2a208bc257
The gofrontend doesn't support the runtime.SetCgoTraceback function,
which is specifically for handling mixed Go and C tracebacks.
Use a build tag to avoid compiling the runtime/testdata/testprogcgo
files that refer to SetCgoTraceback. These files are not currently
compiled anyhow, but they will be with a future gotools patch.
Reviewed-on: https://go-review.googlesource.com/46452
From-SVN: r249556
125 lines
2.3 KiB
Go
125 lines
2.3 KiB
Go
// Copyright 2016 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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// +build !plan9,!windows
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// +build !gccgo
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package main
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// Run a slow C function saving a CPU profile.
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/*
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#include <stdint.h>
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#include <time.h>
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#include <pthread.h>
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int threadSalt1;
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int threadSalt2;
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void cpuHogThread() {
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int foo = threadSalt1;
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int i;
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for (i = 0; i < 100000; i++) {
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if (foo > 0) {
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foo *= foo;
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} else {
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foo *= foo + 1;
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}
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}
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threadSalt2 = foo;
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}
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static int cpuHogThreadCount;
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struct cgoTracebackArg {
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uintptr_t context;
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uintptr_t sigContext;
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uintptr_t* buf;
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uintptr_t max;
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};
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// pprofCgoThreadTraceback is passed to runtime.SetCgoTraceback.
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// For testing purposes it pretends that all CPU hits in C code are in cpuHog.
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void pprofCgoThreadTraceback(void* parg) {
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struct cgoTracebackArg* arg = (struct cgoTracebackArg*)(parg);
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arg->buf[0] = (uintptr_t)(cpuHogThread) + 0x10;
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arg->buf[1] = 0;
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__sync_add_and_fetch(&cpuHogThreadCount, 1);
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}
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// getCPUHogThreadCount fetches the number of times we've seen cpuHogThread
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// in the traceback.
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int getCPUHogThreadCount() {
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return __sync_add_and_fetch(&cpuHogThreadCount, 0);
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}
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static void* cpuHogDriver(void* arg __attribute__ ((unused))) {
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while (1) {
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cpuHogThread();
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}
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return 0;
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}
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void runCPUHogThread(void) {
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pthread_t tid;
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pthread_create(&tid, 0, cpuHogDriver, 0);
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}
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*/
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import "C"
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import (
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"fmt"
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"io/ioutil"
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"os"
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"runtime"
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"runtime/pprof"
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"time"
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"unsafe"
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)
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func init() {
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register("CgoPprofThread", CgoPprofThread)
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register("CgoPprofThreadNoTraceback", CgoPprofThreadNoTraceback)
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}
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func CgoPprofThread() {
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runtime.SetCgoTraceback(0, unsafe.Pointer(C.pprofCgoThreadTraceback), nil, nil)
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pprofThread()
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}
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func CgoPprofThreadNoTraceback() {
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pprofThread()
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}
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func pprofThread() {
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f, err := ioutil.TempFile("", "prof")
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if err != nil {
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fmt.Fprintln(os.Stderr, err)
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os.Exit(2)
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}
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if err := pprof.StartCPUProfile(f); err != nil {
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fmt.Fprintln(os.Stderr, err)
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os.Exit(2)
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}
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C.runCPUHogThread()
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t0 := time.Now()
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for C.getCPUHogThreadCount() < 2 && time.Since(t0) < time.Second {
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time.Sleep(100 * time.Millisecond)
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}
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pprof.StopCPUProfile()
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name := f.Name()
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if err := f.Close(); err != nil {
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fmt.Fprintln(os.Stderr, err)
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os.Exit(2)
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}
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fmt.Println(name)
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}
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