diff options
Diffstat (limited to 'src/runtime/testdata/testprogcgo/threadpprof.go')
-rw-r--r-- | src/runtime/testdata/testprogcgo/threadpprof.go | 123 |
1 files changed, 123 insertions, 0 deletions
diff --git a/src/runtime/testdata/testprogcgo/threadpprof.go b/src/runtime/testdata/testprogcgo/threadpprof.go new file mode 100644 index 0000000..ec5e750 --- /dev/null +++ b/src/runtime/testdata/testprogcgo/threadpprof.go @@ -0,0 +1,123 @@ +// Copyright 2016 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. + +//go:build !plan9 && !windows +// +build !plan9,!windows + +package main + +// Run a slow C function saving a CPU profile. + +/* +#include <stdint.h> +#include <time.h> +#include <pthread.h> + +int threadSalt1; +int threadSalt2; + +void cpuHogThread() { + int foo = threadSalt1; + int i; + + for (i = 0; i < 100000; i++) { + if (foo > 0) { + foo *= foo; + } else { + foo *= foo + 1; + } + } + threadSalt2 = foo; +} + +void cpuHogThread2() { +} + +struct cgoTracebackArg { + uintptr_t context; + uintptr_t sigContext; + uintptr_t* buf; + uintptr_t max; +}; + +// pprofCgoThreadTraceback is passed to runtime.SetCgoTraceback. +// For testing purposes it pretends that all CPU hits in C code are in cpuHog. +void pprofCgoThreadTraceback(void* parg) { + struct cgoTracebackArg* arg = (struct cgoTracebackArg*)(parg); + arg->buf[0] = (uintptr_t)(cpuHogThread) + 0x10; + arg->buf[1] = (uintptr_t)(cpuHogThread2) + 0x4; + arg->buf[2] = 0; +} + +static void* cpuHogDriver(void* arg __attribute__ ((unused))) { + while (1) { + cpuHogThread(); + } + return 0; +} + +void runCPUHogThread(void) { + pthread_t tid; + pthread_create(&tid, 0, cpuHogDriver, 0); +} +*/ +import "C" + +import ( + "context" + "fmt" + "os" + "runtime" + "runtime/pprof" + "time" + "unsafe" +) + +func init() { + register("CgoPprofThread", CgoPprofThread) + register("CgoPprofThreadNoTraceback", CgoPprofThreadNoTraceback) +} + +func CgoPprofThread() { + runtime.SetCgoTraceback(0, unsafe.Pointer(C.pprofCgoThreadTraceback), nil, nil) + pprofThread() +} + +func CgoPprofThreadNoTraceback() { + pprofThread() +} + +func pprofThread() { + f, err := os.CreateTemp("", "prof") + if err != nil { + fmt.Fprintln(os.Stderr, err) + os.Exit(2) + } + + if err := pprof.StartCPUProfile(f); err != nil { + fmt.Fprintln(os.Stderr, err) + os.Exit(2) + } + + // This goroutine may receive a profiling signal while creating the C-owned + // thread. If it does, the SetCgoTraceback handler will make the leaf end of + // the stack look almost (but not exactly) like the stacks the test case is + // trying to find. Attach a profiler label so the test can filter out those + // confusing samples. + pprof.Do(context.Background(), pprof.Labels("ignore", "ignore"), func(ctx context.Context) { + C.runCPUHogThread() + }) + + time.Sleep(1 * time.Second) + + pprof.StopCPUProfile() + + name := f.Name() + if err := f.Close(); err != nil { + fmt.Fprintln(os.Stderr, err) + os.Exit(2) + } + + fmt.Println(name) +} |