Question

Code:

#include <iostream>
#include <thread>

void hello()
{
    std::cout << "Hello World" << std::endl;
}

int main()
{
    try
    {
        std::cout << "creating thread" << std::endl;
        std::thread t(hello);
        std::cout << "waiting" << std::endl;
        t.join();
        std::cout << "done" << std::endl;
    }
    catch(std::exception& ex)
    {
        std::cout << ex.what() << std::endl;
    }
}

Build:

g++ -Wall -fexceptions -std=c++0x -pthread  -g     -c /home/alex/tmp/thread_test/main.cpp -o obj/Debug/main.o
g++  -o bin/Debug/thread_test obj/Debug/main.o    
Output size is 106.62 KB
Process terminated with status 0 (0 minutes, 0 seconds)
0 errors, 0 warnings

Result:

creating thread
Operation not permitted

How this can be fixed?

Edit:
Running the program with strace:

alex@alex-64:~/tmp/thread_test/bin/Debug$ strace ./thread_test
execve("./thread_test", ["./thread_test"], [/* 38 vars */]) = 0
brk(0)                                  = 0x189a000
access("/etc/ld.so.nohwcap", F_OK)      = -1 ENOENT (No such file or directory)
mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f7c60cbc000
access("/etc/ld.so.preload", R_OK)      = -1 ENOENT (No such file or directory)
open("/etc/ld.so.cache", O_RDONLY)      = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=121299, ...}) = 0
mmap(NULL, 121299, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f7c60c9e000
close(3)                                = 0
access("/etc/ld.so.nohwcap", F_OK)      = -1 ENOENT (No such file or directory)
open("/usr/lib/x86_64-linux-gnu/libstdc++.so.6", O_RDONLY) = 3
read(3, "\177ELF\2\1\1\0\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0P\244\5\0\0\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0644, st_size=991424, ...}) = 0
mmap(NULL, 3171440, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7f7c60797000
mprotect(0x7f7c6087f000, 2097152, PROT_NONE) = 0
mmap(0x7f7c60a7f000, 40960, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0xe8000) = 0x7f7c60a7f000
mmap(0x7f7c60a89000, 83056, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x7f7c60a89000
close(3)                                = 0
access("/etc/ld.so.nohwcap", F_OK)      = -1 ENOENT (No such file or directory)
open("/lib/x86_64-linux-gnu/libgcc_s.so.1", O_RDONLY) = 3
read(3, "\177ELF\2\1\1\0\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0\260(\0\0\0\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0644, st_size=88384, ...}) = 0
mmap(NULL, 2184216, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7f7c60581000
mprotect(0x7f7c60596000, 2093056, PROT_NONE) = 0
mmap(0x7f7c60795000, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x14000) = 0x7f7c60795000
close(3)                                = 0
access("/etc/ld.so.nohwcap", F_OK)      = -1 ENOENT (No such file or directory)
open("/lib/x86_64-linux-gnu/libc.so.6", O_RDONLY) = 3
read(3, "\177ELF\2\1\1\0\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0 \24\2\0\0\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0755, st_size=1685816, ...}) = 0
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f7c60c9d000
mmap(NULL, 3801960, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7f7c601e0000
mprotect(0x7f7c60377000, 2093056, PROT_NONE) = 0
mmap(0x7f7c60576000, 20480, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x196000) = 0x7f7c60576000
mmap(0x7f7c6057b000, 21352, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x7f7c6057b000
close(3)                                = 0
access("/etc/ld.so.nohwcap", F_OK)      = -1 ENOENT (No such file or directory)
open("/lib/x86_64-linux-gnu/libm.so.6", O_RDONLY) = 3
read(3, "\177ELF\2\1\1\0\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0\360>\0\0\0\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0644, st_size=538928, ...}) = 0
mmap(NULL, 2633960, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7f7c5ff5c000
mprotect(0x7f7c5ffdf000, 2093056, PROT_NONE) = 0
mmap(0x7f7c601de000, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x82000) = 0x7f7c601de000
close(3)                                = 0
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f7c60c9c000
mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f7c60c9a000
arch_prctl(ARCH_SET_FS, 0x7f7c60c9a740) = 0
mprotect(0x7f7c601de000, 4096, PROT_READ) = 0
mprotect(0x7f7c60576000, 16384, PROT_READ) = 0
mprotect(0x7f7c60795000, 4096, PROT_READ) = 0
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f7c60c99000
mprotect(0x7f7c60a7f000, 32768, PROT_READ) = 0
mprotect(0x603000, 4096, PROT_READ)     = 0
mprotect(0x7f7c60cbe000, 4096, PROT_READ) = 0
munmap(0x7f7c60c9e000, 121299)          = 0
fstat(1, {st_mode=S_IFCHR|0620, st_rdev=makedev(136, 2), ...}) = 0
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f7c60cbb000
write(1, "creating thread\n", 16creating thread
)       = 16
brk(0)                                  = 0x189a000
brk(0x18bb000)                          = 0x18bb000
write(1, "Operation not permitted\n", 24Operation not permitted
) = 24
exit_group(0)                           = ?

Answer 1

Your problem is that you forgot to specify -lpthread or -pthread flag to the compiler. So it assumes a single-threaded mode when building your program.

The exception is thrown by the standard C++ library:

(gdb) catch throw
Function "__cxa_throw" not defined.
Catchpoint 1 (throw)
(gdb) run
Starting program: /tmp/test 
creating thread
Catchpoint 1 (exception thrown), 0x00007ffff7b8eff0 in __cxa_throw () from /usr/lib/x86_64-linux-gnu/libstdc++.so.6
(gdb) where
#0  0x00007ffff7b8eff0 in __cxa_throw () from /usr/lib/x86_64-linux-gnu/libstdc++.so.6
#1  0x00007ffff7b3ba3e in std::__throw_system_error(int) () from /usr/lib/x86_64-linux-gnu/libstdc++.so.6
#2  0x00007ffff7b45cb7 in std::thread::_M_start_thread(std::shared_ptr<std::thread::_Impl_base>) () from /usr/lib/x86_64-linux-gnu/libstdc++.so.6
#3  0x00000000004012d4 in std::thread::thread<void (&)()>(void (&&&)()) ()
#4  0x0000000000400f0e in main ()
(gdb)  quit

I don’t have any desire to check source code for that, but it is most likely they use “lazy” dynamic linking to determine if POSIX threads family of functions are available. And throw exceptions otherwise. That way, you get that exception unless linking with pthread library.

That has nothing to do with virtual memory or other resource limits as I initially thought might be happening because system calls do not report any errors. So just do:

g++ -std=c++0x -o test ./test.cpp -pthread

… and it will work.

UPDATE:

As @ildjaRN pointed out, you already specify -pthread. I suggest you specify it after your object files (source files for a single invocation compile & link), otherwise it might not get picked up.

Here is how to make sure it is picked up – you can run ldd and make sure that pthread.so makes it in:

$ g++ -std=c++0x -lpthread -o test ./test.cpp
$ ldd ./test | grep pthread
$ g++ -std=c++0x -o test ./test.cpp -lpthread
$ ldd ./test | grep pthread
    libpthread.so.0 => /lib/x86_64-linux-gnu/libpthread.so.0 (0x00007ff2a9073000)
$ 

Hope it helps. Good luck!