From c2b1463153e0095cf66ca362409d70ff0b6aad26 Mon Sep 17 00:00:00 2001 From: Michael Anthony Knyszek Date: Fri, 23 Feb 2024 23:26:49 +0000 Subject: [PATCH] internal/trace/v2: break up ordering.Advance into dispatched methods Currently ordering.Advance is one massive switch statement. This isn't amazing for readability because it's hard to see at a glance what happens before and after. Some of the state sharing is nice, but otherwise, it can get confusing quickly (especially where break is used, and where there are nested switches). This CL breaks up the switch statement into individual methods on ordering.Advance which are loaded and dispatched from a table. This CL uses a table instead of a switch statement because the arguments passed are all the same each time, and the table can provide a very precise mapping for each event; with a switch, we'd be tempted to group cases that call the same handler method together. It also prevents us from using defer in many cases, which may help clean up the code. (Each case in the switch is completely self-contained, yet we can't use a defer because it's function-scoped.) As an aside, this should also improve performance a bit. The Go compiler doesn't handle massive irregular functions very well, especially one with a lot of return points and (previously) a conditionally deferred call. Change-Id: I3ef2cf75301c795b6f23da1e058b0ac303fea8bd Reviewed-on: https://go-review.googlesource.com/c/go/+/566576 Auto-Submit: Michael Knyszek LUCI-TryBot-Result: Go LUCI Reviewed-by: Michael Pratt --- src/internal/trace/v2/order.go | 1709 +++++++++++++++++--------------- 1 file changed, 925 insertions(+), 784 deletions(-) diff --git a/src/internal/trace/v2/order.go b/src/internal/trace/v2/order.go index f3fb1fb9a7..e5fcd20a61 100644 --- a/src/internal/trace/v2/order.go +++ b/src/internal/trace/v2/order.go @@ -74,578 +74,693 @@ func (o *ordering) Advance(ev *baseEvent, evt *evTable, m ThreadID, gen uint64) newCtx = curCtx } - // Generates an event from the current context. - currentEvent := func() Event { - return Event{table: evt, ctx: curCtx, base: *ev} - } - - switch typ := ev.typ; typ { - // Handle procs. - case go122.EvProcStatus: - pid := ProcID(ev.args[0]) - status := go122.ProcStatus(ev.args[1]) - if int(status) >= len(go122ProcStatus2ProcState) { - return false, fmt.Errorf("invalid status for proc %d: %d", pid, status) - } - oldState := go122ProcStatus2ProcState[status] - if s, ok := o.pStates[pid]; ok { - if status == go122.ProcSyscallAbandoned && s.status == go122.ProcSyscall { - // ProcSyscallAbandoned is a special case of ProcSyscall. It indicates a - // potential loss of information, but if we're already in ProcSyscall, - // we haven't lost the relevant information. Promote the status and advance. - oldState = ProcRunning - ev.args[1] = uint64(go122.ProcSyscall) - } else if status == go122.ProcSyscallAbandoned && s.status == go122.ProcSyscallAbandoned { - // If we're passing through ProcSyscallAbandoned, then there's no promotion - // to do. We've lost the M that this P is associated with. However it got there, - // it's going to appear as idle in the API, so pass through as idle. - oldState = ProcIdle - ev.args[1] = uint64(go122.ProcSyscallAbandoned) - } else if s.status != status { - return false, fmt.Errorf("inconsistent status for proc %d: old %v vs. new %v", pid, s.status, status) - } - s.seq = makeSeq(gen, 0) // Reset seq. + f := orderingDispatch[ev.typ] + if f == nil { + return false, fmt.Errorf("bad event type found while ordering: %v", ev.typ) + } + newCtx, ok, err := f(o, ev, evt, m, gen, curCtx) + if err == nil && ok && ms != nil { + // Update the mState for this event. + ms.p = newCtx.P + ms.g = newCtx.G + } + return ok, err +} + +type orderingHandleFunc func(o *ordering, ev *baseEvent, evt *evTable, m ThreadID, gen uint64, curCtx schedCtx) (schedCtx, bool, error) + +var orderingDispatch = [256]orderingHandleFunc{ + // Procs. + go122.EvProcsChange: (*ordering).advanceAnnotation, + go122.EvProcStart: (*ordering).advanceProcStart, + go122.EvProcStop: (*ordering).advanceProcStop, + go122.EvProcSteal: (*ordering).advanceProcSteal, + go122.EvProcStatus: (*ordering).advanceProcStatus, + + // Goroutines. + go122.EvGoCreate: (*ordering).advanceGoCreate, + go122.EvGoCreateSyscall: (*ordering).advanceGoCreateSyscall, + go122.EvGoStart: (*ordering).advanceGoStart, + go122.EvGoDestroy: (*ordering).advanceGoStopExec, + go122.EvGoDestroySyscall: (*ordering).advanceGoDestroySyscall, + go122.EvGoStop: (*ordering).advanceGoStopExec, + go122.EvGoBlock: (*ordering).advanceGoStopExec, + go122.EvGoUnblock: (*ordering).advanceGoUnblock, + go122.EvGoSyscallBegin: (*ordering).advanceGoSyscallBegin, + go122.EvGoSyscallEnd: (*ordering).advanceGoSyscallEnd, + go122.EvGoSyscallEndBlocked: (*ordering).advanceGoSyscallEndBlocked, + go122.EvGoStatus: (*ordering).advanceGoStatus, + + // STW. + go122.EvSTWBegin: (*ordering).advanceGoRangeBegin, + go122.EvSTWEnd: (*ordering).advanceGoRangeEnd, + + // GC events. + go122.EvGCActive: (*ordering).advanceGCActive, + go122.EvGCBegin: (*ordering).advanceGCBegin, + go122.EvGCEnd: (*ordering).advanceGCEnd, + go122.EvGCSweepActive: (*ordering).advanceGCSweepActive, + go122.EvGCSweepBegin: (*ordering).advanceGCSweepBegin, + go122.EvGCSweepEnd: (*ordering).advanceGCSweepEnd, + go122.EvGCMarkAssistActive: (*ordering).advanceGoRangeActive, + go122.EvGCMarkAssistBegin: (*ordering).advanceGoRangeBegin, + go122.EvGCMarkAssistEnd: (*ordering).advanceGoRangeEnd, + go122.EvHeapAlloc: (*ordering).advanceHeapMetric, + go122.EvHeapGoal: (*ordering).advanceHeapMetric, + + // Annotations. + go122.EvGoLabel: (*ordering).advanceAnnotation, + go122.EvUserTaskBegin: (*ordering).advanceUserTaskBegin, + go122.EvUserTaskEnd: (*ordering).advanceUserTaskEnd, + go122.EvUserRegionBegin: (*ordering).advanceUserRegionBegin, + go122.EvUserRegionEnd: (*ordering).advanceUserRegionEnd, + go122.EvUserLog: (*ordering).advanceAnnotation, + + // Coroutines. Added in Go 1.23. + go122.EvGoSwitch: (*ordering).advanceGoSwitch, + go122.EvGoSwitchDestroy: (*ordering).advanceGoSwitch, + go122.EvGoCreateBlocked: (*ordering).advanceGoCreate, +} + +func (o *ordering) advanceProcStatus(ev *baseEvent, evt *evTable, m ThreadID, gen uint64, curCtx schedCtx) (schedCtx, bool, error) { + pid := ProcID(ev.args[0]) + status := go122.ProcStatus(ev.args[1]) + if int(status) >= len(go122ProcStatus2ProcState) { + return curCtx, false, fmt.Errorf("invalid status for proc %d: %d", pid, status) + } + oldState := go122ProcStatus2ProcState[status] + if s, ok := o.pStates[pid]; ok { + if status == go122.ProcSyscallAbandoned && s.status == go122.ProcSyscall { + // ProcSyscallAbandoned is a special case of ProcSyscall. It indicates a + // potential loss of information, but if we're already in ProcSyscall, + // we haven't lost the relevant information. Promote the status and advance. + oldState = ProcRunning + ev.args[1] = uint64(go122.ProcSyscall) + } else if status == go122.ProcSyscallAbandoned && s.status == go122.ProcSyscallAbandoned { + // If we're passing through ProcSyscallAbandoned, then there's no promotion + // to do. We've lost the M that this P is associated with. However it got there, + // it's going to appear as idle in the API, so pass through as idle. + oldState = ProcIdle + ev.args[1] = uint64(go122.ProcSyscallAbandoned) + } else if s.status != status { + return curCtx, false, fmt.Errorf("inconsistent status for proc %d: old %v vs. new %v", pid, s.status, status) + } + s.seq = makeSeq(gen, 0) // Reset seq. + } else { + o.pStates[pid] = &pState{id: pid, status: status, seq: makeSeq(gen, 0)} + if gen == o.initialGen { + oldState = ProcUndetermined } else { - o.pStates[pid] = &pState{id: pid, status: status, seq: makeSeq(gen, 0)} - if gen == o.initialGen { - oldState = ProcUndetermined - } else { - oldState = ProcNotExist - } + oldState = ProcNotExist } - ev.extra(version.Go122)[0] = uint64(oldState) // Smuggle in the old state for StateTransition. + } + ev.extra(version.Go122)[0] = uint64(oldState) // Smuggle in the old state for StateTransition. - // Bind the proc to the new context, if it's running. - if status == go122.ProcRunning || status == go122.ProcSyscall { - newCtx.P = pid - } - // If we're advancing through ProcSyscallAbandoned *but* oldState is running then we've - // promoted it to ProcSyscall. However, because it's ProcSyscallAbandoned, we know this - // P is about to get stolen and its status very likely isn't being emitted by the same - // thread it was bound to. Since this status is Running -> Running and Running is binding, - // we need to make sure we emit it in the right context: the context to which it is bound. - // Find it, and set our current context to it. - if status == go122.ProcSyscallAbandoned && oldState == ProcRunning { - // N.B. This is slow but it should be fairly rare. - found := false - for mid, ms := range o.mStates { - if ms.p == pid { - curCtx.M = mid - curCtx.P = pid - curCtx.G = ms.g - found = true - } - } - if !found { - return false, fmt.Errorf("failed to find sched context for proc %d that's about to be stolen", pid) + // Bind the proc to the new context, if it's running. + newCtx := curCtx + if status == go122.ProcRunning || status == go122.ProcSyscall { + newCtx.P = pid + } + // If we're advancing through ProcSyscallAbandoned *but* oldState is running then we've + // promoted it to ProcSyscall. However, because it's ProcSyscallAbandoned, we know this + // P is about to get stolen and its status