Exemplo n.º 1
0
void printTime(char* systime, char* icutime) {
    printf("System Time:  %s\n", systime);
    printf("ICU Time:     %s\n", icutime);
    printf("STD=%s DST=%s OFFSET=%d\n", uprv_tzname(0), uprv_tzname(1), uprv_timezone());
}
Exemplo n.º 2
0
void
TimeZone::initDefault()
{ 
    // We access system timezone data through TPlatformUtilities,
    // including tzset(), timezone, and tzname[].
    int32_t rawOffset = 0;
    const char *hostID;

    // First, try to create a system timezone, based
    // on the string ID in tzname[0].
    {
        // NOTE: Local mutex here. TimeZone mutex below
        // mutexed to avoid threading issues in the platform functions.
        // Some of the locale/timezone OS functions may not be thread safe,
        // so the intent is that any setting from anywhere within ICU
        // happens while the ICU mutex is held.
        // The operating system might actually use ICU to implement timezones.
        // So we may have ICU calling ICU here, like on AIX.
        // In order to prevent a double lock of a non-reentrant mutex in a
        // different part of ICU, we use TZSET_LOCK to allow only one instance
        // of ICU to query these thread unsafe OS functions at any given time.
        Mutex lock(&TZSET_LOCK);

        ucln_i18n_registerCleanup(UCLN_I18N_TIMEZONE, timeZone_cleanup);
        uprv_tzset(); // Initialize tz... system data
        
        // Get the timezone ID from the host.  This function should do
        // any required host-specific remapping; e.g., on Windows this
        // function maps the Date and Time control panel setting to an
        // ICU timezone ID.
        hostID = uprv_tzname(0);
        
        // Invert sign because UNIX semantics are backwards
        rawOffset = uprv_timezone() * -U_MILLIS_PER_SECOND;
    }

    UBool initialized;
    UMTX_CHECK(&LOCK, (DEFAULT_ZONE != NULL), initialized);
    if (initialized) {
        /* Hrmph? Either a race condition happened, or tzset initialized ICU. */
        return;
    }

    TimeZone* default_zone = NULL;

    /* Make sure that the string is NULL terminated to prevent BoundsChecker/Purify warnings. */
    UnicodeString hostStrID(hostID, -1, US_INV);
    hostStrID.append((UChar)0);
    hostStrID.truncate(hostStrID.length()-1);
    default_zone = createSystemTimeZone(hostStrID);
#ifdef U_WINDOWS
    uprv_free(const_cast<char *>(hostID));
#endif

    int32_t hostIDLen = hostStrID.length();
    if (default_zone != NULL && rawOffset != default_zone->getRawOffset()
        && (3 <= hostIDLen && hostIDLen <= 4))
    {
        // Uh oh. This probably wasn't a good id.
        // It was probably an ambiguous abbreviation
        delete default_zone;
        default_zone = NULL;
    }

    // Construct a fixed standard zone with the host's ID
    // and raw offset.
    if (default_zone == NULL) {
        default_zone = new SimpleTimeZone(rawOffset, hostStrID);
    }

    // If we _still_ don't have a time zone, use GMT.
    if (default_zone == NULL) {
        const TimeZone* temptz = getGMT();
        // If we can't use GMT, get out.
        if (temptz == NULL) {
            return;
        }
        default_zone = temptz->clone();
    }

    // If DEFAULT_ZONE is still NULL, set it up.
    umtx_lock(&LOCK);
    if (DEFAULT_ZONE == NULL) {
        DEFAULT_ZONE = default_zone;
        default_zone = NULL;
        ucln_i18n_registerCleanup(UCLN_I18N_TIMEZONE, timeZone_cleanup);
    }
    umtx_unlock(&LOCK);
    
    delete default_zone;
}
Exemplo n.º 3
0
static void TestPUtilAPI(void){

    double  n1=0.0, y1=0.0, expn1, expy1;
    double  value1 = 0.021;
    UVersionInfo versionArray = {0x01, 0x00, 0x02, 0x02};
    char versionString[17]; /* xxx.xxx.xxx.xxx\0 */
    char *str=0;
    UBool isTrue=FALSE;

