Added new files to support the new fast pipes. After the follow-on
commits, pipe performance should increase significantly. The pipe(2) system call is currently supported, while fifofs will be added later.
This commit is contained in:
John Dyson
parent
adb2fd2d93
commit
10c5615c1d
573
sys/kern/sys_pipe.c
Normal file
573
sys/kern/sys_pipe.c
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@ -0,0 +1,573 @@
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/*
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* Copyright (c) 1996 John S. Dyson
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice immediately at the beginning of the file, without modification,
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* this list of conditions, and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. Absolutely no warranty of function or purpose is made by the author
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* John S. Dyson.
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* 4. This work was done expressly for inclusion into FreeBSD. Other use
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* is allowed if this notation is included.
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* 5. Modifications may be freely made to this file if the above conditions
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* are met.
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*
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* $Id$
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*/
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#ifndef OLD_PIPE
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/*
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* This file contains a high-performance replacement for the socket-based
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* pipes scheme originally used in FreeBSD/4.4Lite. It does not support
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* all features of sockets, but does do everything that pipes normally
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* do.
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*/
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/proc.h>
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#include <sys/file.h>
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#include <sys/protosw.h>
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#include <sys/stat.h>
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#include <sys/filedesc.h>
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#include <sys/malloc.h>
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#include <sys/ioctl.h>
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#include <sys/stat.h>
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#include <sys/select.h>
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#include <sys/signalvar.h>
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#include <sys/errno.h>
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#include <sys/queue.h>
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#include <sys/vmmeter.h>
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#include <sys/kernel.h>
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#include <sys/sysproto.h>
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#include <sys/pipe.h>
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#include <vm/vm.h>
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#include <vm/vm_prot.h>
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#include <vm/vm_param.h>
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#include <vm/lock.h>
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#include <vm/vm_object.h>
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#include <vm/vm_kern.h>
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#include <vm/vm_extern.h>
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#include <vm/pmap.h>
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#include <vm/vm_map.h>
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static int pipe_read __P((struct file *fp, struct uio *uio,
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struct ucred *cred));
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static int pipe_write __P((struct file *fp, struct uio *uio,
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struct ucred *cred));
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static int pipe_close __P((struct file *fp, struct proc *p));
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static int pipe_select __P((struct file *fp, int which, struct proc *p));
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static int pipe_ioctl __P((struct file *fp, int cmd, caddr_t data, struct proc *p));
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static struct fileops pipeops =
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{ pipe_read, pipe_write, pipe_ioctl, pipe_select, pipe_close };
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/*
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* Default pipe buffer size(s), this can be kind-of large now because pipe
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* space is pageable. The pipe code will try to maintain locality of
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* reference for performance reasons, so small amounts of outstanding I/O
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* will not wipe the cache.
