diff options
Diffstat (limited to 'sys/kern/kern_kthread.c')
| -rw-r--r-- | sys/kern/kern_kthread.c | 184 |
1 files changed, 184 insertions, 0 deletions
diff --git a/sys/kern/kern_kthread.c b/sys/kern/kern_kthread.c new file mode 100644 index 0000000..a456a86 --- /dev/null +++ b/sys/kern/kern_kthread.c @@ -0,0 +1,184 @@ +/* + * Copyright (c) 1999 Peter Wemm <peter@FreeBSD.org> + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + * + * $FreeBSD$ + */ + +#include <sys/param.h> +#include <sys/systm.h> +#include <sys/kthread.h> +#include <sys/lock.h> +#include <sys/mutex.h> +#include <sys/proc.h> +#include <sys/resourcevar.h> +#include <sys/signalvar.h> +#include <sys/sx.h> +#include <sys/unistd.h> +#include <sys/wait.h> + +#include <machine/stdarg.h> + +/* + * Start a kernel process. This is called after a fork() call in + * mi_startup() in the file kern/init_main.c. + * + * This function is used to start "internal" daemons and intended + * to be called from SYSINIT(). + */ +void +kproc_start(udata) + const void *udata; +{ + const struct kproc_desc *kp = udata; + int error; + + error = kthread_create((void (*)(void *))kp->func, NULL, + kp->global_procpp, 0, "%s", kp->arg0); + if (error) + panic("kproc_start: %s: error %d", kp->arg0, error); +} + +/* + * Create a kernel process/thread/whatever. It shares its address space + * with proc0 - ie: kernel only. + * + * func is the function to start. + * arg is the parameter to pass to function on first startup. + * newpp is the return value pointing to the thread's struct proc. + * flags are flags to fork1 (in unistd.h) + * fmt and following will be *printf'd into (*newpp)->p_comm (for ps, etc.). + */ +int +kthread_create(void (*func)(void *), void *arg, + struct proc **newpp, int flags, const char *fmt, ...) +{ + int error; + va_list ap; + struct proc *p2; + + if (!proc0.p_stats /* || proc0.p_stats->p_start.tv_sec == 0 */) + panic("kthread_create called too soon"); + + error = fork1(&thread0, RFMEM | RFFDG | RFPROC | RFSTOPPED | flags, + &p2); + if (error) + return error; + + /* save a global descriptor, if desired */ + if (newpp != NULL) + *newpp = p2; + + /* this is a non-swapped system process */ + PROC_LOCK(p2); + p2->p_flag |= P_SYSTEM | P_KTHREAD; + p2->p_procsig->ps_flag |= PS_NOCLDWAIT; + _PHOLD(p2); + PROC_UNLOCK(p2); + + /* set up arg0 for 'ps', et al */ + va_start(ap, fmt); + vsnprintf(p2->p_comm, sizeof(p2->p_comm), fmt, ap); + va_end(ap); + + /* call the processes' main()... */ + cpu_set_fork_handler(FIRST_THREAD_IN_PROC(p2), func, arg); + + /* Delay putting it on the run queue until now. */ + mtx_lock_spin(&sched_lock); + p2->p_sflag |= PS_INMEM; + if (!(flags & RFSTOPPED)) { + p2->p_stat = SRUN; + setrunqueue(FIRST_THREAD_IN_PROC(p2)); /* XXXKSE */ + } + mtx_unlock_spin(&sched_lock); + + return 0; +} + +void +kthread_exit(int ecode) +{ + struct thread *td; + struct proc *p; + + td = curthread; + p = td->td_proc; + sx_xlock(&proctree_lock); + PROC_LOCK(p); + proc_reparent(p, initproc); + PROC_UNLOCK(p); + sx_xunlock(&proctree_lock); + exit1(td, W_EXITCODE(ecode, 0)); +} + +/* + * Advise a kernel process to suspend (or resume) in its main loop. + * Participation is voluntary. + */ +int +kthread_suspend(struct proc *p, int timo) +{ + /* + * Make sure this is indeed a system process and we can safely + * use the p_siglist field. + */ + PROC_LOCK(p); + if ((p->p_flag & P_KTHREAD) == 0) { + PROC_UNLOCK(p); + return (EINVAL); + } + SIGADDSET(p->p_siglist, SIGSTOP); + wakeup(p); + return msleep(&p->p_siglist, &p->p_mtx, PPAUSE | PDROP, "suspkt", timo); +} + +int +kthread_resume(struct proc *p) +{ + /* + * Make sure this is indeed a system process and we can safely + * use the p_siglist field. + */ + PROC_LOCK(p); + if ((p->p_flag & P_KTHREAD) == 0) { + PROC_UNLOCK(p); + return (EINVAL); + } + SIGDELSET(p->p_siglist, SIGSTOP); + PROC_UNLOCK(p); + wakeup(&p->p_siglist); + return (0); +} + +void +kthread_suspend_check(struct proc *p) +{ + PROC_LOCK(p); + while (SIGISMEMBER(p->p_siglist, SIGSTOP)) { + wakeup(&p->p_siglist); + msleep(&p->p_siglist, &p->p_mtx, PPAUSE, "ktsusp", 0); + } + PROC_UNLOCK(p); +} |
