olivierli@chromium.org catan-team@chromium.org

Every 10 seconds, a boolean is recorded to this histogram to indicate whether {BrowserProcessAndThreadType} was hung. The thread is hung if the current work unit started running more than 10 seconds ago and this was not labeled as "working as intended" by InvalidateActiveExpectations() (Prior to 2021-07-09 with IgnoreHangsInScope). Recording is skipped if the hang watcher detects an irregular heartbeat (e.g. when the machine sleeps). Warning: Starting with 104.0.5112.79 hang counts have gone way up on macOS which is due to additional coverage added and not necessarily to regressions. See: crrev.com/c/3035824 Deprecated. For Chrome M127 and higher, look at HangWatcher.IsThreadHung.<process>.<phase> instead.

olivierli@chromium.org catan-team@chromium.org

Every 10 seconds, a boolean is recorded to this histogram to indicate whether {BrowserProcessAndThreadType} was hung during {LifetimePhase}. The thread is hung if the current work unit started running more than 10 seconds ago and this was not labeled as "working as intended" by InvalidateActiveExpectations(). Recording is skipped if the hang watcher detects an irregular heartbeat (e.g. when the machine sleeps).

olivierli@chromium.org catan-team@chromium.org

Every 10 seconds, a boolean is recorded to this histogram to indicate whether {NonBrowserProcessAndThreadType} was hung. The thread is hung if the current work unit started running more than 10 seconds ago and this was not labeled as "working as intended" by InvalidateActiveExpectations() (Prior to 2021-07-09 with IgnoreHangsInScope). Recording is skipped if the hang watcher detects an irregular heartbeat (e.g. when the machine sleeps). Warning: Starting with 104.0.5112.79 hang counts have gone way up on macOS which is due to additional coverage added and not necessarily to regressions. See: crrev.com/c/3035824

olivierli@chromium.org catan-team@chromium.org

Every 10 seconds, a boolean is recorded to this histogram to indicate whether {ThreadSetType} thread was hung. A thread is hung if the current work unit started running more than 10 seconds ago and this was not labeled as "working as intended" by InvalidateActiveExpectations(). Recording is skipped if the hang watcher detects an irregular heartbeat (e.g. when the machine sleeps). Warning: Starting at 150.0.7865.0, background renderer threads are no longer considered critical.

olivierli@chromium.org catan-team@chromium.org

Because HangWatcher start is delayed until the sandbox is initialized on Linux and ChromeOS, this measures the delta between the time HangWatcher would have started in an unsandboxed process and the time the HangWatcher actually started. The metric is emitted in the process type's main function (e.g. RendererMain, UtilityMain) right after the sandbox is engaged and right before HangWatcher is started. This will be used to evaluate whether hangs are missed during startup because of this delay. Warning: this histogram was expired from 2023-12-22 to 2025-07-04; data may be missing.