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*/
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#define PIPESIZE (16384)
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#define MINPIPESIZE (PIPESIZE/3)
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#define MAXPIPESIZE (2*PIPESIZE/3)
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static void pipeclose __P((struct pipe *cpipe));
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static void pipebufferinit __P((struct pipe *cpipe));
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static void pipeinit __P((struct pipe *cpipe));
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static __inline int pipelock __P((struct pipe *cpipe));
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static __inline void pipeunlock __P((struct pipe *cpipe));
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/*
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* The pipe system call for the DTYPE_PIPE type of pipes
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*/
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/* ARGSUSED */
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int
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pipe(p, uap, retval)
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struct proc *p;
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struct pipe_args /* {
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int dummy;
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} */ *uap;
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int retval[];
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{
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register struct filedesc *fdp = p->p_fd;
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struct file *rf, *wf;
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struct pipe *rpipe, *wpipe;
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int fd, error;
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rpipe = malloc( sizeof (*rpipe), M_TEMP, M_WAITOK);
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pipeinit(rpipe);
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wpipe = malloc( sizeof (*wpipe), M_TEMP, M_WAITOK);
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pipeinit(wpipe);
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error = falloc(p, &rf, &fd);
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if (error)
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goto free2;
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retval[0] = fd;
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rf->f_flag = FREAD | FWRITE;
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rf->f_type = DTYPE_PIPE;
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rf->f_ops = &pipeops;
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rf->f_data = (caddr_t)rpipe;
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error = falloc(p, &wf, &fd);
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if (error)
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goto free3;
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wf->f_flag = FREAD | FWRITE;
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wf->f_type = DTYPE_PIPE;
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wf->f_ops = &pipeops;
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wf->f_data = (caddr_t)wpipe;
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retval[1] = fd;
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rpipe->pipe_peer = wpipe;
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wpipe->pipe_peer = rpipe;
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return (0);
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free3:
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ffree(rf);
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fdp->fd_ofiles[retval[0]] = 0;
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free2:
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(void)pipeclose(wpipe);
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free1:
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(void)pipeclose(rpipe);
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return (error);
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}
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/*
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* initialize and allocate VM and memory for pipe
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*/
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static void
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pipeinit(cpipe)
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struct pipe *cpipe;
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{
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int npages;
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npages = round_page(PIPESIZE)/PAGE_SIZE;
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/*
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* Create an object, I don't like the idea of paging to/from
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* kernel_object.
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*/
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cpipe->pipe_buffer.object = vm_object_allocate(OBJT_DEFAULT, npages);
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/*
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* Insert the object into the kernel map, and allocate kva for it.
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* The map entry is, by default, pageable.
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*/
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if (vm_map_find(kernel_map, cpipe->pipe_buffer.object, 0,
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(vm_offset_t *) &cpipe->pipe_buffer.buffer, PIPESIZE, 1,
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VM_PROT_ALL, VM_PROT_ALL, 0) != KERN_SUCCESS)
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panic("pipeinit: cannot allocate pipe -- out of kvm");
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cpipe->pipe_buffer.in = 0;
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cpipe->pipe_buffer.out = 0;
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cpipe->pipe_buffer.cnt = 0;
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cpipe->pipe_buffer.size = PIPESIZE;
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cpipe->pipe_state = 0;
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cpipe->pipe_peer = NULL;
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cpipe->pipe_busy = 0;
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cpipe->pipe_ctime = time;
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cpipe->pipe_atime = time;
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cpipe->pipe_mtime = time;
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bzero(&cpipe->pipe_sel, sizeof cpipe->pipe_sel);
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}
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/*
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* lock a pipe for I/O, blocking other access
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*/
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static __inline int
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pipelock(cpipe)
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struct pipe *cpipe;
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{
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while (cpipe->pipe_state & PIPE_LOCK) {
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cpipe->pipe_state |= PIPE_LWANT;
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if (tsleep( &cpipe->pipe_state, PRIBIO|PCATCH, "pipelk", 0)) {
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return ERESTART;
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}
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}
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cpipe->pipe_state |= PIPE_LOCK;
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return 0;
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}
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/*
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* unlock a pipe I/O lock
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*/
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static __inline void
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pipeunlock(cpipe)
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struct pipe *cpipe;
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{
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cpipe->pipe_state &= ~PIPE_LOCK;
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if (cpipe->pipe_state & PIPE_LWANT) {
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cpipe->pipe_state &= ~PIPE_LWANT;
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wakeup(&cpipe->pipe_state);
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}
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return;
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}
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/* ARGSUSED */
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static int
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pipe_read(fp, uio, cred)
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struct file *fp;
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struct uio *uio;
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struct ucred *cred;
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{
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struct pipe *rpipe = (struct pipe *) fp->f_data;
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int error = 0;
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int nread = 0;
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++rpipe->pipe_busy;
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while (uio->uio_resid) {
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if (rpipe->pipe_buffer.cnt > 0) {
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int size = rpipe->pipe_buffer.size - rpipe->pipe_buffer.out;
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if (size > rpipe->pipe_buffer.cnt)
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size = rpipe->pipe_buffer.cnt;
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if (size > uio->uio_resid)
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size = uio->uio_resid;
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if ((error = pipelock(rpipe)) == 0) {
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error = uiomove( &rpipe->pipe_buffer.buffer[rpipe->pipe_buffer.out],
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size, uio);
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pipeunlock(rpipe);
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}
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if (error) {
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break;
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}
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rpipe->pipe_buffer.out += size;
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if (rpipe->pipe_buffer.out >= rpipe->pipe_buffer.size)
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rpipe->pipe_buffer.out = 0;
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rpipe->pipe_buffer.cnt -= size;
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nread += size;
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rpipe->pipe_atime = time;
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} else {
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/*
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* detect EOF condition
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*/
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if (rpipe->pipe_state & PIPE_EOF) {
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break;
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}
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/*
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* If the "write-side" has been blocked, wake it up now.
