metrics/debug_test.go


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package metrics

import (
    "runtime"
    "runtime/debug"
    "testing"
    "time"
)

func BenchmarkDebugGCStats(b *testing.B) {
    r := NewRegistry()
    RegisterDebugGCStats(r)
    b.ResetTimer()
    for i := 0; i < b.N; i++ {
        CaptureDebugGCStatsOnce(r)
    }
}

func TestDebugGCStatsBlocking(t *testing.T) {
    if g := runtime.GOMAXPROCS(0); g < 2 {
        t.Skipf("skipping TestDebugGCMemStatsBlocking with GOMAXPROCS=%d\n", g)
        return
    }
    ch := make(chan int)
    go testDebugGCStatsBlocking(ch)
    var gcStats debug.GCStats
    t0 := time.Now()
    debug.ReadGCStats(&gcStats)
    t1 := time.Now()
    t.Log("i++ during debug.ReadGCStats:", <-ch)
    go testDebugGCStatsBlocking(ch)
    d := t1.Sub(t0)
    t.Log(d)
    time.Sleep(d)
    t.Log("i++ during time.Sleep:", <-ch)
}

func testDebugGCStatsBlocking(ch chan int) {
    i := 0
    for {
        select {
        case ch <- i:
            return
        default:
            i++
        }
    }
}