go/src/runtime/mstats.go

type mstats …

var memstats …

type MemStats …

func init() { … }

// ReadMemStats populates m with memory allocator statistics.
//
// The returned memory allocator statistics are up to date as of the
// call to ReadMemStats. This is in contrast with a heap profile,
// which is a snapshot as of the most recently completed garbage
// collection cycle.
func ReadMemStats(m *MemStats) { … }

var doubleCheckReadMemStats …

// readmemstats_m populates stats for internal runtime values.
//
// The world must be stopped.
func readmemstats_m(stats *MemStats) { … }

//go:linkname readGCStats runtime/debug.readGCStats
func readGCStats(pauses *[]uint64) { … }

// readGCStats_m must be called on the system stack because it acquires the heap
// lock. See mheap for details.
//
//go:systemstack
func readGCStats_m(pauses *[]uint64) { … }

// flushmcache flushes the mcache of allp[i].
//
// The world must be stopped.
//
//go:nowritebarrier
func flushmcache(i int) { … }

// flushallmcaches flushes the mcaches of all Ps.
//
// The world must be stopped.
//
//go:nowritebarrier
func flushallmcaches() { … }

type sysMemStat …

// load atomically reads the value of the stat.
//
// Must be nosplit as it is called in runtime initialization, e.g. newosproc0.
//
//go:nosplit
func (s *sysMemStat) load() uint64 { … }

// add atomically adds the sysMemStat by n.
//
// Must be nosplit as it is called in runtime initialization, e.g. newosproc0.
//
//go:nosplit
func (s *sysMemStat) add(n int64) { … }

type heapStatsDelta …

// merge adds in the deltas from b into a.
func (a *heapStatsDelta) merge(b *heapStatsDelta) { … }

type consistentHeapStats …

// acquire returns a heapStatsDelta to be updated. In effect,
// it acquires the shard for writing. release must be called
// as soon as the relevant deltas are updated.
//
// The returned heapStatsDelta must be updated atomically.
//
// The caller's P must not change between acquire and
// release. This also means that the caller should not
// acquire a P or release its P in between. A P also must
// not acquire a given consistentHeapStats if it hasn't
// yet released it.
//
// nosplit because a stack growth in this function could
// lead to a stack allocation that could reenter the
// function.
//
//go:nosplit
func (m *consistentHeapStats) acquire() *heapStatsDelta { … }

// release indicates that the writer is done modifying
// the delta. The value returned by the corresponding
// acquire must no longer be accessed or modified after
// release is called.
//
// The caller's P must not change between acquire and
// release. This also means that the caller should not
// acquire a P or release its P in between.
//
// nosplit because a stack growth in this function could
// lead to a stack allocation that causes another acquire
// before this operation has completed.
//
//go:nosplit
func (m *consistentHeapStats) release() { … }

// unsafeRead aggregates the delta for this shard into out.
//
// Unsafe because it does so without any synchronization. The
// world must be stopped.
func (m *consistentHeapStats) unsafeRead(out *heapStatsDelta) { … }

// unsafeClear clears the shard.
//
// Unsafe because the world must be stopped and values should
// be donated elsewhere before clearing.
func (m *consistentHeapStats) unsafeClear() { … }

// read takes a globally consistent snapshot of m
// and puts the aggregated value in out. Even though out is a
// heapStatsDelta, the resulting values should be complete and
// valid statistic values.
//
// Not safe to call concurrently. The world must be stopped
// or metricsSema must be held.
func (m *consistentHeapStats) read(out *heapStatsDelta) { … }

type cpuStats …

// accumulateGCPauseTime add dt*stwProcs to the GC CPU pause time stats. dt should be
// the actual time spent paused, for orthogonality. maxProcs should be GOMAXPROCS,
// not work.stwprocs, since this number must be comparable to a total time computed
// from GOMAXPROCS.
func (s *cpuStats) accumulateGCPauseTime(dt int64, maxProcs int32) { … }

// accumulate takes a cpuStats and adds in the current state of all GC CPU
// counters.
//
// gcMarkPhase indicates that we're in the mark phase and that certain counter
// values should be used.
func (s *cpuStats) accumulate(now int64, gcMarkPhase bool) { … }