/*
* tclWinThread.c --
*
* This file implements the Windows-specific thread operations.
*
* Copyright © 1998 Sun Microsystems, Inc.
* Copyright © 1999 Scriptics Corporation
* Copyright © 2008 George Peter Staplin
*
* See the file "license.terms" for information on usage and redistribution of
* this file, and for a DISCLAIMER OF ALL WARRANTIES.
*/
#include "tclWinInt.h"
/* Workaround for mingw versions which don't provide this in float.h */
#ifndef _MCW_EM
# define _MCW_EM 0x0008001F /* Error masks */
# define _MCW_RC 0x00000300 /* Rounding */
# define _MCW_PC 0x00030000 /* Precision */
_CRTIMP unsigned int __cdecl _controlfp (unsigned int unNew, unsigned int unMask);
#endif
/*
* This is the global lock used to serialize access to other serialization
* data structures.
*/
static CRITICAL_SECTION globalLock;
static int initialized = 0;
/*
* This is the global lock used to serialize initialization and finalization
* of Tcl as a whole.
*/
static CRITICAL_SECTION initLock;
/*
* allocLock is used by Tcl's version of malloc for synchronization. For
* obvious reasons, cannot use any dynamically allocated storage.
*/
#if TCL_THREADS
/*
* Although CRITICAL_SECTIONs can be nested, we need to keep track
* of their lock counts for condition variables.
*/
typedef struct WMutex {
CRITICAL_SECTION crit;
volatile LONG thread;
int counter;
} WMutex;
static struct WMutex allocLock;
static WMutex *allocLockPtr = &allocLock;
static int allocOnce = 0;
#endif /* TCL_THREADS */
/*
* The joinLock serializes Create- and ExitThread. This is necessary to
* prevent a race where a new joinable thread exits before the creating thread
* had the time to create the necessary data structures in the emulation
* layer.
*/
static CRITICAL_SECTION joinLock;
/*
* Additions by AOL for specialized thread memory allocator.
*/
#ifdef USE_THREAD_ALLOC
static DWORD tlsKey;
typedef struct {
Tcl_Mutex tlock;
WMutex wm;
} allocMutex;
#endif /* USE_THREAD_ALLOC */
static void WMutexInit(WMutex *);
static void WMutexDestroy(WMutex *);
/*
* The per thread data passed from TclpThreadCreate
* to TclWinThreadStart.
*/
typedef struct {
LPTHREAD_START_ROUTINE lpStartAddress;
/* Original startup routine */
LPVOID lpParameter; /* Original startup data */
unsigned int fpControl; /* Floating point control word from the
* main thread */
} WinThread;
/*
*----------------------------------------------------------------------
*
* TclWinThreadStart --
*
* This procedure is the entry point for all new threads created
* by Tcl on Windows.
*
* Results:
* Various, depending on the result of the wrapped thread start
* routine.
*
* Side effects:
* Arbitrary, since user code is executed.
*
*----------------------------------------------------------------------
*/
static DWORD WINAPI
TclWinThreadStart(
LPVOID lpParameter) /* The WinThread structure pointer passed
* from TclpThreadCreate */
{
WinThread *winThreadPtr = (WinThread *) lpParameter;
LPTHREAD_START_ROUTINE lpOrigStartAddress;
LPVOID lpOrigParameter;
if (!winThreadPtr) {
return TCL_ERROR;
}
_controlfp(winThreadPtr->fpControl, _MCW_EM | _MCW_RC | 0x03000000 /* _MCW_DN */
#if !defined(_WIN64)
| _MCW_PC
#endif
);
lpOrigStartAddress = winThreadPtr->lpStartAddress;
lpOrigParameter = winThreadPtr->lpParameter;
Tcl_Free(winThreadPtr);
return lpOrigStartAddress(lpOrigParameter);
}
/*
*----------------------------------------------------------------------
*
* TclpThreadCreate --
*
* This procedure creates a new thread.
*
* Results:
* TCL_OK if the thread could be created. The thread ID is returned in a
* parameter.
*
* Side effects:
* A new thread is created.
