| // Copyright 2024 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. |
| |
| // Code generated by "gen.bash" from internal/trace/v2; DO NOT EDIT. |
| |
| //go:build go1.21 |
| |
| package oldtrace |
| |
| import "errors" |
| |
| type orderEvent struct { |
| ev Event |
| proc *proc |
| } |
| |
| type gStatus int |
| |
| type gState struct { |
| seq uint64 |
| status gStatus |
| } |
| |
| const ( |
| gDead gStatus = iota |
| gRunnable |
| gRunning |
| gWaiting |
| |
| unordered = ^uint64(0) |
| garbage = ^uint64(0) - 1 |
| noseq = ^uint64(0) |
| seqinc = ^uint64(0) - 1 |
| ) |
| |
| // stateTransition returns goroutine state (sequence and status) when the event |
| // becomes ready for merging (init) and the goroutine state after the event (next). |
| func stateTransition(ev *Event) (g uint64, init, next gState) { |
| // Note that we have an explicit return in each case, as that produces slightly better code (tested on Go 1.19). |
| |
| switch ev.Type { |
| case EvGoCreate: |
| g = ev.Args[0] |
| init = gState{0, gDead} |
| next = gState{1, gRunnable} |
| return |
| case EvGoWaiting, EvGoInSyscall: |
| g = ev.G |
| init = gState{1, gRunnable} |
| next = gState{2, gWaiting} |
| return |
| case EvGoStart, EvGoStartLabel: |
| g = ev.G |
| init = gState{ev.Args[1], gRunnable} |
| next = gState{ev.Args[1] + 1, gRunning} |
| return |
| case EvGoStartLocal: |
| // noseq means that this event is ready for merging as soon as |
| // frontier reaches it (EvGoStartLocal is emitted on the same P |
| // as the corresponding EvGoCreate/EvGoUnblock, and thus the latter |
| // is already merged). |
| // seqinc is a stub for cases when event increments g sequence, |
| // but since we don't know current seq we also don't know next seq. |
| g = ev.G |
| init = gState{noseq, gRunnable} |
| next = gState{seqinc, gRunning} |
| return |
| case EvGoBlock, EvGoBlockSend, EvGoBlockRecv, EvGoBlockSelect, |
| EvGoBlockSync, EvGoBlockCond, EvGoBlockNet, EvGoSleep, |
| EvGoSysBlock, EvGoBlockGC: |
| g = ev.G |
| init = gState{noseq, gRunning} |
| next = gState{noseq, gWaiting} |
| return |
| case EvGoSched, EvGoPreempt: |
| g = ev.G |
| init = gState{noseq, gRunning} |
| next = gState{noseq, gRunnable} |
| return |
| case EvGoUnblock, EvGoSysExit: |
| g = ev.Args[0] |
| init = gState{ev.Args[1], gWaiting} |
| next = gState{ev.Args[1] + 1, gRunnable} |
| return |
| case EvGoUnblockLocal, EvGoSysExitLocal: |
| g = ev.Args[0] |
| init = gState{noseq, gWaiting} |
| next = gState{seqinc, gRunnable} |
| return |
| case EvGCStart: |
| g = garbage |
| init = gState{ev.Args[0], gDead} |
| next = gState{ev.Args[0] + 1, gDead} |
| return |
| default: |
| // no ordering requirements |
| g = unordered |
| return |
| } |
| } |
| |
| func transitionReady(g uint64, curr, init gState) bool { |
| return g == unordered || (init.seq == noseq || init.seq == curr.seq) && init.status == curr.status |
| } |
| |
| func transition(gs map[uint64]gState, g uint64, init, next gState) error { |
| if g == unordered { |
| return nil |
| } |
| curr := gs[g] |
| if !transitionReady(g, curr, init) { |
| // See comment near the call to transition, where we're building the frontier, for details on how this could |
| // possibly happen. |
| return errors.New("encountered impossible goroutine state transition") |
| } |
| switch next.seq { |
| case noseq: |
| next.seq = curr.seq |
| case seqinc: |
| next.seq = curr.seq + 1 |
| } |
| gs[g] = next |
| return nil |
| } |
| |
| type orderEventList []orderEvent |
| |
| func (l *orderEventList) Less(i, j int) bool { |
| return (*l)[i].ev.Ts < (*l)[j].ev.Ts |
| } |
| |
| type eventList []Event |
| |
| func (l *eventList) Len() int { |
| return len(*l) |
| } |
| |
| func (l *eventList) Less(i, j int) bool { |
| return (*l)[i].Ts < (*l)[j].Ts |
| } |
| |
| func (l *eventList) Swap(i, j int) { |
| (*l)[i], (*l)[j] = (*l)[j], (*l)[i] |
| } |
| |
| func (h *orderEventList) Push(x orderEvent) { |
| *h = append(*h, x) |
| heapUp(h, len(*h)-1) |
| } |
| |
| func (h *orderEventList) Pop() orderEvent { |
| n := len(*h) - 1 |
| (*h)[0], (*h)[n] = (*h)[n], (*h)[0] |
| heapDown(h, 0, n) |
| x := (*h)[len(*h)-1] |
| *h = (*h)[:len(*h)-1] |
| return x |
| } |
| |
| func heapUp(h *orderEventList, j int) { |
| for { |
| i := (j - 1) / 2 // parent |
| if i == j || !h.Less(j, i) { |
| break |
| } |
| (*h)[i], (*h)[j] = (*h)[j], (*h)[i] |
| j = i |
| } |
| } |
| |
| func heapDown(h *orderEventList, i0, n int) bool { |
| i := i0 |
| for { |
| j1 := 2*i + 1 |
| if j1 >= n || j1 < 0 { // j1 < 0 after int overflow |
| break |
| } |
| j := j1 // left child |
| if j2 := j1 + 1; j2 < n && h.Less(j2, j1) { |
| j = j2 // = 2*i + 2 // right child |
| } |
| if !h.Less(j, i) { |
| break |
| } |
| (*h)[i], (*h)[j] = (*h)[j], (*h)[i] |
| i = j |
| } |
| return i > i0 |
| } |