pthread_getattr_np.c raw

   1  #define _GNU_SOURCE
   2  #include "pthread_impl.h"
   3  #include "libc.h"
   4  #include <sys/mman.h>
   5  
   6  int pthread_getattr_np(pthread_t t, pthread_attr_t *a)
   7  {
   8  	*a = (pthread_attr_t){0};
   9  	a->_a_detach = t->detach_state>=DT_DETACHED;
  10  	a->_a_guardsize = t->guard_size;
  11  	if (t->stack) {
  12  		a->_a_stackaddr = (uintptr_t)t->stack;
  13  		a->_a_stacksize = t->stack_size;
  14  	} else {
  15  		char *p = (void *)libc.auxv;
  16  		size_t l = PAGE_SIZE;
  17  		p += -(uintptr_t)p & PAGE_SIZE-1;
  18  		a->_a_stackaddr = (uintptr_t)p;
  19  		while (mremap(p-l-PAGE_SIZE, PAGE_SIZE, 2*PAGE_SIZE, 0)==MAP_FAILED && errno==ENOMEM)
  20  			l += PAGE_SIZE;
  21  		a->_a_stacksize = l;
  22  	}
  23  	return 0;
  24  }
  25