Method Details

• getOS

  public static String getOS()

  Returns the OS of the system running I2P as a lower-case string for reference in clients.config and plugin.config files.

  matches the conventions of the Go cross compiler.

  Returns:

  the OS of the system running I2P as a lower-case string

• getArch

  public static String getArch()

  Returns the architecture of the system running I2P as a string for reference in clients.config and plugin.config files.

  matches the conventions of the Go cross compiler.

  Returns:

  the architecture of the system running I2P as a string

• isWindows

  public static boolean isWindows()

  Whether the OS is Windows.

  Returns:

  true when os.name starts with "Win", resolved once at class load

• isMac

  public static boolean isMac()

  Whether the OS is Mac.

  Returns:

  true when os.name starts with "Mac", resolved once at class load

• isAndroid

  public static boolean isAndroid()

  Whether the OS is Android.

  Returns:

  true when java.vendor contains "Android"

• isApache

  public static boolean isApache()

  Apache Harmony JVM, or Android.

  Returns:

  true when java.vendor starts with "Apache", or on Android

• isGNU

  public static boolean isGNU()

  Gij or JamVM with GNU Classpath.

  Returns:

  true if running on the GNU Java runtime

• isGentoo

  public static boolean isGentoo()

  True if Gentoo.

  Returns:

  true when os.version names gentoo or a hardened kernel

• isOpenJDK

  public static boolean isOpenJDK()

  True if OpenJDK.

  Returns:

  whether open j d k

• isARM

  public static boolean isARM()

  Speed: do not cripple down for powerful ARM.

  Returns:

  whether a r m

• isX86

  public static boolean isX86()

  True if x86.

  Returns:

  whether x86

• isZeroVM

  public static boolean isZeroVM()

  Is this a very slow interpreted mode VM?

  Returns:

  whether zero v m

• isSlow

  public static boolean isSlow()

  Our best guess on whether this is a slow architecture / OS / JVM, using some simple heuristics.

  Returns:

  the cached verdict, OR-ed with a live core count, native big integer, and heap size check that is suppressed by the override property

• isJava6

  public static boolean isJava6()

  Better than (new VersionComparator()).compare(System.getProperty(String)"java.version"), "1.6") >= 0 as it handles Android also, where java.version = "0".

  Returns:

  true if Java 1.6 or higher, or Android API 9 or higher

• isJava7

  public static boolean isJava7()

  Better than (new VersionComparator()).compare(System.getProperty(String)"java.version"), "1.7") >= 0 as it handles Android also, where java.version = "0".

  Returns:

  true if Java 1.7 or higher, or Android API 19 or higher

• isJava8

  public static boolean isJava8()

  True if the JVM is Java 8 or higher, false for Android.

  Returns:

  true if Java 1.8 or higher, false for Android.

• isJava9

  public static boolean isJava9()

  True if the JVM is Java 9 or higher, false for Android.

  Returns:

  true if Java 9 or higher, false for Android.

• isJava10

  public static boolean isJava10()

  True if the JVM is Java 10 or higher, false for Android.

  Returns:

  true if Java 10 or higher, false for Android.

• isJava11

  public static boolean isJava11()

  True if the JVM is Java 11 or higher, false for Android.

  Returns:

  true if Java 11 or higher, false for Android.

• isJava12

  public static boolean isJava12()

  True if the JVM is Java 12 or higher, false for Android.

  Returns:

  true if Java 12 or higher, false for Android.

• isJava13

  public static boolean isJava13()

  True if the JVM is Java 13 or higher, false for Android.

  Returns:

  true if Java 13 or higher, false for Android.

• isJava14

  public static boolean isJava14()

  True if the JVM is Java 14 or higher, false for Android.

  Returns:

  true if Java 14 or higher, false for Android.

• isJava15

  public static boolean isJava15()

  True if the JVM is Java 15 or higher, false for Android.

  Returns:

  true if Java 15 or higher, false for Android.

• isJava16

  public static boolean isJava16()

  True if the JVM is Java 16 or higher, false for Android.

  Returns:

  true if Java 16 or higher, false for Android.

• isJava17

  public static boolean isJava17()

  True if the JVM is Java 17 or higher, false for Android.

  Returns:

  true if Java 17 or higher, false for Android.

• isJava18

  public static boolean isJava18()

  True if the JVM is Java 18 or higher, false for Android.

  Returns:

  true if Java 18 or higher, false for Android.

