OpenFPGA/libs/EXTERNAL/tcl8.6.12/unix/tclUnixTime.c

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/*
* tclUnixTime.c --
*
* Contains Unix specific versions of Tcl functions that obtain time
* values from the operating system.
*
* Copyright (c) 1995 Sun Microsystems, Inc.
*
* See the file "license.terms" for information on usage and redistribution of
* this file, and for a DISCLAIMER OF ALL WARRANTIES.
*/
#include "tclInt.h"
#include <locale.h>
#if defined(TCL_WIDE_CLICKS) && defined(MAC_OSX_TCL)
#include <mach/mach_time.h>
#endif
/*
* TclpGetDate is coded to return a pointer to a 'struct tm'. For thread
* safety, this structure must be in thread-specific data. The 'tmKey'
* variable is the key to this buffer.
*/
static Tcl_ThreadDataKey tmKey;
typedef struct ThreadSpecificData {
struct tm gmtime_buf;
struct tm localtime_buf;
} ThreadSpecificData;
/*
* If we fall back on the thread-unsafe versions of gmtime and localtime, use
* this mutex to try to protect them.
*/
TCL_DECLARE_MUTEX(tmMutex)
static char *lastTZ = NULL; /* Holds the last setting of the TZ
* environment variable, or an empty string if
* the variable was not set. */
/*
* Static functions declared in this file.
*/
static void SetTZIfNecessary(void);
static void CleanupMemory(ClientData clientData);
static void NativeScaleTime(Tcl_Time *timebuf,
ClientData clientData);
static void NativeGetTime(Tcl_Time *timebuf,
ClientData clientData);
/*
* TIP #233 (Virtualized Time): Data for the time hooks, if any.
*/
Tcl_GetTimeProc *tclGetTimeProcPtr = NativeGetTime;
Tcl_ScaleTimeProc *tclScaleTimeProcPtr = NativeScaleTime;
ClientData tclTimeClientData = NULL;
/*
*----------------------------------------------------------------------
*
* TclpGetSeconds --
*
* This procedure returns the number of seconds from the epoch. On most
* Unix systems the epoch is Midnight Jan 1, 1970 GMT.
*
* Results:
* Number of seconds from the epoch.
*
* Side effects:
* None.
*
*----------------------------------------------------------------------
*/
unsigned long
TclpGetSeconds(void)
{
return time(NULL);
}
/*
*----------------------------------------------------------------------
*
* TclpGetMicroseconds --
*
* This procedure returns the number of microseconds from the epoch.
* On most Unix systems the epoch is Midnight Jan 1, 1970 GMT.
*
* Results:
* Number of microseconds from the epoch.
*
* Side effects:
* None.
*
*----------------------------------------------------------------------
*/
Tcl_WideInt
TclpGetMicroseconds(void)
{
Tcl_Time time;
tclGetTimeProcPtr(&time, tclTimeClientData);
return ((Tcl_WideInt)time.sec)*1000000 + time.usec;
}
/*
*----------------------------------------------------------------------
*
* TclpGetClicks --
*
* This procedure returns a value that represents the highest resolution
* clock available on the system. There are no garantees on what the
* resolution will be. In Tcl we will call this value a "click". The
* start time is also system dependent.
*
* Results:
* Number of clicks from some start time.
*
* Side effects:
* None.
*
*----------------------------------------------------------------------
*/
unsigned long
TclpGetClicks(void)
{
unsigned long now;
#ifdef NO_GETTOD
if (tclGetTimeProcPtr != NativeGetTime) {
Tcl_Time time;
tclGetTimeProcPtr(&time, tclTimeClientData);
now = time.sec*1000000 + time.usec;
} else {
/*
* A semi-NativeGetTime, specialized to clicks.
*/
struct tms dummy;
now = (unsigned long) times(&dummy);
}
#else
Tcl_Time time;
tclGetTimeProcPtr(&time, tclTimeClientData);
now = time.sec*1000000 + time.usec;
#endif
return now;
}
#ifdef TCL_WIDE_CLICKS
/*
*----------------------------------------------------------------------
*
* TclpGetWideClicks --
*
* This procedure returns a WideInt value that represents the highest
* resolution clock available on the system. There are no garantees on
* what the resolution will be. In Tcl we will call this value a "click".
* The start time is also system dependent.
*
* Results:
* Number of WideInt clicks from some start time.
*
* Side effects:
* None.