*
*----------------------------------------------------------------------
*/
int
TclpThreadCreate(
Tcl_ThreadId *idPtr, /* Return, the ID of the thread. */
Tcl_ThreadCreateProc *proc, /* Main() function of the thread. */
void *clientData, /* The one argument to Main(). */
size_t stackSize, /* Size of stack for the new thread. */
int flags) /* Flags controlling behaviour of the new
* thread. */
{
WinThread *winThreadPtr; /* Per-thread startup info */
HANDLE tHandle;
winThreadPtr = (WinThread *)Tcl_Alloc(sizeof(WinThread));
winThreadPtr->lpStartAddress = (LPTHREAD_START_ROUTINE) proc;
winThreadPtr->lpParameter = clientData;
winThreadPtr->fpControl = _controlfp(0, 0);
EnterCriticalSection(&joinLock);
*idPtr = 0; /* must initialize as Tcl_Thread is a pointer and
* on WIN64 sizeof void* != sizeof unsigned */
#if defined(_MSC_VER) || defined(__MSVCRT__)
tHandle = (HANDLE) _beginthreadex(NULL, (unsigned)stackSize,
(Tcl_ThreadCreateProc*) TclWinThreadStart, winThreadPtr,
0, (unsigned *)idPtr);
#else
tHandle = CreateThread(NULL, (DWORD)stackSize,
TclWinThreadStart, winThreadPtr, 0, (LPDWORD)idPtr);
#endif
if (tHandle == NULL) {
LeaveCriticalSection(&joinLock);
return TCL_ERROR;
} else {
if (flags & TCL_THREAD_JOINABLE) {
TclRememberJoinableThread(*idPtr);
}
/*
* The only purpose of this is to decrement the reference count so the
* OS resources will be reacquired when the thread closes.
*/
CloseHandle(tHandle);
LeaveCriticalSection(&joinLock);
return TCL_OK;
}
}
/*
*----------------------------------------------------------------------
*
* Tcl_JoinThread --
*
* This procedure waits upon the exit of the specified thread.
*
* Results:
* TCL_OK if the wait was successful, TCL_ERROR else.
*
* Side effects:
* The result area is set to the exit code of the thread we
* waited upon.
*
*----------------------------------------------------------------------
*/
int
Tcl_JoinThread(
Tcl_ThreadId threadId, /* Id of the thread to wait upon */
int *result) /* Reference to the storage the result of the
* thread we wait upon will be written into. */
{
return TclJoinThread(threadId, result);
}
/*
*----------------------------------------------------------------------
*
* TclpThreadExit --
*
* This procedure terminates the current thread.
*
* Results:
* None.
*
* Side effects:
* This procedure terminates the current thread.
*
*----------------------------------------------------------------------
*/
TCL_NORETURN void
TclpThreadExit(
int status)
{
EnterCriticalSection(&joinLock);
TclSignalExitThread(Tcl_GetCurrentThread(), status);
LeaveCriticalSection(&joinLock);
#if defined(_MSC_VER) || defined(__MSVCRT__)
_endthreadex((unsigned) status);
#else
ExitThread((DWORD) status);
#endif
}
/*
*----------------------------------------------------------------------
*
* Tcl_GetCurrentThread --
*
* This procedure returns the ID of the currently running thread.
*
* Results:
* A thread ID.
*
* Side effects:
* None.
*
*----------------------------------------------------------------------
*/
Tcl_ThreadId
Tcl_GetCurrentThread(void)
{
return (Tcl_ThreadId)INT2PTR(GetCurrentThreadId());
}
/*
*----------------------------------------------------------------------
*
* TclpInitLock
*
* This procedure is used to grab a lock that serializes initialization
* and finalization of Tcl. On some platforms this may also initialize
* the mutex used to serialize creation of more mutexes and thread local
* storage keys.
*
* Results:
* None.
*
* Side effects:
* Acquire the initialization mutex.
*
*----------------------------------------------------------------------
*/
void
TclpInitLock(void)
{
if (!initialized) {
/*
* There is a fundamental race here that is solved by creating the
* first Tcl interpreter in a single threaded environment. Once the
* interpreter has been created, it is safe to create more threads
* that create interpreters in parallel.
*/
initialized = 1;
InitializeCriticalSection(&joinLock);
InitializeCriticalSection(&initLock);
InitializeCriticalSection(&globalLock);
}
EnterCriticalSection(&initLock);
}
/*
*----------------------------------------------------------------------
*
* TclpInitUnlock
*
* This procedure is used to release a lock that serializes
* initialization and finalization of Tcl.
*
* Results:
* None.
*
* Side effects:
* Release the initialization mutex.
*
*----------------------------------------------------------------------
*/
void
TclpInitUnlock(void)
{
LeaveCriticalSection(&initLock);
}
/*
*----------------------------------------------------------------------
*
* TclpGlobalLock
*
* This procedure is used to grab a lock that serializes creation of
* mutexes, condition variables, and thread local storage keys.