    log_verbose("Testing the API uprv_modf()\n");
    y1 = uprv_modf(value1, &n1);
    expn1=0;
    expy1=0.021;
    if(y1 != expy1   || n1 != expn1){
        log_err("Error in uprv_modf.  Expected IntegralValue=%f, Got=%f, \n Expected FractionalValue=%f, Got=%f\n",
             expn1, n1, expy1, y1);
    }
    if(VERBOSITY){
        log_verbose("[float]  x = %f  n = %f y = %f\n", value1, n1, y1);
    }
    log_verbose("Testing the API uprv_fmod()\n");
    expn1=uprv_fmod(30.50, 15.00);
    doAssert(expn1, 0.5, "uprv_fmod(30.50, 15.00) failed.");

    log_verbose("Testing the API uprv_ceil()\n");
    expn1=uprv_ceil(value1);
    doAssert(expn1, 1, "uprv_ceil(0.021) failed.");

    log_verbose("Testing the API uprv_floor()\n");
    expn1=uprv_floor(value1);
    doAssert(expn1, 0, "uprv_floor(0.021) failed.");

    log_verbose("Testing the API uprv_fabs()\n");
    expn1=uprv_fabs((2.02-1.345));
    doAssert(expn1, 0.675, "uprv_fabs(2.02-1.345) failed.");
    
    log_verbose("Testing the API uprv_fmax()\n");
    doAssert(uprv_fmax(2.4, 1.2), 2.4, "uprv_fmax(2.4, 1.2) failed.");

    log_verbose("Testing the API uprv_fmax() with x value= NaN\n");
    expn1=uprv_fmax(uprv_getNaN(), 1.2);
    doAssert(expn1, uprv_getNaN(), "uprv_fmax(uprv_getNaN(), 1.2) failed. when one parameter is NaN");

    log_verbose("Testing the API uprv_fmin()\n");
    doAssert(uprv_fmin(2.4, 1.2), 1.2, "uprv_fmin(2.4, 1.2) failed.");

    log_verbose("Testing the API uprv_fmin() with x value= NaN\n");
    expn1=uprv_fmin(uprv_getNaN(), 1.2);
    doAssert(expn1, uprv_getNaN(), "uprv_fmin(uprv_getNaN(), 1.2) failed. when one parameter is NaN");

    log_verbose("Testing the API uprv_max()\n");
    doAssert(uprv_max(4, 2), 4, "uprv_max(4, 2) failed.");

    log_verbose("Testing the API uprv_min()\n");
    doAssert(uprv_min(-4, 2), -4, "uprv_min(-4, 2) failed.");

    log_verbose("Testing the API uprv_trunc()\n");
    doAssert(uprv_trunc(12.3456), 12, "uprv_trunc(12.3456) failed.");
    doAssert(uprv_trunc(12.234E2), 1223, "uprv_trunc(12.234E2) failed.");
    doAssert(uprv_trunc(uprv_getNaN()), uprv_getNaN(), "uprv_trunc(uprv_getNaN()) failed. with parameter=NaN");
    doAssert(uprv_trunc(uprv_getInfinity()), uprv_getInfinity(), "uprv_trunc(uprv_getInfinity()) failed. with parameter=Infinity");


    log_verbose("Testing the API uprv_pow10()\n");
    doAssert(uprv_pow10(4), 10000, "uprv_pow10(4) failed.");

    log_verbose("Testing the API uprv_log10()\n");
    doAssert(uprv_log10(3456), 3, "uprv_log10(3456) failed.");
#ifdef OS390
    doAssert(uprv_log10(1.0e55), 55, "uprv_log10(1.0e55) failed.");
#else
    doAssert(uprv_log10(1.0e300), 300, "uprv_log10(1.0e300) failed.");
#endif          
    log_verbose("Testing the API uprv_isNegativeInfinity()\n");
    isTrue=uprv_isNegativeInfinity(uprv_getInfinity() * -1);
    if(isTrue != TRUE){
        log_err("ERROR: uprv_isNegativeInfinity failed.\n");
    }
    log_verbose("Testing the API uprv_isPositiveInfinity()\n");
    isTrue=uprv_isPositiveInfinity(uprv_getInfinity());
    if(isTrue != TRUE){
        log_err("ERROR: uprv_isPositiveInfinity failed.\n");
    }
    log_verbose("Testing the API uprv_isInfinite()\n");
    isTrue=uprv_isInfinite(uprv_getInfinity());
    if(isTrue != TRUE){
        log_err("ERROR: uprv_isInfinite failed.\n");
    }

