Re-posted from the Microsoft Insiders forum, at the suggestion of members of that forum. Apologies if that's not the appropriate thing to do; please let me know.
http://answers.microsoft.com/en-us/insider/forum/insider_apps-insider_other/window-bash-cant-debug-multithreaded-applications/5e1914ad-7ba2-4507-b21e-4a8b990d69b7?tm=1460769755172
I'm seeing lots of crashes in more complicated Linux applications running on Windows. (Did I mention that it's really cool that I'm running Linux applications on Windows?) I'm trying to track down exactly what's going on. gdb is
my first go-to tool for debugging applications under Linux; I think it wouldn't be too much to say that it's the standard Linux tool for lots of types of debugging. But I'm finding that it can't debug even the simplest of threaded applications on Windows
Bash. (It has no such problem under a real Linux kernel.)
Here's a minimal reproducer:
#include <pthread.h>
// Make thread spin indefinitely
void *spin(void * no_arg)
{
while (1) ;
return NULL;
}
int main()
{
pthread_t spin_thread;
pthread_create(&spin_thread, NULL, spin, NULL);
while (1) ;
return 0;
}
To compile, write to a file and run "gcc <filename> -lpthread -g". Then, to test, do "gdb ./a.out". Once you get to the gdb prompt, type "run". What I see is:
(gdb) run
Starting program: /mnt/c/Users/[me]/linwrapper/a.out
warning: Error disabling address space randomization: Success
warning: linux_ptrace_test_ret_to_nx: PTRACE_KILL waitpid returned -1: Interrupted system call
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
[New Thread 0x7ff5ff600700 (LWP 414)]
Cannot find user-level thread for LWP 410: generic error
(gdb)
On a real Linux kernel, "run" doesn't return until you hit Ctrl-C, because the command spins forever. It certainly doesn't error out.
I write and work with a lot of code in C/C++. And threads are pretty much unavoidable these days. And I'm not going to pretend that my code never has bugs :-) Is there a good way to debug multithreaded Linux apps in Windows
Bash?
