Class NoOpGpuStats

java.lang.Object
oshi.hardware.common.NoOpGpuStats
All Implemented Interfaces:
AutoCloseable, GpuStats
@ThreadSafe public final class NoOpGpuStats extends Object implements GpuStats
A no-op GpuStats implementation returned by platforms that do not support a native stats session.

While the session is open, all primitive metric getters return -1 (or -1L / -1d), except getGpuTicks() which returns new GpuTicks(0L, 0L) as its sentinel. After close() is called, all getters throw IllegalStateException. close() is idempotent.

  • Constructor Details

    • NoOpGpuStats

      public NoOpGpuStats()

  • Method Details

    • close

      public void close()
      Description copied from interface: GpuStats
      Releases any native resources held by this session. Safe to call multiple times; subsequent calls after the first are no-ops. Does not throw checked exceptions.
      Specified by:
      close in interface AutoCloseable
      Specified by:
      close in interface GpuStats

    • isClosed

      public boolean isClosed()
      Description copied from interface: GpuStats
      Returns true if GpuStats.close() has been called on this session. Does not throw.
      Specified by:
      isClosed in interface GpuStats
      Returns:
      true if this session is closed

    • getGpuTicks

      public GpuTicks getGpuTicks()
      Description copied from interface: GpuStats
      Returns a snapshot of cumulative GPU active and idle ticks in opaque, platform-native units. The counters are monotonically increasing; diff two snapshots to compute utilization: 
      long dActive = curr.getActiveTicks() - prev.getActiveTicks();
long dIdle = curr.getIdleTicks() - prev.getIdleTicks();
long dTotal = dActive + dIdle;
double utilPct = dTotal > 0 ? dActive * 100.0 / dTotal : -1d;

      Both counters are 0 on platforms where tick-level GPU metrics are not available (see GpuTicks for the sentinel semantics). Use GpuStats.getGpuUtilization() as an alternative.

      Specified by:
      getGpuTicks in interface GpuStats
      Returns:
      a GpuTicks snapshot; never null

    • getGpuUtilization

      public double getGpuUtilization()
      Description copied from interface: GpuStats
      Returns the instantaneous GPU core utilization as a percentage, computed internally as a delta between the current sample and the previous one recorded by this session.

      Behaviour on the first call is implementation-dependent. Backends that derive utilization from an energy or residency counter record an initial baseline on the first call and return -1; subsequent calls return the utilization computed over the elapsed interval. Backends that read an instantaneous hardware register may return a valid value immediately. To ensure the first polling iteration returns a valid value on delta-based backends, call this method once as a priming step before the polling loop begins: 

      stats.getGpuUtilization(); // prime — may return -1 on delta-based backends
Thread.sleep(intervalMs);
double util = stats.getGpuUtilization(); // valid on all backends
      Specified by:
      getGpuUtilization in interface GpuStats
      Returns:
      utilization in the range 0.0 to 100.0, or -1 if not available or not yet primed

    • getVramUsed

      public long getVramUsed()
      Description copied from interface: GpuStats
      Returns the amount of dedicated VRAM currently in use.
      Specified by:
      getVramUsed in interface GpuStats
      Returns:
      bytes of VRAM in use, or -1 if unavailable

    • getSharedMemoryUsed

      public long getSharedMemoryUsed()
      Description copied from interface: GpuStats
      Returns the amount of shared system memory currently used by this GPU.
      Specified by:
      getSharedMemoryUsed in interface GpuStats
      Returns:
      bytes of shared memory in use, or -1 if unavailable

    • getTemperature

      public double getTemperature()
      Description copied from interface: GpuStats
      Returns the GPU temperature.
      Specified by:
      getTemperature in interface GpuStats
      Returns:
      temperature in degrees Celsius, or -1 if unavailable

    • getPowerDraw

      public double getPowerDraw()
      Description copied from interface: GpuStats
      Returns the GPU power consumption. On backends that derive power from an energy counter (e.g. macOS Apple Silicon via IOReport), this is computed as a delta between the current sample and the previous one; the first call records the initial baseline and returns -1. On backends that read an instantaneous hardware sensor (e.g. Windows via NVML/ADL/LHM), a valid value may be returned immediately.

      To ensure the first polling iteration returns a valid value on delta-based backends, call this method once as a priming step before the polling loop begins: 

      stats.getPowerDraw(); // prime — may return -1 on delta-based backends
Thread.sleep(intervalMs);
double watts = stats.getPowerDraw(); // valid on all backends
      Specified by:
      getPowerDraw in interface GpuStats
      Returns:
      power draw in watts, or -1 if unavailable or not yet primed

    • getCoreClockMhz

      public long getCoreClockMhz()
      Description copied from interface: GpuStats
      Returns the current GPU core clock speed.
      Specified by:
      getCoreClockMhz in interface GpuStats
      Returns:
      core clock in MHz, or -1 if unavailable

    • getMemoryClockMhz

      public long getMemoryClockMhz()
      Description copied from interface: GpuStats
      Returns the current GPU memory clock speed.
      Specified by:
      getMemoryClockMhz in interface GpuStats
      Returns:
      memory clock in MHz, or -1 if unavailable

    • getFanSpeedPercent

      public double getFanSpeedPercent()
      Description copied from interface: GpuStats
      Returns the GPU fan speed as a percentage of maximum.
      Specified by:
      getFanSpeedPercent in interface GpuStats
      Returns:
      fan speed in the range 0.0 to 100.0, or -1 if unavailable