duktape-1.5.2/src-separate/duk_hobject_alloc.c

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/*
 *  Hobject allocation.
 *
 *  Provides primitive allocation functions for all object types (plain object,
 *  compiled function, native function, thread).  The object return is not yet
 *  in "heap allocated" list and has a refcount of zero, so caller must careful.
 */
 
#include "duk_internal.h"
 
DUK_LOCAL void duk__init_object_parts(duk_heap *heap, duk_hobject *obj, duk_uint_t hobject_flags) {
#ifdef DUK_USE_EXPLICIT_NULL_INIT
    DUK_HOBJECT_SET_PROPS(heap, obj, NULL);
#endif
 
    /* XXX: macro? sets both heaphdr and object flags */
    obj->hdr.h_flags = hobject_flags;
    DUK_HEAPHDR_SET_TYPE(&obj->hdr, DUK_HTYPE_OBJECT);  /* also goes into flags */
 
#if defined(DUK_USE_HEAPPTR16)
    /* Zero encoded pointer is required to match NULL */
    DUK_HEAPHDR_SET_NEXT(heap, &obj->hdr, NULL);
#if defined(DUK_USE_DOUBLE_LINKED_HEAP)
    DUK_HEAPHDR_SET_PREV(heap, &obj->hdr, NULL);
#endif
#endif
    DUK_ASSERT_HEAPHDR_LINKS(heap, &obj->hdr);
    DUK_HEAP_INSERT_INTO_HEAP_ALLOCATED(heap, &obj->hdr);
 
    /*
     *  obj->props is intentionally left as NULL, and duk_hobject_props.c must deal
     *  with this properly.  This is intentional: empty objects consume a minimum
     *  amount of memory.  Further, an initial allocation might fail and cause
     *  'obj' to "leak" (require a mark-and-sweep) since it is not reachable yet.
     */
}
 
/*
 *  Allocate an duk_hobject.
 *
 *  The allocated object has no allocation for properties; the caller may
 *  want to force a resize if a desired size is known.
 *
 *  The allocated object has zero reference count and is not reachable.
 *  The caller MUST make the object reachable and increase its reference
 *  count before invoking any operation that might require memory allocation.
 */
 
DUK_INTERNAL duk_hobject *duk_hobject_alloc(duk_heap *heap, duk_uint_t hobject_flags) {
    duk_hobject *res;
 
    DUK_ASSERT(heap != NULL);
 
    /* different memory layout, alloc size, and init */
    DUK_ASSERT((hobject_flags & DUK_HOBJECT_FLAG_COMPILEDFUNCTION) == 0);
    DUK_ASSERT((hobject_flags & DUK_HOBJECT_FLAG_NATIVEFUNCTION) == 0);
    DUK_ASSERT((hobject_flags & DUK_HOBJECT_FLAG_THREAD) == 0);
 
    res = (duk_hobject *) DUK_ALLOC(heap, sizeof(duk_hobject));
    if (!res) {
        return NULL;
    }
    DUK_MEMZERO(res, sizeof(duk_hobject));
 
    duk__init_object_parts(heap, res, hobject_flags);
 
    return res;
}
 
DUK_INTERNAL duk_hcompiledfunction *duk_hcompiledfunction_alloc(duk_heap *heap, duk_uint_t hobject_flags) {
    duk_hcompiledfunction *res;
 
    res = (duk_hcompiledfunction *) DUK_ALLOC(heap, sizeof(duk_hcompiledfunction));
    if (!res) {
        return NULL;
    }
    DUK_MEMZERO(res, sizeof(duk_hcompiledfunction));
 
    duk__init_object_parts(heap, &res->obj, hobject_flags);
 
#ifdef DUK_USE_EXPLICIT_NULL_INIT
#ifdef DUK_USE_HEAPPTR16
    /* NULL pointer is required to encode to zero, so memset is enough. */
#else
    res->data = NULL;
    res->funcs = NULL;
    res->bytecode = NULL;
#endif
#endif
 
    return res;
}
 
DUK_INTERNAL duk_hnativefunction *duk_hnativefunction_alloc(duk_heap *heap, duk_uint_t hobject_flags) {
    duk_hnativefunction *res;
 
    res = (duk_hnativefunction *) DUK_ALLOC(heap, sizeof(duk_hnativefunction));
    if (!res) {
        return NULL;
    }
    DUK_MEMZERO(res, sizeof(duk_hnativefunction));
 
    duk__init_object_parts(heap, &res->obj, hobject_flags);
 
#ifdef DUK_USE_EXPLICIT_NULL_INIT
    res->func = NULL;
#endif
 
    return res;
}
 
DUK_INTERNAL duk_hbufferobject *duk_hbufferobject_alloc(duk_heap *heap, duk_uint_t hobject_flags) {
    duk_hbufferobject *res;
 
    res = (duk_hbufferobject *) DUK_ALLOC(heap, sizeof(duk_hbufferobject));
    if (!res) {
        return NULL;
    }
    DUK_MEMZERO(res, sizeof(duk_hbufferobject));
 
    duk__init_object_parts(heap, &res->obj, hobject_flags);
 
#ifdef DUK_USE_EXPLICIT_NULL_INIT
    res->buf = NULL;
#endif
 
    DUK_ASSERT_HBUFFEROBJECT_VALID(res);
    return res;
}
 
/*
 *  Allocate a new thread.
 *
 *  Leaves the built-ins array uninitialized.  The caller must either
 *  initialize a new global context or share existing built-ins from
 *  another thread.
 */
 
DUK_INTERNAL duk_hthread *duk_hthread_alloc(duk_heap *heap, duk_uint_t hobject_flags) {
    duk_hthread *res;
 
    res = (duk_hthread *) DUK_ALLOC(heap, sizeof(duk_hthread));
    if (!res) {
        return NULL;
    }
    DUK_MEMZERO(res, sizeof(duk_hthread));
 
    duk__init_object_parts(heap, &res->obj, hobject_flags);
 
#ifdef DUK_USE_EXPLICIT_NULL_INIT
    res->ptr_curr_pc = NULL;
    res->heap = NULL;
    res->valstack = NULL;
    res->valstack_end = NULL;
    res->valstack_bottom = NULL;
    res->valstack_top = NULL;
    res->callstack = NULL;
    res->catchstack = NULL;
    res->resumer = NULL;
    res->compile_ctx = NULL,
#ifdef DUK_USE_HEAPPTR16
    res->strs16 = NULL;
#else
    res->strs = NULL;
#endif
    {
        int i;
        for (i = 0; i < DUK_NUM_BUILTINS; i++) {
            res->builtins[i] = NULL;
        }
    }
#endif
    /* when nothing is running, API calls are in non-strict mode */
    DUK_ASSERT(res->strict == 0);
 
    res->heap = heap;
    res->valstack_max = DUK_VALSTACK_DEFAULT_MAX;
    res->callstack_max = DUK_CALLSTACK_DEFAULT_MAX;
    res->catchstack_max = DUK_CATCHSTACK_DEFAULT_MAX;
 
    return res;
}
 
#if 0  /* unused now */
DUK_INTERNAL duk_hobject *duk_hobject_alloc_checked(duk_hthread *thr, duk_uint_t hobject_flags) {
    duk_hobject *res = duk_hobject_alloc(thr->heap, hobject_flags);
    if (!res) {
        DUK_ERROR_ALLOC_DEFMSG(thr);
    }
    return res;
}
#endif