*
*----------------------------------------------------------------------
*/
Tcl_WideInt
TclpGetWideClicks(void)
{
Tcl_WideInt now;
if (tclGetTimeProcPtr != NativeGetTime) {
Tcl_Time time;
tclGetTimeProcPtr(&time, tclTimeClientData);
now = ((Tcl_WideInt)time.sec)*1000000 + time.usec;
} else {
#ifdef MAC_OSX_TCL
now = (Tcl_WideInt) (mach_absolute_time() & INT64_MAX);
#else
#error Wide high-resolution clicks not implemented on this platform
#endif
}
return now;
}
/*
*----------------------------------------------------------------------
*
* TclpWideClicksToNanoseconds --
*
* This procedure converts click values from the TclpGetWideClicks native
* resolution to nanosecond resolution.
*
* Results:
* Number of nanoseconds from some start time.
*
* Side effects:
* None.
*
*----------------------------------------------------------------------
*/
double
TclpWideClicksToNanoseconds(
Tcl_WideInt clicks)
{
double nsec;
if (tclGetTimeProcPtr != NativeGetTime) {
nsec = clicks * 1000;
} else {
#ifdef MAC_OSX_TCL
static mach_timebase_info_data_t tb;
static uint64_t maxClicksForUInt64;
if (!tb.denom) {
mach_timebase_info(&tb);
maxClicksForUInt64 = UINT64_MAX / tb.numer;
}
if ((uint64_t) clicks < maxClicksForUInt64) {
nsec = ((uint64_t) clicks) * tb.numer / tb.denom;
} else {
nsec = ((long double) (uint64_t) clicks) * tb.numer / tb.denom;
}
#else
#error Wide high-resolution clicks not implemented on this platform
#endif
}
return nsec;
}
/*
*----------------------------------------------------------------------
*
* TclpWideClickInMicrosec --
*
* This procedure return scale to convert click values from the
* TclpGetWideClicks native resolution to microsecond resolution
* and back.
*
* Results:
* 1 click in microseconds as double.
*
* Side effects:
* None.
*
*----------------------------------------------------------------------
*/
double
TclpWideClickInMicrosec(void)
{
if (tclGetTimeProcPtr != NativeGetTime) {
return 1.0;
} else {
#ifdef MAC_OSX_TCL
static int initialized = 0;
static double scale = 0.0;
if (initialized) {
return scale;
} else {
mach_timebase_info_data_t tb;
mach_timebase_info(&tb);
/* value of tb.numer / tb.denom = 1 click in nanoseconds */
scale = ((double)tb.numer) / tb.denom / 1000;
initialized = 1;
return scale;
}
#else
#error Wide high-resolution clicks not implemented on this platform
#endif
}
}
#endif /* TCL_WIDE_CLICKS */
/*
*----------------------------------------------------------------------
*
* Tcl_GetTime --
*
* Gets the current system time in seconds and microseconds since the
* beginning of the epoch: 00:00 UCT, January 1, 1970.
*
* This function is hooked, allowing users to specify their own virtual
* system time.
*
* Results:
* Returns the current time in timePtr.
*
* Side effects:
* None.
*
*----------------------------------------------------------------------
*/
void
Tcl_GetTime(
Tcl_Time *timePtr) /* Location to store time information. */
{
tclGetTimeProcPtr(timePtr, tclTimeClientData);
}
/*
*----------------------------------------------------------------------
*
* TclpGetDate --
*
* This function converts between seconds and struct tm. If useGMT is
* true, then the returned date will be in Greenwich Mean Time (GMT).
* Otherwise, it will be in the local time zone.
*
* Results:
* Returns a static tm structure.
*
* Side effects:
* None.
*
*----------------------------------------------------------------------
*/
struct tm *
TclpGetDate(
const time_t *time,
int useGMT)
{
if (useGMT) {
return TclpGmtime(time);
} else {
return TclpLocaltime(time);
}
}
/*
*----------------------------------------------------------------------
*
* TclpGmtime --
*
* Wrapper around the 'gmtime' library function to make it thread safe.
*
* Results:
* Returns a pointer to a 'struct tm' in thread-specific data.
*
* Side effects:
* Invokes gmtime or gmtime_r as appropriate.
*
*----------------------------------------------------------------------
*/
struct tm *
TclpGmtime(
const time_t *timePtr) /* Pointer to the number of seconds since the
* local system's epoch */
{
/*
* Get a thread-local buffer to hold the returned time.
*/
ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&tmKey);
#ifdef HAVE_GMTIME_R
gmtime_r(timePtr, &tsdPtr->gmtime_buf);
#else
Tcl_MutexLock(&tmMutex);
memcpy(&tsdPtr->gmtime_buf, gmtime(timePtr), sizeof(struct tm));
Tcl_MutexUnlock(&tmMutex);
#endif
return &tsdPtr->gmtime_buf;
}
/*
*----------------------------------------------------------------------
*
* TclpLocaltime --
*
* Wrapper around the 'localtime' library function to make it thread
* safe.
*
* Results:
* Returns a pointer to a 'struct tm' in thread-specific data.
