From d33ee0c5e52cbdc66066f54b9b2e2c930268784a Mon Sep 17 00:00:00 2001 From: Rob Pike Date: Tue, 9 Sep 2014 12:31:07 -0700 Subject: [PATCH] testing: read coverage counters atomically For -mode=atomic, we need to read the counters using an atomic load to avoid a race. Not worth worrying about when -mode=atomic is set during generation of the profile, so we use atomic loads always. Fixes #8630. LGTM=rsc R=dvyukov, rsc CC=golang-codereviews https://golang.org/cl/141800043 --- src/testing/cover.go | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/src/testing/cover.go b/src/testing/cover.go index eb7249dccd..a4ce37f7c2 100644 --- a/src/testing/cover.go +++ b/src/testing/cover.go @@ -9,6 +9,7 @@ package testing import ( "fmt" "os" + "sync/atomic" ) // CoverBlock records the coverage data for a single basic block. @@ -44,8 +45,8 @@ type Cover struct { func Coverage() float64 { var n, d int64 for _, counters := range cover.Counters { - for _, c := range counters { - if c > 0 { + for i := range counters { + if atomic.LoadUint32(&counters[i]) > 0 { n++ } d++ @@ -84,11 +85,13 @@ func coverReport() { } var active, total int64 + var count uint32 for name, counts := range cover.Counters { blocks := cover.Blocks[name] - for i, count := range counts { + for i := range counts { stmts := int64(blocks[i].Stmts) total += stmts + count = atomic.LoadUint32(&counts[i]) // For -mode=atomic. if count > 0 { active += stmts } -- 2.50.0