Clone the current process into two branches. In the child, Pid
is unified to child. In the original process, Pid is unified to
the process identifier of the created child. Both parent and
child are fully functional Prolog processes running the same
program. The processes share open I/O streams that refer to Unix
native streams, such as files, sockets and pipes. Data is not
shared, though on most Unix systems data is initially shared and
duplicated only if one of the programs attempts to modify the
data.
Unix fork() is the only way to create new processes and fork/1
is a simple direct interface to it.
- Errors
- -
permission_error(fork, process, main) is raised if
the calling thread is not the only thread in the
process. Forking a Prolog process with threads
will typically deadlock because only the calling
thread is cloned in the fork, while all thread
synchronization are cloned.