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

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/*
* Heap creation and destruction
*/
#include "duk_internal.h"
typedef struct duk_internal_thread_state duk_internal_thread_state;
struct duk_internal_thread_state {
duk_ljstate lj;
duk_bool_t creating_error;
duk_hthread *curr_thread;
duk_int_t call_recursion_depth;
};
DUK_EXTERNAL duk_hthread *duk_create_heap(duk_alloc_function alloc_func,
duk_realloc_function realloc_func,
duk_free_function free_func,
void *heap_udata,
duk_fatal_function fatal_handler) {
duk_heap *heap = NULL;
duk_hthread *thr;
/* Assume that either all memory funcs are NULL or non-NULL, mixed
* cases will now be unsafe.
*/
/* XXX: just assert non-NULL values here and make caller arguments
* do the defaulting to the default implementations (smaller code)?
*/
if (!alloc_func) {
DUK_ASSERT(realloc_func == NULL);
DUK_ASSERT(free_func == NULL);
#if defined(DUK_USE_PROVIDE_DEFAULT_ALLOC_FUNCTIONS)
alloc_func = duk_default_alloc_function;
realloc_func = duk_default_realloc_function;
free_func = duk_default_free_function;
#else
DUK_D(DUK_DPRINT("no allocation functions given and no default providers"));
return NULL;
#endif
} else {
DUK_ASSERT(realloc_func != NULL);
DUK_ASSERT(free_func != NULL);
}
if (!fatal_handler) {
fatal_handler = duk_default_fatal_handler;
}
DUK_ASSERT(alloc_func != NULL);
DUK_ASSERT(realloc_func != NULL);
DUK_ASSERT(free_func != NULL);
DUK_ASSERT(fatal_handler != NULL);
heap = duk_heap_alloc(alloc_func, realloc_func, free_func, heap_udata, fatal_handler);
if (!heap) {
return NULL;
}
thr = heap->heap_thread;
DUK_ASSERT(thr != NULL);
DUK_ASSERT(thr->heap != NULL);
return thr;
}
DUK_EXTERNAL void duk_destroy_heap(duk_hthread *thr) {
duk_heap *heap;
if (!thr) {
return;
}
DUK_ASSERT_API_ENTRY(thr);
heap = thr->heap;
DUK_ASSERT(heap != NULL);
duk_heap_free(heap);
}
DUK_EXTERNAL void duk_suspend(duk_hthread *thr, duk_thread_state *state) {
duk_internal_thread_state *snapshot = (duk_internal_thread_state *) (void *) state;
duk_heap *heap;
duk_ljstate *lj;
DUK_ASSERT_API_ENTRY(thr);
DUK_ASSERT(thr->heap != NULL);
DUK_ASSERT(state != NULL); /* unvalidated */
/* Currently not supported when called from within a finalizer.
* If that is done, the finalizer will remain running indefinitely,
* preventing other finalizers from executing. The assert is a bit
* wider, checking that it would be OK to run pending finalizers.
*/
DUK_ASSERT(thr->heap->pf_prevent_count == 0);
/* Currently not supported to duk_suspend() from an errCreate()
* call.
*/
DUK_ASSERT(thr->heap->creating_error == 0);
heap = thr->heap;
lj = &heap->lj;
duk_push_tval(thr, &lj->value1);
duk_push_tval(thr, &lj->value2);
/* XXX: creating_error == 0 is asserted above, so no need to store. */
duk_memcpy((void *) &snapshot->lj, (const void *) lj, sizeof(duk_ljstate));
snapshot->creating_error = heap->creating_error;
snapshot->curr_thread = heap->curr_thread;
snapshot->call_recursion_depth = heap->call_recursion_depth;
lj->jmpbuf_ptr = NULL;
lj->type = DUK_LJ_TYPE_UNKNOWN;
DUK_TVAL_SET_UNDEFINED(&lj->value1);
DUK_TVAL_SET_UNDEFINED(&lj->value2);
heap->creating_error = 0;
heap->curr_thread = NULL;
heap->call_recursion_depth = 0;
}
DUK_EXTERNAL void duk_resume(duk_hthread *thr, const duk_thread_state *state) {
const duk_internal_thread_state *snapshot = (const duk_internal_thread_state *) (const void *) state;
duk_heap *heap;
DUK_ASSERT_API_ENTRY(thr);
DUK_ASSERT(thr->heap != NULL);
DUK_ASSERT(state != NULL); /* unvalidated */
/* Shouldn't be necessary if duk_suspend() is called before
* duk_resume(), but assert in case API sequence is incorrect.
*/
DUK_ASSERT(thr->heap->pf_prevent_count == 0);
DUK_ASSERT(thr->heap->creating_error == 0);
heap = thr->heap;
duk_memcpy((void *) &heap->lj, (const void *) &snapshot->lj, sizeof(duk_ljstate));
heap->creating_error = snapshot->creating_error;
heap->curr_thread = snapshot->curr_thread;
heap->call_recursion_depth = snapshot->call_recursion_depth;
duk_pop_2(thr);
}
/* XXX: better place for this */
DUK_EXTERNAL void duk_set_global_object(duk_hthread *thr) {
duk_hobject *h_glob;
duk_hobject *h_prev_glob;
duk_hobjenv *h_env;
duk_hobject *h_prev_env;
DUK_ASSERT_API_ENTRY(thr);
DUK_D(DUK_DPRINT("replace global object with: %!T", duk_get_tval(thr, -1)));
h_glob = duk_require_hobject(thr, -1);
DUK_ASSERT(h_glob != NULL);
/*
* Replace global object.
*/
h_prev_glob = thr->builtins[DUK_BIDX_GLOBAL];
DUK_UNREF(h_prev_glob);
thr->builtins[DUK_BIDX_GLOBAL] = h_glob;
DUK_HOBJECT_INCREF(thr, h_glob);
DUK_HOBJECT_DECREF_ALLOWNULL(thr, h_prev_glob); /* side effects, in theory (referenced by global env) */
/*
* Replace lexical environment for global scope
*
* Create a new object environment for the global lexical scope.
* We can't just reset the _Target property of the current one,
* because the lexical scope is shared by other threads with the
* same (initial) built-ins.
*/
h_env = duk_hobjenv_alloc(thr,
DUK_HOBJECT_FLAG_EXTENSIBLE |
DUK_HOBJECT_CLASS_AS_FLAGS(DUK_HOBJECT_CLASS_OBJENV));
DUK_ASSERT(h_env != NULL);
DUK_ASSERT(DUK_HOBJECT_GET_PROTOTYPE(thr->heap, (duk_hobject *) h_env) == NULL);
DUK_ASSERT(h_env->target == NULL);
DUK_ASSERT(h_glob != NULL);
h_env->target = h_glob;
DUK_HOBJECT_INCREF(thr, h_glob);
DUK_ASSERT(h_env->has_this == 0);
/* [ ... new_glob ] */
h_prev_env = thr->builtins[DUK_BIDX_GLOBAL_ENV];
thr->builtins[DUK_BIDX_GLOBAL_ENV] = (duk_hobject *) h_env;
DUK_HOBJECT_INCREF(thr, (duk_hobject *) h_env);
DUK_HOBJECT_DECREF_ALLOWNULL(thr, h_prev_env); /* side effects */
DUK_UNREF(h_env); /* without refcounts */
DUK_UNREF(h_prev_env);
/* [ ... new_glob ] */
duk_pop(thr);
/* [ ... ] */
}