*
* This lock must be different than the initLock because the initLock is
* held during creation of synchronization objects.
*
* Results:
* None.
*
* Side effects:
* Acquire the global mutex.
*
*----------------------------------------------------------------------
*/
void
TclpGlobalLock(void)
{
if (!initialized) {
/*
* There is a fundamental race here that is solved by creating the
* first Tcl interpreter in a single threaded environment. Once the
* interpreter has been created, it is safe to create more threads
* that create interpreters in parallel.
*/
initialized = 1;
InitializeCriticalSection(&joinLock);
InitializeCriticalSection(&initLock);
InitializeCriticalSection(&globalLock);
}
EnterCriticalSection(&globalLock);
}
/*
*----------------------------------------------------------------------
*
* TclpGlobalUnlock
*
* This procedure is used to release a lock that serializes creation and
* deletion of synchronization objects.
*
* Results:
* None.
*
* Side effects:
* Release the global mutex.
*
*----------------------------------------------------------------------
*/
void
TclpGlobalUnlock(void)
{
LeaveCriticalSection(&globalLock);
}
/*
*----------------------------------------------------------------------
*
* Tcl_GetAllocMutex
*
* This procedure returns a pointer to a statically initialized mutex for
* use by the memory allocator. The allocator must use this lock, because
* all other locks are allocated...
*
* Results:
* A pointer to a mutex that is suitable for passing to Tcl_MutexLock and
* Tcl_MutexUnlock.
*
* Side effects:
* None.
*
*----------------------------------------------------------------------
*/
Tcl_Mutex *
Tcl_GetAllocMutex(void)
{
#if TCL_THREADS
if (!allocOnce) {
WMutexInit(&allocLock);
allocOnce = 1;
}
return (Tcl_Mutex *) &allocLockPtr;
#else
return NULL;
#endif
}
/*
*----------------------------------------------------------------------
*
* TclFinalizeLock
*
* This procedure is used to destroy all private resources used in this
* file.
*
* Results:
* None.
*
* Side effects:
* Destroys everything private. TclpInitLock must be held entering this
* function.
*
*----------------------------------------------------------------------
*/
void
TclFinalizeLock(void)
{
TclpGlobalLock();
DeleteCriticalSection(&joinLock);
/*
* Destroy the critical section that we are holding!
*/
DeleteCriticalSection(&globalLock);
initialized = 0;
#if TCL_THREADS
if (allocOnce) {
WMutexDestroy(&allocLock);
allocOnce = 0;
}
#endif
LeaveCriticalSection(&initLock);
/*
* Destroy the critical section that we were holding.
*/
DeleteCriticalSection(&initLock);
}
#if TCL_THREADS
static void
WMutexInit(
WMutex *wmPtr)
{
wmPtr->thread = 0;
wmPtr->counter = 0;
InitializeCriticalSection(&wmPtr->crit);
}
static void
WMutexDestroy(
WMutex *wmPtr)
{
DeleteCriticalSection(&wmPtr->crit);
assert(wmPtr->thread == 0 && wmPtr->counter == 0);
}
static void
WMutexLock(
WMutex *wmPtr)
{
LONG mythread = GetCurrentThreadId();
if (wmPtr->thread == mythread) {
// We owned the lock already, so it's recursive.
wmPtr->counter++;
} else {
// We don't own the lock, so we can safely lock it. Then we own it.
EnterCriticalSection(&wmPtr->crit);
wmPtr->thread = mythread;
}
}
static void
WMutexUnlock(
WMutex *wmPtr)
{
assert(wmPtr->thread == GetCurrentThreadId());
if (wmPtr->counter) {
// It's recursive
wmPtr->counter--;
} else {
wmPtr->thread = 0;
LeaveCriticalSection(&wmPtr->crit);
}
}
/* locally used prototype */
static void FinalizeConditionEvent(void *data);
/*
*----------------------------------------------------------------------
*
* Tcl_MutexLock --
*
* This procedure is invoked to lock a mutex. This is a self initializing
* mutex that is automatically finalized during Tcl_Finalize.
*
* Results:
* None.
*
* Side effects:
* May block the current thread. The mutex is acquired when this returns.
*
*----------------------------------------------------------------------
*/
void
Tcl_MutexLock(
Tcl_Mutex *mutexPtr) /* Really (WMutex **) */
{
WMutex *wmPtr;
if (*mutexPtr == NULL) {
TclpGlobalLock();
/*
* Double inside global lock check to avoid a race.
