RUMP_LWPROC(3) | Library Functions Manual | RUMP_LWPROC(3) |
rump_lwproc
—
#include <rump/rump.h>
int
rump_pub_lwproc_rfork
(int
flags);
int
rump_pub_lwproc_newlwp
(pid_t
pid);
void
rump_pub_lwproc_switch
(struct
lwp *l);
void
rump_pub_lwproc_releaselwp
();
struct lwp *
rump_pub_lwproc_curlwp
();
In the rump kernel model, each host thread (implemented for example with pthreads or green threads) is either bound to a rump kernel lwp or accesses the rump kernel with an implicit thread context associated with pid 1. An implicit thread context is created every time the rump kernel is entered and disbanded upon exit. While convenient for occasional calls, creating an implicit thread uses a shared resource which can become highly contended in a multithreaded situation. It is therefore recommended that dedicated threads are created.
The association between host threads and the rump kernel curlwp is left to the caller. It is possible to create a dedicated host thread for every rump kernel lwp or multiplex them on top of a single host thread. After rump kernel lwps have been created, switching curlwp is very cheap. In case multiple lwps/processes are created, it is the caller's responsibility to keep track of them and release them when they are no longer necessary. A rump kernel lwp will persist until it is explicitly released. A rump kernel process will persist until all of its lwps have been released, at which point the process is automatically released.
rump_pub_lwproc_rfork
()RUMP_RFFDG
RUMP_RFCFDG
This routine returns 0 for success or an errno indicating the
reason for failure. The new process id can be retrieved in the normal
fashion by calling rump_sys_getpid
().
rump_pub_lwproc_newlwp
(pid)rump_pub_lwproc_switch
(l)NULL
sets curlwp to implicit context. Switching to an already running lwp, i.e.
attempting to use the same curlwp in two host threads simultaneously
causes a fatal error.rump_pub_lwproc_releaselwp
()rump_pub_lwproc_curlwp
()NULL
if the current context is
an implicit context.rump_pub_lwproc_rfork
() and
rump_pub_lwproc_newlwp
() return 0 on success or an
errno indicating the reason for failure.
rump_pub_lwproc_curlwp
() returns curlwp or
NULL
if the current context is an implicit context.
rump_lwproc
first appeared in NetBSD
6.0.
October 27, 2014 | NetBSD 9.0 |