memory: add ref/unref (46637be2) · Commits · SUMMER2020 / students / proj-2021291

include/exec/memory.h

+30 −0

Original line number	Diff line number	Diff line
		@@ -247,6 +247,36 @@ void memory_region_init(MemoryRegion *mr,
		struct Object *owner,
		const char *name,
		uint64_t size);

		/**
		* memory_region_ref: Add 1 to a memory region's reference count
		*
		* Whenever memory regions are accessed outside the BQL, they need to be
		* preserved against hot-unplug. MemoryRegions actually do not have their
		* own reference count; they piggyback on a QOM object, their "owner".
		* This function adds a reference to the owner.
		*
		* All MemoryRegions must have an owner if they can disappear, even if the
		* device they belong to operates exclusively under the BQL. This is because
		* the region could be returned at any time by memory_region_find, and this
		* is usually under guest control.
		*
		* @mr: the #MemoryRegion
		*/
		void memory_region_ref(MemoryRegion *mr);

		/**
		* memory_region_unref: Remove 1 to a memory region's reference count
		*
		* Whenever memory regions are accessed outside the BQL, they need to be
		* preserved against hot-unplug. MemoryRegions actually do not have their
		* own reference count; they piggyback on a QOM object, their "owner".
		* This function removes a reference to the owner and possibly destroys it.
		*
		* @mr: the #MemoryRegion
		*/
		void memory_region_unref(MemoryRegion *mr);

		/**
		* memory_region_init_io: Initialize an I/O memory region.
		*

+14 −0

Original line number	Diff line number	Diff line
		@@ -1019,6 +1019,20 @@ Object memory_region_owner(MemoryRegion mr)
		return mr->owner;
		}

		void memory_region_ref(MemoryRegion *mr)
		{
		if (mr && mr->owner) {
		object_ref(mr->owner);
		}
		}

		void memory_region_unref(MemoryRegion *mr)
		{
		if (mr && mr->owner) {
		object_unref(mr->owner);
		}
		}

		uint64_t memory_region_size(MemoryRegion *mr)
		{
		if (int128_eq(mr->size, int128_2_64())) {