From 27eed480eee240e8417d07d2f56b6b650a87006b Mon Sep 17 00:00:00 2001
From: Carlo Cabrera <30379873+carlocab@users.noreply.github.com>
Date: Wed, 3 May 2023 17:48:21 +0800
Subject: [PATCH] github_runner_matrix: improve macOS timeout handling

1. Use the maximum timeout possible for GitHub-hosted macOS runners
2. When using a short timeout, use an even shorter timeout on ARM
   runners.

Our ARM runners are typically at least twice as fast as our Intel
runners on any given job. So, if it takes an ARM runner over half the
timeout to complete a job, it's almost certain that the Intel runner
will not complete the job within the timeout.

Setting an even shorter timeout on the ARM runners will help us abandon
jobs that are unlikely to be completed within the timeout well before we
hit the requested timeout.
---
 Library/Homebrew/github_runner_matrix.rb | 35 +++++++++++++++---------
 1 file changed, 22 insertions(+), 13 deletions(-)

diff --git a/Library/Homebrew/github_runner_matrix.rb b/Library/Homebrew/github_runner_matrix.rb
index 4506e84e65..76462179ff 100644
--- a/Library/Homebrew/github_runner_matrix.rb
+++ b/Library/Homebrew/github_runner_matrix.rb
@@ -63,6 +63,7 @@ class GitHubRunnerMatrix
   private
 
   SELF_HOSTED_LINUX_RUNNER = "linux-self-hosted-1"
+  GITHUB_ACTIONS_LONG_TIMEOUT = 4320
 
   sig { returns(LinuxRunnerSpec) }
   def linux_runner_spec
@@ -76,7 +77,7 @@ class GitHubRunnerMatrix
         options: "--user=linuxbrew -e GITHUB_ACTIONS_HOMEBREW_SELF_HOSTED",
       },
       workdir:   "/github/home",
-      timeout:   4320,
+      timeout:   GITHUB_ACTIONS_LONG_TIMEOUT,
       cleanup:   linux_runner == SELF_HOSTED_LINUX_RUNNER,
     )
   end
@@ -130,33 +131,41 @@ class GitHubRunnerMatrix
       runner_timeout += 30 if macos_version <= :big_sur
 
       # Use GitHub Actions macOS Runner for testing dependents if compatible with timeout.
-      runner, cleanup = if (@dependent_matrix || use_github_runner) &&
-                           macos_version <= NEWEST_GITHUB_ACTIONS_MACOS_RUNNER &&
-                           runner_timeout <= GITHUB_ACTIONS_RUNNER_TIMEOUT
-        ["macos-#{version}", true]
+      runner, runner_timeout = if (@dependent_matrix || use_github_runner) &&
+                                  macos_version <= NEWEST_GITHUB_ACTIONS_MACOS_RUNNER &&
+                                  runner_timeout <= GITHUB_ACTIONS_RUNNER_TIMEOUT
+        ["macos-#{version}", GITHUB_ACTIONS_RUNNER_TIMEOUT]
       else
-        ["#{version}#{ephemeral_suffix}", false]
+        ["#{version}#{ephemeral_suffix}", runner_timeout]
       end
 
       spec = MacOSRunnerSpec.new(
         name:    "macOS #{version}-x86_64",
         runner:  runner,
         timeout: runner_timeout,
-        cleanup: cleanup,
+        cleanup: !runner.end_with?(ephemeral_suffix),
       )
       @runners << create_runner(:macos, :x86_64, spec, macos_version)
 
       next if macos_version < :big_sur
 
+      runner = +"#{version}-arm64"
+
       # Use bare metal runner when testing dependents on ARM64 Monterey.
       use_ephemeral = macos_version >= (@dependent_matrix ? :ventura : :monterey)
-      runner, cleanup = if use_ephemeral
-        ["#{version}-arm64#{ephemeral_suffix}", false]
-      else
-        ["#{version}-arm64", true]
-      end
+      runner << ephemeral_suffix if use_ephemeral
 
-      spec = MacOSRunnerSpec.new(name: "macOS #{version}-arm64", runner: runner, timeout: timeout, cleanup: cleanup)
+      runner.freeze
+
+      # The ARM runners are typically over twice as fast as the Intel runners.
+      runner_timeout = timeout
+      runner_timeout /= 2 if timeout < GITHUB_ACTIONS_LONG_TIMEOUT
+      spec = MacOSRunnerSpec.new(
+        name:    "macOS #{version}-arm64",
+        runner:  runner,
+        timeout: runner_timeout,
+        cleanup: !runner.end_with?(ephemeral_suffix),
+      )
       @runners << create_runner(:macos, :arm64, spec, macos_version)
     end