#include <iostream>
#include <map>
#include <thread>
#define SIZE 1024
#define AMOUNT 100000
#define THREADS 4
class A
{
private:
char a[SIZE];
};
void test()
{
std::cout << "test start\n";
std::map<int, A*> container;
for(int i=0; i<AMOUNT; i++)
{
A* a = new A();
std::pair<int, A*>p = std::make_pair(i, a);
container.insert(p);
}
std::cout << "test release\n";
for(int i=0; i<AMOUNT; i++)
{
auto iter = container.find(i);
delete iter->second;
container.erase(iter);
}
std::cout << "test end\n";
}
int main()
{
std::thread ts[THREADS];
for(int i=0; i<THREADS; i++)
{
ts[i] = std::thread(test);
}
for(std::thread& x: ts)
{
x.join();
}
return 0;
}
上面是一段简单的C++代码。
使用以下命令进行编译：g++ -pthread -o one one.cpp -Wall -std=c++11 -O3
ldd one，输出如下：
linux-vdso.so.1 => (0x00007ffebafce000)
libstdc++.so.6 => /usr/lib/x86_64-linux-gnu/libstdc++.so.6 (0x00007fb47352a000)
libgcc_s.so.1 => /lib/x86_64-linux-gnu/libgcc_s.so.1 (0x00007fb473313000)
libpthread.so.0 => /lib/x86_64-linux-gnu/libpthread.so.0 (0x00007fb4730f4000)
libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007fb472d2a000)
libm.so.6 => /lib/x86_64-linux-gnu/libm.so.6 (0x00007fb472a22000)
/lib64/ld-linux-x86-64.so.2 (0x00005654c5112000)
运行 ./one，一切正常。
然后我尝试一个静态链接：g++ -pthread -o one one.cpp -Wall -std=c++11 -O3 -static
ldd one，得到：
not a dynamic executable
但是当我运行它时，出了一些问题...
test start
Segmentation fault (core dumped)
重新使用-g编译，然后gdb会显示：
wang[00:35][~/test]$ gdb one
GNU gdb (Ubuntu 7.10-1ubuntu2) 7.10
Copyright (C) 2015 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law. Type "show copying"
and "show warranty" for details.
This GDB was configured as "x86_64-linux-gnu".
Type "show configuration" for configuration details.
For bug reporting instructions, please see:
<http://www.gnu.org/software/gdb/bugs/>.
Find the GDB manual and other documentation resources online at:
<http://www.gnu.org/software/gdb/documentation/>.
For help, type "help".
Type "apropos word" to search for commands related to "word"...
Reading symbols from one...done.
(gdb) run
Starting program: /home/wang/test/one
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
[New Thread 0x7ffff7ffa700 (LWP 3623)]
test start
[New Thread 0x7ffff77f8700 (LWP 3624)]
test start
[New Thread 0x7ffff6ff7700 (LWP 3625)]
test start
[New Thread 0x7ffff67f6700 (LWP 3626)]
test start
Program received signal SIGSEGV, Segmentation fault.
0x0000000000000000 in ?? ()
(gdb)
为什么要这样做？
更新 ==============================
使用 boost::thread 库（版本：1.60），
替换 std::thread 为 boost::thread，并进行静态链接，
g++ -pthread -o one1 one.cpp -Wall -std=c++11 -O3 -I /opt/boost/include/ -L /opt/boost/lib/ -lboost_system -lboost_thread -static
没有发生任何问题！
困惑......
g++ -o one one.cpp -Wall -std=c++11 -O3 pthread？ - P.Ppanic: Page table fault when accessing virtual address 0。 - Y00