lltimer.cpp

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#include "linden_common.h"

#include "lltimer.h"

#include "u64.h"

#if LL_WINDOWS
#       define WIN32_LEAN_AND_MEAN
#       include <winsock2.h>
#       include <windows.h>
#elif LL_LINUX || LL_SOLARIS || LL_DARWIN
#       include <errno.h>
#       include <sys/time.h>
#else 
#       error "architecture not supported"
#endif


//
// Locally used constants
//
const U32 SEC_PER_DAY = 86400;
const F64 SEC_TO_MICROSEC = 1000000.f;
const U64 SEC_TO_MICROSEC_U64 = 1000000;
const F64 USEC_TO_SEC_F64 = 0.000001;


//---------------------------------------------------------------------------
// Globals and statics
//---------------------------------------------------------------------------

S32 gUTCOffset = 0; // viewer's offset from server UTC, in seconds
LLTimer* LLTimer::sTimer = NULL;

F64 gClockFrequency = 0.0;
F64 gClockFrequencyInv = 0.0;
F64 gClocksToMicroseconds = 0.0;
U64 gTotalTimeClockCount = 0;
U64 gLastTotalTimeClockCount = 0;

//
// Forward declarations
//


//---------------------------------------------------------------------------
// Implementation
//---------------------------------------------------------------------------

#if LL_WINDOWS
void ms_sleep(U32 ms)
{
        Sleep(ms);
}
#elif LL_LINUX || LL_SOLARIS || LL_DARWIN
void ms_sleep(U32 ms)
{
        long mslong = ms; // tv_nsec is a long
        struct timespec thiswait, nextwait;
        bool sleep_more = false;

        thiswait.tv_sec = ms / 1000;
        thiswait.tv_nsec = (mslong % 1000) * 1000000l;
        do {
                int result = nanosleep(&thiswait, &nextwait);

                // check if sleep was interrupted by a signal; unslept
                // remainder was written back into 't' and we just nanosleep
                // again.
                sleep_more = (result == -1 && EINTR == errno);

                if (sleep_more)
                {
                        if ( nextwait.tv_sec > thiswait.tv_sec ||
                             (nextwait.tv_sec == thiswait.tv_sec &&
                              nextwait.tv_nsec >= thiswait.tv_nsec) )
                        {
                                // if the remaining time isn't actually going
                                // down then we're being shafted by low clock
                                // resolution - manually massage the sleep time
                                // downward.
                                if (nextwait.tv_nsec > 1000000) {
                                        // lose 1ms
                                        nextwait.tv_nsec -= 1000000;
                                } else {
                                        if (nextwait.tv_sec == 0) {
                                                // already so close to finished
                                                sleep_more = false;
                                        } else {
                                                // lose up to 1ms
                                                nextwait.tv_nsec = 0;
                                        }
                                }
                        }
                        thiswait = nextwait;
                }
        } while (sleep_more);
}
#else
# error "architecture not supported"
#endif

//
// CPU clock/other clock frequency and count functions
//

#if LL_WINDOWS
U64 get_clock_count()
{
        static bool firstTime = true;
        static U64 offset;
                // ensures that callers to this function never have to deal with wrap

        // QueryPerformanceCounter implementation
        LARGE_INTEGER clock_count;
        QueryPerformanceCounter(&clock_count);
        if (firstTime) {
                offset = clock_count.QuadPart;
                firstTime = false;
        }
        return clock_count.QuadPart - offset;
}

F64 calc_clock_frequency(U32 uiMeasureMSecs)
{
        __int64 freq;
        QueryPerformanceFrequency((LARGE_INTEGER *) &freq);
        return (F64)freq;
}
#endif // LL_WINDOWS


#if LL_LINUX || LL_DARWIN || LL_SOLARIS
// Both Linux and Mac use gettimeofday for accurate time
F64 calc_clock_frequency(unsigned int uiMeasureMSecs)
{
        return 1000000.0; // microseconds, so 1 Mhz.
}

U64 get_clock_count()
{
        // Linux clocks are in microseconds
        struct timeval tv;
        gettimeofday(&tv, NULL);
        return tv.tv_sec*SEC_TO_MICROSEC_U64 + tv.tv_usec;
}
#endif


void update_clock_frequencies()
{
        gClockFrequency = calc_clock_frequency(50U);
        gClockFrequencyInv = 1.0/gClockFrequency;
        gClocksToMicroseconds = gClockFrequencyInv * SEC_TO_MICROSEC;
}



// returns a U64 number that represents the number of 
// microseconds since the unix epoch - Jan 1, 1970
U64 totalTime()
{
        U64 current_clock_count = get_clock_count();
        if (!gTotalTimeClockCount)
        {
                update_clock_frequencies();
                gTotalTimeClockCount = current_clock_count;

