Function _memory_global_cache_insert

vm/ByteCodeTranslator/src/rpmalloc.c:447–491

Insert the given list of memory page spans in the global cache for small/medium blocks

//! Insert the given list of memory page spans in the global cache for small/medium blocks
static void
_memory_global_cache_insert(span_t* first_span, size_t list_size, size_t page_count) {
	assert((list_size == 1) || (first_span->next_span != 0));
#if MAX_SPAN_CACHE_DIVISOR > 0
	while (1) {
		size_t span_class_idx = _span_class_from_page_count(page_count);
		void* global_span_ptr = atomic_load_ptr(&_memory_span_cache[span_class_idx]);
		if (global_span_ptr != SPAN_LIST_LOCK_TOKEN) {
			uintptr_t global_list_size = (uintptr_t)global_span_ptr & ~SPAN_MASK;
			span_t* global_span = (span_t*)((void*)((uintptr_t)global_span_ptr & SPAN_MASK));

#ifdef GLOBAL_SPAN_CACHE_MULTIPLIER
			size_t cache_limit = GLOBAL_SPAN_CACHE_MULTIPLIER * (_memory_max_allocation[span_class_idx] / MAX_SPAN_CACHE_DIVISOR);
			if ((global_list_size >= cache_limit) && (global_list_size > MIN_SPAN_CACHE_SIZE))
				break;
#endif
			//We only have 16 bits for size of list, avoid overflow
			if ((global_list_size + list_size) > 0xFFFF)
				break;

			//Use prev_span as skip pointer over this sublist range of spans
			first_span->data.list_size = (uint32_t)list_size;
			first_span->prev_span = global_span;

			//Insert sublist into global cache
			global_list_size += list_size;
			void* first_span_ptr = (void*)((uintptr_t)first_span | global_list_size);
			if (atomic_cas_ptr(&_memory_span_cache[span_class_idx], first_span_ptr, global_span_ptr))
				return;
		}
		else {
			//Atomic operation failed, yield timeslice and retry
			thread_yield();
			atomic_thread_fence_acquire();
		}
	}
#endif
	//Global cache full, release pages
	for (size_t ispan = 0; ispan < list_size; ++ispan) {
		assert(first_span);
		span_t* next_span = first_span->next_span;
		_memory_unmap(first_span, page_count);
		first_span = next_span;
	}
}

//! Extract a number of memory page spans from the global cache for small/medium blocks
static span_t*