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// 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.
// +build linux,amd64 freebsd,amd64
package main
// Test that we can collect a lot of colliding profiling signals from
// an external C thread. This used to fail when built with the race
// detector, because a call of the predeclared function copy was
// turned into a call to runtime.slicecopy, which is not marked nosplit.
/*
#include <signal.h>
#include <stdint.h>
#include <pthread.h>
#include <sched.h>
struct cgoTracebackArg {
uintptr_t context;
uintptr_t sigContext;
uintptr_t* buf;
uintptr_t max;
};
static int raceprofCount;
// We want a bunch of different profile stacks that collide in the
// hash table maintained in runtime/cpuprof.go. This code knows the
// size of the hash table (1 << 10) and knows that the hash function
// is simply multiplicative.
void raceprofTraceback(void* parg) {
struct cgoTracebackArg* arg = (struct cgoTracebackArg*)(parg);
raceprofCount++;
arg->buf[0] = raceprofCount * (1 << 10);
arg->buf[1] = 0;
}
static void* raceprofThread(void* p) {
int i;
for (i = 0; i < 100; i++) {
pthread_kill(pthread_self(), SIGPROF);
sched_yield();
}
return 0;
}
void runRaceprofThread() {
pthread_t tid;
pthread_create(&tid, 0, raceprofThread, 0);
pthread_join(tid, 0);
}
*/
import "C"
import (
"bytes"
"fmt"
"runtime"
"runtime/pprof"
"unsafe"
)
func init() {
register("CgoRaceprof", CgoRaceprof)
}
func CgoRaceprof() {
runtime.SetCgoTraceback(0, unsafe.Pointer(C.raceprofTraceback), nil, nil)
var buf bytes.Buffer
pprof.StartCPUProfile(&buf)
C.runRaceprofThread()
fmt.Println("OK")
}
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