1// Copyright 2023 The Go Authors. All rights reserved. 2// Use of this source code is governed by a BSD-style 3// license that can be found in the LICENSE file. 4 5// Tests a G being created from within a syscall. 6// 7// Specifically, it tests a scenerio wherein a C 8// thread is calling into Go, creating a goroutine in 9// a syscall (in the tracer's model). Because the actual 10// m can be reused, it's possible for that m to have never 11// had its P (in _Psyscall) stolen if the runtime doesn't 12// model the scenario correctly. Make sure we reject such 13// traces. 14 15package main 16 17import ( 18 "internal/trace" 19 "internal/trace/event/go122" 20 testgen "internal/trace/internal/testgen/go122" 21) 22 23func main() { 24 testgen.Main(gen) 25} 26 27func gen(t *testgen.Trace) { 28 t.ExpectFailure(".*expected a proc but didn't have one.*") 29 30 g := t.Generation(1) 31 32 // A C thread calls into Go and acquires a P. It returns 33 // back to C, destroying the G. It then comes back to Go 34 // on the same thread and again returns to C. 35 // 36 // Note: on pthread platforms this can't happen on the 37 // same thread because the m is stashed in TLS between 38 // calls into Go, until the thread dies. This is still 39 // possible on other platforms, however. 40 b0 := g.Batch(trace.ThreadID(0), 0) 41 b0.Event("GoCreateSyscall", trace.GoID(4)) 42 b0.Event("ProcStatus", trace.ProcID(0), go122.ProcIdle) 43 b0.Event("ProcStart", trace.ProcID(0), testgen.Seq(1)) 44 b0.Event("GoSyscallEndBlocked") 45 b0.Event("GoStart", trace.GoID(4), testgen.Seq(1)) 46 b0.Event("GoSyscallBegin", testgen.Seq(2), testgen.NoStack) 47 b0.Event("GoDestroySyscall") 48 b0.Event("GoCreateSyscall", trace.GoID(4)) 49 b0.Event("GoSyscallEnd") 50 b0.Event("GoSyscallBegin", testgen.Seq(3), testgen.NoStack) 51 b0.Event("GoDestroySyscall") 52} 53