Set array capacity/shared immediately after alloc

If auto-compaction is enabled, then we have to set the capacity/shared
immediately after allocating a heap array. If compaction runs before
capacity/shared is set then it could cause the array to be re-embedded,
which can cause crashes.
This commit is contained in:
Peter Zhu 2022-11-14 15:40:47 -05:00
parent 6dd1a5f532
commit 9a6c3355c5

10
array.c
View File

@ -837,11 +837,11 @@ ary_new(VALUE klass, long capa)
}
else {
ary = ary_alloc_heap(klass);
ARY_SET_CAPA(ary, capa);
assert(!ARY_EMBED_P(ary));
ptr = ary_heap_alloc(ary, capa);
ARY_SET_PTR(ary, ptr);
ARY_SET_CAPA(ary, capa);
ARY_SET_HEAP_LEN(ary, 0);
}
@ -945,11 +945,11 @@ ec_ary_new(rb_execution_context_t *ec, VALUE klass, long capa)
}
else {
ary = ec_ary_alloc_heap(ec, klass);
ARY_SET_CAPA(ary, capa);
assert(!ARY_EMBED_P(ary));
ptr = ary_heap_alloc(ary, capa);
ARY_SET_PTR(ary, ptr);
ARY_SET_CAPA(ary, capa);
ARY_SET_HEAP_LEN(ary, 0);
}
@ -1056,6 +1056,7 @@ ary_make_shared(VALUE ary)
/* Shared roots cannot be embedded because the reference count
* (refcnt) is stored in as.heap.aux.capa. */
VALUE shared = ary_alloc_heap(0);
FL_SET_SHARED_ROOT(shared);
if (ARY_EMBED_P(ary)) {
/* Cannot use ary_heap_alloc because we don't want to allocate
@ -1074,7 +1075,6 @@ ary_make_shared(VALUE ary)
ARY_SET_LEN(shared, capa);
ary_mem_clear(shared, len, capa - len);
FL_SET_SHARED_ROOT(shared);
ARY_SET_SHARED_ROOT_REFCNT(shared, 1);
FL_SET_SHARED(ary);
RB_DEBUG_COUNTER_INC(obj_ary_shared_create);
@ -1348,11 +1348,11 @@ ary_make_partial(VALUE ary, VALUE klass, long offset, long len)
return result;
}
else {
VALUE shared = ary_make_shared(ary);
VALUE result = ary_alloc_heap(klass);
assert(!ARY_EMBED_P(result));
VALUE shared = ary_make_shared(ary);
ARY_SET_PTR(result, RARRAY_CONST_PTR_TRANSIENT(ary));
ARY_SET_LEN(result, RARRAY_LEN(ary));
rb_ary_set_shared(result, shared);