{
  "schemaVersion": 1,
  "license": "CC0-1.0",
  "generatedAt": "2026-10-17T22:31:46.294148+00:00",
  "method": "Duplicate a one-page pipe with tee(2), consume and hash the first branch, overwrite the file, then consume and hash the other branch.",
  "limits": [
    "This uses the Linux tee system call, not a test of GNU tee.",
    "Mutation deliberately violates the source-lifetime requirement.",
    "One host; no TCP, checksum-algorithm failure, performance or crash measurement."
  ],
  "environment": {
    "kernel": "6.8.0-146-generic",
    "python": "3.12.3",
    "machine": "x86_64",
    "filesystem_magic_label": "ext2/ext3"
  },
  "repetitions": 5,
  "casesPerRepetition": 2,
  "sourceSha256": "54c8a96b7d07ccccd510eedf513a545f3f48c8a0bbfc58107ae00fb08193261a",
  "helperSha256": "b67fb20a42c36fa650d83815895df8a980ad023beec0cb21029c59dd8915da39",
  "observations": [
    {
      "repetition": 1,
      "mode": "sendfile",
      "page_size_bytes": 4096,
      "enqueue_return_bytes": 4096,
      "tee_return_bytes": 4096,
      "events": [
        "enqueue",
        "tee",
        "read-first",
        "hash-first",
        "overwrite-source",
        "read-second",
        "hash-second"
      ],
      "first_consumer": {
        "bytes": 4096,
        "sha256": "6896d9ea3f73a4434f5832bc65714e7d066f177373f36f34dc8a6f735daa41b1",
        "uniform_byte": "A"
      },
      "second_consumer": {
        "bytes": 4096,
        "sha256": "725bcd6c66d02acf6ebeab9c92410e010ea22e336876256aaf05a211f4ce1902",
        "uniform_byte": "B"
      },
      "consumer_hashes_equal": false
    },
    {
      "repetition": 1,
      "mode": "buffered",
      "page_size_bytes": 4096,
      "enqueue_return_bytes": 4096,
      "tee_return_bytes": 4096,
      "events": [
        "enqueue",
        "tee",
        "read-first",
        "hash-first",
        "overwrite-source",
        "read-second",
        "hash-second"
      ],
      "first_consumer": {
        "bytes": 4096,
        "sha256": "6896d9ea3f73a4434f5832bc65714e7d066f177373f36f34dc8a6f735daa41b1",
        "uniform_byte": "A"
      },
      "second_consumer": {
        "bytes": 4096,
        "sha256": "6896d9ea3f73a4434f5832bc65714e7d066f177373f36f34dc8a6f735daa41b1",
        "uniform_byte": "A"
      },
      "consumer_hashes_equal": true
    },
    {
      "repetition": 2,
      "mode": "sendfile",
      "page_size_bytes": 4096,
      "enqueue_return_bytes": 4096,
      "tee_return_bytes": 4096,
      "events": [
        "enqueue",
        "tee",
        "read-first",
        "hash-first",
        "overwrite-source",
        "read-second",
        "hash-second"
      ],
      "first_consumer": {
        "bytes": 4096,
        "sha256": "6896d9ea3f73a4434f5832bc65714e7d066f177373f36f34dc8a6f735daa41b1",
        "uniform_byte": "A"
      },
      "second_consumer": {
        "bytes": 4096,
        "sha256": "725bcd6c66d02acf6ebeab9c92410e010ea22e336876256aaf05a211f4ce1902",
        "uniform_byte": "B"
      },
      "consumer_hashes_equal": false
    },
    {
      "repetition": 2,
      "mode": "buffered",
      "page_size_bytes": 4096,
      "enqueue_return_bytes": 4096,
      "tee_return_bytes": 4096,
      "events": [
        "enqueue",
        "tee",
        "read-first",
        "hash-first",
        "overwrite-source",
        "read-second",
        "hash-second"
      ],
      "first_consumer": {
        "bytes": 4096,
        "sha256": "6896d9ea3f73a4434f5832bc65714e7d066f177373f36f34dc8a6f735daa41b1",
        "uniform_byte": "A"
      },
      "second_consumer": {
        "bytes": 4096,
        "sha256": "6896d9ea3f73a4434f5832bc65714e7d066f177373f36f34dc8a6f735daa41b1",
        "uniform_byte": "A"
      },
      "consumer_hashes_equal": true
    },
    {
      "repetition": 3,
      "mode": "sendfile",
      "page_size_bytes": 4096,
      "enqueue_return_bytes": 4096,
      "tee_return_bytes": 4096,
      "events": [
        "enqueue",
        "tee",
        "read-first",
        "hash-first",
        "overwrite-source",
        "read-second",
