Here are some cons of the MT model over the single-threaded process:
| Context | Multiprocess (single-threaded) model | Multithreaded (MT) model |
| Thread-safety | No such requirement; processes always have address space separation. | The most serious downside: every function in the MT application that can be run in parallel by threads must be written, verified, and documented to be thread-safe. This includes the app code and the project libraries, as well as any third-party libraries it links into. |
| Application integrity | In a large MT app, if any one thread encounters a fatal error (such as a segfault), the entire app is now buggy and will have to shut down. | In a multiprocess app, ... |
