Raise the HTTP server’s listen backlog to 128 - #1
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sideshowbarker wants to merge 1 commit into
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Problem: In a macOS 27 environment, Speedometer 2/3 wedged partway through, with every browser process idle, after 45/48 and 6/58 tests. StyleBenchConservative never reached its first test — so three of the ten suites couldn’t be run in that environment at all. Cause: The benchmark server is a single-threaded HTTPServer with the default listen backlog of 5, and it accepts connections one at a time. Speedometer burst opens 7–8 connections in 1ms (TodoMVC-WebComponents fetches 20 files in two such waves). So the queue overflows at the edge. Linux then queues the overflow, and the client retransmits 1s later; but macOS aborts it with a reset — which RequestServer reports as curl error 56, and LibWeb as a failed script load. Which fetch loses is a race: a lost speculative preload is harmless, since the script element fetches again on its own — but a lost script fetch leaves the app under test un- initialized. A test step throws, the runner’s promise never resolves, and nothing’s left pending — hence the idle browser. One Speedometer 2 run on this server had 14 fetches reset yet still completed, others never got Flight-TodoMVC up at all, and StyleBenchConservative lost its own runner scripts, tests.js and style-bench.js, and never started. Fix: Give the server a backlog of 128, which is the most macOS allows and more than any suite opens at once. With that one change, and none to the browser, Speedometer 2/3, and StyleBenchConservative all run to completion in the tested environment — without a single failed load.
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Problem: In a macOS 27 environment, Speedometer 2/3 wedged partway through, with every browser process idle, after 45/48 and 6/58 tests. StyleBenchConservative never reached its first test — so three of the ten suites couldn’t be run in that environment at all.
Cause: The benchmark server is a single-threaded
HTTPServerwith the default listen backlog of 5, and it accepts connections one at a time. Speedometer burst opens 7–8 connections in 1ms (TodoMVC-WebComponents fetches 20 files in two such waves). So the queue overflows at the edge. Linux then queues the overflow, and the client retransmits 1s later; but macOS aborts it with a reset — which RequestServer reports as curl error 56, and LibWeb as a failed script load. Which fetch loses is a race: a lost speculative preload is harmless, since the script element fetches again on its own — but a lost script fetch leaves the app under test uninitialized. A test step throws, the runner’s promise never resolves, and nothing’s left pending — hence the idle browser. One Speedometer 2 run on this server had 14 fetches reset yet still completed, others never got Flight-TodoMVC up at all, and StyleBenchConservative lost its own runner scripts,tests.jsandstyle-bench.js, and never started.Fix: Give the server a backlog of 128, which is the most macOS allows and more than any suite opens at once. With that one change, and none to the browser, Speedometer 2/3, and StyleBenchConservative all run to completion in the tested environment — without a single failed load.