#if LL_WINDOWS
                // Synch us up with local time (even though we PROBABLY don't need to, this is how it was implemented)
                // Unix platforms use gettimeofday so they are synced, although this probably isn't a good assumption to
                // make in the future.

                gTotalTimeClockCount = (U64)(time(NULL) * gClockFrequency);
#endif

                // Update the last clock count
                gLastTotalTimeClockCount = current_clock_count;
        }
        else
        {
                if (current_clock_count >= gLastTotalTimeClockCount)
                {
                        // No wrapping, we're all okay.
                        gTotalTimeClockCount += current_clock_count - gLastTotalTimeClockCount;
                }
                else
                {
                        // We've wrapped.  Compensate correctly
                        gTotalTimeClockCount += (0xFFFFFFFFFFFFFFFFULL - gLastTotalTimeClockCount) + current_clock_count;
                }

                // Update the last clock count
                gLastTotalTimeClockCount = current_clock_count;
        }

        // Return the total clock tick count in microseconds.
        return (U64)(gTotalTimeClockCount*gClocksToMicroseconds);
}



LLTimer::LLTimer()
{
        if (!gClockFrequency)
        {
                update_clock_frequencies();
        }

        mStarted = TRUE;
        reset();
}

LLTimer::~LLTimer()
{
}

// static
U64 LLTimer::getTotalTime()
{
        // simply call into the implementation function.
        return totalTime();
}       

// static
F64 LLTimer::getTotalSeconds()
{
        return U64_to_F64(getTotalTime()) * USEC_TO_SEC_F64;
}

void LLTimer::reset()
{
        mLastClockCount = get_clock_count();
        mExpirationTicks = 0;
}


U64 LLTimer::getCurrentClockCount()
{
        return get_clock_count();
}


void LLTimer::setLastClockCount(U64 current_count)
{
        mLastClockCount = current_count;
}


static
U64 getElapsedTimeAndUpdate(U64& lastClockCount)
{
        U64 current_clock_count = get_clock_count();
        U64 result;

        if (current_clock_count >= lastClockCount)
        {
                result = current_clock_count - lastClockCount;
        }
        else
        {
                // time has gone backward
                result = 0;
        }

        lastClockCount = current_clock_count;

        return result;
}


F64 LLTimer::getElapsedTimeF64() const
{
        U64 last = mLastClockCount;
        return (F64)getElapsedTimeAndUpdate(last) * gClockFrequencyInv;
}

F32 LLTimer::getElapsedTimeF32() const
{
        return (F32)getElapsedTimeF64();
}

F64 LLTimer::getElapsedTimeAndResetF64()
{
        return (F64)getElapsedTimeAndUpdate(mLastClockCount) * gClockFrequencyInv;
}

F32 LLTimer::getElapsedTimeAndResetF32()
{
        return (F32)getElapsedTimeAndResetF64();
}


void  LLTimer::setTimerExpirySec(F32 expiration)
{
        mExpirationTicks = get_clock_count()
                + (U64)((F32)(expiration * gClockFrequency));
}

F32 LLTimer::getRemainingTimeF32() const
{
        U64 cur_ticks = get_clock_count();
        if (cur_ticks > mExpirationTicks)
        {
                return 0.0f;
        }
        return F32((mExpirationTicks - cur_ticks) * gClockFrequencyInv);
}


BOOL  LLTimer::checkExpirationAndReset(F32 expiration)
{
        U64 cur_ticks = get_clock_count();
        if (cur_ticks < mExpirationTicks)
        {
                return FALSE;
        }

        mExpirationTicks = cur_ticks
                + (U64)((F32)(expiration * gClockFrequency));
        return TRUE;
}


BOOL  LLTimer::hasExpired() const
{
        return (get_clock_count() >= mExpirationTicks)
                ? TRUE : FALSE;
}


BOOL LLTimer::knownBadTimer()
{
        BOOL failed = FALSE;

#if LL_WINDOWS
        WCHAR bad_pci_list[][10] = {L"1039:0530",
                                                        L"1039:0620",
                                                            L"10B9:0533",
                                                            L"10B9:1533",
                                                            L"1106:0596",
                                                            L"1106:0686",
                                                            L"1166:004F",
                                                            L"1166:0050",
                                                            L"8086:7110",
                                                            L"\0"
        };

        HKEY hKey = NULL;
        LONG nResult = ::RegOpenKeyEx(HKEY_LOCAL_MACHINE,L"SYSTEM\\CurrentControlSet\\Enum\\PCI", 0,
                                                                  KEY_EXECUTE | KEY_QUERY_VALUE | KEY_ENUMERATE_SUB_KEYS, &hKey);
        
        WCHAR name[1024];
        DWORD name_len = 1024;
        FILETIME scrap;

