go/src/runtime/trace.go

var trace …

var traceAdvanceSema …

var traceShutdownSema …

// StartTrace enables tracing for the current process.
// While tracing, the data will be buffered and available via [ReadTrace].
// StartTrace returns an error if tracing is already enabled.
// Most clients should use the [runtime/trace] package or the [testing] package's
// -test.trace flag instead of calling StartTrace directly.
func StartTrace() error { … }

// StopTrace stops tracing, if it was previously enabled.
// StopTrace only returns after all the reads for the trace have completed.
func StopTrace() { … }

// traceAdvance moves tracing to the next generation, and cleans up the current generation,
// ensuring that it's flushed out before returning. If stopTrace is true, it disables tracing
// altogether instead of advancing to the next generation.
//
// traceAdvanceSema must not be held.
//
// traceAdvance is called by golang.org/x/exp/trace using linkname.
//
//go:linkname traceAdvance
func traceAdvance(stopTrace bool) { … }

func traceNextGen(gen uintptr) uintptr { … }

// traceRegisterLabelsAndReasons re-registers mark worker labels and
// goroutine stop/block reasons in the string table for the provided
// generation. Note: the provided generation must not have started yet.
func traceRegisterLabelsAndReasons(gen uintptr) { … }

// ReadTrace returns the next chunk of binary tracing data, blocking until data
// is available. If tracing is turned off and all the data accumulated while it
// was on has been returned, ReadTrace returns nil. The caller must copy the
// returned data before calling ReadTrace again.
// ReadTrace must be called from one goroutine at a time.
func ReadTrace() []byte { … }

// readTrace0 is ReadTrace's continuation on g0. This must run on the
// system stack because it acquires trace.lock.
//
//go:systemstack
func readTrace0() (buf []byte, park bool) { … }

// traceReader returns the trace reader that should be woken up, if any.
// Callers should first check (traceEnabled() || traceShuttingDown()).
//
// This must run on the system stack because it acquires trace.lock.
//
//go:systemstack
func traceReader() *g { … }

// traceReaderAvailable returns the trace reader if it is not currently
// scheduled and should be. Callers should first check that
// (traceEnabled() || traceShuttingDown()) is true.
func traceReaderAvailable() *g { … }

var traceAdvancer …

type traceAdvancerState …

// start starts a new traceAdvancer.
func (s *traceAdvancerState) start() { … }

// stop stops a traceAdvancer and blocks until it exits.
func (s *traceAdvancerState) stop() { … }

const defaultTraceAdvancePeriod …

type wakeableSleep …

// newWakeableSleep initializes a new wakeableSleep and returns it.
func newWakeableSleep() *wakeableSleep { … }

// sleep sleeps for the provided duration in nanoseconds or until
// another goroutine calls wake.
//
// Must not be called by more than one goroutine at a time and
// must not be called concurrently with close.
func (s *wakeableSleep) sleep(ns int64) { … }

// wake awakens any goroutine sleeping on the timer.
//
// Safe for concurrent use with all other methods.
func (s *wakeableSleep) wake() { … }

// close wakes any goroutine sleeping on the timer and prevents
// further sleeping on it.
//
// Once close is called, the wakeableSleep must no longer be used.
//
// It must only be called once no goroutine is sleeping on the
// timer *and* nothing else will call wake concurrently.
func (s *wakeableSleep) close() { … }