Techniques for transitioning between thread-confined memory segments and shared memory segments are disclosed. The system may instantiate a confined memory segment view. The confined memory segment view confines access to a memory segment to a particular thread. The system may further receive a request to change access permissions for the confined memory segment to allow access by a first set of one or more threads. Responsive to receiving the request to change access permissions for the confined memory segment, the system may instantiate a new memory segment view, wherein the new memory segment view permits access to the memory segment by the first set of one or more threads. The system may also copy metadata from the confined memory segment view to the new memory segment view. The system may de-allocate the memory segment in response to determining that there are no memory segment views associated with the memory segment.