1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
|
// Copyright The OpenTelemetry Authors
// SPDX-License-Identifier: Apache-2.0
#ifdef __unix__
// Verifies that IDs don't clash after forking the process.
//
// See https://github.com/opentracing-contrib/nginx-opentracing/issues/52
# include "src/common/random.h"
# include <stdint.h>
# include <sys/mman.h>
# include <sys/wait.h>
# include <unistd.h>
# include <cstdlib>
# include <iostream>
using opentelemetry::sdk::common::Random;
static uint64_t *child_id;
int main()
{
// Set up shared memory to communicate between parent and child processes.
//
// See https://stackoverflow.com/a/13274800/4447365
child_id = static_cast<uint64_t *>(
mmap(nullptr, sizeof(*child_id), PROT_READ | PROT_WRITE, MAP_SHARED | MAP_ANONYMOUS, -1, 0));
*child_id = 0;
if (fork() == 0)
{
*child_id = Random::GenerateRandom64();
exit(EXIT_SUCCESS);
}
else
{
wait(nullptr);
auto parent_id = Random::GenerateRandom64();
auto child_id_copy = *child_id;
munmap(static_cast<void *>(child_id), sizeof(*child_id));
if (parent_id == child_id_copy)
{
std::cerr << "Child and parent ids are the same value " << parent_id << "\n";
return -1;
}
}
return 0;
}
#else
int main()
{
return 0;
}
#endif
|