#if 0
    log_verbose("Testing the API uprv_digitsAfterDecimal()....\n");
    doAssert(uprv_digitsAfterDecimal(value1), 3, "uprv_digitsAfterDecimal() failed.");
    doAssert(uprv_digitsAfterDecimal(1.2345E2), 2, "uprv_digitsAfterDecimal(1.2345E2) failed.");
    doAssert(uprv_digitsAfterDecimal(1.2345E-2), 6, "uprv_digitsAfterDecimal(1.2345E-2) failed.");
    doAssert(uprv_digitsAfterDecimal(1.2345E2), 2, "uprv_digitsAfterDecimal(1.2345E2) failed.");
    doAssert(uprv_digitsAfterDecimal(-1.2345E-20), 24, "uprv_digitsAfterDecimal(1.2345E-20) failed.");
    doAssert(uprv_digitsAfterDecimal(1.2345E20), 0, "uprv_digitsAfterDecimal(1.2345E20) failed.");
    doAssert(uprv_digitsAfterDecimal(-0.021), 3, "uprv_digitsAfterDecimal(-0.021) failed.");
    doAssert(uprv_digitsAfterDecimal(23.0), 0, "uprv_digitsAfterDecimal(23.0) failed.");
    doAssert(uprv_digitsAfterDecimal(0.022223333321), 9, "uprv_digitsAfterDecimal(0.022223333321) failed.");
#endif


    log_verbose("Testing the API u_versionToString().....\n");
    u_versionToString(versionArray, versionString);
    if(strcmp(versionString, "1.0.2.2") != 0){
        log_err("ERROR: u_versionToString() failed. Expected: 1.0.2.2, Got=%s\n", versionString);
    }
    log_verbose("Testing the API u_versionToString().....with versionArray=NULL\n");
    u_versionToString(NULL, versionString);
    if(strcmp(versionString, "") != 0){
        log_err("ERROR: u_versionToString() failed. with versionArray=NULL. It should just return\n");
    }
    log_verbose("Testing the API u_versionToString().....with versionArray=NULL\n");
    u_versionToString(NULL, versionString);
    if(strcmp(versionString, "") != 0){
        log_err("ERROR: u_versionToString() failed . It should just return\n");
    }
    log_verbose("Testing the API u_versionToString().....with versionString=NULL\n");
    u_versionToString(versionArray, NULL);
    if(strcmp(versionString, "") != 0){
        log_err("ERROR: u_versionToString() failed. with versionArray=NULL  It should just return\n");
    }
    versionArray[0] = 0x0a;
    log_verbose("Testing the API u_versionToString().....\n");
    u_versionToString(versionArray, versionString);
    if(strcmp(versionString, "10.0.2.2") != 0){
        log_err("ERROR: u_versionToString() failed. Expected: 10.0.2.2, Got=%s\n", versionString);
    }
    versionArray[0] = 0xa0;
    u_versionToString(versionArray, versionString);
    if(strcmp(versionString, "160.0.2.2") != 0){
        log_err("ERROR: u_versionToString() failed. Expected: 160.0.2.2, Got=%s\n", versionString);
    }
    versionArray[0] = 0xa0;
    versionArray[1] = 0xa0;
    u_versionToString(versionArray, versionString);
    if(strcmp(versionString, "160.160.2.2") != 0){
        log_err("ERROR: u_versionToString() failed. Expected: 160.160.2.2, Got=%s\n", versionString);
    }
    versionArray[0] = 0x01;
    versionArray[1] = 0x0a;
    u_versionToString(versionArray, versionString);
    if(strcmp(versionString, "1.10.2.2") != 0){
        log_err("ERROR: u_versionToString() failed. Expected: 160.160.2.2, Got=%s\n", versionString);
    }

