)]}'
{
  "commit": "a4de90e0c2e038ab0462490a72d6697a25c49063",
  "tree": "bfd56c71736266a2221e76f3916b2a7a9e2c69a3",
  "parents": [
    "83347c648ceef075d7137b7d7656729125eb8bc3"
  ],
  "author": {
    "name": "S Ashwin Balaji",
    "email": "sashwinbalaji@google.com",
    "time": "Thu Aug 13 12:07:49 2026 +0100"
  },
  "committer": {
    "name": "S Ashwin Balaji",
    "email": "sashwinbalaji@google.com",
    "time": "Thu Aug 13 12:07:49 2026 +0100"
  },
  "message": "tracing v2: pin the 32-bit wrapping cursor contract\n\nPositions are wrapping logical tickets: the physical slot is\npos \u0026 (num_chunks - 1), capacity is the unsigned modular difference of\nthe cursors, and ordering goes through IsPositionAtOrAfter()\u0027s\nhalf-space comparison. That comparison is valid only within 2^31\nadvances; the ring keeps live cursors at most num_chunks apart, and\nStep 1 assumes no actor compares a sample held across ~a complete\n32-bit lap (at 256-byte chunks one lap is 2^32 * 256B \u003d 1 TiB of\ntraffic through a single producer ring). Both bounds are now stated at\nthe cursor fields and at the comparison, with a TODO to revisit before\nthe cursors become a cross-process ABI.\n\nAdds direct boundary tests: equality at and away from the wrap, one\nadvance across zero, the largest in-contract distance 2^31 - 1, and\nthe exactly-2^31 cliff documented as outside the contract (both\nviewpoints report \"before\"). Delayed-claim-at-rollover coverage\nalready exists in the delayed-writer and reclaim tests seeded at\n0xffffffff.\n\nNo behavior change; comments and tests only.\n\nBug: 536851377\n",
  "tree_diff": [
    {
      "type": "modify",
      "old_id": "35a9e1c2612c8fe82b4e1f10bce2de6c89bacea7",
      "old_mode": 33188,
      "old_path": "src/tracing/v2/shared_ring_buffer.h",
      "new_id": "dac7bd2e966472810769d08442481bae04332607",
      "new_mode": 33188,
      "new_path": "src/tracing/v2/shared_ring_buffer.h"
    },
    {
      "type": "modify",
      "old_id": "99df57a67475110a9346853dbeb59ee19f959f96",
      "old_mode": 33188,
      "old_path": "src/tracing/v2/shared_ring_buffer_unittest.cc",
      "new_id": "9f030338928ad1a902114035f961dbe46030b89d",
      "new_mode": 33188,
      "new_path": "src/tracing/v2/shared_ring_buffer_unittest.cc"
    }
  ]
}