static void jl_ast_ctx_leave(jl_ast_context_t *ctx)
{
JL_SIGATOMIC_END();
if (--ctx->ref)
return;
JL_LOCK_NOGC(&flisp_lock);
ctx->task = NULL;
jl_ast_context_list_t *node = &ctx->list;
jl_ast_context_list_delete(node);
jl_ast_context_list_insert(&jl_ast_ctx_freed, node);
JL_UNLOCK_NOGC(&flisp_lock);
}
void jl_mach_gc_end(void)
{
JL_LOCK_NOGC(gc_suspend);
jl_gc_safepoint_activated = 0;
for (size_t i = 0;i < suspended_threads.len;i++) {
uintptr_t item = (uintptr_t)suspended_threads.items[i];
int16_t tid = (int16_t)item;
int8_t gc_state = (int8_t)(item >> 8);
jl_all_task_states[tid].ptls->gc_state = gc_state;
thread_resume(pthread_mach_thread_np(jl_all_task_states[tid].system_id));
}
suspended_threads.len = 0;
JL_UNLOCK_NOGC(gc_suspend);
}
static jl_sym_t *_jl_symbol(const char *str, size_t len)
{
jl_sym_t *volatile *slot;
jl_sym_t *node = symtab_lookup(&symtab, str, len, &slot);
if (node == NULL) {
JL_LOCK_NOGC(&gc_perm_lock);
// Someone might have updated it, check and look up again
if (*slot != NULL && (node = symtab_lookup(slot, str, len, &slot))) {
JL_UNLOCK_NOGC(&gc_perm_lock);
return node;
}
node = mk_symbol(str, len);
jl_atomic_store_release(slot, node);
JL_UNLOCK_NOGC(&gc_perm_lock);
}
return node;
}
static jl_ast_context_t *jl_ast_ctx_enter(void)
{
jl_ptls_t ptls = jl_get_ptls_states();
JL_SIGATOMIC_BEGIN();
JL_LOCK_NOGC(&flisp_lock);
jl_ast_context_list_t *node;
jl_ast_context_t *ctx;
// First check if the current task is using one of the contexts
for (node = jl_ast_ctx_using;node;(node = node->next)) {
ctx = jl_ast_context_list_item(node);
if (ctx->task == ptls->current_task) {
ctx->ref++;
JL_UNLOCK_NOGC(&flisp_lock);
return ctx;
}
}
// If not, grab one from the free list
if ((node = jl_ast_ctx_freed)) {
jl_ast_context_list_delete(node);
jl_ast_context_list_insert(&jl_ast_ctx_using, node);
ctx = jl_ast_context_list_item(node);
ctx->ref = 1;
ctx->task = ptls->current_task;
ctx->module = NULL;
JL_UNLOCK_NOGC(&flisp_lock);
return ctx;
}
// Construct a new one if we can't find any
ctx = (jl_ast_context_t*)calloc(1, sizeof(jl_ast_context_t));
ctx->ref = 1;
ctx->task = ptls->current_task;
node = &ctx->list;
jl_ast_context_list_insert(&jl_ast_ctx_using, node);
JL_UNLOCK_NOGC(&flisp_lock);
jl_init_ast_ctx(ctx);
return ctx;
}
void jl_mach_gc_begin(void)
{
JL_LOCK_NOGC(gc_suspend);
jl_gc_safepoint_activated = 1;
JL_UNLOCK_NOGC(gc_suspend);
}
//exc_server uses dlsym to find symbol
JL_DLLEXPORT
kern_return_t catch_exception_raise(mach_port_t exception_port,
mach_port_t thread,
mach_port_t task,
exception_type_t exception,
exception_data_t code,
mach_msg_type_number_t code_count)
{
unsigned int count = MACHINE_THREAD_STATE_COUNT;
unsigned int exc_count = X86_EXCEPTION_STATE64_COUNT;
x86_exception_state64_t exc_state;
x86_thread_state64_t state;
#ifdef LIBOSXUNWIND
if (thread == mach_profiler_thread) {
return profiler_segv_handler(exception_port, thread, task, exception, code, code_count);
}
#endif
int16_t tid;
#ifdef JULIA_ENABLE_THREADING
jl_tls_states_t *ptls = NULL;
for (tid = 0;tid < jl_n_threads;tid++) {
if (pthread_mach_thread_np(jl_all_task_states[tid].system_id) == thread) {
ptls = jl_all_task_states[tid].ptls;
break;
}
}
if (!ptls) {
// We don't know about this thread, let the kernel try another handler
// instead. This shouldn't actually happen since we only register the
// handler for the threads we know about.
jl_safe_printf("ERROR: Exception handler triggered on unmanaged thread.\n");
return KERN_INVALID_ARGUMENT;
}
#else
jl_tls_states_t *ptls = &jl_tls_states;
tid = 0;
#endif
kern_return_t ret = thread_get_state(thread, x86_EXCEPTION_STATE64, (thread_state_t)&exc_state, &exc_count);
HANDLE_MACH_ERROR("thread_get_state", ret);
uint64_t fault_addr = exc_state.__faultvaddr;
#ifdef JULIA_ENABLE_THREADING
if (fault_addr == (uintptr_t)jl_gc_signal_page) {
JL_LOCK_NOGC(gc_suspend);
if (!jl_gc_safepoint_activated) {
// GC is done before we get the message, do nothing and return
JL_UNLOCK_NOGC(gc_suspend);
return KERN_SUCCESS;
}
// Otherwise, set the gc state of the thread, suspend and record it
int8_t gc_state = ptls->gc_state;
ptls->gc_state = JL_GC_STATE_WAITING;
uintptr_t item = tid | (((uintptr_t)gc_state) << 16);
arraylist_push(&suspended_threads, (void*)item);
thread_suspend(thread);
JL_UNLOCK_NOGC(gc_suspend);
return KERN_SUCCESS;
}
#endif
#ifdef SEGV_EXCEPTION
if (1) {
#else
if (msync((void*)(fault_addr & ~(jl_page_size - 1)), 1, MS_ASYNC) == 0) { // check if this was a valid address
#endif
jl_value_t *excpt;
if (is_addr_on_stack(ptls, (void*)fault_addr)) {
excpt = jl_stackovf_exception;
}
#ifdef SEGV_EXCEPTION
else if (msync((void*)(fault_addr & ~(jl_page_size - 1)), 1, MS_ASYNC) != 0) {
// no page mapped at this address
excpt = jl_segv_exception;
}
#endif
else {
if (!(exc_state.__err & WRITE_FAULT))
return KERN_INVALID_ARGUMENT; // rethrow the SEGV since it wasn't an error with writing to read-only memory
excpt = jl_readonlymemory_exception;
}
jl_throw_in_thread(tid, thread, excpt);
return KERN_SUCCESS;
}
else {
kern_return_t ret = thread_get_state(thread, x86_THREAD_STATE64, (thread_state_t)&state, &count);
HANDLE_MACH_ERROR("thread_get_state", ret);
jl_critical_error(SIGSEGV, (unw_context_t*)&state,
ptls->bt_data, &ptls->bt_size);
return KERN_INVALID_ARGUMENT;
}
}
static void attach_exception_port(thread_port_t thread)
{
kern_return_t ret;
// http://www.opensource.apple.com/source/xnu/xnu-2782.1.97/osfmk/man/thread_set_exception_ports.html
ret = thread_set_exception_ports(thread, EXC_MASK_BAD_ACCESS, segv_port, EXCEPTION_DEFAULT, MACHINE_THREAD_STATE);
HANDLE_MACH_ERROR("thread_set_exception_ports", ret);
}