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Diffstat (limited to '')
| -rw-r--r-- | src/runtime/trace2event.go | 194 |
1 files changed, 194 insertions, 0 deletions
diff --git a/src/runtime/trace2event.go b/src/runtime/trace2event.go new file mode 100644 index 0000000..1f2a9f7 --- /dev/null +++ b/src/runtime/trace2event.go @@ -0,0 +1,194 @@ +// Copyright 2023 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +//go:build goexperiment.exectracer2 + +// Trace event writing API for trace2runtime.go. + +package runtime + +import ( + "runtime/internal/sys" +) + +// Event types in the trace, args are given in square brackets. +// +// Naming scheme: +// - Time range event pairs have suffixes "Begin" and "End". +// - "Start", "Stop", "Create", "Destroy", "Block", "Unblock" +// are suffixes reserved for scheduling resources. +// +// NOTE: If you add an event type, make sure you also update all +// tables in this file! +type traceEv uint8 + +const ( + traceEvNone traceEv = iota // unused + + // Structural events. + traceEvEventBatch // start of per-M batch of events [generation, M ID, timestamp, batch length] + traceEvStacks // start of a section of the stack table [...traceEvStack] + traceEvStack // stack table entry [ID, ...{PC, func string ID, file string ID, line #}] + traceEvStrings // start of a section of the string dictionary [...traceEvString] + traceEvString // string dictionary entry [ID, length, string] + traceEvCPUSamples // start of a section of CPU samples [...traceEvCPUSample] + traceEvCPUSample // CPU profiling sample [timestamp, M ID, P ID, goroutine ID, stack ID] + traceEvFrequency // timestamp units per sec [freq] + + // Procs. + traceEvProcsChange // current value of GOMAXPROCS [timestamp, GOMAXPROCS, stack ID] + traceEvProcStart // start of P [timestamp, P ID, P seq] + traceEvProcStop // stop of P [timestamp] + traceEvProcSteal // P was stolen [timestamp, P ID, P seq, M ID] + traceEvProcStatus // P status at the start of a generation [timestamp, P ID, status] + + // Goroutines. + traceEvGoCreate // goroutine creation [timestamp, new goroutine ID, new stack ID, stack ID] + traceEvGoCreateSyscall // goroutine appears in syscall (cgo callback) [timestamp, new goroutine ID] + traceEvGoStart // goroutine starts running [timestamp, goroutine ID, goroutine seq] + traceEvGoDestroy // goroutine ends [timestamp] + traceEvGoDestroySyscall // goroutine ends in syscall (cgo callback) [timestamp] + traceEvGoStop // goroutine yields its time, but is runnable [timestamp, reason, stack ID] + traceEvGoBlock // goroutine blocks [timestamp, reason, stack ID] + traceEvGoUnblock // goroutine is unblocked [timestamp, goroutine ID, goroutine seq, stack ID] + traceEvGoSyscallBegin // syscall enter [timestamp, P seq, stack ID] + traceEvGoSyscallEnd // syscall exit [timestamp] + traceEvGoSyscallEndBlocked // syscall exit and it blocked at some point [timestamp] + traceEvGoStatus // goroutine status at the start of a generation [timestamp, goroutine ID, M ID, status] + + // STW. + traceEvSTWBegin // STW start [timestamp, kind] + traceEvSTWEnd // STW done [timestamp] + + // GC events. + traceEvGCActive // GC active [timestamp, seq] + traceEvGCBegin // GC start [timestamp, seq, stack ID] + traceEvGCEnd // GC done [timestamp, seq] + traceEvGCSweepActive // GC sweep active [timestamp, P ID] + traceEvGCSweepBegin // GC sweep start [timestamp, stack ID] + traceEvGCSweepEnd // GC sweep done [timestamp, swept bytes, reclaimed bytes] + traceEvGCMarkAssistActive // GC mark assist active [timestamp, goroutine ID] + traceEvGCMarkAssistBegin // GC mark assist start [timestamp, stack ID] + traceEvGCMarkAssistEnd // GC mark assist done [timestamp] + traceEvHeapAlloc // gcController.heapLive change [timestamp, heap alloc in bytes] + traceEvHeapGoal // gcController.heapGoal() change [timestamp, heap goal in bytes] + + // Annotations. + traceEvGoLabel // apply string label to current running goroutine [timestamp, label string ID] + traceEvUserTaskBegin // trace.NewTask [timestamp, internal task ID, internal parent task ID, name string ID, stack ID] + traceEvUserTaskEnd // end of a task [timestamp, internal task ID, stack ID] + traceEvUserRegionBegin // trace.{Start,With}Region [timestamp, internal task ID, name string ID, stack ID] + traceEvUserRegionEnd // trace.