• isJava19

  public static boolean isJava19()

  True if the JVM is Java 19 or higher, false for Android.

  Returns:

  true if Java 19 or higher, false for Android.

• isJava20

  public static boolean isJava20()

  True if the JVM is Java 20 or higher, false for Android.

  Returns:

  true if Java 20 or higher, false for Android.

• isJava21

  public static boolean isJava21()

  True if the JVM is Java 21 or higher, false for Android.

  Returns:

  true if Java 21 or higher, false for Android.

• isJava22

  public static boolean isJava22()

  True if the JVM is Java 22 or higher, false for Android.

  Returns:

  true if Java 21 or higher, false for Android.

• isJava

  public static boolean isJava(int minVersion)

  Handles Android also.

  Parameters:

  minVersion - e.g. 11

  Returns:

  true if greater than or equal to minVersion

• isJava

  public static boolean isJava(String minVersion)

  Handles Android, and minVersions in both forms (e.g. 11 or 1.11).

  Parameters:

  minVersion - either 1.x or x form works

  Returns:

  true if greater than or equal to minVersion

• is64Bit

  public static boolean is64Bit()

  This isn't always correct. http://stackoverflow.com/questions/807263/how-do-i-detect-which-kind-of-jre-is-installed-32bit-vs-64bit os.arch is the bitness of the JREchecking OS bitness on Windowssun.arch.data.model not on all JVMs sun.arch.data.model == 64 => 64 bit processor sun.arch.data.model == 32 => A 32 bit JVM but could be either 32 or 64 bit processor or libs os.arch contains "64" could be 32 or 64 bit libs.

  Returns:

  whether 64 bit

• isLinuxService

  public static boolean isLinuxService()

  Whether running as a Linux service.

  Returns:

  whether linux service

• isWindowsService

  public static boolean isWindowsService()

  Whether running as a Windows service.

  Returns:

  whether windows service

• isService

  public static boolean isService()

  Whether running as a service under either platform.

  Returns:

  true for a Linux daemon user or a Tanuki wrapper on Windows

• getAndroidVersion

  public static int getAndroidVersion()

  Identical to android.os.Build.VERSION.SDK_INT. For use outside of Android code.

  Returns:

  The SDK (API) version, e.g. 8 for Froyo, 0 if unknown

• hasWrapper

  public static boolean hasWrapper()

  Is the wrapper present? Same as I2PAppContext.hasWrapper().

  Returns:

  whether wrapper is present

• getMaxMemory

  public static long getMaxMemory()

  Runtime.getRuntime().maxMemory() but check for bogus values.

  Returns:

  the max memory

• getCores

  public static int getCores()

  Total CPUs including parked/offline cores. On Linux, reads /sys/devices/system/cpu/present to get the full CPU topology regardless of cpufreq governor parking. Falls back to Runtime.getRuntime().availableProcessors().

  Returns:

  never smaller than 1

• usableCores

  public static int usableCores()

  Calculate how many (virtual) cores should be actually used by a thread pool.

  Returns:

  1 on Windows and macOS, or 3/4 of the logical cores on x86

• getSystemTimeZone

  public static TimeZone getSystemTimeZone()

  The system's time zone, which is probably different from the JVM time zone, because Router changes the JVM default to GMT. It saves the old default in the context properties where we can get it. Use this to format a time in local time zone with DateFormat.setTimeZone().

  Returns:

  non-null

• getSystemTimeZone

  public static TimeZone getSystemTimeZone(I2PAppContext ctx)

  The system's time zone, which is probably different from the JVM time zone, because Router changes the JVM default to GMT. It saves the old default in the context properties where we can get it. Use this to format a time in local time zone with DateFormat.setTimeZone().

  Parameters:

  ctx - the application context whose properties hold the saved system time zone ID

  Returns:

  the saved system time zone, or the JVM default if none was saved

• main

  public static void main(String[] args)

  Print the Java version and VM this router is running under, for diagnosing a user-reported problem from the console output.

  Parameters:

  args - ignored, no arguments are parsed

• getCPULoad

  public static int getCPULoad()

  Retrieve CPU Load of the JVM.

  The MXBean query is expensive — on JDK 19+ each call reads /proc via Files.lines. So results are cached for CPU_LOAD_CACHE_MS. Callers such as the JobQueue pumper and the throttlers only need a coarse periodic sample, so up to 1s of staleness is acceptable.

