diff options
Diffstat (limited to 'lib/textui/log_memstats.go')
-rw-r--r-- | lib/textui/log_memstats.go | 16 |
1 files changed, 14 insertions, 2 deletions
diff --git a/lib/textui/log_memstats.go b/lib/textui/log_memstats.go index 6e3c3a1..31d526f 100644 --- a/lib/textui/log_memstats.go +++ b/lib/textui/log_memstats.go @@ -11,6 +11,13 @@ import ( "time" ) +// LiveMemUse is an object that stringifies as the live memory use of +// the program. +// +// It is intended to be used with dlog by attaching it as a field, so +// that all log lines include the current memory use: +// +// ctx = dlog.WithField(ctx, "mem", new(textui.LiveMemUse)) type LiveMemUse struct { mu sync.Mutex stats runtime.MemStats @@ -19,14 +26,19 @@ type LiveMemUse struct { var _ fmt.Stringer = (*LiveMemUse)(nil) -var liveMemUseUpdateInterval = Tunable(1 * time.Second) +// LiveMemUseUpdateInterval is the shortest interval on which +// LiveMemUse is willing to update; we have this minimum interval +// because it stops the world to collect memory statistics, so we +// don't want to be updating the statistics too often. +var LiveMemUseUpdateInterval = Tunable(1 * time.Second) +// String implements fmt.Stringer. func (o *LiveMemUse) String() string { o.mu.Lock() // runtime.ReadMemStats() calls stopTheWorld(), so we want to // rate-limit how often we call it. - if now := time.Now(); now.Sub(o.last) > liveMemUseUpdateInterval { + if now := time.Now(); now.Sub(o.last) > LiveMemUseUpdateInterval { runtime.ReadMemStats(&o.stats) o.last = now } |