*/
if (*mutexPtr == NULL) {
wmPtr = (WMutex *) Tcl_Alloc(sizeof(WMutex));
WMutexInit(wmPtr);
*mutexPtr = (Tcl_Mutex) wmPtr;
TclRememberMutex(mutexPtr);
}
TclpGlobalUnlock();
}
wmPtr = *((WMutex **)mutexPtr);
WMutexLock(wmPtr);
}
/*
*----------------------------------------------------------------------
*
* Tcl_MutexUnlock --
*
* This procedure is invoked to unlock a mutex.
*
* Results:
* None.
*
* Side effects:
* The mutex is released when this returns.
*
*----------------------------------------------------------------------
*/
void
Tcl_MutexUnlock(
Tcl_Mutex *mutexPtr) /* Really (WMutex **) */
{
WMutex *wmPtr = *((WMutex **)mutexPtr);
WMutexUnlock(wmPtr);
}
/*
*----------------------------------------------------------------------
*
* TclpFinalizeMutex --
*
* This procedure is invoked to clean up one mutex. This is only safe to
* call at the end of time.
*
* Results:
* None.
*
* Side effects:
* The mutex list is deallocated.
*
*----------------------------------------------------------------------
*/
void
TclpFinalizeMutex(
Tcl_Mutex *mutexPtr) /* Really (WMutex **) */
{
WMutex *wmPtr = *(WMutex **)mutexPtr;
if (wmPtr != NULL) {
WMutexDestroy(wmPtr);
Tcl_Free(wmPtr);
*mutexPtr = NULL;
}
}
/*
*----------------------------------------------------------------------
*
* Tcl_ConditionWait --
*
* This procedure is invoked to wait on a condition variable. The mutex
* is atomically released as part of the wait, and automatically grabbed
* when the condition is signaled.
*
* The mutex must be held when this procedure is called.
*
* Results:
* None.
*
* Side effects:
* May block the current thread. The mutex is acquired when this returns.
* Will allocate memory for a CONDITION_VARIABLE and initialize the first
* time this Tcl_Condition is used.
*
*----------------------------------------------------------------------
*/
void
Tcl_ConditionWait(
Tcl_Condition *condPtr, /* Really (WinCondition **) */
Tcl_Mutex *mutexPtr, /* Really (CRITICAL_SECTION **) */
const Tcl_Time *timePtr) /* Timeout on waiting period */
{
CONDITION_VARIABLE *cvPtr; /* Per-condition queue head */
WMutex *wmPtr; /* Caller's Mutex, after casting */
DWORD wtime; /* Windows time value */
if (timePtr == NULL) {
wtime = INFINITE;
} else {
wtime = (DWORD)timePtr->sec * 1000 + (DWORD)timePtr->usec / 1000;
}
if (*condPtr == NULL) {
TclpGlobalLock();
if (*condPtr == NULL) {
cvPtr = (CONDITION_VARIABLE *)Tcl_Alloc(sizeof(*cvPtr));
InitializeConditionVariable(cvPtr);
*condPtr = (Tcl_Condition) cvPtr;
TclRememberCondition(condPtr);
}
TclpGlobalUnlock();
}
wmPtr = *((WMutex **)mutexPtr);
cvPtr = *((CONDITION_VARIABLE **)condPtr);
int counter = wmPtr->counter;
wmPtr->counter = 0;
LONG mythread = GetCurrentThreadId();
assert(wmPtr->thread == mythread);
wmPtr->thread = 0;
if (SleepConditionVariableCS(cvPtr,
&wmPtr->crit, wtime) == 0) {
DWORD err = GetLastError();
if (err != ERROR_TIMEOUT) {
Tcl_Panic(
"Tcl_ConditionWait: SleepConditionVariableCS error %d",
err);
}
}
wmPtr->counter = counter;
wmPtr->thread = mythread;
}
/*
*----------------------------------------------------------------------
*
* Tcl_ConditionNotify --
*
* This procedure is invoked to signal a condition variable.
*
* The mutex must be held during this call to avoid races, but this
* interface does not enforce that.
*
* Results:
* None.
*
* Side effects:
* May unblock another thread.
*
*----------------------------------------------------------------------
*/
void
Tcl_ConditionNotify(
Tcl_Condition *condPtr)
{
CONDITION_VARIABLE *cvPtr;
/* If uninitialized, no could be waiting on the condition variable */
if (*condPtr != NULL) {
cvPtr = *((CONDITION_VARIABLE **)condPtr);
if (cvPtr) {
WakeAllConditionVariable(cvPtr);
}
}
}
/*
*----------------------------------------------------------------------
*
* TclpFinalizeCondition --
*
* This procedure is invoked to clean up a condition variable. This is
* only safe to call at the end of time.