{End,With}Region [timestamp, internal task ID, name string ID, stack ID] + traceEvUserLog // trace.Log [timestamp, internal task ID, key string ID, stack, value string ID] +) + +// traceArg is a simple wrapper type to help ensure that arguments passed +// to traces are well-formed. +type traceArg uint64 + +// traceEventWriter is the high-level API for writing trace events. +// +// See the comment on traceWriter about style for more details as to why +// this type and its methods are structured the way they are. +type traceEventWriter struct { + w traceWriter +} + +// eventWriter creates a new traceEventWriter. It is the main entrypoint for writing trace events. +// +// Before creating the event writer, this method will emit a status for the current goroutine +// or proc if it exists, and if it hasn't had its status emitted yet. goStatus and procStatus indicate +// what the status of goroutine or P should be immediately *before* the events that are about to +// be written using the eventWriter (if they exist). No status will be written if there's no active +// goroutine or P. +// +// Callers can elect to pass a constant value here if the status is clear (e.g. a goroutine must have +// been Runnable before a GoStart). Otherwise, callers can query the status of either the goroutine +// or P and pass the appropriate status. +// +// In this case, the default status should be traceGoBad or traceProcBad to help identify bugs sooner. +func (tl traceLocker) eventWriter(goStatus traceGoStatus, procStatus traceProcStatus) traceEventWriter { + w := tl.writer() + if pp := tl.mp.p.ptr(); pp != nil && !pp.trace.statusWasTraced(tl.gen) && pp.trace.acquireStatus(tl.gen) { + w = w.writeProcStatus(uint64(pp.id), procStatus, pp.trace.inSweep) + } + if gp := tl.mp.curg; gp != nil && !gp.trace.statusWasTraced(tl.gen) && gp.trace.acquireStatus(tl.gen) { + w = w.writeGoStatus(uint64(gp.goid), int64(tl.mp.procid), goStatus, gp.inMarkAssist) + } + return traceEventWriter{w} +} + +// commit writes out a trace event and calls end. It's a helper to make the +// common case of writing out a single event less error-prone. +func (e traceEventWriter) commit(ev traceEv, args ...traceArg) { + e = e.write(ev, args...) + e.end() +} + +// write writes an event into the trace. +func (e traceEventWriter) write(ev traceEv, args ...traceArg) traceEventWriter { + e.w = e.w.event(ev, args...) + return e +} + +// end finishes writing to the trace. The traceEventWriter must not be used after this call. +func (e traceEventWriter) end() { + e.w.end() +} + +// traceEventWrite is the part of traceEvent that actually writes the event. +func (w traceWriter) event(ev traceEv, args ...traceArg) traceWriter { + // Make sure we have room. + w, _ = w.ensure(1 + (len(args)+1)*traceBytesPerNumber) + + // Compute the timestamp diff that we'll put in the trace. + ts := traceClockNow() + if ts <= w.traceBuf.lastTime { + ts = w.traceBuf.lastTime + 1 + } + tsDiff := uint64(ts - w.traceBuf.lastTime) + w.traceBuf.lastTime = ts + + // Write out event. + w.byte(byte(ev)) + w.varint(tsDiff) + for _, arg := range args { + w.varint(uint64(arg)) + } + return w +} + +// stack takes a stack trace skipping the provided number of frames. +// It then returns a traceArg representing that stack which may be +// passed to write. +func (tl traceLocker) stack(skip int) traceArg { + return traceArg(traceStack(skip, tl.mp, tl.gen)) +} + +// startPC takes a start PC for a goroutine and produces a unique +// stack ID for it. +// +// It then returns a traceArg representing that stack which may be +// passed to write. +func (tl traceLocker) startPC(pc uintptr) traceArg { + // +PCQuantum because makeTraceFrame expects return PCs and subtracts PCQuantum. + return traceArg(trace.stackTab[tl.gen%2].put([]uintptr{ + logicalStackSentinel, + startPCForTrace(pc) + sys.PCQuantum, + })) +} + +// string returns a traceArg representing s which may be passed to write. +// The string is assumed to be relatively short and popular, so it may be +// stored for a while in the string dictionary. +func (tl traceLocker) string(s string) traceArg { + return traceArg(trace.stringTab[tl.gen%2].put(tl.gen, s)) +} + +// uniqueString returns a traceArg representing s which may be passed to write. +// The string is assumed to be unique or long, so it will be written out to +// the trace eagerly. +func (tl traceLocker) uniqueString(s string) traceArg { + return traceArg(trace.stringTab[tl.gen%2].emit(tl.gen, s)) +} |