OVMS3/OVMS.V3/components/duktape/src-input/duk_bi_thread.c

326 lines
11 KiB
C

/*
* Thread builtins
*/
#include "duk_internal.h"
/*
* Constructor
*/
#if defined(DUK_USE_COROUTINE_SUPPORT)
DUK_INTERNAL duk_ret_t duk_bi_thread_constructor(duk_hthread *thr) {
duk_hthread *new_thr;
duk_hobject *func;
/* Check that the argument is callable; this is not 100% because we
* don't allow native functions to be a thread's initial function.
* Resume will reject such functions in any case.
*/
/* XXX: need a duk_require_func_promote_lfunc() */
func = duk_require_hobject_promote_lfunc(thr, 0);
DUK_ASSERT(func != NULL);
duk_require_callable(thr, 0);
duk_push_thread(thr);
new_thr = (duk_hthread *) duk_known_hobject(thr, -1);
new_thr->state = DUK_HTHREAD_STATE_INACTIVE;
/* push initial function call to new thread stack; this is
* picked up by resume().
*/
duk_push_hobject(new_thr, func);
return 1; /* return thread */
}
#endif
/*
* Resume a thread.
*
* The thread must be in resumable state, either (a) new thread which hasn't
* yet started, or (b) a thread which has previously yielded. This method
* must be called from an ECMAScript function.
*
* Args:
* - thread
* - value
* - isError (defaults to false)
*
* Note: yield and resume handling is currently asymmetric.
*/
#if defined(DUK_USE_COROUTINE_SUPPORT)
DUK_INTERNAL duk_ret_t duk_bi_thread_resume(duk_hthread *ctx) {
duk_hthread *thr = (duk_hthread *) ctx;
duk_hthread *thr_resume;
duk_hobject *caller_func;
duk_small_uint_t is_error;
DUK_DDD(DUK_DDDPRINT("Duktape.Thread.resume(): thread=%!T, value=%!T, is_error=%!T",
(duk_tval *) duk_get_tval(thr, 0),
(duk_tval *) duk_get_tval(thr, 1),
(duk_tval *) duk_get_tval(thr, 2)));
DUK_ASSERT(thr->state == DUK_HTHREAD_STATE_RUNNING);
DUK_ASSERT(thr->heap->curr_thread == thr);
thr_resume = duk_require_hthread(thr, 0);
DUK_ASSERT(duk_get_top(thr) == 3);
is_error = (duk_small_uint_t) duk_to_boolean_top_pop(thr);
DUK_ASSERT(duk_get_top(thr) == 2);
/* [ thread value ] */
/*
* Thread state and calling context checks
*/
if (thr->callstack_top < 2) {
DUK_DD(DUK_DDPRINT("resume state invalid: callstack should contain at least 2 entries (caller and Duktape.Thread.resume)"));
goto state_error;
}
DUK_ASSERT(thr->callstack_curr != NULL);
DUK_ASSERT(thr->callstack_curr->parent != NULL);
DUK_ASSERT(DUK_ACT_GET_FUNC(thr->callstack_curr) != NULL); /* us */
DUK_ASSERT(DUK_HOBJECT_IS_NATFUNC(DUK_ACT_GET_FUNC(thr->callstack_curr)));
DUK_ASSERT(DUK_ACT_GET_FUNC(thr->callstack_curr->parent) != NULL); /* caller */
caller_func = DUK_ACT_GET_FUNC(thr->callstack_curr->parent);
if (!DUK_HOBJECT_IS_COMPFUNC(caller_func)) {
DUK_DD(DUK_DDPRINT("resume state invalid: caller must be ECMAScript code"));
goto state_error;
}
/* Note: there is no requirement that: 'thr->callstack_preventcount == 1'
* like for yield.
*/
if (thr_resume->state != DUK_HTHREAD_STATE_INACTIVE &&
thr_resume->state != DUK_HTHREAD_STATE_YIELDED) {
DUK_DD(DUK_DDPRINT("resume state invalid: target thread must be INACTIVE or YIELDED"));
goto state_error;
}
DUK_ASSERT(thr_resume->state == DUK_HTHREAD_STATE_INACTIVE ||
thr_resume->state == DUK_HTHREAD_STATE_YIELDED);
/* Further state-dependent pre-checks */
if (thr_resume->state == DUK_HTHREAD_STATE_YIELDED) {
/* no pre-checks now, assume a previous yield() has left things in
* tip-top shape (longjmp handler will assert for these).
