rust: Call _coz_add_delays() after counter increments#270
Merged
emeryberger merged 1 commit intoplasma-umass:masterfrom Feb 23, 2026
Merged
rust: Call _coz_add_delays() after counter increments#270emeryberger merged 1 commit intoplasma-umass:masterfrom
emeryberger merged 1 commit intoplasma-umass:masterfrom
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The Rust crate was not calling `_coz_add_delays()` after incrementing progress counters. The C `COZ_INCREMENT_COUNTER` macro in `coz.h` calls `_call_coz_add_delays()` after every increment — this is required for the profiler to inject virtual delays for causal profiling experiments. Without this call, the profiler detects 0 experiments despite counters being incremented correctly. Also changes the atomic ordering from SeqCst to Relaxed to match the C implementation (`__ATOMIC_RELAXED`), which is sufficient since libcoz uses its own synchronization. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
emeryberger
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Feb 23, 2026
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Summary
The Rust crate was not calling
_coz_add_delays()after incrementing progress counters, causing the profiler to detect 0 experiments despite counters being incremented correctly.The C
COZ_INCREMENT_COUNTERmacro incoz.hcalls_call_coz_add_delays()after every increment — this is how the profiler injects virtual delays for causal profiling experiments. The Rust crate was missing this critical call.This PR:
coz_add_delays()function that dynamically loads_coz_add_delaysviadlsym(matching the existing pattern for_coz_get_counter)coz_add_delays()after every counter increment inCounter::increment()SeqCsttoRelaxedto match the C implementation (__ATOMIC_RELAXED)Testing
Tested by profiling
rustdoc(the Rust documentation tool) with coz on thestm32f4crate (~224k LOC, ~35s documentation time):throughput_pointentries correctly recorded🤖 Generated with Claude Code