perf: return TimerSequenceID by value instead of pointer - #11177
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Change timer helper functions to return (TimerSequenceID, bool) instead of *TimerSequenceID to avoid heap allocations on every call. Eliminates ~171MB of allocations per 5-minute benchmark run.
prathyushpv
reviewed
Aug 19, 2026
| TimerCreated: timerInfo.TaskStatus == TimerTaskStatusCreated, | ||
| Attempt: 1, | ||
| } | ||
| }, true |
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This is always true, so it is fine if we don't return the boolean here.
prathyushpv
approved these changes
Aug 19, 2026
Resolves conflicts with temporalio#11565, which split the activity timer getters into free functions plus thin method wrappers. Both forms now return (TimerSequenceID, bool), and getActivityTimerDeadlines iterates over the getters instead of over their results.
Unlike the activity getters, this one has no early returns, so the bool could never be false and the conditional around the call never filtered anything.
yiminc
approved these changes
Aug 19, 2026
yiminc
enabled auto-merge (squash)
August 19, 2026 03:59
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Motivation
TimerSequenceID(~48 bytes) is heap-allocated and returned as a*TimerSequenceIDfrom 5 getter functions:getUserTimerTimeout,getActivityScheduleToStartTimeout,getActivityScheduleToCloseTimeout,getActivityStartToCloseTimeout, andgetActivityHeartbeatTimeout. These are called for every pending timer/activity duringLoadAndSortUserTimers()andLoadAndSortActivityTimers()— a hot path in every workflow task.Callers were already dereferencing the pointer before appending to the value-type
[]TimerSequenceIDslice, so the existing code was allocating on the heap only to immediately copy to the stack.Changes
TimerSequenceIDis now returned by value with a(TimerSequenceID, bool)tupleImpact
Eliminates one heap allocation per getter call on the timer-sorting hot path.
Tests
service/history/workflow(1075 tests): ✅ passed