Description

This PR enhances the live allocation profiling system with comprehensive diagnostic capabilities to better track and troubleshoot allocation/deallocation mismatches and data loss.

Key Changes:

1. New Performance Event Types

• Added PERF_CUSTOM_EVENT_LOST_ALLOCATION to track lost allocation and deallocation events separately
• Added PERF_CUSTOM_EVENT_ALLOCATION_TRACKER_STATE to periodically report the allocation tracker's internal state

2. Enhanced Event Structures

• LostAllocationEvent: Replaces generic lost events with separate counters for lost_alloc_count and lost_dealloc_count
• AllocationTrackerStateEvent: Reports tracked_addresse_count and address_conflict_count from the library

3. Improved Statistics Tracking

• Added EVENT_DEALLOC_LOST stat to separately track lost deallocation events
• Added ALREADY_EXISTING_ALLOCATION_COUNT stat to count duplicate allocations at the same address (indicating missed free events)

4. Allocation Tracker Enhancements

• Split lost_count into separate lost_alloc_count and lost_dealloc_count atomics for granular tracking
• Added address_conflict_count to track hash collisions in the address set
• Implemented push_allocation_tracker_state() to periodically report library state to the profiler
• Integrated state reporting with the timer callback mechanism

5. Live Allocation Diagnostics

• Added register_library_state() method to synchronize library state with profiler's view
• Tracks address_conflict_count and tracked_address_count per PID

6. Enhanced Logging and Visibility

• Consolidated diagnostic logging in register_library_state() showing:
  • Live allocations tracked by profiler (_address_map.size())
  • Unique stacks (_unique_stacks.size())
  • Library-tracked addresses (_tracked_address_count)
  • Address conflicts from library (_address_conflict_count)
• Above log was moved from aggregation phase, because consistency between library and profiler can only be assessed when library sends its status
• Added debug logging for clearing live allocations and state reporting

Benefits:

These diagnostics provide better visibility into allocation tracking health, making it easier to identify when events are lost, when allocations/deallocations are mismatched, and when the library and profiler states diverge. This is crucial for debugging live heap profiling in production environments.