        "hash-second"
      ],
      "first_consumer": {
        "bytes": 4096,
        "sha256": "6896d9ea3f73a4434f5832bc65714e7d066f177373f36f34dc8a6f735daa41b1",
        "uniform_byte": "A"
      },
      "second_consumer": {
        "bytes": 4096,
        "sha256": "725bcd6c66d02acf6ebeab9c92410e010ea22e336876256aaf05a211f4ce1902",
        "uniform_byte": "B"
      },
      "consumer_hashes_equal": false
    },
    {
      "repetition": 3,
      "mode": "buffered",
      "page_size_bytes": 4096,
      "enqueue_return_bytes": 4096,
      "tee_return_bytes": 4096,
      "events": [
        "enqueue",
        "tee",
        "read-first",
        "hash-first",
        "overwrite-source",
        "read-second",
        "hash-second"
      ],
      "first_consumer": {
        "bytes": 4096,
        "sha256": "6896d9ea3f73a4434f5832bc65714e7d066f177373f36f34dc8a6f735daa41b1",
        "uniform_byte": "A"
      },
      "second_consumer": {
        "bytes": 4096,
        "sha256": "6896d9ea3f73a4434f5832bc65714e7d066f177373f36f34dc8a6f735daa41b1",
        "uniform_byte": "A"
      },
      "consumer_hashes_equal": true
    },
    {
      "repetition": 4,
      "mode": "sendfile",
      "page_size_bytes": 4096,
      "enqueue_return_bytes": 4096,
      "tee_return_bytes": 4096,
      "events": [
        "enqueue",
        "tee",
        "read-first",
        "hash-first",
        "overwrite-source",
        "read-second",
        "hash-second"
      ],
      "first_consumer": {
        "bytes": 4096,
        "sha256": "6896d9ea3f73a4434f5832bc65714e7d066f177373f36f34dc8a6f735daa41b1",
        "uniform_byte": "A"
      },
      "second_consumer": {
        "bytes": 4096,
        "sha256": "725bcd6c66d02acf6ebeab9c92410e010ea22e336876256aaf05a211f4ce1902",
        "uniform_byte": "B"
      },
      "consumer_hashes_equal": false
    },
    {
      "repetition": 4,
      "mode": "buffered",
      "page_size_bytes": 4096,
      "enqueue_return_bytes": 4096,
      "tee_return_bytes": 4096,
      "events": [
        "enqueue",
        "tee",
        "read-first",
        "hash-first",
        "overwrite-source",
        "read-second",
        "hash-second"
      ],
      "first_consumer": {
        "bytes": 4096,
        "sha256": "6896d9ea3f73a4434f5832bc65714e7d066f177373f36f34dc8a6f735daa41b1",
        "uniform_byte": "A"
      },
      "second_consumer": {
        "bytes": 4096,
        "sha256": "6896d9ea3f73a4434f5832bc65714e7d066f177373f36f34dc8a6f735daa41b1",
        "uniform_byte": "A"
      },
      "consumer_hashes_equal": true
    },
    {
      "repetition": 5,
      "mode": "sendfile",
      "page_size_bytes": 4096,
      "enqueue_return_bytes": 4096,
      "tee_return_bytes": 4096,
      "events": [
        "enqueue",
        "tee",
        "read-first",
        "hash-first",
        "overwrite-source",
        "read-second",
        "hash-second"
      ],
      "first_consumer": {
        "bytes": 4096,
        "sha256": "6896d9ea3f73a4434f5832bc65714e7d066f177373f36f34dc8a6f735daa41b1",
        "uniform_byte": "A"
      },
      "second_consumer": {
        "bytes": 4096,
        "sha256": "725bcd6c66d02acf6ebeab9c92410e010ea22e336876256aaf05a211f4ce1902",
        "uniform_byte": "B"
      },
      "consumer_hashes_equal": false
    },
    {
      "repetition": 5,
      "mode": "buffered",
      "page_size_bytes": 4096,
      "enqueue_return_bytes": 4096,
      "tee_return_bytes": 4096,
      "events": [
        "enqueue",
        "tee",
        "read-first",
        "hash-first",
        "overwrite-source",
        "read-second",
        "hash-second"
      ],
      "first_consumer": {
        "bytes": 4096,
        "sha256": "6896d9ea3f73a4434f5832bc65714e7d066f177373f36f34dc8a6f735daa41b1",
        "uniform_byte": "A"
      },
      "second_consumer": {
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        "sha256": "6896d9ea3f73a4434f5832bc65714e7d066f177373f36f34dc8a6f735daa41b1",
        "uniform_byte": "A"
      },
      "consumer_hashes_equal": true
    }
  ]
}