/*
* This replaces __pthread_initialize_minimal() from libnacl and
* __pthread_initialize() from libpthread.
*/
void __pthread_initialize(void) {
struct nc_combined_tdb *tdb;
/*
* Allocate the area. If malloc fails here, we'll crash before it returns.
*/
size_t combined_size = __nacl_tls_combined_size(sizeof(*tdb));
void *combined_area = malloc(combined_size);
/*
* Initialize TLS proper (i.e., __thread variable initializers).
*/
void *tp = __nacl_tls_initialize_memory(combined_area, sizeof(*tdb));
tdb = get_irt_tdb(tp);
__nc_initialize_unjoinable_thread(tdb);
tdb->tdb.irt_thread_data = combined_area;
/*
* Now install it for later fetching.
* This is what our private version of __nacl_read_tp will read.
*/
NACL_SYSCALL(second_tls_set)(tp);
/*
* Finally, do newlib per-thread initialization.
*/
__newlib_thread_init();
__nc_initialize_globals();
}
static void nc_thread_starter(void) {
nc_thread_descriptor_t *tdb = nc_get_tdb();
__newlib_thread_init();
#if defined(NACL_IN_IRT)
g_is_irt_internal_thread = 1;
#endif
void *retval = tdb->start_func(tdb->state);
/*
* Free handler list to prevent memory leak in case function returns
* without calling pthread_cleanup_pop(), although doing that is unspecified
* behaviour.
*/
while (NULL != __nc_cleanup_handlers) {
pthread_cleanup_pop(0);
}
/* If the function returns, terminate the thread. */
pthread_exit(retval);
/* NOTREACHED */
/* TODO(gregoryd) - add assert */
}
/* See tls.h. */
int __pthread_initialize_minimal(size_t tdb_size) {
/* Use sbrk not malloc here since the library is not initialized yet. */
size_t combined_size = __nacl_tls_combined_size(tdb_size);
/* Adapt size for sbrk. */
/* TODO(robertm): this is somewhat arbitrary - re-examine). */
combined_size = (combined_size + 15) & ~15;
void *combined_area = sbrk(combined_size); /* (uses nacl_sysbrk) */
__nacl_tls_data_bss_initialize_from_template(combined_area);
/* Patch the first word of the TDB to contain the "base" of the TLS area. */
void *tdb = __nacl_tls_tdb_start(combined_area);
*(void**) tdb = tdb;
/* Set %gs, r9, or equivalent platform-specific mechanism. Requires
* a syscall since certain bitfields of these registers are trusted. */
NACL_SYSCALL(tls_init)(tdb, tdb_size);
/* initialize newlib's thread-specific pointer. */
__newlib_thread_init();
return 0;
}
/*
* This is the real first entry point for new threads.
*/
static void irt_start_thread(void) {
struct nc_combined_tdb *tdb = get_irt_tdb(__nacl_read_tp());
/*
* Fetch the user's start routine.
*/
void (*user_start)(void) = (void (*)(void)) tdb->tdb.start_func;
/*
* Now do per-thread initialization for the IRT-private C library state.
*/
__newlib_thread_init();
/*
* Finally, run the user code.
*/
(*user_start)();
/*
* That should never return. Crash hard if it does.
*/
while (1) *(volatile int *) 0 = 0; /* Crash. */
}