHandleInfo *handleInfoPtr;
/* A console handle can either be input or output, not both */
if (permissions != TCL_READABLE && permissions != TCL_WRITABLE) {
return NULL;
}
ConsoleInit();
chanInfoPtr = (ConsoleChannelInfo *)Tcl_Alloc(sizeof(*chanInfoPtr));
memset(chanInfoPtr, 0, sizeof(*chanInfoPtr));
chanInfoPtr->permissions = permissions;
chanInfoPtr->handle = handle;
chanInfoPtr->channel = (Tcl_Channel) NULL;
chanInfoPtr->threadId = Tcl_GetCurrentThread();
/*
* Use the pointer for the name of the result channel. This keeps the
* channel names unique, since some may share handles (stdin/stdout/stderr
* for instance).
*/
TclWinGenerateChannelName(channelName, "file", chanInfoPtr);
if (permissions & TCL_READABLE) {
/*
* Make sure the console input buffer is ready for only character
* input notifications and the buffer is set for line buffering. IOW,
* we only want to catch when complete lines are ready for reading.
*/
chanInfoPtr->flags |= CONSOLE_READ_OPS;
GetConsoleMode(handle, &chanInfoPtr->initMode);
#ifdef OBSOLETE
/* Why was priority being set on console input? Code smell */
SetThreadPriority(infoPtr->reader.thread, THREAD_PRIORITY_HIGHEST);
#endif
} else {
/* Already checked permissions is WRITABLE if not READABLE */
/* TODO - enable ansi escape processing? */
}
/*
* Global lock but that's ok. See comments top of file. Allocations
* will happen only a few times in the life of a process and that too
* generally at start up where only one thread is active.
*/
AcquireSRWLockExclusive(&gConsoleLock); /*Allocate needs exclusive lock */
handleInfoPtr = FindConsoleInfo(chanInfoPtr);
if (handleInfoPtr == NULL) {
/* Not found. Allocate one */
handleInfoPtr = AllocateConsoleHandleInfo(handle, permissions);
} else {
/* Found. Its direction (read/write) better be the same */
if (handleInfoPtr->permissions != permissions) {
handleInfoPtr = NULL;
}
}
if (handleInfoPtr == NULL) {
ReleaseSRWLockExclusive(&gConsoleLock);
if (permissions == TCL_READABLE) {
SetConsoleMode(handle, chanInfoPtr->initMode);
}
Tcl_Free(chanInfoPtr);
return NULL;
}
/*
* There is effectively a reference to this structure from the Tcl
* channel subsystem. So record that. This reference will be dropped
* when the Tcl channel is closed.
*/
chanInfoPtr->numRefs = 1;
/*
* Need to keep track of number of referencing channels for closing.
* The pointer is safe since there is a reference held to it from
* gConsoleHandleInfoList but still need to lock the structure itself
*/
AcquireSRWLockExclusive(&handleInfoPtr->lock);
handleInfoPtr->numRefs += 1;
ReleaseSRWLockExclusive(&handleInfoPtr->lock);
ReleaseSRWLockExclusive(&gConsoleLock);
/* Note Tcl_CreateChannel never fails other than panic on error */
chanInfoPtr->channel = Tcl_CreateChannel(&consoleChannelType, channelName,
chanInfoPtr, permissions);
/*
* Consoles have default translation of auto and ^Z eof char, which means
* that a ^Z will be accepted as EOF when reading.
*/
Tcl_SetChannelOption(NULL, chanInfoPtr->channel, "-translation", "auto");
Tcl_SetChannelOption(NULL, chanInfoPtr->channel, "-encoding", "utf-16");
return chanInfoPtr->channel;
}
/*
*----------------------------------------------------------------------
*
* ConsoleThreadActionProc --
*
* Insert or remove any thread local refs to this channel.
*
* Results:
* None.
*
* Side effects:
* Changes thread local list of valid channels.
*
*----------------------------------------------------------------------
*/
static void
ConsoleThreadActionProc(
void *instanceData,
int action)
{
ConsoleChannelInfo *chanInfoPtr = (ConsoleChannelInfo *)instanceData;
/* No need for any locks as no other thread will be writing to it */
if (action == TCL_CHANNEL_THREAD_INSERT) {
ConsoleInit(); /* Needed to set up event source handlers for this thread */
chanInfoPtr->threadId = Tcl_GetCurrentThread();
} else {
chanInfoPtr->threadId = NULL;
}
}
/*
*----------------------------------------------------------------------
*
* ConsoleSetOptionProc --
*
* Sets an option on a channel.
*
* Results:
* A standard Tcl result. Also sets the interp's result on error if
* interp is not NULL.
*
* Side effects:
* May modify an option on a console. Sets Error message if needed (by
* calling Tcl_BadChannelOption).
*
*----------------------------------------------------------------------
*/
static int
ConsoleSetOptionProc(
void *instanceData, /* File state. */
Tcl_Interp *interp, /* For error reporting - can be NULL. */
const char *optionName, /* Which option to set? */
const char *value) /* New value for option. */
{
ConsoleChannelInfo *chanInfoPtr = (ConsoleChannelInfo *)instanceData;
int len = strlen(optionName);
int vlen = strlen(value);
/*
* Option -inputmode normal|password|raw
*/
if ((chanInfoPtr->flags & CONSOLE_READ_OPS) && (len > 1) &&
(strncmp(optionName, "-inputmode", len) == 0)) {
DWORD mode;
if (GetConsoleMode(chanInfoPtr->handle, &mode) == 0) {
Tcl_WinConvertError(GetLastError());
if (interp != NULL) {
Tcl_SetObjResult(interp, Tcl_ObjPrintf(
"couldn't read console mode: %s",
Tcl_PosixError(interp)));
}
return TCL_ERROR;
}
if (strncasecmp(value, "NORMAL", vlen) == 0) {
mode |=
ENABLE_ECHO_INPUT | ENABLE_LINE_INPUT | ENABLE_PROCESSED_INPUT;
} else if (strncasecmp(value, "PASSWORD", vlen) == 0) {
mode |= ENABLE_LINE_INPUT|ENABLE_PROCESSED_INPUT;
mode &= ~ENABLE_ECHO_INPUT;
} else if (strncasecmp(value, "RAW", vlen) == 0) {
mode &= ~(ENABLE_ECHO_INPUT | ENABLE_LINE_INPUT | ENABLE_PROCESSED_INPUT);
} else if (strncasecmp(value, "RESET", vlen) == 0) {
/*
* Reset to the initial mode, whatever that is.