very likely isn't being emitted by the same + // thread it was bound to. Since this status is Running -> Running and Running is binding, + // we need to make sure we emit it in the right context: the context to which it is bound. + // Find it, and set our current context to it. + if status == go122.ProcSyscallAbandoned && oldState == ProcRunning { + // N.B. This is slow but it should be fairly rare. + found := false + for mid, ms := range o.mStates { + if ms.p == pid { + curCtx.M = mid + curCtx.P = pid + curCtx.G = ms.g + found = true } } - o.queue.push(currentEvent()) - case go122.EvProcStart: - pid := ProcID(ev.args[0]) - seq := makeSeq(gen, ev.args[1]) - - // Try to advance. We might fail here due to sequencing, because the P hasn't - // had a status emitted, or because we already have a P and we're in a syscall, - // and we haven't observed that it was stolen from us yet. - state, ok := o.pStates[pid] - if !ok || state.status != go122.ProcIdle || !seq.succeeds(state.seq) || curCtx.P != NoProc { - // We can't make an inference as to whether this is bad. We could just be seeing - // a ProcStart on a different M before the proc's state was emitted, or before we - // got to the right point in the trace. - // - // Note that we also don't advance here if we have a P and we're in a syscall. - return false, nil + if !found { + return curCtx, false, fmt.Errorf("failed to find sched context for proc %d that's about to be stolen", pid) } - // We can advance this P. Check some invariants. - // - // We might have a goroutine if a goroutine is exiting a syscall. - reqs := event.SchedReqs{Thread: event.MustHave, Proc: event.MustNotHave, Goroutine: event.MayHave} - if err := validateCtx(curCtx, reqs); err != nil { - return false, err - } - state.status = go122.ProcRunning - state.seq = seq - newCtx.P = pid - o.queue.push(currentEvent()) - case go122.EvProcStop: - // We must be able to advance this P. - // - // There are 2 ways a P can stop: ProcStop and ProcSteal. ProcStop is used when the P - // is stopped by the same M that started it, while ProcSteal is used when another M - // steals the P by stopping it from a distance. + } + o.queue.push(Event{table: evt, ctx: curCtx, base: *ev}) + return newCtx, true, nil +} + +func (o *ordering) advanceProcStart(ev *baseEvent, evt *evTable, m ThreadID, gen uint64, curCtx schedCtx) (schedCtx, bool, error) { + pid := ProcID(ev.args[0]) + seq := makeSeq(gen, ev.args[1]) + + // Try to advance. We might fail here due to sequencing, because the P hasn't + // had a status emitted, or because we already have a P and we're in a syscall, + // and we haven't observed that it was stolen from us yet. + state, ok := o.pStates[pid] + if !ok || state.status != go122.ProcIdle || !seq.succeeds(state.seq) || curCtx.P != NoProc { + // We can't make an inference as to whether this is bad. We could just be seeing + // a ProcStart on a different M before the proc's state was emitted, or before we + // got to the right point in the trace. // - // Since a P is bound to an M, and we're stopping on the same M we started, it must - // always be possible to advance the current M's P from a ProcStop. This is also why - // ProcStop doesn't need a sequence number. - state, ok := o.pStates[curCtx.P] - if !ok { - return false, fmt.Errorf("event %s for proc (%v) that doesn't exist", go122.EventString(typ), curCtx.P) - } - if state.status != go122.ProcRunning && state.status != go122.ProcSyscall { - return false, fmt.Errorf("%s event for proc that's not %s or %s", go122.EventString(typ), go122.ProcRunning, go122.ProcSyscall) - } - reqs := event.SchedReqs{Thread: event.MustHave, Proc: event.MustHave, Goroutine: event.MayHave} - if err := validateCtx(curCtx, reqs); err != nil { - return false, err + // Note that we also don't advance here if we have a P and we're in a syscall. + return curCtx, false, nil + } + // We can advance this P. Check some invariants. + // + // We might have a goroutine if a goroutine is exiting a syscall. + reqs := event.SchedReqs{Thread: event.MustHave, Proc: event.MustNotHave, Goroutine: event.MayHave} + if err := validateCtx(curCtx, reqs); err != nil { + return curCtx, false, err + } + state.status = go122.ProcRunning + state.seq = seq + newCtx := curCtx + newCtx.P = pid + o.queue.push(Event{table: evt, ctx: curCtx, base: *ev}) + return newCtx, true, nil +} + +func (o *ordering) advanceProcStop(ev *baseEvent, evt *evTable, m ThreadID, gen uint64, curCtx schedCtx) (schedCtx, bool, error) { + // We must be able to advance this P. + // + // There are 2 ways a P can stop: ProcStop and ProcSteal. ProcStop is used when the P + // is stopped by the same M that started it, while ProcSteal is used when another M + // steals the P by stopping it from a distance. + // + // Since a P is bound to an M, and we're stopping on the same M we started, it must + // always be possible to advance the current M's P from a ProcStop. This is also why + // ProcStop doesn't need a sequence number. + state, ok := o.pStates[curCtx.P] + if !ok { + return curCtx, false, fmt.Errorf("event %s for proc (%v) that doesn't exist", go122.EventString(ev.typ), curCtx.P) + } + if state.status != go122.ProcRunning && state.status != go122.ProcSyscall { + return curCtx, false, fmt.Errorf("%s event for proc that's not %s or %s", go122.EventString(ev.typ), go122.ProcRunning, go122.ProcSyscall) + } + reqs := event.SchedReqs{Thread: event.MustHave, Proc: event.MustHave, Goroutine: event.MayHave} + if err := validateCtx(curCtx, reqs); err != nil { + return curCtx, false, err + } + state.status = go122.ProcIdle + newCtx := curCtx + newCtx.P = NoProc + o.queue.push(Event{table: evt, ctx: curCtx, base: *ev}) + return newCtx, true, nil +} + +func (o *ordering) advanceProcSteal(ev *baseEvent, evt *evTable, m ThreadID, gen uint64, curCtx schedCtx) (schedCtx, bool, error) { + pid := ProcID(ev.args[0]) + seq := makeSeq(gen, ev.args[1]) + state, ok := o.pStates[pid] + if !ok || (state.status != go122.ProcSyscall && state.status != go122.ProcSyscallAbandoned) || !seq.succeeds(state.seq) { + // We can't make an inference as to whether this is bad. We could just be seeing + // a ProcStart on a different M before the proc's state was emitted, or before we + // got to the right point in the trace. + return curCtx, false, nil + } + // We can advance this P. Check some invariants. + reqs := event.SchedReqs{Thread: event.MustHave, Proc: event.MayHave, Goroutine: event.MayHave} + if err := validateCtx(curCtx, reqs); err != nil { + return curCtx, false, err + } + // Smuggle in the P state that let us advance so we can surface information to the event. + // Specifically, we need to make sure that the event is interpreted not as a transition of + // ProcRunning -> ProcIdle but ProcIdle -> ProcIdle instead. + // + // ProcRunning is binding, but we may be running with a P on the current M and we can't + // bind another P. This P is about to go ProcIdle anyway. + oldStatus := state.status + ev.extra(version.Go122)[0] = uint64(oldStatus) + + // Update the P's status and sequence number. + state.status = go122.ProcIdle + state.seq = seq + + // If we've lost information then don't try to do anything with the M. + // It may have moved on and we can't be sure. + if oldStatus == go122.ProcSyscallAbandoned { + o.queue.push(Event{table: evt, ctx: curCtx, base: *ev}) + return curCtx, true, nil + } + + // Validate that the M we're stealing from is what we expect. + mid := ThreadID(ev.args[2]) // The M we're stealing from. + + newCtx := curCtx + if mid == curCtx.M { + // We're stealing from ourselves. This behaves like a ProcStop. + if curCtx.P != pid { + return curCtx, false, fmt.Errorf("tried to self-steal proc %d (thread %d), but got proc %d instead", pid, mid, curCtx.P) } - state.status = go122.ProcIdle newCtx.P = NoProc - o.queue.push(currentEvent()) - case go122.EvProcSteal: - pid := ProcID(ev.args[0]) - seq := makeSeq(gen, ev.args[1]) - state, ok := o.pStates[pid] - if !ok || (state.status != go122.ProcSyscall && state.status != go122.ProcSyscallAbandoned) || !seq.succeeds(state.seq) { - // We can't make an inference as to whether this is bad. We could just be seeing - // a ProcStart on a different M before the proc's state was emitted, or before we - // got to the right point in the trace. - return false, nil - } - // We can advance this P. Check some invariants. - reqs := event.SchedReqs{Thread: event.MustHave, Proc: event.MayHave, Goroutine: event.MayHave} - if err := validateCtx(curCtx, reqs); err != nil { - return false, err - } - // Smuggle in the P state that let us advance so we can surface information to the event. - // Specifically, we need to make sure that the event is interpreted not as a transition of - // ProcRunning -> ProcIdle but ProcIdle -> ProcIdle instead. - // - // ProcRunning is binding, but we may be running with a P on the current M and we can't - // bind another P. This P is about to go ProcIdle anyway. - oldStatus := state.status - ev.extra(version.Go122)[0] = uint64(oldStatus) - - // Update the P's status and sequence number. - state.status = go122.ProcIdle - state.seq = seq - - // If we've lost information then don't try to do anything with the M. - // It may have moved on and we can't be sure. - if oldStatus == go122.ProcSyscallAbandoned { - o.queue.push(currentEvent()) - break - } + o.queue.push(Event{table: evt, ctx: curCtx, base: *ev}) + return newCtx, true, nil + } - // Validate that the M we're stealing from is what we expect. - mid := ThreadID(ev.args[2]) // The