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Turn some defines into enums, plus other minor cleanup in the win con…
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…sole code
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@dkfellows
dkfellows committed Jan 24, 2025
1 parent 07c59c3 commit 3c0d563
Showing 1 changed file with 78 additions and 77 deletions.
155 changes: 78 additions & 77 deletions win/tclWinConsole.c
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Original file line number Diff line number Diff line change
Expand Up @@ -36,9 +36,9 @@
* 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.
* 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
Expand All @@ -58,7 +58,7 @@
*
* 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)
* 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.
Expand Down Expand Up @@ -94,14 +94,18 @@ static int gInitialized = 0;
* 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*/
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_))

#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
Expand All @@ -126,28 +130,34 @@ typedef struct RingBuffer {
*/
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.*/
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 */
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; /* State flags */
} ConsoleHandleInfo;

enum ConsoleHandleInfoFlags {
CONSOLE_DATA_AWAITED = 1 /* An interpreter is awaiting data */
};

/*
* This structure describes per-instance data for a console based channel.
*
Expand Down Expand Up @@ -190,11 +200,14 @@ typedef struct ConsoleChannelInfo {
* 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;

enum ConsoleChannelInfoFlags {
CONSOLE_EVENT_QUEUED = 1, /* Notification event already queued */
CONSOLE_ASYNC = 2, /* Channel is non-blocking. */
CONSOLE_READ_OPS = 4 /* Channel supports read-related ops. */
};

/*
* The following structure is what is added to the Tcl event queue when
* console events are generated.
Expand Down Expand Up @@ -424,7 +437,7 @@ RingBufferIn(
} else {
/* No room at the back. Existing data wrap to front. */
Tcl_Size wrapLen =
ringPtr->start + ringPtr->length - ringPtr->capacity;
ringPtr->start + ringPtr->length - ringPtr->capacity;
memmove(wrapLen + ringPtr->bufPtr, srcPtr, srcLen);
}

Expand Down Expand Up @@ -484,11 +497,8 @@ RingBufferOut(
} else {
Tcl_Size wrapLen = dstCapacity - leadLen;
if (dstPtr) {
memmove(dstPtr,
ringPtr->start + ringPtr->bufPtr,
leadLen);
memmove(
leadLen + dstPtr, ringPtr->bufPtr, wrapLen);
memmove(dstPtr, ringPtr->start + ringPtr->bufPtr, leadLen);
memmove(leadLen + dstPtr, ringPtr->bufPtr, wrapLen);
}
ringPtr->start = wrapLen;
}
Expand Down Expand Up @@ -539,7 +549,6 @@ ReadConsoleChars(
Tcl_Size *nCharsReadPtr)
{
DWORD nRead;
BOOL result;

/*
* If user types a Ctrl-Break or Ctrl-C, ReadConsole will return success
Expand All @@ -561,17 +570,15 @@ ReadConsoleChars(
* 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 {
if (!ReadConsoleW(hConsole, lpBuffer, nChars, &nRead, NULL)) {
return GetLastError();
}
if ((nRead == 0 || nRead == (DWORD)-1)
&& GetLastError() == ERROR_OPERATION_ABORTED) {
nRead = 0;
}
*nCharsReadPtr = nRead;
return 0;
}

/*
Expand Down Expand Up @@ -600,20 +607,17 @@ WriteConsoleChars(
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 {
if (!WriteConsoleW(hConsole, lpBuffer, nChars, &nCharsWritten, NULL)) {
return GetLastError();
}
if (nCharsWritten == (DWORD) -1) {
nCharsWritten = 0;
}
*nCharsWrittenPtr = nCharsWritten;
return 0;
}

/*
Expand Down Expand Up @@ -787,8 +791,7 @@ ConsoleSetupProc(

for (chanInfoPtr = gWatchingChannelList; block && chanInfoPtr != NULL;
chanInfoPtr = chanInfoPtr->nextWatchingChannelPtr) {
ConsoleHandleInfo *handleInfoPtr;
handleInfoPtr = FindConsoleInfo(chanInfoPtr);
ConsoleHandleInfo *handleInfoPtr = FindConsoleInfo(chanInfoPtr);
if (handleInfoPtr != NULL) {
AcquireSRWLockShared(&handleInfoPtr->lock);
/* Remember at most one of READABLE, WRITABLE set */
Expand Down Expand Up @@ -1562,10 +1565,9 @@ ConsoleGetHandleProc(

if (chanInfoPtr->handle == INVALID_HANDLE_VALUE) {
return TCL_ERROR;
} else {
*handlePtr = chanInfoPtr->handle;
return TCL_OK;
}
*handlePtr = chanInfoPtr->handle;
return TCL_OK;
}

/*
Expand All @@ -1583,8 +1585,8 @@ ConsoleGetHandleProc(
*
*------------------------------------------------------------------------
*/
static int
ConsoleDataAvailable(
static int
ConsoleDataAvailable(
HANDLE consoleHandle)
{
INPUT_RECORD input[10];
Expand Down Expand Up @@ -1617,7 +1619,7 @@ ConsoleGetHandleProc(
}
return 0;
}


/*
*----------------------------------------------------------------------
*
Expand All @@ -1634,7 +1636,6 @@ ConsoleGetHandleProc(
*
*----------------------------------------------------------------------
*/

static DWORD WINAPI
ConsoleReaderThread(
LPVOID arg)
Expand Down Expand Up @@ -1968,7 +1969,6 @@ ConsoleWriterThread(
ReleaseSRWLockExclusive(&gConsoleLock);

RingBufferClear(&handleInfoPtr->buffer);

Tcl_Free(handleInfoPtr);

return 0;
Expand Down Expand Up @@ -2023,12 +2023,12 @@ AllocateConsoleHandleInfo(
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 */
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);
Expand Down Expand Up @@ -2071,14 +2071,15 @@ FindConsoleInfo(
const ConsoleChannelInfo *chanInfoPtr)
{
ConsoleHandleInfo *handleInfoPtr;
for (handleInfoPtr = gConsoleHandleInfoList; handleInfoPtr; handleInfoPtr = handleInfoPtr->nextPtr) {
for (handleInfoPtr = gConsoleHandleInfoList; handleInfoPtr;
handleInfoPtr = handleInfoPtr->nextPtr) {
if (handleInfoPtr->console == chanInfoPtr->handle) {
return handleInfoPtr;
}
}
return NULL;
}


/*
*----------------------------------------------------------------------
*
Expand Down Expand Up @@ -2258,7 +2259,7 @@ ConsoleThreadActionProc(
*/
static int
ConsoleSetOptionProc(
void *instanceData, /* File state. */
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. */
Expand Down Expand Up @@ -2347,7 +2348,7 @@ ConsoleSetOptionProc(

static int
ConsoleGetOptionProc(
void *instanceData, /* File state. */
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). */
Expand Down

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