*/
mode = chanInfoPtr->initMode;
} else {
if (interp) {
Tcl_SetObjResult(interp, Tcl_ObjPrintf(
"bad mode \"%s\" for -inputmode: must be"
" normal, password, raw, or reset", value));
Tcl_SetErrorCode(interp, "TCL", "OPERATION", "FCONFIGURE",
"VALUE", (char *)NULL);
}
return TCL_ERROR;
}
if (SetConsoleMode(chanInfoPtr->handle, mode) == 0) {
Tcl_WinConvertError(GetLastError());
if (interp != NULL) {
Tcl_SetObjResult(interp, Tcl_ObjPrintf(
"couldn't set console mode: %s",
Tcl_PosixError(interp)));
}
return TCL_ERROR;
}
return TCL_OK;
}
if (chanInfoPtr->flags & CONSOLE_READ_OPS) {
return Tcl_BadChannelOption(interp, optionName, "inputmode");
} else {
return Tcl_BadChannelOption(interp, optionName, "");
}
}
/*
*----------------------------------------------------------------------
*
* ConsoleGetOptionProc --
*
* Gets a mode associated with an IO channel. If the optionName arg is
* non-NULL, retrieves the value of that option. If the optionName arg is
* NULL, retrieves a list of alternating option names and values for the
* given channel.
*
* Results:
* A standard Tcl result. Also sets the supplied DString to the string
* value of the option(s) returned. Sets error message if needed
* (by calling Tcl_BadChannelOption).
*
*----------------------------------------------------------------------
*/
static int
ConsoleGetOptionProc(
void *instanceData, /* File state. */
Tcl_Interp *interp, /* For error reporting - can be NULL. */
const char *optionName, /* Option to get. */
Tcl_DString *dsPtr) /* Where to store value(s). */
{
ConsoleChannelInfo *chanInfoPtr = (ConsoleChannelInfo *)instanceData;
int valid = 0; /* Flag if valid option parsed. */
unsigned int len;
char buf[TCL_INTEGER_SPACE];
if (optionName == NULL) {
len = 0;
} else {
len = strlen(optionName);
}
/*
* Get option -inputmode
*
* This is a great simplification of the underlying reality, but actually
* represents what almost all scripts really want to know.
*/
if (chanInfoPtr->flags & CONSOLE_READ_OPS) {
if (len == 0) {
Tcl_DStringAppendElement(dsPtr, "-inputmode");
}
if (len==0 || (len>1 && strncmp(optionName, "-inputmode", len)==0)) {
DWORD mode;
valid = 1;
if (GetConsoleMode(chanInfoPtr->handle, &mode) == 0) {
Tcl_WinConvertError(GetLastError());
if (interp != NULL) {
Tcl_SetObjResult(interp, Tcl_ObjPrintf(
"couldn't read console mode: %s",
Tcl_PosixError(interp)));
}
return TCL_ERROR;
}
if (mode & ENABLE_LINE_INPUT) {
if (mode & ENABLE_ECHO_INPUT) {
Tcl_DStringAppendElement(dsPtr, "normal");
} else {
Tcl_DStringAppendElement(dsPtr, "password");
}
} else {
Tcl_DStringAppendElement(dsPtr, "raw");
}
}
} else {
/*
* Output channel. Get option -winsize
* Option is readonly and returned by [fconfigure chan -winsize] but not
* returned by [fconfigure chan] without explicit option name.
*/
if (len == 0) {
Tcl_DStringAppendElement(dsPtr, "-winsize");
}
if (len == 0 || (len > 1 && strncmp(optionName, "-winsize", len) == 0)) {
CONSOLE_SCREEN_BUFFER_INFO consoleInfo;
valid = 1;
if (!GetConsoleScreenBufferInfo(chanInfoPtr->handle,
&consoleInfo)) {
Tcl_WinConvertError(GetLastError());
if (interp != NULL) {
Tcl_SetObjResult(interp, Tcl_ObjPrintf(
"couldn't read console size: %s",
Tcl_PosixError(interp)));
}
return TCL_ERROR;
}
Tcl_DStringStartSublist(dsPtr);
snprintf(buf, sizeof(buf), "%d",
consoleInfo.srWindow.Right - consoleInfo.srWindow.Left + 1);
Tcl_DStringAppendElement(dsPtr, buf);
snprintf(buf, sizeof(buf), "%d",
consoleInfo.srWindow.Bottom - consoleInfo.srWindow.Top + 1);
Tcl_DStringAppendElement(dsPtr, buf);
Tcl_DStringEndSublist(dsPtr);
}
}
if (valid) {
return TCL_OK;
}
if (chanInfoPtr->flags & CONSOLE_READ_OPS) {
return Tcl_BadChannelOption(interp, optionName, "inputmode");
} else {
return Tcl_BadChannelOption(interp, optionName, "winsize");
}
}
/*
* Local Variables:
* mode: c
* c-basic-offset: 4
* fill-column: 78
* End:
*/