Class ResourceTracker

java.lang.Object
express.mvp.myra.transport.memory.ResourceTracker
public final class ResourceTracker extends Object
Tracks native memory allocations for debugging and leak detection.

This tracker maintains a registry of all active allocations with their metadata, enabling detection of memory leaks and analysis of allocation patterns.

Design Goals

  • Low overhead: Thread-safe but minimal synchronization
  • Rich metadata: Captures allocation site, size, time
  • Leak detection: Identifies unreleased allocations at shutdown
  • Configurable: Can be disabled in production

Usage Example

// Enable tracking
ResourceTracker tracker = ResourceTracker.getInstance();
tracker.setEnabled(true);
tracker.setCaptureStackTraces(true); // Expensive, use in dev only

// Track allocation
long id = tracker.trackAllocation("BufferPool", 65536);

// ... use resource ...

// Track release
tracker.trackRelease(id);

// At shutdown, check for leaks
Collection<AllocationRecord> leaks = tracker.getActiveAllocations();
if (!leaks.isEmpty()) {
    logger.warn("Memory leak detected: {} unreleased allocations", leaks.size());
    for (AllocationRecord leak : leaks) {
        logger.warn("  Leaked: {} ({} bytes, allocated at {})",
            leak.getSource(), leak.getSize(), leak.getAllocationTime());
    }
}

Performance Considerations

  • Stack trace capture is expensive - disable in production
  • ConcurrentHashMap provides good concurrent performance
  • ID generation uses AtomicLong for lock-free operation
See Also:

  • Method Details

    • getInstance

      public static ResourceTracker getInstance()
      Returns the singleton instance.
      Returns:
      the tracker instance

    • setEnabled

      public void setEnabled(boolean enabled)
      Enables or disables tracking.
      Parameters:
      enabled - true to enable tracking

    • isEnabled

      public boolean isEnabled()
      Checks if tracking is enabled.
      Returns:
      true if tracking is enabled

    • setCaptureStackTraces

      public void setCaptureStackTraces(boolean capture)
      Enables or disables stack trace capture.

      Warning: Stack trace capture is expensive and should only be enabled during development or debugging.

      Parameters:
      capture - true to capture stack traces

    • trackAllocation

      public long trackAllocation(String source, long sizeBytes)
      Tracks a new allocation.
      Parameters:
      source - identifier for the allocation source (e.g., "BufferPool")
      sizeBytes - the allocation size in bytes
      Returns:
      allocation ID for later release tracking

    • trackRelease

      public boolean trackRelease(long allocationId)
      Tracks release of an allocation.
      Parameters:
      allocationId - the ID returned from trackAllocation
      Returns:
      true if the allocation was found and removed

    • getActiveAllocations

      public Collection<ResourceTracker.AllocationRecord> getActiveAllocations()
      Returns all active (unreleased) allocations.
      Returns:
      collection of active allocation records

    • getActiveAllocationCount

      public int getActiveAllocationCount()
      Returns the number of active allocations.
      Returns:
      active allocation count

    • getActiveAllocationBytes

      public long getActiveAllocationBytes()
      Returns the total bytes currently allocated.
      Returns:
      total active allocation size

    • getTotalAllocated

      public long getTotalAllocated()
      Returns cumulative allocated bytes.
      Returns:
      total allocated bytes

    • getTotalReleased

      public long getTotalReleased()
      Returns cumulative released bytes.
      Returns:
      total released bytes

    • getAllocationCount

      public long getAllocationCount()
      Returns total allocation count.
      Returns:
      allocation count

    • getReleaseCount

      public long getReleaseCount()
      Returns total release count.
      Returns:
      release count

    • clear

      public void clear()
      Clears all tracking data.

    • getSummary

      public String getSummary()
      Returns a summary of tracking statistics.
      Returns:
      formatted statistics string