Segmentation fault: Lua and pthread

[Marc Vollmer <marc.vollmer@...>]

Hi all!

I have a problem with lua and threads. The C program starts, but after a
few loops the program terminates with segmentation fault. It's same
problems with linux and windows (access violation).

Can someone tell me why an segmentation fault happened? Or better, what
am I doing wrong?

Below I have attached the programs.

Thx
Marc

------------------------------------------
-- C program
------------------------------------------
#include <stdio.h>
#include <pthread.h>
#include "lua.h"
#include "lauxlib.h"
#include "lualib.h"

lua_State *masterState;
lua_State *workerState;
pthread_t a_thread;
int stop=0;

void *thread_function(void *arg){
  while (stop==0) {
    luaL_loadfile(workerState,"print.lua");
    lua_pcall(workerState, 0, 0, 0);
  }
  pthread_exit(0);
}

int main() {
  long loop;
  masterState = luaL_newstate();
  luaL_openlibs(masterState); 
  workerState = lua_newthread(masterState);
  pthread_create(&a_thread,NULL, thread_function, NULL);
  for (loop=0; loop<1000000; loop++) {
    printf("Mem: %d\n",lua_gc(masterState,LUA_GCCOUNTB,0)*1024);
    luaL_loadfile(masterState,"fib.lua");
    lua_pcall(masterState, 0, 0, 0);
  }
  stop=1;
  printf("finish");
  return 0;
}

------------------------------------------
-- fib.lua
------------------------------------------
function fastfib(n)
  fibs={[0]=0, 1, 1} -- global variable, outside the function
  for i=3,n do
    fibs[i]=fibs[i-1]+fibs[i-2]
  end
  return fibs[n]
end
a=fastfib(10)
print("fastfib: "..a)

------------------------------------------
-- print.lua
------------------------------------------
for i=1,5 do
  print("lua loop "..i)
end