Half-process: A Process Partially Sharing Its Address Space with Other Processes

Threads share a single address space with each other. On the other hand, a process has its own address space. Since whether to share or not to share the address space depends on each data structure in the whole program, the choice of “a thread or a process” for the whole program is too much “all-or-nothing.” With this motivation, this paper proposes a half-process, a process partially sharing its address space with other processes. This paper describes the design and the kernel-level implementation of the half-process and discusses the potential applicability of the half-process for multi-thread programming with thread-unsafe libraries, intra-node communications in parallel programming frameworks and transparent kernel-level thread migration. In particular, the thread migration based on the half-process is the first work that achieves transparent kernel-level thread migration by solving the problem of sharing global variables between threads.