perf(tracing): cache OTel tid syscall

[morrisonlevi]

Description

This was a feedback item from Bob that I wanted to split out so it can get specific attention. I'm still working on some microbenchmarking numbers.

Reviewer checklist

• Test coverage seems ok.
• Appropriate labels assigned.

[datadog-prod-us1-4]

 

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⚠️ Warnings

🚦 14 Pipeline jobs failed

DataDog/apm-reliability/dd-trace-php | ASAN test_c: [8.2, amd64]     

🧪 1 Test failed

All test failures are known flaky.

❄️ Known flaky: tmp/build_extension/tests/ext/live-debugger/debugger_log_probe.phpt (Installing a live debugger log probe) from php.tmp.build_extension.tests.ext.live.debugger  

int(30)
002+ 
003+ Fatal error: Uncaught Exception: wait for replay timeout in tmp/build_extension/tests/ext/live-debugger/live_debugger.inc:57
004+ Stack trace:
005+ #0 tmp/build_extension/tests/ext/live-debugger/debugger_log_probe.php(37): DebuggerLogReplayer->waitForDebuggerDataAndReplay()
006+ #1 {main}
007+   thrown in tmp/build_extension/tests/ext/live-debugger/live_debugger.inc on line 57
002- array(6) {
003-   ["service"]=>
004-   string(22) "debugger_log_probe.php"
...

Not introduced in this PR.

DataDog/apm-reliability/dd-trace-php | System Tests: [parametric]     

🧪 2 Tests failed

tests.parametric.test_otel_api_interoperability.Test_Otel_API_Interoperability.test_concurrent_traces_in_order[library_env0, parametric-php] from system_tests_suite  

requests.exceptions.HTTPError: 500 Server Error: Internal Server Error for url: http://localhost:4505/trace/otel/start_span

self = <tests.parametric.test_otel_api_interoperability.Test_Otel_API_Interoperability object at 0x7fc80a7601a0>
test_agent = <utils.docker_fixtures._test_agent.TestAgentAPI object at 0x7fc809676f30>
test_library = <utils.docker_fixtures._test_clients._test_client_parametric.ParametricTestClientApi object at 0x7fc809417e90>

    def test_concurrent_traces_in_order(self, test_agent: TestAgentAPI, test_library: APMLibrary):
        """- Basic concurrent traces and spans"""
        with (
            test_library,
...

tests.parametric.test_otel_api_interoperability.Test_Otel_API_Interoperability.test_otel_start_after_datadog_span[library_env0, parametric-php] from system_tests_suite  

requests.exceptions.HTTPError: 500 Server Error: Internal Server Error for url: http://localhost:4500/trace/otel/start_span

self = <tests.parametric.test_otel_api_interoperability.Test_Otel_API_Interoperability object at 0x7fabae293a70>
test_agent = <utils.docker_fixtures._test_agent.TestAgentAPI object at 0x7fabad302630>
test_library = <utils.docker_fixtures._test_clients._test_client_parametric.ParametricTestClientApi object at 0x7fabad736c60>

    def test_otel_start_after_datadog_span(self, test_agent: TestAgentAPI, test_library: APMLibrary):
        """- Start a span using the OTel API while a span created using the Datadog API already exists"""
        with test_library:
            with (
...

DataDog/apm-reliability/dd-trace-php | ASAN test_c with multiple observers: [8.4]     

View all 14 failed jobs.

ℹ️ Info

No other issues found (see more)

❄️ No new flaky tests detected

🔄 Datadog auto-retried 3 jobs - 1 passed on retry

🎯 Code Coverage (details)
• Patch Coverage: 100.00%
• Overall Coverage: 60.63% (-0.04%)

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