c - Start of thread changes already set global variable -

i have ran strange behavior of code, basic flow of code is

main () parses file , sets global variables accordingly.. such as

int frame_size, version;   typedef struct//file parsing variables     {         int frame,         int version; } configuration; ***//the function init_parse calls***     static int handler(void* user, const char* section, const char* name,                        const char* value)     {         configuration* pconfig = (configuration*)user;      #define match(s, n) strcmp(section, s) == 0 && strcmp(name, n) == 0     if (match("protocol", "version")) {         pconfig->version = atoi(value);     }      else if (match("basic", "frames")) {             pconfig->frames= atoi(value);             frame_size=pconfig->frames;                         }     else {         return 0;  /* unknown section/name, error */     }     return 1; }  main (){         configuration config;     if (ini_parse("test.ini", handler, &config) < 0) {                 printf("can't load 'test.ini'\n");                 getchar(); iret = pthread_create(&hthread,null, pcapreader, null);     if(iret)     {         fprintf(stderr,"error - pthread_create() return code: %d\n",iret);         exit(exit_failure);     }          } 

now, line followed main()'s parsing line, seems set, thread started , value frame_size changes 6345720:/

i have double checked code possible replicated variable. thread uses frame_size in loop check limit.

the problem initialization, once initialized, worked charm :)