internal/trace/v2: resolve syscall parsing ambiguity

[gostls13.git] / src / internal / trace / v2 / testdata / generators / go122-syscall-steal-proc-ambiguous.go

diff --git a/src/internal/trace/v2/testdata/generators/go122-syscall-steal-proc-ambiguous.go b/src/internal/trace/v2/testdata/generators/go122-syscall-steal-proc-ambiguous.go
new file mode 100644 (file)
index 0000000..349a575
--- /dev/null
+++ b/src/internal/trace/v2/testdata/generators/go122-syscall-steal-proc-ambiguous.go
@@ -0,0 +1,46 @@
+// 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.
+
+// Tests syscall P stealing.
+//
+// Specifically, it tests a scenerio wherein, without a
+// P sequence number of GoSyscallBegin, the syscall that
+// a ProcSteal applies to is ambiguous. This only happens in
+// practice when the events aren't already properly ordered
+// by timestamp, since the ProcSteal won't be seen until after
+// the correct GoSyscallBegin appears on the frontier.
+
+package main
+
+import (
+       "internal/trace/v2"
+       "internal/trace/v2/event/go122"
+       testgen "internal/trace/v2/internal/testgen/go122"
+)
+
+func main() {
+       testgen.Main(gen)
+}
+
+func gen(t *testgen.Trace) {
+       t.DisableTimestamps()
+
+       g := t.Generation(1)
+
+       // One goroutine does a syscall without blocking, then another one where
+       // it's P gets stolen.
+       b0 := g.Batch(trace.ThreadID(0), 0)
+       b0.Event("ProcStatus", trace.ProcID(0), go122.ProcRunning)
+       b0.Event("GoStatus", trace.GoID(1), trace.ThreadID(0), go122.GoRunning)
+       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)
+       b1.Event("ProcSteal", trace.ProcID(0), testgen.Seq(3), trace.ThreadID(0))
+}