*/
} else {
duk_hobject *h_fun;
DUK_ASSERT(thr_resume->state == DUK_HTHREAD_STATE_INACTIVE);
/* The initial function must be an ECMAScript function (but
* can be bound). We must make sure of that before we longjmp
* because an error in the RESUME handler call processing will
* not be handled very cleanly.
*/
if ((thr_resume->callstack_top != 0) ||
(thr_resume->valstack_top - thr_resume->valstack != 1)) {
goto state_error;
}
duk_push_tval(thr, DUK_GET_TVAL_NEGIDX(thr_resume, -1));
duk_resolve_nonbound_function(thr);
h_fun = duk_require_hobject(thr, -1); /* reject lightfuncs on purpose */
if (!DUK_HOBJECT_IS_CALLABLE(h_fun) || !DUK_HOBJECT_IS_COMPFUNC(h_fun)) {
goto state_error;
}
duk_pop(thr);
}
#if 0
/* This check would prevent a heap destruction time finalizer from
* launching a coroutine, which would ensure that during finalization
* 'thr' would always equal heap_thread. Normal runtime finalizers
* run with ms_running == 0, i.e. outside mark-and-sweep. See GH-2030.
*/
if (thr->heap->ms_running) {
DUK_D(DUK_DPRINT("refuse Duktape.Thread.resume() when ms_running != 0"));
goto state_error;
}
#endif
/*
* The error object has been augmented with a traceback and other
* info from its creation point -- usually another thread. The
* error handler is called here right before throwing, but it also
* runs in the resumer's thread. It might be nice to get a traceback
* from the resumee but this is not the case now.
*/
#if defined(DUK_USE_AUGMENT_ERROR_THROW)
if (is_error) {
DUK_ASSERT_TOP(thr, 2); /* value (error) is at stack top */
duk_err_augment_error_throw(thr); /* in resumer's context */
}
#endif
#if defined(DUK_USE_DEBUG)
if (is_error) {
DUK_DDD(DUK_DDDPRINT("RESUME ERROR: thread=%!T, value=%!T",
(duk_tval *) duk_get_tval(thr, 0),
(duk_tval *) duk_get_tval(thr, 1)));
} else if (thr_resume->state == DUK_HTHREAD_STATE_YIELDED) {
DUK_DDD(DUK_DDDPRINT("RESUME NORMAL: thread=%!T, value=%!T",
(duk_tval *) duk_get_tval(thr, 0),
(duk_tval *) duk_get_tval(thr, 1)));
} else {
DUK_DDD(DUK_DDDPRINT("RESUME INITIAL: thread=%!T, value=%!T",
(duk_tval *) duk_get_tval(thr, 0),
(duk_tval *) duk_get_tval(thr, 1)));
}
#endif
thr->heap->lj.type = DUK_LJ_TYPE_RESUME;
/* lj value2: thread */
DUK_ASSERT(thr->valstack_bottom < thr->valstack_top);
DUK_TVAL_SET_TVAL_UPDREF(thr, &thr->heap->lj.value2, &thr->valstack_bottom[0]); /* side effects */
/* lj value1: value */
DUK_ASSERT(thr->valstack_bottom + 1 < thr->valstack_top);
DUK_TVAL_SET_TVAL_UPDREF(thr, &thr->heap->lj.value1, &thr->valstack_bottom[1]); /* side effects */
DUK_TVAL_CHKFAST_INPLACE_SLOW(&thr->heap->lj.value1);
thr->heap->lj.iserror = is_error;
DUK_ASSERT(thr->heap->lj.jmpbuf_ptr != NULL); /* call is from executor, so we know we have a jmpbuf */
duk_err_longjmp(thr); /* execution resumes in bytecode executor */
DUK_UNREACHABLE();
/* Never here, fall through to error (from compiler point of view). */
state_error:
DUK_DCERROR_TYPE_INVALID_STATE(thr);
}
#endif
/*
* Yield the current thread.
*
* The thread must be in yieldable state: it must have a resumer, and there
* must not be any yield-preventing calls (native calls and constructor calls,
* currently) in the thread's call stack (otherwise a resume would not be
* possible later). This method must be called from an ECMAScript function.
*
* Args:
* - value
* - isError (defaults to false)
*
* Note: yield and resume handling is currently asymmetric.
