96 lines
1.7 KiB
Go
96 lines
1.7 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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//go:build !gccgo
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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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int salt1;
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int salt2;
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void cpuHog() {
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int foo = salt1;
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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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salt2 = foo;
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}
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void cpuHog2() {
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}
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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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// pprofCgoTraceback 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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// Issue #29034: At least 2 frames are required to verify all frames are captured
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// since runtime/pprof ignores the runtime.goexit base frame if it exists.
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void pprofCgoTraceback(void* parg) {
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struct cgoTracebackArg* arg = (struct cgoTracebackArg*)(parg);
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arg->buf[0] = (uintptr_t)(cpuHog) + 0x10;
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arg->buf[1] = (uintptr_t)(cpuHog2) + 0x4;
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arg->buf[2] = 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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"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("CgoPprof", CgoPprof)
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}
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func CgoPprof() {
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runtime.SetCgoTraceback(0, unsafe.Pointer(C.pprofCgoTraceback), nil, nil)
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f, err := os.CreateTemp("", "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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t0 := time.Now()
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for time.Since(t0) < time.Second {
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C.cpuHog()
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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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