static int allocate_transition_tls(int id)
{
/* Libc function to initialize TLS-based locale info for ctype functions. */
extern void __ctype_init(void);
/* We want to free and then reallocate the tls rather than simply
* reinitializing it because its size may have changed. TODO: not sure if
* this is right. 0-ing is one thing, but freeing and reallocating can be
* expensive, esp if syscalls are involved. Check out glibc's
* allocatestack.c for what might work. */
free_transition_tls(id);
void *tcb = allocate_tls();
if (!tcb) {
errno = ENOMEM;
return -1;
}
/* Setup some intitial TLS data for the newly allocated transition tls. */
void *temp_tcb = get_tls_desc();
set_tls_desc(tcb);
begin_safe_access_tls_vars();
__vcoreid = id;
__vcore_context = TRUE;
__ctype_init();
end_safe_access_tls_vars();
set_tls_desc(temp_tcb);
/* Install the new tls into the vcpd. */
set_vcpd_tls_desc(id, tcb);
return 0;
}
/* TODO: probably don't want to dealloc. Considering caching */
static void free_transition_tls(int id)
{
if (get_vcpd_tls_desc(id)) {
/* Note we briefly have no TLS desc in VCPD. This is fine so long as
* that vcore doesn't get started fresh before we put in a new desc */
free_tls(get_vcpd_tls_desc(id));
set_vcpd_tls_desc(id, NULL);
}
}
static int allocate_transition_tls(int id)
{
/* We want to free and then reallocate the tls rather than simply
* reinitializing it because its size may have changed. TODO: not sure if
* this is right. 0-ing is one thing, but freeing and reallocating can be
* expensive, esp if syscalls are involved. Check out glibc's
* allocatestack.c for what might work. */
free_transition_tls(id);
void *tcb = allocate_tls();
if (!tcb) {
errno = ENOMEM;
return -1;
}
set_vcpd_tls_desc(id, tcb);
return 0;
}
