darling-libobjc2/loader.c

93 lines
3.0 KiB
C

#include <stdlib.h>
#include <assert.h>
#include "objc/runtime.h"
#include "lock.h"
#include "loader.h"
#include "magic_objects.h"
/**
* Runtime lock. This is exposed in
*/
static mutex_t objc_runtime_mutex;
void *__objc_runtime_mutex = &objc_runtime_mutex;
void __objc_sync_init(void);
void __objc_init_selector_tables(void);
void __objc_init_protocol_table(void);
void __objc_init_class_tables(void);
void __objc_init_dispatch_tables(void);
/* Number of threads that are alive. */
int __objc_runtime_threads_alive = 1; /* !T:MUTEX */
void __objc_exec_class(struct objc_module_abi_8 *module)
{
static BOOL first_run = YES;
// Check that this module uses an ABI version that we recognise.
// In future, we should pass the ABI version to the class / category load
// functions so that we can change various structures more easily.
assert(objc_check_abi_version(module->version, module->size));
if (first_run)
{
// Create the main runtime lock. This is not safe in theory, but in
// practice the first time that this function is called will be in the
// loader, from the main thread. Future loaders may run concurrently,
// but that is likely to break the semantics of a lot of languages, so
// we don't have to worry about it for a long time.
//
// The only case when this can potentially go badly wrong is when a
// pure-C main() function spawns two threads which then, concurrently,
// call dlopen() or equivalent, and the platform's implementation of
// this does not perform any synchronization.
INIT_LOCK(objc_runtime_mutex);
// Create the lock used to protect the creation of hidden classes by
// @synchronize()
__objc_sync_init();
// Create the various tables that the runtime needs.
__objc_init_selector_tables();
__objc_init_protocol_table();
__objc_init_class_tables();
__objc_init_dispatch_tables();
first_run = NO;
}
// The runtime mutex is held for the entire duration of a load. It does
// not need to be acquired or released in any of the called load functions.
LOCK_UNTIL_RETURN(__objc_runtime_mutex);
struct objc_symbol_table_abi_8 *symbols = module->symbol_table;
// Register all of the selectors used in this module.
if (symbols->selectors)
{
objc_register_selector_array(symbols->selectors,
symbols->selector_count);
}
unsigned short defs = 0;
// Load the classes from this module
for (unsigned short i=0 ; i<symbols->class_count ; i++)
{
objc_load_class(symbols->definitions[defs++]);
}
// Load the categories from this module
for (unsigned short i=0 ; i<symbols->category_count; i++)
{
objc_try_load_category(symbols->definitions[defs++]);
}
// Load the static instances
struct objc_static_instance_list **statics = (void*)symbols->definitions[defs];
while (NULL != statics && NULL != *statics)
{
objc_init_statics(*(statics++));
}
// Fix up the class links for loaded classes.
objc_resolve_class_links();
// Load categories and statics that were deferred.
objc_load_buffered_categories();
objc_init_buffered_statics();
}