gtest-parallel

name	gtest-parallel
description	Run Google Test binaries in parallel using the gtest-parallel script. Use when needing to speed up test execution, run flaky tests with repeat, or filter specific tests.

gtest-parallel

gtest-parallel is a script that executes Google Test binaries in parallel, providing speedup for single-threaded tests and tests that do not run at 100% CPU.

Location

The script is located at third_party/gtest-parallel/gtest-parallel.

Core Flags

Filtering Tests

Use --gtest_filter to run a select set of tests. It supports the same syntax as Google Test (including exclusion with -).

third_party/gtest-parallel/gtest-parallel path/to/binary --gtest_filter=Foo.*:Bar.*

Timeouts

• --timeout=TIMEOUT: Interrupt all remaining processes after the given time (in seconds).
• --timeout_per_test=TIMEOUT_PER_TEST: Interrupt single processes after the given time (in seconds).

Output and Logging

• -d OUTPUT_DIR, --output_dir=OUTPUT_DIR: Output directory for test logs. Logs will be available under gtest-parallel-logs/ inside the specified directory.
• --dump_json_test_results=DUMP_JSON_TEST_RESULTS: Saves the results of the tests as a JSON machine-readable file.

Advanced Usage

Repeating Tests (Flakiness Testing)

Use --repeat=N to run tests multiple times.

third_party/gtest-parallel/gtest-parallel path/to/binary --repeat=1000

Workers

Use -w WORKERS or --workers=WORKERS to specify the number of parallel workers (defaults to the number of cores).

Serializing Test Cases

Use --serialize_test_cases to run tests within the same test case sequentially (useful if they share resources).