  Returns:

  the CPU load

• cpuLoadCacheStale

  static boolean cpuLoadCacheStale(long lastQueried, long now)

  Whether the cached CPU load sample is old enough to refresh. Never-queried (lastQueried == 0) counts as stale so the first call always queries the MXBean instead of returning the 0 initializer.

  Parameters:

  lastQueried - the wall-clock ms of the previous query, or 0

  now - the current wall-clock ms

  Returns:

  true if the cache should be refreshed

• sysLoadCacheStale

  static boolean sysLoadCacheStale(long lastQueried, long now)

  Whether the cached system load sample is old enough to refresh. Never-queried (lastQueried == 0) counts as stale so the first call always queries the MXBean instead of returning the 0 initializer. A wall-clock step backwards (NTP correction, manual change) also counts as stale: a plain age comparison would report the sample as fresh until the clock caught up again, pinning a stale value for the length of the step.

  Parameters:

  lastQueried - the wall-clock ms of the previous query, or 0

  now - the current wall-clock ms

  Returns:

  true if the cache should be refreshed

• getCpuLoadStat

  private static RateStat getCpuLoadStat()

  Resolve and cache the "router.cpuLoad" RateStat handle. The stat is registered once during startup and never replaced, so the handle stays valid for the life of the context. Re-resolves if the context or its StatManager is swapped (as in unit tests).

  Returns:

  the cached stat, or null if it is not registered yet

• getCPULoadAvg

  public static int getCPULoadAvg()

  Retrieve CPU Load Average of the JVM.

  Returns:

  the CPU load avg

• getCPULoadCores

  public static double getCPULoadCores()

  60s-smoothed process CPU load expressed in cores, e.g. 2.3 on a 4-core machine means the JVM recently consumed 2.3 cores on average.

  Returns:

  the cores used, from 0.0 to getCores()

• getSystemLoad

  public static int getSystemLoad()

  Retrieve the system load as a percentage, where 100% equals full system load.

  The MXBean query is a native /proc read and is cached for SYSTEM_LOAD_CACHE_MS, because this sits on the per-request path of both tunnel throttlers while the underlying load average moves on a multi-minute timescale.

  Returns:

  the system load

• getActiveThreads

  public static int getActiveThreads()

  Returns the current number of active (live) threads in the JVM. This includes both daemon and non-daemon threads.

  Returns:

  the estimated number of active threads, or 0 if context or stat manager is unavailable

• getStatRate

  private static Rate getStatRate(StatManager sm, String name, int duration)

  Returns one stat's rate for a period.

  Parameters:

  sm - the stat manager

  name - the stat name

  duration - the rate period, in ms

  Returns:

  the rate, or null if the stat is unknown

• getTunnelBuildSuccess

  public static int getTunnelBuildSuccess()

  Retrieve Tunnel build success as a percentage.

  Returns:

  the tunnel build success

• getTunnelBuildSuccessRatio

  public static double getTunnelBuildSuccessRatio(StatManager sm, int windowMs)

  The canonical tunnel build success ratio: successes over all settled builds, 0.0 to 1.0, for a stated window.

  This is the single source of truth. Three implementations existed and none of them agreed: ProfileOrganizer read getCurrentEventCount() - the current partial period - while asking for the ten minute rate, so it sampled a fraction of one bucket and threw the history away; the copy here read getLastEventCount(), the last completed period; and the Tuner used a different set of stats entirely on an hourly window. That value is not cosmetic - it gates profile eviction, selects the ghost cooldown, and feeds ClientPeerSelector first-hop selection - so a partial-period reading could intermittently drop it under the attack threshold and switch all three to their defensive behaviour on noise.

  Counts events over the last completed window rather than the current partial one, so the reading does not depend on where in the period it was sampled. Partial-period sampling was what made the old value swing, and swing under the attack threshold, which switches off profile eviction and lengthens ghost cooldowns.

  Parameters:

  sm - the stat manager, or null

  windowMs - the averaging window in milliseconds

  Returns:

  the ratio, or NaN if the stats are absent or the window is empty

• buildSuccessRatio

  public static double buildSuccessRatio(double success, double reject, double expire)

  Successes over all settled builds. Pure arithmetic, so it is testable without stats.

  Parameters:

  success - mean successes per period

  reject - mean rejections per period

  expire - mean expiries per period

  Returns:

  the ratio, or NaN when nothing settled in the window