    log_verbose("Testing the API u_versionFromString() ....\n");
    u_versionFromString(versionArray, "1.3.5.6");
    u_versionToString(versionArray, versionString);
    if(strcmp(versionString, "1.3.5.6") != 0){
        log_err("ERROR: u_getVersion() failed. Expected: 1.3.5.6, Got=%s\n",  versionString);
    }
    log_verbose("Testing the API u_versionFromString() where versionArray=NULL....\n");
    u_versionFromString(NULL, "1.3.5.6");
    u_versionToString(versionArray, versionString);
    if(strcmp(versionString, "1.3.5.6") != 0){
        log_err("ERROR: u_getVersion() failed. Expected: 1.3.5.6, Got=%s\n",  versionString);
    }

    log_verbose("Testing the API u_getVersion().....\n");
    u_getVersion(versionArray);
    u_versionToString(versionArray, versionString);
    if(strcmp(versionString, U_ICU_VERSION) != 0){
        log_err("ERROR: u_getVersion() failed. Got=%s, expected %s\n",  versionString, U_ICU_VERSION);
    }
    log_verbose("Testing the API u_errorName()...\n");
    str=(char*)u_errorName((UErrorCode)0);
    if(strcmp(str, "U_ZERO_ERROR") != 0){
        log_err("ERROR: u_getVersion() failed. Expected: U_ZERO_ERROR Got=%s\n",  str);
    }
    log_verbose("Testing the API u_errorName()...\n");
    str=(char*)u_errorName((UErrorCode)-127);
    if(strcmp(str, "U_USING_DEFAULT_WARNING") != 0){
        log_err("ERROR: u_getVersion() failed. Expected: U_USING_DEFAULT_WARNING Got=%s\n",  str);
    }
    log_verbose("Testing the API u_errorName().. with BOGUS ERRORCODE...\n");
    str=(char*)u_errorName((UErrorCode)200);
    if(strcmp(str, "[BOGUS UErrorCode]") != 0){
        log_err("ERROR: u_getVersion() failed. Expected: [BOGUS UErrorCode] Got=%s\n",  str);
    }

    {
        const char* dataDirectory;
        UChar *udataDir=0;
        UChar temp[100];
        char *charvalue=0;
        log_verbose("Testing chars to UChars\n");
        
         /* This cannot really work on a japanese system. u_uastrcpy will have different results than */
        /* u_charsToUChars when there is a backslash in the string! */
        /*dataDirectory=u_getDataDirectory();*/

        dataDirectory="directory1";  /*no backslashes*/
        udataDir=(UChar*)malloc(sizeof(UChar) * (strlen(dataDirectory) + 1));
        u_charsToUChars(dataDirectory, udataDir, (strlen(dataDirectory)+1));
        u_uastrcpy(temp, dataDirectory);
       
        if(u_strcmp(temp, udataDir) != 0){
            log_err("ERROR: u_charsToUChars failed. Expected %s, Got %s\n", austrdup(temp), austrdup(udataDir));
        }
        log_verbose("Testing UChars to chars\n");
        charvalue=(char*)malloc(sizeof(char) * (u_strlen(udataDir) + 1));

        u_UCharsToChars(udataDir, charvalue, (u_strlen(udataDir)+1));
        if(strcmp(charvalue, dataDirectory) != 0){
            log_err("ERROR: u_UCharsToChars failed. Expected %s, Got %s\n", charvalue, dataDirectory);
        }
        free(charvalue);
        free(udataDir);
    }
   
    log_verbose("Testing uprv_timezone()....\n");
    {
        int32_t tzoffset = uprv_timezone();
        log_verbose("Value returned from uprv_timezone = %d\n",  tzoffset);
        if (tzoffset != 28800) {
            log_verbose("***** WARNING: If testing in the PST timezone, t_timezone should return 28800! *****");
        }
        if ((tzoffset % 1800 != 0)) {
            log_err("FAIL: t_timezone may be incorrect. It is not a multiple of 30min.");
        }
        tzoffset=uprv_getUTCtime();