*
* This assumes the Global Lock is held.
*
* Results:
* None.
*
* Side effects:
* The condition variable is deallocated.
*
*----------------------------------------------------------------------
*/
void
TclpFinalizeCondition(
Tcl_Condition *condPtr)
{
CONDITION_VARIABLE *cvPtr = *(CONDITION_VARIABLE **)condPtr;
if (cvPtr) {
Tcl_Free(cvPtr);
*condPtr = NULL;
}
}
/*
* Additions by AOL for specialized thread memory allocator.
*/
#ifdef USE_THREAD_ALLOC
Tcl_Mutex *
TclpNewAllocMutex(void)
{
allocMutex *lockPtr;
lockPtr = (allocMutex *)malloc(sizeof(allocMutex));
if (lockPtr == NULL) {
Tcl_Panic("could not allocate lock");
}
lockPtr->tlock = (Tcl_Mutex)&lockPtr->wm;
WMutexInit(&lockPtr->wm);
return &lockPtr->tlock;
}
void
TclpFreeAllocMutex(
Tcl_Mutex *mutex) /* The alloc mutex to free. */
{
allocMutex *lockPtr = (allocMutex *) mutex;
if (!lockPtr || !lockPtr->tlock) {
return;
}
lockPtr->tlock = NULL;
WMutexDestroy(&lockPtr->wm);
free(lockPtr);
}
void
TclpInitAllocCache(void)
{
/*
* We need to make sure that TclpFreeAllocCache is called on each
* thread that calls this, but only on threads that call this.
*/
tlsKey = TlsAlloc();
if (tlsKey == TLS_OUT_OF_INDEXES) {
Tcl_Panic("could not allocate thread local storage");
}
}
void *
TclpGetAllocCache(void)
{
void *result;
result = TlsGetValue(tlsKey);
if ((result == NULL) && (GetLastError() != NO_ERROR)) {
Tcl_Panic("TlsGetValue failed from TclpGetAllocCache");
}
return result;
}
void
TclpSetAllocCache(
void *ptr)
{
BOOL success;
success = TlsSetValue(tlsKey, ptr);
if (!success) {
Tcl_Panic("TlsSetValue failed from TclpSetAllocCache");
}
}
void
TclpFreeAllocCache(
void *ptr)
{
BOOL success;
if (ptr != NULL) {
/*
* Called by TclFinalizeThreadAlloc() and
* TclFinalizeThreadAllocThread() during Tcl_Finalize() or
* Tcl_FinalizeThread(). This function destroys the tsd key which
* stores allocator caches in thread local storage.
*/
TclFreeAllocCache(ptr);
success = TlsSetValue(tlsKey, NULL);
if (!success) {
Tcl_Panic("TlsSetValue failed from TclpFreeAllocCache");
}
} else {
/*
* Called by us in TclFinalizeThreadAlloc() during the library
* finalization initiated from Tcl_Finalize()
*/
success = TlsFree(tlsKey);
if (!success) {
Tcl_Panic("TlsFree failed from TclpFreeAllocCache");
}
}
}
#endif /* USE_THREAD_ALLOC */
void *
TclpThreadCreateKey(void)
{
DWORD *key;
key = (DWORD *)TclpSysAlloc(sizeof *key);
if (key == NULL) {
Tcl_Panic("unable to allocate thread key!");
}
*key = TlsAlloc();
if (*key == TLS_OUT_OF_INDEXES) {
Tcl_Panic("unable to allocate thread-local storage");
}
return key;
}
void
TclpThreadDeleteKey(
void *keyPtr)
{
DWORD *key = (DWORD *)keyPtr;
if (!TlsFree(*key)) {
Tcl_Panic("unable to delete key");
}
TclpSysFree(keyPtr);
}
void
TclpThreadSetGlobalTSD(
void *tsdKeyPtr,
void *ptr)
{
DWORD *key = (DWORD *)tsdKeyPtr;
if (!TlsSetValue(*key, ptr)) {
Tcl_Panic("unable to set global TSD value");
}
}
void *
TclpThreadGetGlobalTSD(
void *tsdKeyPtr)
{
DWORD *key = (DWORD *)tsdKeyPtr;
return TlsGetValue(*key);
}
#endif /* TCL_THREADS */
/*
* Local Variables:
* mode: c
* c-basic-offset: 4
* fill-column: 78
* End:
*/