diff options
Diffstat (limited to 'sys/kern/kern_kthread.c')
-rw-r--r-- | sys/kern/kern_kthread.c | 144 |
1 files changed, 144 insertions, 0 deletions
diff --git a/sys/kern/kern_kthread.c b/sys/kern/kern_kthread.c new file mode 100644 index 0000000..1f805e7 --- /dev/null +++ b/sys/kern/kern_kthread.c @@ -0,0 +1,144 @@ +/* + * 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/proc.h> +#include <sys/kthread.h> +#include <sys/resourcevar.h> +#include <sys/signalvar.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, kp->arg0); + if (error) + panic("kproc_start: %s: error %d", kp->arg0, error); +} + +/* + * Create a kernel process/thread/whatever. It shares it's address space + * with proc0 - ie: kernel only. + */ +int +kthread_create(void (*func)(void *), void *arg, + struct proc **newpp, 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(&proc0, RFMEM | RFFDG | RFPROC, &p2); + if (error) + return error; + + /* save a global descriptor, if desired */ + if (newpp != NULL) + *newpp = p2; + + /* this is a non-swapped system process */ + p2->p_flag |= P_INMEM | P_SYSTEM; + p2->p_procsig->ps_flag |= PS_NOCLDWAIT; + PHOLD(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(p2, func, arg); + + return 0; +} + +void +kthread_exit(int ecode) +{ + exit1(curproc, W_EXITCODE(ecode, 0)); +} + +/* + * Advise a kernel process to suspend (or resume) in its main loop. + * Participation is voluntary. + */ +int +suspend_kproc(struct proc *p, int timo) +{ + /* + * Make sure this is indeed a system process and we can safely + * use the p_siglist field. + */ + if ((p->p_flag & P_SYSTEM) == 0) + return (EINVAL); + SIGADDSET(p->p_siglist, SIGSTOP); + return tsleep((caddr_t)&p->p_siglist, PPAUSE, "suspkp", timo); +} + +int +resume_kproc(struct proc *p) +{ + /* + * Make sure this is indeed a system process and we can safely + * use the p_siglist field. + */ + if ((p->p_flag & P_SYSTEM) == 0) + return (EINVAL); + SIGDELSET(p->p_siglist, SIGSTOP); + wakeup((caddr_t)&p->p_siglist); + return (0); +} + +void +kproc_suspend_loop(struct proc *p) +{ + while (SIGISMEMBER(p->p_siglist, SIGSTOP)) { + wakeup((caddr_t)&p->p_siglist); + tsleep((caddr_t)&p->p_siglist, PPAUSE, "kpsusp", 0); + } +} |