b0.Event("GoStatus", trace.GoID(1), trace.ThreadID(0), go122.GoSyscall)
	b0.Event("ProcStatus", trace.ProcID(1), go122.ProcIdle)
	b0.Event("ProcStart", trace.ProcID(1), testgen.Seq(1))
	b0.Event("GoSyscallEndBlocked")

	// A bare M stole the goroutine's P at the generation boundary.
	b1 := g.Batch(trace.ThreadID(1), 0)
	b1.Event("ProcStatus", trace.ProcID(0), go122.ProcSyscallAbandoned)

	b0.Event("GoSyscallBegin", testgen.Seq(1), testgen.NoStack)
	b0.Event("GoSyscallEnd")
	b0.Event("GoSyscallBegin", testgen.Seq(2), testgen.NoStack)
	b0.Event("GoSyscallEndBlocked")

	// A running goroutine steals proc 0.
	b1 := g.Batch(trace.ThreadID(1), 0)
	b1.Event("ProcStatus", trace.ProcID(2), go122.ProcRunning)
	b1.Event("GoStatus", trace.GoID(2), trace.ThreadID(1), go122.GoRunning)

	b0 := g.Batch(trace.ThreadID(0), 0)
	b0.Event("GoCreateSyscall", trace.GoID(4))
	b0.Event("ProcStatus", trace.ProcID(0), go122.ProcIdle)
	b0.Event("ProcStart", trace.ProcID(0), testgen.Seq(1))
	b0.Event("GoSyscallEndBlocked")
	b0.Event("GoStart", trace.GoID(4), testgen.Seq(1))
	b0.Event("GoSyscallBegin", testgen.Seq(2), testgen.NoStack)
	b0.Event("GoDestroySyscall")
	b0.Event("GoCreateSyscall", trace.GoID(4))
	b0.Event("GoSyscallEnd")

	g := t.Generation(1)

	// A C thread calls into Go and acquires a P. It returns
	// back to C, destroying the G.
	b0 := g.Batch(trace.ThreadID(0), 0)
	b0.Event("GoCreateSyscall", trace.GoID(4))
	b0.Event("GoSyscallEndBlocked")
	b0.Event("ProcStatus", trace.ProcID(0), go122.ProcIdle)
	b0.Event("ProcStart", trace.ProcID(0), testgen.Seq(1))
	b0.Event("GoStatus", trace.GoID(4), trace.NoThread, go122.GoRunnable)

	// it's mentioned, then there's no GoSyscallBegin to
	// connect the P stealing back to at that point. This
	// special state indicates this to the parser, so it
	// doesn't try to find a GoSyscallEndBlocked that
	// corresponds with the ProcSteal.
	traceProcSyscallAbandoned
)

// writeGoStatus emits a GoStatus event as well as any active ranges on the goroutine.

		Name:         "GoSyscallEnd",
		Args:         []string{"dt"},
		StartEv:      EvGoSyscallBegin,
		IsTimedEvent: true,
	},
	EvGoSyscallEndBlocked: event.Spec{
		Name:         "GoSyscallEndBlocked",
		Args:         []string{"dt"},
		StartEv:      EvGoSyscallBegin,
		IsTimedEvent: true,
	},
	EvGoStatus: event.Spec{
		Name:         "GoStatus",
		Args:         []string{"dt", "g", "m", "gstatus"},

// instantaneous event, gets turned into a 1 ns long pair of
// GoSyscallStart+GoSyscallEnd, unless we observe a GoSysBlock, in which case we
// emit a GoSyscallStart+GoSyscallEndBlocked pair with the correct duration
// (i.e. starting at the original GoSyscall).
//
// The resulting trace treats the old trace as a single, large generation,
// sharing a single evTable for all events.
//

ProcStart dt=206 p=7 p_seq=14
GoSyscallEndBlocked dt=3
GoStart dt=1 g=51 g_seq=2
GoDestroy dt=12
ProcStop dt=18
ProcStart dt=849 p=5 p_seq=6
ProcStop dt=16
ProcStart dt=1359 p=5 p_seq=7
ProcStop dt=12
ProcStart dt=2079 p=5 p_seq=9
GoStart dt=1134 g=52 g_seq=1
GoSyscallBegin dt=39 p_seq=10 stack=78
ProcStart dt=232 p=5 p_seq=12
GoSyscallEndBlocked dt=2
GoStart dt=1 g=52 g_seq=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(Event{table: evt, ctx: curCtx, base: *ev})
	return newCtx, true, nil
}