        S32 key_num = 0;
        WCHAR pci_id[10];

        wcscpy(pci_id, L"0000:0000");    /*Flawfinder: ignore*/

        while (nResult == ERROR_SUCCESS)
        {
                nResult = ::RegEnumKeyEx(hKey, key_num++, name, &name_len, NULL, NULL, NULL, &scrap);

                if (nResult == ERROR_SUCCESS)
                {
                        memcpy(&pci_id[0],&name[4],4);          /* Flawfinder: ignore */
                        memcpy(&pci_id[5],&name[13],4);         /* Flawfinder: ignore */

                        for (S32 check = 0; bad_pci_list[check][0]; check++)
                        {
                                if (!wcscmp(pci_id, bad_pci_list[check]))
                                {
//                                      llwarns << "unreliable PCI chipset found!! " << pci_id << endl;
                                        failed = TRUE;
                                        break;
                                }
                        }
//                      llinfo << "PCI chipset found: " << pci_id << endl;
                        name_len = 1024;
                }
        }
#endif
        return(failed);
}

// 
// NON-MEMBER FUNCTIONS
//

U32 time_corrected()
{
        U32 corrected_time = (U32)time(NULL) + gUTCOffset;
        return corrected_time;
}


// Is the current computer (in its current time zone)
// observing daylight savings time?
BOOL is_daylight_savings()
{
        time_t now = time(NULL);

        // Internal buffer to local server time
        struct tm* internal_time = localtime(&now);

        // tm_isdst > 0  =>  daylight savings
        // tm_isdst = 0  =>  not daylight savings
        // tm_isdst < 0  =>  can't tell
        return (internal_time->tm_isdst > 0);
}


struct tm* utc_to_pacific_time(S32 utc_time, BOOL pacific_daylight_time)
{
        time_t unix_time = (time_t)utc_time;

        S32 pacific_offset_hours;
        if (pacific_daylight_time)
        {
                pacific_offset_hours = -7;
        }
        else
        {
                pacific_offset_hours = -8;
        }

        // We subtract off the PST/PDT offset _before_ getting
        // "UTC" time, because this will handle wrapping around
        // for 5 AM UTC -> 10 PM PDT of the previous day.
        unix_time += pacific_offset_hours * MIN_PER_HOUR * SEC_PER_MIN;
 
        // Internal buffer to PST/PDT (see above)
        struct tm* internal_time = gmtime(&unix_time);

        /*
        // Don't do this, this won't correctly tell you if daylight savings is active in CA or not.
        if (pacific_daylight_time)
        {
                internal_time->tm_isdst = 1;
        }
        */

        return internal_time;
}


void microsecondsToTimecodeString(U64 current_time, char *tcstring)
{
        U64 hours;
        U64 minutes;
        U64 seconds;
        U64 frames;
        U64 subframes;

        hours = current_time / (U64)3600000000ul;
        minutes = current_time / (U64)60000000;
        minutes %= 60;
        seconds = current_time / (U64)1000000;
        seconds %= 60;
        frames = current_time / (U64)41667;
        frames %= 24;
        subframes = current_time / (U64)42;
        subframes %= 100;

        sprintf(tcstring,"%3.3d:%2.2d:%2.2d:%2.2d.%2.2d",(int)hours,(int)minutes,(int)seconds,(int)frames,(int)subframes);              /* Flawfinder: ignore */
}


void secondsToTimecodeString(F32 current_time, char *tcstring)
{
        microsecondsToTimecodeString((U64)((F64)(SEC_TO_MICROSEC*current_time)), tcstring);
}


//
//              LLEventTimer Implementation
//

std::list<LLEventTimer*> LLEventTimer::sActiveList;

LLEventTimer::LLEventTimer(F32 period)
: mEventTimer()
{
        mPeriod = period;
        sActiveList.push_back(this);
}

LLEventTimer::~LLEventTimer() 
{
        sActiveList.remove(this);
}

void LLEventTimer::updateClass() 
{
        std::list<LLEventTimer*> completed_timers;
        for (std::list<LLEventTimer*>::iterator iter = sActiveList.begin(); iter != sActiveList.end(); ) 
        {
                LLEventTimer* timer = *iter++;
                F32 et = timer->mEventTimer.getElapsedTimeF32();
                if (et > timer->mPeriod) {
                        timer->mEventTimer.reset();
                        if ( timer->tick() )
                        {
                                completed_timers.push_back( timer );
                        }
                }
        }

        if ( completed_timers.size() > 0 )
        {
                for (std::list<LLEventTimer*>::iterator completed_iter = completed_timers.begin(); 
                         completed_iter != completed_timers.end(); 
                         completed_iter++ ) 
                {
                        delete *completed_iter;
                }
        }
}

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