    }
}
Exemplo n.º 4
0
static void TestPUtilAPI(void){

    double  n1=0.0, y1=0.0, expn1, expy1;
    double  value1 = 0.021;
    char *str=0;
    UBool isTrue=FALSE;

    log_verbose("Testing the API uprv_modf()\n");
    y1 = uprv_modf(value1, &n1);
    expn1=0;
    expy1=0.021;
    if(y1 != expy1   || n1 != expn1){
        log_err("Error in uprv_modf.  Expected IntegralValue=%f, Got=%f, \n Expected FractionalValue=%f, Got=%f\n",
             expn1, n1, expy1, y1);
    }
    if(getTestOption(VERBOSITY_OPTION)){
        log_verbose("[float]  x = %f  n = %f y = %f\n", value1, n1, y1);
    }
    log_verbose("Testing the API uprv_fmod()\n");
    expn1=uprv_fmod(30.50, 15.00);
    doAssert(expn1, 0.5, "uprv_fmod(30.50, 15.00) failed.");

    log_verbose("Testing the API uprv_ceil()\n");
    expn1=uprv_ceil(value1);
    doAssert(expn1, 1, "uprv_ceil(0.021) failed.");

    log_verbose("Testing the API uprv_floor()\n");
    expn1=uprv_floor(value1);
    doAssert(expn1, 0, "uprv_floor(0.021) failed.");

    log_verbose("Testing the API uprv_fabs()\n");
    expn1=uprv_fabs((2.02-1.345));
    doAssert(expn1, 0.675, "uprv_fabs(2.02-1.345) failed.");
    
    log_verbose("Testing the API uprv_fmax()\n");
    doAssert(uprv_fmax(2.4, 1.2), 2.4, "uprv_fmax(2.4, 1.2) failed.");

    log_verbose("Testing the API uprv_fmax() with x value= NaN\n");
    expn1=uprv_fmax(uprv_getNaN(), 1.2);
    doAssert(expn1, uprv_getNaN(), "uprv_fmax(uprv_getNaN(), 1.2) failed. when one parameter is NaN");

    log_verbose("Testing the API uprv_fmin()\n");
    doAssert(uprv_fmin(2.4, 1.2), 1.2, "uprv_fmin(2.4, 1.2) failed.");

    log_verbose("Testing the API uprv_fmin() with x value= NaN\n");
    expn1=uprv_fmin(uprv_getNaN(), 1.2);
    doAssert(expn1, uprv_getNaN(), "uprv_fmin(uprv_getNaN(), 1.2) failed. when one parameter is NaN");

    log_verbose("Testing the API uprv_max()\n");
    doAssert(uprv_max(4, 2), 4, "uprv_max(4, 2) failed.");

    log_verbose("Testing the API uprv_min()\n");
    doAssert(uprv_min(-4, 2), -4, "uprv_min(-4, 2) failed.");

    log_verbose("Testing the API uprv_trunc()\n");
    doAssert(uprv_trunc(12.3456), 12, "uprv_trunc(12.3456) failed.");
    doAssert(uprv_trunc(12.234E2), 1223, "uprv_trunc(12.234E2) failed.");
    doAssert(uprv_trunc(uprv_getNaN()), uprv_getNaN(), "uprv_trunc(uprv_getNaN()) failed. with parameter=NaN");
    doAssert(uprv_trunc(uprv_getInfinity()), uprv_getInfinity(), "uprv_trunc(uprv_getInfinity()) failed. with parameter=Infinity");


    log_verbose("Testing the API uprv_pow10()\n");
    doAssert(uprv_pow10(4), 10000, "uprv_pow10(4) failed.");

    log_verbose("Testing the API uprv_isNegativeInfinity()\n");
    isTrue=uprv_isNegativeInfinity(uprv_getInfinity() * -1);
    if(isTrue != TRUE){
        log_err("ERROR: uprv_isNegativeInfinity failed.\n");
    }
    log_verbose("Testing the API uprv_isPositiveInfinity()\n");
    isTrue=uprv_isPositiveInfinity(uprv_getInfinity());
    if(isTrue != TRUE){
        log_err("ERROR: uprv_isPositiveInfinity failed.\n");
    }
    log_verbose("Testing the API uprv_isInfinite()\n");
    isTrue=uprv_isInfinite(uprv_getInfinity());
    if(isTrue != TRUE){
        log_err("ERROR: uprv_isInfinite failed.\n");
    }