M we're stealing from. + // We're stealing from some other M. + mState, ok := o.mStates[mid] + if !ok { + return curCtx, false, fmt.Errorf("stole proc from non-existent thread %d", mid) + } - if mid == curCtx.M { - // We're stealing from ourselves. This behaves like a ProcStop. - if curCtx.P != pid { - return false, fmt.Errorf("tried to self-steal proc %d (thread %d), but got proc %d instead", pid, mid, curCtx.P) - } - newCtx.P = NoProc - o.queue.push(currentEvent()) - break - } + // Make sure we're actually stealing the right P. + if mState.p != pid { + return curCtx, false, fmt.Errorf("tried to steal proc %d from thread %d, but got proc %d instead", pid, mid, mState.p) + } - // We're stealing from some other M. - mState, ok := o.mStates[mid] - if !ok { - return false, fmt.Errorf("stole proc from non-existent thread %d", mid) - } + // Tell the M it has no P so it can proceed. + // + // This is safe because we know the P was in a syscall and + // the other M must be trying to get out of the syscall. + // GoSyscallEndBlocked cannot advance until the corresponding + // M loses its P. + mState.p = NoProc + o.queue.push(Event{table: evt, ctx: curCtx, base: *ev}) + return newCtx, true, nil +} - // Make sure we're actually stealing the right P. - if mState.p != pid { - return false, fmt.Errorf("tried to steal proc %d from thread %d, but got proc %d instead", pid, mid, mState.p) - } +func (o *ordering) advanceGoStatus(ev *baseEvent, evt *evTable, m ThreadID, gen uint64, curCtx schedCtx) (schedCtx, bool, error) { + gid := GoID(ev.args[0]) + mid := ThreadID(ev.args[1]) + status := go122.GoStatus(ev.args[2]) - // Tell the M it has no P so it can proceed. - // - // This is safe because we know the P was in a syscall and - // the other M must be trying to get out of the syscall. - // GoSyscallEndBlocked cannot advance until the corresponding - // M loses its P. - mState.p = NoProc - o.queue.push(currentEvent()) - - // Handle goroutines. - case go122.EvGoStatus: - gid := GoID(ev.args[0]) - mid := ThreadID(ev.args[1]) - status := go122.GoStatus(ev.args[2]) - - if int(status) >= len(go122GoStatus2GoState) { - return false, fmt.Errorf("invalid status for goroutine %d: %d", gid, status) + if int(status) >= len(go122GoStatus2GoState) { + return curCtx, false, fmt.Errorf("invalid status for goroutine %d: %d", gid, status) + } + oldState := go122GoStatus2GoState[status] + if s, ok := o.gStates[gid]; ok { + if s.status != status { + return curCtx, false, fmt.Errorf("inconsistent status for goroutine %d: old %v vs. new %v", gid, s.status, status) + } + s.seq = makeSeq(gen, 0) // Reset seq. + } else if gen == o.initialGen { + // Set the state. + o.gStates[gid] = &gState{id: gid, status: status, seq: makeSeq(gen, 0)} + oldState = GoUndetermined + } else { + return curCtx, false, fmt.Errorf("found goroutine status for new goroutine after the first generation: id=%v status=%v", gid, status) + } + ev.extra(version.Go122)[0] = uint64(oldState) // Smuggle in the old state for StateTransition. + + newCtx := curCtx + switch status { + case go122.GoRunning: + // Bind the goroutine to the new context, since it's running. + newCtx.G = gid + case go122.GoSyscall: + if mid == NoThread { + return curCtx, false, fmt.Errorf("found goroutine %d in syscall without a thread", gid) } - oldState := go122GoStatus2GoState[status] - if s, ok := o.gStates[gid]; ok { - if s.status != status { - return false, fmt.Errorf("inconsistent status for goroutine %d: old %v vs. new %v", gid, s.status, status) + // Is the syscall on this thread? If so, bind it to the context. + // Otherwise, we're talking about a G sitting in a syscall on an M. + // Validate the named M. + if mid == curCtx.M { + if gen != o.initialGen && curCtx.G != gid { + // If this isn't the first generation, we *must* have seen this + // binding occur already. Even if the G was blocked in a syscall + // for multiple generations since trace start, we would have seen + // a previous GoStatus event that bound the goroutine to an M. + return curCtx, false, fmt.Errorf("inconsistent thread for syscalling goroutine %d: thread has goroutine %d", gid, curCtx.G) } - s.seq = makeSeq(gen, 0) // Reset seq. - } else if gen == o.initialGen { - // Set the state. - o.gStates[gid] = &gState{id: gid, status: status, seq: makeSeq(gen, 0)} - oldState = GoUndetermined - } else { - return false, fmt.Errorf("found goroutine status for new goroutine after the first generation: id=%v status=%v", gid, status) - } - ev.extra(version.Go122)[0] = uint64(oldState) // Smuggle in the old state for StateTransition. - - switch status { - case go122.GoRunning: - // Bind the goroutine to the new context, since it's running. newCtx.G = gid - case go122.GoSyscall: - if mid == NoThread { - return false, fmt.Errorf("found goroutine %d in syscall without a thread", gid) - } - // Is the syscall on this thread? If so, bind it to the context. - // Otherwise, we're talking about a G sitting in a syscall on an M. - // Validate the named M. - if mid == curCtx.M { - if gen != o.initialGen && curCtx.G != gid { - // If this isn't the first generation, we *must* have seen this - // binding occur already. Even if the G was blocked in a syscall - // for multiple generations since trace start, we would have seen - // a previous GoStatus event that bound the goroutine to an M. - return false, fmt.Errorf("inconsistent thread for syscalling goroutine %d: thread has goroutine %d", gid, curCtx.G) - } - newCtx.G = gid - break - } - // Now we're talking about a thread and goroutine that have been - // blocked on a syscall for the entire generation. This case must - // not have a P; the runtime makes sure that all Ps are traced at - // the beginning of a generation, which involves taking a P back - // from every thread. - ms, ok := o.mStates[mid] - if ok { - // This M has been seen. That means we must have seen this - // goroutine go into a syscall on this thread at some point. - if ms.g != gid { - // But the G on the M doesn't match. Something's wrong. - return false, fmt.Errorf("inconsistent thread for syscalling goroutine %d: thread has goroutine %d", gid, ms.g) - } - // This case is just a Syscall->Syscall event, which needs to - // appear as having the G currently bound to this M. - curCtx.G = ms.g - } else if !ok { - // The M hasn't been seen yet. That means this goroutine - // has just been sitting in a syscall on this M. Create - // a state for it. - o.mStates[mid] = &mState{g: gid, p: NoProc} - // Don't set curCtx.G in this case because this event is the - // binding event (and curCtx represents the "before" state). - } - // Update the current context to the M we're talking about. - curCtx.M = mid - } - o.queue.push(currentEvent()) - case go122.EvGoCreate, go122.EvGoCreateBlocked: - // Goroutines must be created on a running P, but may or may not be created - // by a running goroutine. - reqs := event.SchedReqs{Thread: event.MustHave, Proc: event.MustHave, Goroutine: event.MayHave} - if err := validateCtx(curCtx, reqs); err != nil { - return false, err - } - // If we have a goroutine, it must be running. - if state, ok := o.gStates[curCtx.G]; ok && state.status != go122.GoRunning { - return false, fmt.Errorf("%s event for goroutine that's not %s", go122.EventString(typ), GoRunning) - } - // This goroutine created another. Add a state for it. - newgid := GoID(ev.args[0]) - if _, ok := o.gStates[newgid]; ok { - return false, fmt.Errorf("tried to create goroutine (%v) that already exists", newgid) - } - status := go122.GoRunnable - if typ == go122.EvGoCreateBlocked { - status = go122.GoWaiting - } - o.gStates[newgid] = &gState{id: newgid, status: status, seq: makeSeq(gen, 0)} - o.queue.push(currentEvent()) - case go122.EvGoDestroy, go122.EvGoStop, go122.EvGoBlock: - // These are goroutine events that all require an active running - // goroutine on some thread. They must *always* be advance-able, - // since running goroutines are bound to their M. - if err := validateCtx(curCtx, event.UserGoReqs); err != nil { - return false, err - } - state, ok := o.gStates[curCtx.G] - if !ok { - return false, fmt.Errorf("event %s for goroutine (%v) that doesn't exist", go122.EventString(typ), curCtx.G) - } - if state.status != go122.GoRunning { - return false, fmt.Errorf("%s event for goroutine that's not %s", go122.EventString(typ), GoRunning) - } - // Handle each case slightly differently; we just group them together - // because they have shared preconditions. - switch typ { - case go122.EvGoDestroy: - // This goroutine is exiting itself. - delete(o.gStates, curCtx.G) - newCtx.G = NoGoroutine - case go122.EvGoStop: - // Goroutine stopped (yielded). It's runnable but not running on this M. - state.status = go122.GoRunnable - newCtx.G = NoGoroutine - case go122.EvGoBlock: - // Goroutine blocked. It's waiting now and not running on this M. - state.status = go122.GoWaiting - newCtx.G = NoGoroutine - } - o.queue.push(currentEvent()) - case go122.EvGoStart: - gid := GoID(ev.args[0]) - seq := makeSeq(gen, ev.args[1]) - state, ok := o.gStates[gid] - if !ok || state.status != go122.GoRunnable || !seq.succeeds(state.seq) { - // We can't make an inference as to whether this is bad. We could just be seeing - // a GoStart on a different M before the goroutine was created, before it had its - // state emitted, or before we got to the right point in the trace yet. - return false, nil - } - // We can advance this goroutine. Check some invariants. - reqs := event.SchedReqs{Thread: event.MustHave, Proc: event.MustHave, Goroutine: event.MustNotHave} - if err := validateCtx(curCtx, reqs); err != nil { - return false, err - } - state.status = go122.GoRunning - state.seq = seq - newCtx.G = gid - o.queue.push(currentEvent()) - case go122.EvGoUnblock: - // N.B. These both reference the goroutine to unblock, not the current goroutine. - gid := GoID(ev.args[0]) - seq := makeSeq(gen, ev.args[1]) - state, ok := o.gStates[gid] - if !ok || state.status != go122.GoWaiting || !seq.succeeds(state.seq) { - // We can't make an inference as to whether this is bad. We could just be seeing - // a GoUnblock on a different M before the goroutine was created and blocked itself, - // before it had its state emitted, or before we got to the right point in the trace yet. - return false, nil + break } + // Now we're talking about a thread and goroutine that have been + // blocked on a syscall for the entire generation. This case must + // not have a P; the runtime makes sure that all Ps are traced at + // the beginning of a generation, which involves taking a P back + // from every thread. + ms, ok := o.mStates[mid] + if ok { + // This M has been seen. That means we must have seen this + // goroutine go into a syscall on this thread at some point. + if ms.g != gid { + // But the G on the M doesn't match. Something's wrong. + return curCtx, false, fmt.Errorf("inconsistent thread for syscalling goroutine %d: thread has goroutine %d", gid, ms.g) + } + // This case is just a Syscall->Syscall event, which needs to + // appear as having the G currently bound to this M. + curCtx.G = ms.g + } else if !ok { + // The M hasn't been seen yet. That means this goroutine + // has just been sitting in a syscall on this M. Create + // a state for it. + o.mStates[mid] = &mState{g: gid, p: NoProc} + // Don't set curCtx.G in this case because this event is the + // binding event (and curCtx represents the "before" state). + } + // Update the current context to the M we're talking about. + curCtx.M = mid + } + o.queue.push(Event{table: evt, ctx: curCtx, base: *ev}) + return newCtx, true, nil +} + +func (o *ordering) advanceGoCreate(ev *baseEvent, evt *evTable, m ThreadID, gen uint64, curCtx schedCtx) (schedCtx, bool, error) { + // Goroutines must be created on a running P, but may or may not be created + // by a running goroutine. + reqs := event.SchedReqs{Thread: event.MustHave, Proc: event.MustHave, Goroutine: event.MayHave} + if err := validateCtx(curCtx, reqs); err != nil { + return curCtx, false, err + } + // If we have a goroutine, it must be running. + if state, ok := o.gStates[curCtx.G]; ok && state.status != go122.GoRunning { + return curCtx, false, fmt.Errorf("%s event for goroutine that's not %s", go122.EventString(ev.typ), GoRunning) + } + // This goroutine created another. Add a state for it. + newgid := GoID(ev.args[0]) + if _, ok := o.gStates[newgid]; ok { + return curCtx, false, fmt.Errorf("tried to create goroutine (%v) that already exists", newgid) + } + status := go122.GoRunnable + if ev.typ == go122.EvGoCreateBlocked { + status = go122.GoWaiting + } + o.gStates[newgid] = &gState{id: newgid, status: status, seq: makeSeq(gen, 0)} + o.queue.push(Event{table: evt, ctx: curCtx, base: *ev}) + return curCtx, true, nil +} + +func (o *ordering) advanceGoStopExec(ev *baseEvent, evt *evTable, m ThreadID, gen uint64, curCtx schedCtx) (schedCtx, bool, error) { + // These are goroutine events that all require an active running + // goroutine on some thread. They must *always* be advance-able, + // since running goroutines are bound to their M. + if err := validateCtx(curCtx, event.UserGoReqs); err != nil { + return curCtx, false, err + } + state, ok := o.gStates[curCtx.G] + if !ok { + return curCtx, false, fmt.Errorf("event %s for goroutine (%v) that doesn't exist", go122.EventString(ev.typ), curCtx.G) + } + if state.status != go122.GoRunning { + return curCtx, false, fmt.Errorf("%s event for goroutine that's not %s", go122.EventString(ev.typ), GoRunning) + } + // Handle each case slightly differently; we just group them together + // because they have shared preconditions. + newCtx := curCtx + switch ev.typ { + case go122.EvGoDestroy: + // This goroutine is exiting itself. + delete(o.gStates, curCtx.G) + newCtx.G = NoGoroutine + case go122.EvGoStop: + // Goroutine stopped (yielded). It's runnable but not running on this M. state.status = go122.GoRunnable - state.seq = seq - // N.B. No context to validate. Basically anything can unblock - // a goroutine (e.g. sysmon). - o.queue.push(currentEvent()) - case go122.EvGoSwitch, go122.EvGoSwitchDestroy: - // GoSwitch and GoSwitchDestroy represent a trio of events: - // - Unblock of the goroutine to switch to. - // - Block or destroy of the current goroutine. - // - Start executing the next goroutine. - // - // Because it acts like a GoStart for the next goroutine, we can - // only advance it if the sequence numbers line up. - // - // The current goroutine on the thread must be actively running. - if err := validateCtx(curCtx, event.UserGoReqs); err != nil { - return false, err - } - curGState, ok := o.gStates[curCtx.G] - if !ok { - return false, fmt.Errorf("event %s for goroutine (%v) that doesn't exist", go122.EventString(typ), curCtx.G) - } - if curGState.status != go122.GoRunning { - return false, fmt.Errorf("%s event for goroutine that's not %s", go122.EventString(typ), GoRunning) - } - nextg := GoID(ev.args[0]) - seq := makeSeq(gen, ev.args[1]) // seq is for nextg, not curCtx.G. - nextGState, ok := o.gStates[nextg] - if !ok || nextGState.status != go122.GoWaiting || !seq.succeeds(nextGState.seq) { - // We can't make an inference as to whether this is bad. We could just be seeing - // a GoSwitch on a different M before the goroutine was created, before it had its - // state emitted, or before we got to the right point in the trace yet. - return false, nil - } - o.queue.push(currentEvent()) - - // Update the state of the executing goroutine and emit an event for it - // (GoSwitch and GoSwitchDestroy will be interpreted as GoUnblock events - // for nextg). - switch typ { - case go122.EvGoSwitch: - // Goroutine blocked. It's waiting now and not running on this M. - curGState.status = go122.GoWaiting - - // Emit a GoBlock event. - // TODO(mknyszek): Emit a reason. - o.queue.push(makeEvent(evt, curCtx, go122.EvGoBlock, ev.time, 0 /* no reason */, 0 /* no stack */)) - case go122.EvGoSwitchDestroy: - // This goroutine is exiting itself. - delete(o.gStates, curCtx.G) - - // Emit a GoDestroy event. - o.queue.push(makeEvent(evt, curCtx, go122.EvGoDestroy, ev.time)) - } - // Update the state of the next goroutine. - nextGState.status = go122.GoRunning - nextGState.seq = seq - newCtx.G = nextg - - // Queue an event for the next goroutine starting to run. - startCtx := curCtx - startCtx.G = NoGoroutine - o.queue.push(makeEvent(evt, startCtx, go122.EvGoStart, ev.time, uint64(nextg), ev.args[1])) - case go122.EvGoSyscallBegin: - // Entering a syscall requires an active running goroutine with a - // proc on some thread. It is always advancable. - if err := validateCtx(curCtx, event.UserGoReqs); err != nil { - return false, err - } - state, ok := o.gStates[curCtx.G] - if !ok { - return false, fmt.Errorf("event %s for goroutine (%v) that doesn't exist", go122.EventString(typ), curCtx.G) - } - if state.status != go122.GoRunning { - return false, fmt.Errorf("%s event for goroutine that's not %s", go122.EventString(typ), GoRunning) - } - // Goroutine entered a syscall. It's still running on this P and M. - state.status = go122.GoSyscall + newCtx.G = NoGoroutine + case go122.EvGoBlock: + // Goroutine blocked. It's waiting now and not running on this M. + state.status = go122.GoWaiting + newCtx.G = NoGoroutine + } + o.queue.push(Event{table: evt, ctx: curCtx, base: *ev}) + return newCtx, true, nil +} + +func (o *ordering) advanceGoStart(ev *baseEvent, evt *evTable, m ThreadID, gen uint64, curCtx schedCtx) (schedCtx, bool, error) { + gid := GoID(ev.args[0]) + seq := makeSeq(gen, ev.args[1]) + state, ok := o.gStates[gid] + if !ok || state.status != go122.GoRunnable || !seq.succeeds(state.seq) { + // We can't make an inference as to whether this is bad. We could just be seeing + // a GoStart on a different M before the goroutine was created, before it had its + // state emitted, or before we got to the right point in the trace yet. + return curCtx, false, nil + } + // We can advance this goroutine. Check some invariants. + reqs := event.SchedReqs{Thread: event.MustHave, Proc: event.MustHave, Goroutine: event.MustNotHave} + if err := validateCtx(curCtx, reqs); err != nil { + return curCtx, false, err + } + state.status = go122.GoRunning + state.seq = seq + newCtx := curCtx + newCtx.G = gid + o.queue.push(Event{table: evt, ctx: curCtx, base: *ev}) + return newCtx, true, nil +} + +func (o *ordering) advanceGoUnblock(ev *baseEvent, evt *evTable, m ThreadID, gen uint64, curCtx schedCtx) (schedCtx, bool, error) { + // N.B. These both reference the goroutine to unblock, not the current goroutine. + gid := GoID(ev.args[0]) + seq := makeSeq(gen, ev.args[1]) + state, ok := o.gStates[gid] + if !ok || state.status != go122.GoWaiting || !seq.succeeds(state.seq) { + // We can't make an inference as to whether this is bad. We could just be seeing + // a GoUnblock on a different M before the goroutine was created and blocked itself, + // before it had its state emitted, or before we got to the right point in the trace yet. + return curCtx, false, nil + } + state.status = go122.GoRunnable + state.seq = seq + // N.B. No context to validate. Basically anything can unblock + // a goroutine (e.g. sysmon). + o.queue.push(Event{table: evt, ctx: curCtx, base: *ev}) + return curCtx, true, nil +} + +func (o *ordering) advanceGoSwitch(ev *baseEvent, evt *evTable, m ThreadID, gen uint64, curCtx schedCtx) (schedCtx, bool, error) { + // GoSwitch and GoSwitchDestroy represent a trio of events: + // - Unblock of the goroutine to switch to. + // - Block or destroy of the current goroutine. + // - Start executing the next goroutine. + // + // Because it acts like a GoStart for the next goroutine, we can + // only advance it if the sequence numbers line up. + // + // The current goroutine on the thread must be actively running. + if err := validateCtx(curCtx, event.UserGoReqs); err != nil { + return curCtx, false, err + } + curGState, ok := o.gStates[curCtx.G] + if !ok { + return curCtx, false, fmt.Errorf("event %s for goroutine (%v) that doesn't exist", go122.EventString(ev.typ), curCtx.G) + } + if curGState.status != go122.GoRunning { + return curCtx, false, fmt.Errorf("%s event for goroutine that's not %s", go122.EventString(ev.typ), GoRunning) + } + nextg := GoID(ev.args[0]) + seq := makeSeq(gen, ev.args[1]) // seq is for nextg, not curCtx.G. + nextGState, ok := o.gStates[nextg] + if !ok || nextGState.status != go122.GoWaiting || !seq.succeeds(nextGState.seq) { + // We can't make an inference as to whether this is bad. We could just be seeing + // a GoSwitch on a different M before the goroutine was created, before it had its + // state emitted, or before we got to the right point in the trace yet. + return curCtx, false, nil + } + o.queue.push(Event{table: evt, ctx: curCtx, base: *ev}) + + // Update the state of the executing goroutine and emit an event for it + // (GoSwitch and GoSwitchDestroy will be interpreted as GoUnblock events + // for nextg). + switch ev.typ { + case go122.EvGoSwitch: + // Goroutine blocked. It's waiting now and not running on this M. + curGState.status = go122.GoWaiting + + // Emit a GoBlock event. + // TODO(mknyszek): Emit a reason. + o.queue.push(makeEvent(evt, curCtx, go122.EvGoBlock, ev.time, 0 /* no reason */, 0 /* no stack */)) + case go122.EvGoSwitchDestroy: + // This goroutine is exiting itself. + delete(o.gStates, curCtx.G) + + // Emit a GoDestroy event. + o.queue.push(makeEvent(evt, curCtx, go122.EvGoDestroy, ev.time)) + } + // Update the state of the next goroutine. + nextGState.status = go122.GoRunning + nextGState.seq = seq + newCtx := curCtx + newCtx.G = nextg + + // Queue an event for the next goroutine starting to run. + startCtx := curCtx + startCtx.G = NoGoroutine + o.queue.push(makeEvent(evt, startCtx, go122.EvGoStart, ev.time, uint64(nextg), ev.args[1])) + return newCtx, true, nil +} + +func (o *ordering) advanceGoSyscallBegin(ev *baseEvent, evt *evTable, m ThreadID, gen uint64, curCtx schedCtx) (schedCtx, bool, error) { + // Entering a syscall requires an active running goroutine with a + // proc on some thread. It is always advancable. + if err := validateCtx(curCtx, event.UserGoReqs); err != nil { + return curCtx, false, err + } + state, ok := o.gStates[curCtx.G] + if !ok { + return curCtx, false, fmt.Errorf("event %s for goroutine (%v) that doesn't exist", go122.EventString(ev.typ), curCtx.G) + } + if state.status != go122.GoRunning { + return curCtx, false, fmt.Errorf("%s event for goroutine that's not %s", go122.EventString(ev.typ), GoRunning) + } + // Goroutine entered a syscall. It's still running on this P and M. + state.status = go122.GoSyscall + pState, ok := o.pStates[curCtx.P] + if !ok { + return curCtx, false, fmt.Errorf("uninitialized proc %d found during %s", curCtx.P, go122.EventString(ev.typ)) + } + pState.status = go122.ProcSyscall + // Validate the P sequence number on the event and advance it. + // + // We have a P sequence number for what is supposed to be a goroutine event + // so that we can correctly model P stealing. Without this sequence number here, + // the syscall from which a ProcSteal event is stealing can be ambiguous in the + // face of broken timestamps. See the go122-syscall-steal-proc-ambiguous test for + // more details. + // + // Note that because this sequence number only exists as a tool for disambiguation, + // we can enforce that we have the right sequence number at this point; we don't need + // to back off and see if any other events will advance. This is a running P. + pSeq := makeSeq(gen, ev.args[0]) + if !pSeq.succeeds(pState.seq) { + return curCtx, false, fmt.Errorf("failed to advance %s: can't make sequence: %s -> %s", go122.EventString(ev.typ), pState.seq, pSeq) + } + pState.seq = pSeq + o.queue.push(Event{table: evt, ctx: curCtx, base: *ev}) + return curCtx, true, nil +} + +func (o *ordering) advanceGoSyscallEnd(ev *baseEvent, evt *evTable, m ThreadID, gen uint64, curCtx schedCtx) (schedCtx, bool, error) { + // This event is always advance-able because it happens on the same + // thread that EvGoSyscallStart happened, and the goroutine can't leave + // that thread until its done. + if err := validateCtx(curCtx, event.UserGoReqs); err != nil { + return curCtx, false, err + } + state, ok := o.gStates[curCtx.G] + if !ok { + return curCtx, false, fmt.Errorf("event %s for goroutine (%v) that doesn't exist", go122.EventString(ev.typ), curCtx.G) + } + if state.status != go122.GoSyscall { + return curCtx, false, fmt.Errorf("%s event for goroutine that's not %s", go122.EventString(ev.typ), GoRunning) + } + state.status = go122.GoRunning + + // Transfer the P back to running from syscall. + pState, ok := o.pStates[curCtx.P] + if !ok { + return curCtx, false, fmt.Errorf("uninitialized proc %d found during %s", curCtx.P, go122.EventString(ev.typ)) + } + if pState.status != go122.ProcSyscall { + return curCtx, false, fmt.Errorf("expected proc %d in state %v, but got %v instead", curCtx.P, go122.ProcSyscall, pState.status) + } + pState.status = go122.ProcRunning + o.queue.push(Event{table: evt, ctx: curCtx, base: *ev}) + return curCtx, true, nil +} + +func (o *ordering) advanceGoSyscallEndBlocked(ev *baseEvent, evt *evTable, m ThreadID, gen uint64, curCtx schedCtx) (schedCtx, bool, error) { + // This event becomes advanceable when its P is not in a syscall state + // (lack of a P altogether is also acceptable for advancing). + // The transfer out of ProcSyscall can happen either voluntarily via + // ProcStop or involuntarily via ProcSteal. We may also acquire a new P + // before we get here (after the transfer out) but that's OK: that new + // P won't be in the ProcSyscall state anymore. + // + // Basically: while we have a preemptible P, don't advance, because we + // *know* from the event that we're going to lose it at some point during + // the syscall. We shouldn't advance until that happens. + if curCtx.P != NoProc { pState, ok := o.pStates[curCtx.P] if !ok { - return false, fmt.Errorf("uninitialized proc %d found during %s", curCtx.P, go122.EventString(typ)) - } - pState.status = go122.ProcSyscall - // Validate the P sequence number on the event and advance it. - // - // We have a P sequence number for what is supposed to be a goroutine event - // so that we can correctly model P stealing. Without this sequence number here, - // the syscall from which a ProcSteal event is stealing can be ambiguous in the - // face of broken timestamps. See the go122-syscall-steal-proc-ambiguous test for - // more details. - // - // Note that because this sequence number only exists as a tool for disambiguation, - // we can enforce that we have the right sequence number at this point; we don't need - // to back off and see if any other events will advance. This is a running P. - pSeq := makeSeq(gen, ev.args[0]) - if !pSeq.succeeds(pState.seq) { - return false, fmt.Errorf("failed to advance %s: can't make sequence: %s -> %s", go122.EventString(typ), pState.seq, pSeq) - } - pState.seq = pSeq - o.queue.push(currentEvent()) - case go122.EvGoSyscallEnd: - // This event is always advance-able because it happens on the same - // thread that EvGoSyscallStart happened, and the goroutine can't leave - // that thread until its done. - if err := validateCtx(curCtx, event.UserGoReqs); err != nil { - return false, err - } - state, ok := o.gStates[curCtx.G] - if !ok { - return false, fmt.Errorf("event %s for goroutine (%v) that doesn't exist", go122.EventString(typ), curCtx.G) + return curCtx, false, fmt.Errorf("uninitialized proc %d found during %s", curCtx.P, go122.EventString(ev.typ)) } - if state.status != go122.GoSyscall { - return false, fmt.Errorf("%s event for goroutine that's not %s", go122.EventString(typ), GoRunning) + if pState.status == go122.ProcSyscall { + return curCtx, false, nil } - state.status = go122.GoRunning + } + // As mentioned above, we may have a P here if we ProcStart + // before this event. + if err := validateCtx(curCtx, event.SchedReqs{Thread: event.MustHave, Proc: event.MayHave, Goroutine: event.MustHave}); err != nil { + return curCtx, false, err + } + state, ok := o.gStates[curCtx.G] + if !ok { + return curCtx, false, fmt.Errorf("event %s for goroutine (%v) that doesn't exist", go122.EventString(ev.typ), curCtx.G) + } + if state.status != go122.GoSyscall { + return curCtx, false, fmt.Errorf("%s event for goroutine that's not %s", go122.EventString(ev.typ), GoRunning) + } + newCtx := curCtx + newCtx.G = NoGoroutine + state.status = go122.GoRunnable + o.queue.push(Event{table: evt, ctx: curCtx, base: *ev}) + return newCtx, true, nil +} + +func (o *ordering) advanceGoCreateSyscall(ev *baseEvent, evt *evTable, m ThreadID, gen uint64, curCtx schedCtx) (schedCtx, bool, error) { + // This event indicates that a goroutine is effectively + // being created out of a cgo callback. Such a goroutine + // is 'created' in the syscall state. + if err := validateCtx(curCtx, event.SchedReqs{Thread: event.MustHave, Proc: event.MayHave, Goroutine: event.MustNotHave}); err != nil { + return curCtx, false, err + } + // This goroutine is effectively being created. Add a state for it. + newgid := GoID(ev.args[0]) + if _, ok := o.gStates[newgid]; ok { + return curCtx, false, fmt.Errorf("tried to create goroutine (%v) in syscall that already exists", newgid) + } + o.gStates[newgid] = &gState{id: newgid, status: go122.GoSyscall, seq: makeSeq(gen, 0)} + // Goroutine is executing. Bind it to the context. + newCtx := curCtx + newCtx.G = newgid + o.queue.push(Event{table: evt, ctx: curCtx, base: *ev}) + return newCtx, true, nil +} + +func (o *ordering) advanceGoDestroySyscall(ev *baseEvent, evt *evTable, m ThreadID, gen uint64, curCtx schedCtx) (schedCtx, bool, error) { + // This event indicates that a goroutine created for a + // cgo callback is disappearing, either because the callback + // ending or the C thread that called it is being destroyed. + // + // Also, treat this as if we lost our P too. + // The thread ID may be reused by the platform and we'll get + // really confused if we try to steal the P is this is running + // with later. The new M with the same ID could even try to + // steal back this P from itself! + // + // The runtime is careful to make sure that any GoCreateSyscall + // event will enter the runtime emitting events for reacquiring a P. + // + // Note: we might have a P here. The P might not be released + // eagerly by the runtime, and it might get stolen back later + // (or never again, if the program is going to exit). + if err := validateCtx(curCtx, event.SchedReqs{Thread: event.MustHave, Proc: event.MayHave, Goroutine: event.MustHave}); err != nil { + return curCtx, false, err + } + // Check to make sure the goroutine exists in the right state. + state, ok := o.gStates[curCtx.G] + if !ok { + return curCtx, false, fmt.Errorf("event %s for goroutine (%v) that doesn't exist", go122.EventString(ev.typ), curCtx.G) + } + if state.status != go122.GoSyscall { + return curCtx, false, fmt.Errorf("%s event for goroutine that's not %v", go122.EventString(ev.typ), GoSyscall) + } + // This goroutine is exiting itself. + delete(o.gStates, curCtx.G) + newCtx := curCtx + newCtx.G = NoGoroutine - // Transfer the P back to running from syscall. + // If we have a proc, then we're dissociating from it now. See the comment at the top of the case. + if curCtx.P != NoProc { pState, ok := o.pStates[curCtx.P] if !ok { - return false, fmt.Errorf("uninitialized proc %d found during %s", curCtx.P, go122.EventString(typ)) + return curCtx, false, fmt.Errorf("found invalid proc %d during %s", curCtx.P, go122.EventString(ev.typ)) } if pState.status != go122.ProcSyscall { - return false, fmt.Errorf("expected proc %d in state %v, but got %v instead", curCtx.P, go122.ProcSyscall, pState.status) - } - pState.status = go122.ProcRunning - o.queue.push(currentEvent()) - case go122.EvGoSyscallEndBlocked: - // This event becomes advanceable when its P is not in a syscall state - // (lack of a P altogether is also acceptable for advancing). - // The transfer out of ProcSyscall can happen either voluntarily via - // ProcStop or involuntarily via ProcSteal. We may also acquire a new P - // before we get here (after the transfer out) but that's OK: that new - // P won't be in the ProcSyscall state anymore. - // - // Basically: while we have a preemptible P, don't advance, because we - // *know* from the event that we're going to lose it at some point during - // the syscall. We shouldn't advance until that happens. - if curCtx.P != NoProc { - pState, ok := o.pStates[curCtx.P] - if !ok { - return false, fmt.Errorf("uninitialized proc %d found during %s", curCtx.P, go122.EventString(typ)) - } - if pState.status == go122.ProcSyscall { - return false, nil - } - } - // As mentioned above, we may have a P here if we ProcStart - // before this event. - if err := validateCtx(curCtx, event.SchedReqs{Thread: event.MustHave, Proc: event.MayHave, Goroutine: event.MustHave}); err != nil { - return false, err - } - state, ok := o.gStates[curCtx.G] - if !ok { - return false, fmt.Errorf("event %s for goroutine (%v) that doesn't exist", go122.EventString(typ), curCtx.G) - } - if state.status != go122.GoSyscall { - return false, fmt.Errorf("%s event for goroutine that's not %s", go122.EventString(typ), GoRunning) + return curCtx, false, fmt.Errorf("proc %d in unexpected state %s during %s", curCtx.P, pState.status, go122.EventString(ev.typ)) } - newCtx.G = NoGoroutine - state.status = go122.GoRunnable - o.queue.push(currentEvent()) - case go122.EvGoCreateSyscall: - // This event indicates that a goroutine is effectively - // being created out of a cgo callback. Such a goroutine - // is 'created' in the syscall state. - if err := validateCtx(curCtx, event.SchedReqs{Thread: event.MustHave, Proc: event.MayHave, Goroutine: event.MustNotHave}); err != nil { - return false, err - } - // This goroutine is effectively being created. Add a state for it. - newgid := GoID(ev.args[0]) - if _, ok := o.gStates[newgid]; ok { - return false, fmt.Errorf("tried to create goroutine (%v) in syscall that already exists", newgid) - } - o.gStates[newgid] = &gState{id: newgid, status: go122.GoSyscall, seq: makeSeq(gen, 0)} - // Goroutine is executing. Bind it to the context. - newCtx.G = newgid - o.queue.push(currentEvent()) - case go122.EvGoDestroySyscall: - // This event indicates that a goroutine created for a - // cgo callback is disappearing, either because the callback - // ending or the C thread that called it is being destroyed. - // - // Also, treat this as if we lost our P too. - // The thread ID may be reused by the platform and we'll get - // really confused if we try to steal the P is this is running - // with later. The new M with the same ID could even try to - // steal back this P from itself! - // - // The runtime is careful to make sure that any GoCreateSyscall - // event will enter the runtime emitting events for reacquiring a P. - // - // Note: we might have a P here. The P might not be released - // eagerly by the runtime, and it might get stolen back later - // (or never again, if the program is going to exit). - if err := validateCtx(curCtx, event.SchedReqs{Thread: event.MustHave, Proc: event.MayHave, Goroutine: event.MustHave}); err != nil { - return false, err - } - // Check to make sure the goroutine exists in the right state. - state, ok := o.gStates[curCtx.G] - if !ok { - return false, fmt.Errorf("event %s for goroutine (%v) that doesn't exist", go122.EventString(typ), curCtx.G) - } - if state.status != go122.GoSyscall { - return false, fmt.Errorf("%s event for goroutine that's not %v", go122.EventString(typ), GoSyscall) - } - // This goroutine is exiting itself. - delete(o.gStates, curCtx.G) - newCtx.G = NoGoroutine + // See the go122-create-syscall-reuse-thread-id test case for more details. + pState.status = go122.ProcSyscallAbandoned + newCtx.P = NoProc - // If we have a proc, then we're dissociating from it now. See the comment at the top of the case. - if curCtx.P != NoProc { - pState, ok := o.pStates[curCtx.P] - if !ok { - return false, fmt.Errorf("found invalid proc %d during %s", curCtx.P, go122.EventString(typ)) - } - if pState.status != go122.ProcSyscall { - return false, fmt.Errorf("proc %d in unexpected state %s during %s", curCtx.P, pState.status, go122.EventString(typ)) - } - // See the go122-create-syscall-reuse-thread-id test case for more details. - pState.status = go122.ProcSyscallAbandoned - newCtx.P = NoProc - - // Queue an extra self-ProcSteal event. - extra := makeEvent(evt, curCtx, go122.EvProcSteal, ev.time, uint64(curCtx.P)) - extra.base.extra(version.Go122)[0] = uint64(go122.ProcSyscall) - o.queue.push(extra) - } - o.queue.push(currentEvent()) + // Queue an extra self-ProcSteal event. + extra := makeEvent(evt, curCtx, go122.EvProcSteal, ev.time, uint64(curCtx.P)) + extra.base.extra(version.Go122)[0] = uint64(go122.ProcSyscall) + o.queue.push(extra) + } + o.queue.push(Event{table: evt, ctx: curCtx, base: *ev}) + return newCtx, true, nil +} +func (o *ordering) advanceUserTaskBegin(ev *baseEvent, evt *evTable, m ThreadID, gen uint64, curCtx schedCtx) (schedCtx, bool, error) { // Handle tasks. Tasks are interesting because: // - There's no Begin event required to reference a task. // - End for a particular task ID can appear multiple times. @@ -653,265 +768,291 @@ func (o *ordering) Advance(ev *baseEvent, evt *evTable, m ThreadID, gen uint64) // thing we have to be sure of is that a task didn't begin // after it had already begun. Task IDs are allowed to be // reused, so we don't care about a Begin after an End. - case go122.EvUserTaskBegin: - id := TaskID(ev.args[0]) - if _, ok := o.activeTasks[id]; ok { - return false, fmt.Errorf("task ID conflict: %d", id) - } - // Get the parent ID, but don't validate it. There's no guarantee - // we actually have information on whether it's active. - parentID := TaskID(ev.args[1]) - if parentID == BackgroundTask { - // Note: a value of 0 here actually means no parent, *not* the - // background task. Automatic background task attachment only - // applies to regions. - parentID = NoTask - ev.args[1] = uint64(NoTask) - } + id := TaskID(ev.args[0]) + if _, ok := o.activeTasks[id]; ok { + return curCtx, false, fmt.Errorf("task ID conflict: %d", id) + } + // Get the parent ID, but don't validate it. There's no guarantee + // we actually have information on whether it's active. + parentID := TaskID(ev.args[1]) + if parentID == BackgroundTask { + // Note: a value of 0 here actually means no parent, *not* the + // background task. Automatic background task attachment only + // applies to regions. + parentID = NoTask + ev.args[1] = uint64(NoTask) + } - // Validate the name and record it. We'll need to pass it through to - // EvUserTaskEnd. - nameID := stringID(ev.args[2]) - name, ok := evt.strings.get(nameID) - if !ok { - return false, fmt.Errorf("invalid string ID %v for %v event", nameID, typ) - } - o.activeTasks[id] = taskState{name: name, parentID: parentID} - if err := validateCtx(curCtx, event.UserGoReqs); err != nil { - return false, err - } - o.queue.push(currentEvent()) - case go122.EvUserTaskEnd: - id := TaskID(ev.args[0]) - if ts, ok := o.activeTasks[id]; ok { - // Smuggle the task info. This may happen in a different generation, - // which may not have the name in its string table. Add it to the extra - // strings table so we can look it up later. - ev.extra(version.Go122)[0] = uint64(ts.parentID) - ev.extra(version.Go122)[1] = uint64(evt.addExtraString(ts.name)) - delete(o.activeTasks, id) - } else { - // Explicitly clear the task info. - ev.extra(version.Go122)[0] = uint64(NoTask) - ev.extra(version.Go122)[1] = uint64(evt.addExtraString("")) - } - if err := validateCtx(curCtx, event.UserGoReqs); err != nil { - return false, err - } - o.queue.push(currentEvent()) + // Validate the name and record it. We'll need to pass it through to + // EvUserTaskEnd. + nameID := stringID(ev.args[2]) + name, ok := evt.strings.get(nameID) + if !ok { + return curCtx, false, fmt.Errorf("invalid string ID %v for %v event", nameID, ev.typ) + } + o.activeTasks[id] = taskState{name: name, parentID: parentID} + if err := validateCtx(curCtx, event.UserGoReqs); err != nil { + return curCtx, false, err + } + o.queue.push(Event{table: evt, ctx: curCtx, base: *ev}) + return curCtx, true, nil +} - // Handle user regions. - case go122.EvUserRegionBegin: - if err := validateCtx(curCtx, event.UserGoReqs); err != nil { - return false, err - } - tid := TaskID(ev.args[0]) - nameID := stringID(ev.args[1]) - name, ok := evt.strings.get(nameID) - if !ok { - return false, fmt.Errorf("invalid string ID %v for %v event", nameID, typ) - } - gState, ok := o.gStates[curCtx.G] - if !ok { - return false, fmt.Errorf("encountered EvUserRegionBegin without known state for current goroutine %d", curCtx.G) - } - if err := gState.beginRegion(userRegion{tid, name}); err != nil { - return false, err - } - o.queue.push(currentEvent()) - case go122.EvUserRegionEnd: - if err := validateCtx(curCtx, event.UserGoReqs); err != nil { - return false, err - } - tid := TaskID(ev.args[0]) - nameID := stringID(ev.args[1]) - name, ok := evt.strings.get(nameID) - if !ok { - return false, fmt.Errorf("invalid string ID %v for %v event", nameID, typ) - } - gState, ok := o.gStates[curCtx.G] - if !ok { - return false, fmt.Errorf("encountered EvUserRegionEnd without known state for current goroutine %d", curCtx.G) - } - if err := gState.endRegion(userRegion{tid, name}); err != nil { - return false, err - } - o.queue.push(currentEvent()) +func (o *ordering) advanceUserTaskEnd(ev *baseEvent, evt *evTable, m ThreadID, gen uint64, curCtx schedCtx) (schedCtx, bool, error) { + id := TaskID(ev.args[0]) + if ts, ok := o.activeTasks[id]; ok { + // Smuggle the task info. This may happen in a different generation, + // which may not have the name in its string table. Add it to the extra + // strings table so we can look it up later. + ev.extra(version.Go122)[0] = uint64(ts.parentID) + ev.extra(version.Go122)[1] = uint64(evt.addExtraString(ts.name)) + delete(o.activeTasks, id) + } else { + // Explicitly clear the task info. + ev.extra(version.Go122)[0] = uint64(NoTask) + ev.extra(version.Go122)[1] = uint64(evt.addExtraString("")) + } + if err := validateCtx(curCtx, event.UserGoReqs); err != nil { + return curCtx, false, err + } + o.queue.push(Event{table: evt, ctx: curCtx, base: *ev}) + return curCtx, true, nil +} - // Handle the GC mark phase. - // - // We have sequence numbers for both start and end because they - // can happen on completely different threads. We want an explicit - // partial order edge between start and end here, otherwise we're - // relying entirely on timestamps to make sure we don't advance a - // GCEnd for a _different_ GC cycle if timestamps are wildly broken. - case go122.EvGCActive: - seq := ev.args[0] - if gen == o.initialGen { - if o.gcState != gcUndetermined { - return false, fmt.Errorf("GCActive in the first generation isn't first GC event") - } - o.gcSeq = seq - o.gcState = gcRunning - o.queue.push(currentEvent()) - break - } - if seq != o.gcSeq+1 { - // This is not the right GC cycle. - return false, nil - } - if o.gcState != gcRunning { - return false, fmt.Errorf("encountered GCActive while GC was not in progress") - } - o.gcSeq = seq - if err := validateCtx(curCtx, event.UserGoReqs); err != nil { - return false, err - } - o.queue.push(currentEvent()) - case go122.EvGCBegin: - seq := ev.args[0] - if o.gcState == gcUndetermined { - o.gcSeq = seq - o.gcState = gcRunning - o.queue.push(currentEvent()) - break - } - if seq != o.gcSeq+1 { - // This is not the right GC cycle. - return false, nil - } - if o.gcState == gcRunning { - return false, fmt.Errorf("encountered GCBegin while GC was already in progress") +func (o *ordering) advanceUserRegionBegin(ev *baseEvent, evt *evTable, m ThreadID, gen uint64, curCtx schedCtx) (schedCtx, bool, error) { + if err := validateCtx(curCtx, event.UserGoReqs); err != nil { + return curCtx, false, err + } + tid := TaskID(ev.args[0]) + nameID := stringID(ev.args[1]) + name, ok := evt.strings.get(nameID) + if !ok { + return curCtx, false, fmt.Errorf("invalid string ID %v for %v event", nameID, ev.typ) + } + gState, ok := o.gStates[curCtx.G] + if !ok { + return curCtx, false, fmt.Errorf("encountered EvUserRegionBegin without known state for current goroutine %d", curCtx.G) + } + if err := gState.beginRegion(userRegion{tid, name}); err != nil { + return curCtx, false, err + } + o.queue.push(Event{table: evt, ctx: curCtx, base: *ev}) + return curCtx, true, nil +} + +func (o *ordering) advanceUserRegionEnd(ev *baseEvent, evt *evTable, m ThreadID, gen uint64, curCtx schedCtx) (schedCtx, bool, error) { + if err := validateCtx(curCtx, event.UserGoReqs); err != nil { + return curCtx, false, err + } + tid := TaskID(ev.args[0]) + nameID := stringID(ev.args[1]) + name, ok := evt.strings.get(nameID) + if !ok { + return curCtx, false, fmt.Errorf("invalid string ID %v for %v event", nameID, ev.typ) + } + gState, ok := o.gStates[curCtx.G] + if !ok { + return curCtx, false, fmt.Errorf("encountered EvUserRegionEnd without known state for current goroutine %d", curCtx.G) + } + if err := gState.endRegion(userRegion{tid, name}); err != nil { + return curCtx, false, err + } + o.queue.push(Event{table: evt, ctx: curCtx, base: *ev}) + return curCtx, true, nil +} + +// Handle the GC mark phase. +// +// We have sequence numbers for both start and end because they +// can happen on completely different threads. We want an explicit +// partial order edge between start and end here, otherwise we're +// relying entirely on timestamps to make sure we don't advance a +// GCEnd for a _different_ GC cycle if timestamps are wildly broken. +func (o *ordering) advanceGCActive(ev *baseEvent, evt *evTable, m ThreadID, gen uint64, curCtx schedCtx) (schedCtx, bool, error) { + seq := ev.args[0] + if gen == o.initialGen { + if o.gcState != gcUndetermined { + return curCtx, false, fmt.Errorf("GCActive in the first generation isn't first GC event") } o.gcSeq = seq o.gcState = gcRunning - if err := validateCtx(curCtx, event.UserGoReqs); err != nil { - return false, err - } - o.queue.push(currentEvent()) - case go122.EvGCEnd: - seq := ev.args[0] - if seq != o.gcSeq+1 { - // This is not the right GC cycle. - return false, nil - } - if o.gcState == gcNotRunning { - return false, fmt.Errorf("encountered GCEnd when GC was not in progress") - } - if o.gcState == gcUndetermined { - return false, fmt.Errorf("encountered GCEnd when GC was in an undetermined state") - } + o.queue.push(Event{table: evt, ctx: curCtx, base: *ev}) + return curCtx, true, nil + } + if seq != o.gcSeq+1 { + // This is not the right GC cycle. + return curCtx, false, nil + } + if o.gcState != gcRunning { + return curCtx, false, fmt.Errorf("encountered GCActive while GC was not in progress") + } + o.gcSeq = seq + if err := validateCtx(curCtx, event.UserGoReqs); err != nil { + return curCtx, false, err + } + o.queue.push(Event{table: evt, ctx: curCtx, base: *ev}) + return curCtx, true, nil +} + +func (o *ordering) advanceGCBegin(ev *baseEvent, evt *evTable, m ThreadID, gen uint64, curCtx schedCtx) (schedCtx, bool, error) { + seq := ev.args[0] + if o.gcState == gcUndetermined { o.gcSeq = seq - o.gcState = gcNotRunning - if err := validateCtx(curCtx, event.UserGoReqs); err != nil { - return false, err - } - o.queue.push(currentEvent()) + o.gcState = gcRunning + o.queue.push(Event{table: evt, ctx: curCtx, base: *ev}) + return curCtx, true, nil + } + if seq != o.gcSeq+1 { + // This is not the right GC cycle. + return curCtx, false, nil + } + if o.gcState == gcRunning { + return curCtx, false, fmt.Errorf("encountered GCBegin while GC was already in progress") + } + o.gcSeq = seq + o.gcState = gcRunning + if err := validateCtx(curCtx, event.UserGoReqs); err != nil { + return curCtx, false, err + } + o.queue.push(Event{table: evt, ctx: curCtx, base: *ev}) + return curCtx, true, nil +} + +func (o *ordering) advanceGCEnd(ev *baseEvent, evt *evTable, m ThreadID, gen uint64, curCtx schedCtx) (schedCtx, bool, error) { + seq := ev.args[0] + if seq != o.gcSeq+1 { + // This is not the right GC cycle. + return curCtx, false, nil + } + if o.gcState == gcNotRunning { + return curCtx, false, fmt.Errorf("encountered GCEnd when GC was not in progress") + } + if o.gcState == gcUndetermined { + return curCtx, false, fmt.Errorf("encountered GCEnd when GC was in an undetermined state") + } + o.gcSeq = seq + o.gcState = gcNotRunning + if err := validateCtx(curCtx, event.UserGoReqs); err != nil { + return curCtx, false, err + } + o.queue.push(Event{table: evt, ctx: curCtx, base: *ev}) + return curCtx, true, nil +} +func (o *ordering) advanceAnnotation(ev *baseEvent, evt *evTable, m ThreadID, gen uint64, curCtx schedCtx) (schedCtx, bool, error) { // Handle simple instantaneous events that require a G. - case go122.EvGoLabel, go122.EvProcsChange, go122.EvUserLog: - if err := validateCtx(curCtx, event.UserGoReqs); err != nil { - return false, err - } - o.queue.push(currentEvent()) + if err := validateCtx(curCtx, event.UserGoReqs); err != nil { + return curCtx, false, err + } + o.queue.push(Event{table: evt, ctx: curCtx, base: *ev}) + return curCtx, true, nil +} - // Handle allocation states, which don't require a G. - case go122.EvHeapAlloc, go122.EvHeapGoal: - if err := validateCtx(curCtx, event.SchedReqs{Thread: event.MustHave, Proc: event.MustHave, Goroutine: event.MayHave}); err != nil { - return false, err - } - o.queue.push(currentEvent()) +func (o *ordering) advanceHeapMetric(ev *baseEvent, evt *evTable, m ThreadID, gen uint64, curCtx schedCtx) (schedCtx, bool, error) { + // Handle allocation metrics, which don't require a G. + if err := validateCtx(curCtx, event.SchedReqs{Thread: event.MustHave, Proc: event.MustHave, Goroutine: event.MayHave}); err != nil { + return curCtx, false, err + } + o.queue.push(Event{table: evt, ctx: curCtx, base: *ev}) + return curCtx, true, nil +} +func (o *ordering) advanceGCSweepBegin(ev *baseEvent, evt *evTable, m ThreadID, gen uint64, curCtx schedCtx) (schedCtx, bool, error) { // Handle sweep, which is bound to a P and doesn't require a G. - case go122.EvGCSweepBegin: - if err := validateCtx(curCtx, event.SchedReqs{Thread: event.MustHave, Proc: event.MustHave, Goroutine: event.MayHave}); err != nil { - return false, err - } - if err := o.pStates[curCtx.P].beginRange(makeRangeType(typ, 0)); err != nil { - return false, err - } - o.queue.push(currentEvent()) - case go122.EvGCSweepActive: - pid := ProcID(ev.args[0]) - // N.B. In practice Ps can't block while they're sweeping, so this can only - // ever reference curCtx.P. However, be lenient about this like we are with - // GCMarkAssistActive; there's no reason the runtime couldn't change to block - // in the middle of a sweep. - pState, ok := o.pStates[pid] - if !ok { - return false, fmt.Errorf("encountered GCSweepActive for unknown proc %d", pid) - } - if err := pState.activeRange(makeRangeType(typ, 0), gen == o.initialGen); err != nil { - return false, err - } - o.queue.push(currentEvent()) - case go122.EvGCSweepEnd: - if err := validateCtx(curCtx, event.SchedReqs{Thread: event.MustHave, Proc: event.MustHave, Goroutine: event.MayHave}); err != nil { - return false, err - } - _, err := o.pStates[curCtx.P].endRange(typ) - if err != nil { - return false, err - } - o.queue.push(currentEvent()) + if err := validateCtx(curCtx, event.SchedReqs{Thread: event.MustHave, Proc: event.MustHave, Goroutine: event.MayHave}); err != nil { + return curCtx, false, err + } + if err := o.pStates[curCtx.P].beginRange(makeRangeType(ev.typ, 0)); err != nil { + return curCtx, false, err + } + o.queue.push(Event{table: evt, ctx: curCtx, base: *ev}) + return curCtx, true, nil +} + +func (o *ordering) advanceGCSweepActive(ev *baseEvent, evt *evTable, m ThreadID, gen uint64, curCtx schedCtx) (schedCtx, bool, error) { + pid := ProcID(ev.args[0]) + // N.B. In practice Ps can't block while they're sweeping, so this can only + // ever reference curCtx.P. However, be lenient about this like we are with + // GCMarkAssistActive; there's no reason the runtime couldn't change to block + // in the middle of a sweep. + pState, ok := o.pStates[pid] + if !ok { + return curCtx, false, fmt.Errorf("encountered GCSweepActive for unknown proc %d", pid) + } + if err := pState.activeRange(makeRangeType(ev.typ, 0), gen == o.initialGen); err != nil { + return curCtx, false, err + } + o.queue.push(Event{table: evt, ctx: curCtx, base: *ev}) + return curCtx, true, nil +} + +func (o *ordering) advanceGCSweepEnd(ev *baseEvent, evt *evTable, m ThreadID, gen uint64, curCtx schedCtx) (schedCtx, bool, error) { + if err := validateCtx(curCtx, event.SchedReqs{Thread: event.MustHave, Proc: event.MustHave, Goroutine: event.MayHave}); err != nil { + return curCtx, false, err + } + _, err := o.pStates[curCtx.P].endRange(ev.typ) + if err != nil { + return curCtx, false, err + } + o.queue.push(Event{table: evt, ctx: curCtx, base: *ev}) + return curCtx, true, nil +} +func (o *ordering) advanceGoRangeBegin(ev *baseEvent, evt *evTable, m ThreadID, gen uint64, curCtx schedCtx) (schedCtx, bool, error) { // Handle special goroutine-bound event ranges. - case go122.EvSTWBegin, go122.EvGCMarkAssistBegin: - if err := validateCtx(curCtx, event.UserGoReqs); err != nil { - return false, err - } - desc := stringID(0) - if typ == go122.EvSTWBegin { - desc = stringID(ev.args[0]) - } - gState, ok := o.gStates[curCtx.G] - if !ok { - return false, fmt.Errorf("encountered event of type %d without known state for current goroutine %d", typ, curCtx.G) - } - if err := gState.beginRange(makeRangeType(typ, desc)); err != nil { - return false, err - } - o.queue.push(currentEvent()) - case go122.EvGCMarkAssistActive: - gid := GoID(ev.args[0]) - // N.B. Like GoStatus, this can happen at any time, because it can - // reference a non-running goroutine. Don't check anything about the - // current scheduler context. - gState, ok := o.gStates[gid] - if !ok { - return false, fmt.Errorf("uninitialized goroutine %d found during %s", gid, go122.EventString(typ)) - } - if err := gState.activeRange(makeRangeType(typ, 0), gen == o.initialGen); err != nil { - return false, err - } - o.queue.push(currentEvent()) - case go122.EvSTWEnd, go122.EvGCMarkAssistEnd: - if err := validateCtx(curCtx, event.UserGoReqs); err != nil { - return false, err - } - gState, ok := o.gStates[curCtx.G] - if !ok { - return false, fmt.Errorf("encountered event of type %d without known state for current goroutine %d", typ, curCtx.G) - } - desc, err := gState.endRange(typ) - if err != nil { - return false, err - } - if typ == go122.EvSTWEnd { - // Smuggle the kind into the event. - // Don't use ev.extra here so we have symmetry with STWBegin. - ev.args[0] = uint64(desc) - } - o.queue.push(currentEvent()) - default: - return false, fmt.Errorf("bad event type found while ordering: %v", ev.typ) + if err := validateCtx(curCtx, event.UserGoReqs); err != nil { + return curCtx, false, err } - if ms != nil { - // Update the mState for this event. - ms.p = newCtx.P - ms.g = newCtx.G + desc := stringID(0) + if ev.typ == go122.EvSTWBegin { + desc = stringID(ev.args[0]) + } + gState, ok := o.gStates[curCtx.G] + if !ok { + return curCtx, false, fmt.Errorf("encountered event of type %d without known state for current goroutine %d", ev.typ, curCtx.G) + } + if err := gState.beginRange(makeRangeType(ev.typ, desc)); err != nil { + return curCtx, false, err + } + o.queue.push(Event{table: evt, ctx: curCtx, base: *ev}) + return curCtx, true, nil +} + +func (o *ordering) advanceGoRangeActive(ev *baseEvent, evt *evTable, m ThreadID, gen uint64, curCtx schedCtx) (schedCtx, bool, error) { + gid := GoID(ev.args[0]) + // N.B. Like GoStatus, this can happen at any time, because it can + // reference a non-running goroutine. Don't check anything about the + // current scheduler context. + gState, ok := o.gStates[gid] + if !ok { + return curCtx, false, fmt.Errorf("uninitialized goroutine %d found during %s", gid, go122.EventString(ev.typ)) + } + if err := gState.activeRange(makeRangeType(ev.typ, 0), gen == o.initialGen); err != nil { + return curCtx, false, err + } + o.queue.push(Event{table: evt, ctx: curCtx, base: *ev}) + return curCtx, true, nil +} + +func (o *ordering) advanceGoRangeEnd(ev *baseEvent, evt *evTable, m ThreadID, gen uint64, curCtx schedCtx) (schedCtx, bool, error) { + if err := validateCtx(curCtx, event.UserGoReqs); err != nil { + return curCtx, false, err + } + gState, ok := o.gStates[curCtx.G] + if !ok { + return curCtx, false, fmt.Errorf("encountered event of type %d without known state for current goroutine %d", ev.typ, curCtx.G) + } + desc, err := gState.endRange(ev.typ) + if err != nil { + return curCtx, false, err + } + if ev.typ == go122.EvSTWEnd { + // Smuggle the kind into the event. + // Don't use ev.extra here so we have symmetry with STWBegin. + ev.args[0] = uint64(desc) } - return true, nil + o.queue.push(Event{table: evt, ctx: curCtx, base: *ev}) + return curCtx, true, nil } // Next returns the next event in the ordering. -- 2.50.0