*
* Side effects:
* Invokes localtime or localtime_r as appropriate.
*
*----------------------------------------------------------------------
*/
struct tm *
TclpLocaltime(
const time_t *timePtr) /* Pointer to the number of seconds since the
* local system's epoch */
{
/*
* Get a thread-local buffer to hold the returned time.
*/
ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&tmKey);
SetTZIfNecessary();
#ifdef HAVE_LOCALTIME_R
localtime_r(timePtr, &tsdPtr->localtime_buf);
#else
Tcl_MutexLock(&tmMutex);
memcpy(&tsdPtr->localtime_buf, localtime(timePtr), sizeof(struct tm));
Tcl_MutexUnlock(&tmMutex);
#endif
return &tsdPtr->localtime_buf;
}
/*
*----------------------------------------------------------------------
*
* Tcl_SetTimeProc --
*
* TIP #233 (Virtualized Time): Registers two handlers for the
* virtualization of Tcl's access to time information.
*
* Results:
* None.
*
* Side effects:
* Remembers the handlers, alters core behaviour.
*
*----------------------------------------------------------------------
*/
void
Tcl_SetTimeProc(
Tcl_GetTimeProc *getProc,
Tcl_ScaleTimeProc *scaleProc,
ClientData clientData)
{
tclGetTimeProcPtr = getProc;
tclScaleTimeProcPtr = scaleProc;
tclTimeClientData = clientData;
}
/*
*----------------------------------------------------------------------
*
* Tcl_QueryTimeProc --
*
* TIP #233 (Virtualized Time): Query which time handlers are registered.
*
* Results:
* None.
*
* Side effects:
* None.
*
*----------------------------------------------------------------------
*/
void
Tcl_QueryTimeProc(
Tcl_GetTimeProc **getProc,
Tcl_ScaleTimeProc **scaleProc,
ClientData *clientData)
{
if (getProc) {
*getProc = tclGetTimeProcPtr;
}
if (scaleProc) {
*scaleProc = tclScaleTimeProcPtr;
}
if (clientData) {
*clientData = tclTimeClientData;
}
}
/*
*----------------------------------------------------------------------
*
* NativeScaleTime --
*
* TIP #233: Scale from virtual time to the real-time. For native scaling
* the relationship is 1:1 and nothing has to be done.
*
* Results:
* Scales the time in timePtr.
*
* Side effects:
* See above.
*
*----------------------------------------------------------------------
*/
static void
NativeScaleTime(
Tcl_Time *timePtr,
ClientData clientData)
{
/* Native scale is 1:1. Nothing is done */
}
/*
*----------------------------------------------------------------------
*
* NativeGetTime --
*
* TIP #233: Gets the current system time in seconds and microseconds
* since the beginning of the epoch: 00:00 UCT, January 1, 1970.
*
* Results:
* Returns the current time in timePtr.
*
* Side effects:
* None.
*
*----------------------------------------------------------------------
*/
static void
NativeGetTime(
Tcl_Time *timePtr,
ClientData clientData)
{
struct timeval tv;
(void) gettimeofday(&tv, NULL);
timePtr->sec = tv.tv_sec;
timePtr->usec = tv.tv_usec;
}
/*
*----------------------------------------------------------------------
*
* SetTZIfNecessary --
*
* Determines whether a call to 'tzset' is needed prior to the next call
* to 'localtime' or examination of the 'timezone' variable.
*
* Results:
* None.
*
* Side effects:
* If 'tzset' has never been called in the current process, or if the
* value of the environment variable TZ has changed since the last call
* to 'tzset', then 'tzset' is called again.
*
*----------------------------------------------------------------------
*/
static void
SetTZIfNecessary(void)
{
const char *newTZ = getenv("TZ");
Tcl_MutexLock(&tmMutex);
if (newTZ == NULL) {
newTZ = "";
}
if (lastTZ == NULL || strcmp(lastTZ, newTZ)) {
tzset();
if (lastTZ == NULL) {
Tcl_CreateExitHandler(CleanupMemory, NULL);
} else {
ckfree(lastTZ);
}
lastTZ = ckalloc(strlen(newTZ) + 1);
strcpy(lastTZ, newTZ);
}
Tcl_MutexUnlock(&tmMutex);
}
/*
*----------------------------------------------------------------------
*
* CleanupMemory --
*
* Releases the private copy of the TZ environment variable upon exit
* from Tcl.
*
* Results:
* None.
*
* Side effects:
* Frees allocated memory.
*
*----------------------------------------------------------------------
*/
static void
CleanupMemory(
ClientData ignored)
{
ckfree(lastTZ);
}
/*
* Local Variables:
* mode: c
* c-basic-offset: 4
* fill-column: 78
* End:
*/