#if 0
    log_verbose("Testing the API uprv_digitsAfterDecimal()....\n");
    doAssert(uprv_digitsAfterDecimal(value1), 3, "uprv_digitsAfterDecimal() failed.");
    doAssert(uprv_digitsAfterDecimal(1.2345E2), 2, "uprv_digitsAfterDecimal(1.2345E2) failed.");
    doAssert(uprv_digitsAfterDecimal(1.2345E-2), 6, "uprv_digitsAfterDecimal(1.2345E-2) failed.");
    doAssert(uprv_digitsAfterDecimal(1.2345E2), 2, "uprv_digitsAfterDecimal(1.2345E2) failed.");
    doAssert(uprv_digitsAfterDecimal(-1.2345E-20), 24, "uprv_digitsAfterDecimal(1.2345E-20) failed.");
    doAssert(uprv_digitsAfterDecimal(1.2345E20), 0, "uprv_digitsAfterDecimal(1.2345E20) failed.");
    doAssert(uprv_digitsAfterDecimal(-0.021), 3, "uprv_digitsAfterDecimal(-0.021) failed.");
    doAssert(uprv_digitsAfterDecimal(23.0), 0, "uprv_digitsAfterDecimal(23.0) failed.");
    doAssert(uprv_digitsAfterDecimal(0.022223333321), 9, "uprv_digitsAfterDecimal(0.022223333321) failed.");
#endif

    log_verbose("Testing the API u_errorName()...\n");
    str=(char*)u_errorName((UErrorCode)0);
    if(strcmp(str, "U_ZERO_ERROR") != 0){
        log_err("ERROR: u_getVersion() failed. Expected: U_ZERO_ERROR Got=%s\n",  str);
    }
    log_verbose("Testing the API u_errorName()...\n");
    str=(char*)u_errorName((UErrorCode)-127);
    if(strcmp(str, "U_USING_DEFAULT_WARNING") != 0){
        log_err("ERROR: u_getVersion() failed. Expected: U_USING_DEFAULT_WARNING Got=%s\n",  str);
    }
    log_verbose("Testing the API u_errorName().. with BOGUS ERRORCODE...\n");
    str=(char*)u_errorName((UErrorCode)200);
    if(strcmp(str, "[BOGUS UErrorCode]") != 0){
        log_err("ERROR: u_getVersion() failed. Expected: [BOGUS UErrorCode] Got=%s\n",  str);
    }

    {
        const char* dataDirectory;
        int32_t dataDirectoryLen;
        UChar *udataDir=0;
        UChar temp[100];
        char *charvalue=0;
        log_verbose("Testing chars to UChars\n");
        
         /* This cannot really work on a japanese system. u_uastrcpy will have different results than */
        /* u_charsToUChars when there is a backslash in the string! */
        /*dataDirectory=u_getDataDirectory();*/

        dataDirectory="directory1";  /*no backslashes*/
        dataDirectoryLen=(int32_t)strlen(dataDirectory);
        udataDir=(UChar*)malloc(sizeof(UChar) * (dataDirectoryLen + 1));
        u_charsToUChars(dataDirectory, udataDir, (dataDirectoryLen + 1));
        u_uastrcpy(temp, dataDirectory);
       
        if(u_strcmp(temp, udataDir) != 0){
            log_err("ERROR: u_charsToUChars failed. Expected %s, Got %s\n", austrdup(temp), austrdup(udataDir));
        }
        log_verbose("Testing UChars to chars\n");
        charvalue=(char*)malloc(sizeof(char) * (u_strlen(udataDir) + 1));