*/
#if defined(DUK_USE_COROUTINE_SUPPORT)
DUK_INTERNAL duk_ret_t duk_bi_thread_yield(duk_hthread *thr) {
duk_hobject *caller_func;
duk_small_uint_t is_error;
DUK_DDD(DUK_DDDPRINT("Duktape.Thread.yield(): value=%!T, is_error=%!T",
(duk_tval *) duk_get_tval(thr, 0),
(duk_tval *) duk_get_tval(thr, 1)));
DUK_ASSERT(thr->state == DUK_HTHREAD_STATE_RUNNING);
DUK_ASSERT(thr->heap->curr_thread == thr);
DUK_ASSERT(duk_get_top(thr) == 2);
is_error = (duk_small_uint_t) duk_to_boolean_top_pop(thr);
DUK_ASSERT(duk_get_top(thr) == 1);
/* [ value ] */
/*
* Thread state and calling context checks
*/
if (!thr->resumer) {
DUK_DD(DUK_DDPRINT("yield state invalid: current thread must have a resumer"));
goto state_error;
}
DUK_ASSERT(thr->resumer->state == DUK_HTHREAD_STATE_RESUMED);
if (thr->callstack_top < 2) {
DUK_DD(DUK_DDPRINT("yield state invalid: callstack should contain at least 2 entries (caller and Duktape.Thread.yield)"));
goto state_error;
}
DUK_ASSERT(thr->callstack_curr != NULL);
DUK_ASSERT(thr->callstack_curr->parent != NULL);
DUK_ASSERT(DUK_ACT_GET_FUNC(thr->callstack_curr) != NULL); /* us */
DUK_ASSERT(DUK_HOBJECT_IS_NATFUNC(DUK_ACT_GET_FUNC(thr->callstack_curr)));
DUK_ASSERT(DUK_ACT_GET_FUNC(thr->callstack_curr->parent) != NULL); /* caller */
caller_func = DUK_ACT_GET_FUNC(thr->callstack_curr->parent);
if (!DUK_HOBJECT_IS_COMPFUNC(caller_func)) {
DUK_DD(DUK_DDPRINT("yield state invalid: caller must be ECMAScript code"));
goto state_error;
}
DUK_ASSERT(thr->callstack_preventcount >= 1); /* should never be zero, because we (Duktape.Thread.yield) are on the stack */
if (thr->callstack_preventcount != 1) {
/* Note: the only yield-preventing call is Duktape.Thread.yield(), hence check for 1, not 0 */
DUK_DD(DUK_DDPRINT("yield state invalid: there must be no yield-preventing calls in current thread callstack (preventcount is %ld)",
(long) thr->callstack_preventcount));
goto state_error;
}
/*
* The error object has been augmented with a traceback and other
* info from its creation point -- usually the current thread.
* The error handler, however, is called right before throwing
* and runs in the yielder's thread.
*/
#if defined(DUK_USE_AUGMENT_ERROR_THROW)
if (is_error) {
DUK_ASSERT_TOP(thr, 1); /* value (error) is at stack top */
duk_err_augment_error_throw(thr); /* in yielder's context */
}
#endif
#if defined(DUK_USE_DEBUG)
if (is_error) {
DUK_DDD(DUK_DDDPRINT("YIELD ERROR: value=%!T",
(duk_tval *) duk_get_tval(thr, 0)));
} else {
DUK_DDD(DUK_DDDPRINT("YIELD NORMAL: value=%!T",
(duk_tval *) duk_get_tval(thr, 0)));
}
#endif
/*
* Process yield
*
* After longjmp(), processing continues in bytecode executor longjmp
* handler, which will e.g. update thr->resumer to NULL.
*/
thr->heap->lj.type = DUK_LJ_TYPE_YIELD;
/* lj value1: value */
DUK_ASSERT(thr->valstack_bottom < thr->valstack_top);
DUK_TVAL_SET_TVAL_UPDREF(thr, &thr->heap->lj.value1, &thr->valstack_bottom[0]); /* side effects */
DUK_TVAL_CHKFAST_INPLACE_SLOW(&thr->heap->lj.value1);
thr->heap->lj.iserror = is_error;
DUK_ASSERT(thr->heap->lj.jmpbuf_ptr != NULL); /* call is from executor, so we know we have a jmpbuf */
duk_err_longjmp(thr); /* execution resumes in bytecode executor */
DUK_UNREACHABLE();
/* Never here, fall through to error (from compiler point of view). */
state_error:
DUK_DCERROR_TYPE_INVALID_STATE(thr);
}
#endif
#if defined(DUK_USE_COROUTINE_SUPPORT)
DUK_INTERNAL duk_ret_t duk_bi_thread_current(duk_hthread *thr) {
duk_push_current_thread(thr);
return 1;
}
#endif