TimeZone* U_EXPORT2
TimeZone::createTimeZone(const UnicodeString& ID)
{
/* We first try to lookup the zone ID in our system list. If this
* fails, we try to parse it as a custom string GMT[+-]hh:mm. If
* all else fails, we return GMT, which is probably not what the
* user wants, but at least is a functioning TimeZone object.
*
* We cannot return NULL, because that would break compatibility
* with the JDK.
*/
TimeZone* result = createSystemTimeZone(ID);
if (result == 0) {
U_DEBUG_TZ_MSG(("failed to load system time zone with id - falling to custom"));
result = createCustomTimeZone(ID);
}
if (result == 0) {
U_DEBUG_TZ_MSG(("failed to load time zone with id - falling to GMT"));
const TimeZone* temptz = getGMT();
if (temptz == NULL) {
result = NULL;
} else {
result = temptz->clone();
}
}
return result;
}
TimeZone*
TimeZone::createTimeZone(const UnicodeString& ID)
{
/* We first try to lookup the zone ID in our system list. If this
* fails, we try to parse it as a custom string GMT[+-]hh:mm. If
* all else fails, we return GMT, which is probably not what the
* user wants, but at least is a functioning TimeZone object.
*/
TimeZone* result = 0;
if (haveZoneData()) {
result = createSystemTimeZone(ID);
}
if (result == 0) {
result = createCustomTimeZone(ID);
}
if (result == 0) {
result = getGMT()->clone();
}
return result;
}
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;
}
/**
* 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;
}