        u_UCharsToChars(udataDir, charvalue, (u_strlen(udataDir)+1));
        if(strcmp(charvalue, dataDirectory) != 0){
            log_err("ERROR: u_UCharsToChars failed. Expected %s, Got %s\n", charvalue, dataDirectory);
        }
        free(charvalue);
        free(udataDir);
    }
   
    log_verbose("Testing uprv_timezone()....\n");
    {
        int32_t tzoffset = uprv_timezone();
        log_verbose("Value returned from uprv_timezone = %d\n",  tzoffset);
        if (tzoffset != 28800) {
            log_verbose("***** WARNING: If testing in the PST timezone, t_timezone should return 28800! *****");
        }
        if ((tzoffset % 1800 != 0)) {
            log_info("Note: t_timezone offset of %ld (for %s : %s) is not a multiple of 30min.", tzoffset, uprv_tzname(0), uprv_tzname(1));
        }
        /*tzoffset=uprv_getUTCtime();*/

    }
}
Exemplo n.º 5
0
/**
 * Initialize DEFAULT_ZONE from the system default time zone.  The
 * caller should confirm that DEFAULT_ZONE is NULL before calling.
 * Upon return, DEFAULT_ZONE will not be NULL, unless operator new()
 * returns NULL.
 *
 * Must be called OUTSIDE mutex.
 */
void
TimeZone::initDefault()
{ 
    // We access system timezone data through TPlatformUtilities,
    // including tzset(), timezone, and tzname[].
    int32_t rawOffset = 0;
    const char *hostID;

    // First, try to create a system timezone, based
    // on the string ID in tzname[0].
    {
        // NOTE: Global mutex here; TimeZone mutex above
        // mutexed to avoid threading issues in the platform fcns.
        // Some of the locale/timezone OS functions may not be thread safe, 
        //  so the intent is that any setting from anywhere within ICU 
        //  happens with the ICU global mutex held.
        Mutex lock; 
        uprv_tzset(); // Initialize tz... system data
        
        // Get the timezone ID from the host.  This function should do
        // any required host-specific remapping; e.g., on Windows this
        // function maps the Date and Time control panel setting to an
        // ICU timezone ID.
        hostID = uprv_tzname(0);
        
        // Invert sign because UNIX semantics are backwards
        rawOffset = uprv_timezone() * -U_MILLIS_PER_SECOND;
    }

    TimeZone* default_zone = NULL;

    if (haveZoneData()) {
        default_zone = createSystemTimeZone(hostID);

        // If we couldn't get the time zone ID from the host, use
        // the default host timezone offset.  Further refinements
        // to this include querying the host to determine if DST
        // is in use or not and possibly using the host locale to
        // select from multiple zones at a the same offset.  We
        // don't do any of this now, but we could easily add this.
        if (default_zone == NULL) {
            // Use the designated default in the time zone list that has the
            // appropriate GMT offset, if there is one.

            const OffsetIndex* index = INDEX_BY_OFFSET;

            for (;;) {
                if (index->gmtOffset > rawOffset) {
                    // Went past our desired offset; no match found
                    break;
                }
                if (index->gmtOffset == rawOffset) {
                    // Found our desired offset
                    default_zone = createSystemTimeZone(ZONE_IDS[index->defaultZone]);
                    break;
                }
                // Compute the position of the next entry.  If the delta value
                // in this entry is zero, then there is no next entry.
                uint16_t delta = index->nextEntryDelta;
                if (delta == 0) {
                    break;
                }
                index = (const OffsetIndex*)((int8_t*)index + delta);
            }
        }
    }

    // If we _still_ don't have a time zone, use GMT.  This
    // can only happen if the raw offset returned by
    // uprv_timezone() does not correspond to any system zone.
    if (default_zone == NULL) {
        default_zone = getGMT()->clone();
    }

    // If DEFAULT_ZONE is still NULL, set it up.
    umtx_lock(&LOCK);
    if (DEFAULT_ZONE == NULL) {
        DEFAULT_ZONE = default_zone;
        default_zone = NULL;
    }
    umtx_unlock(&LOCK);

    delete default_zone;
}