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*/
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if (rpipe->pipe_state & PIPE_WANTW) {
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rpipe->pipe_state &= ~PIPE_WANTW;
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wakeup(rpipe);
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}
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if ((nread > 0) || (rpipe->pipe_state & PIPE_NBIO))
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break;
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if (rpipe->pipe_peer == NULL)
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break;
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/*
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* If there is no more to read in the pipe, reset
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* it's pointers to the beginning. This improves
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* cache hit stats.
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*/
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if ((error = pipelock(rpipe)) == 0) {
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if (rpipe->pipe_buffer.cnt == 0) {
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rpipe->pipe_buffer.in = 0;
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rpipe->pipe_buffer.out = 0;
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}
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pipeunlock(rpipe);
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} else {
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break;
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}
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rpipe->pipe_state |= PIPE_WANTR;
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if (tsleep(rpipe, PRIBIO|PCATCH, "piperd", 0)) {
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error = ERESTART;
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break;
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}
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}
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}
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--rpipe->pipe_busy;
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if ((rpipe->pipe_busy == 0) && (rpipe->pipe_state & PIPE_WANT)) {
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rpipe->pipe_state &= ~(PIPE_WANT|PIPE_WANTW);
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wakeup(rpipe);
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} else if (rpipe->pipe_buffer.cnt < MINPIPESIZE) {
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/*
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* If there is no more to read in the pipe, reset
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* it's pointers to the beginning. This improves
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* cache hit stats.
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*/
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if ((error == 0) && (error = pipelock(rpipe)) == 0) {
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if (rpipe->pipe_buffer.cnt == 0) {
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rpipe->pipe_buffer.in = 0;
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rpipe->pipe_buffer.out = 0;
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}
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pipeunlock(rpipe);
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}
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/*
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* If the "write-side" has been blocked, wake it up now.
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*/
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if (rpipe->pipe_state & PIPE_WANTW) {
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rpipe->pipe_state &= ~PIPE_WANTW;
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wakeup(rpipe);
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}
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}
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if (rpipe->pipe_state & PIPE_SEL) {
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rpipe->pipe_state &= ~PIPE_SEL;
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selwakeup(&rpipe->pipe_sel);
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}
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return error;
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}
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/* ARGSUSED */
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static int
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pipe_write(fp, uio, cred)
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struct file *fp;
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struct uio *uio;
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struct ucred *cred;
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{
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||||
struct pipe *rpipe = (struct pipe *) fp->f_data;
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struct pipe *wpipe = rpipe->pipe_peer;
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int error = 0;
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/*
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* detect loss of pipe read side, issue SIGPIPE if lost.
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*/
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if (wpipe == NULL || (wpipe->pipe_state & PIPE_EOF)) {
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psignal(curproc, SIGPIPE);
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return 0;
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}
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++wpipe->pipe_busy;
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while (uio->uio_resid) {
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int space = wpipe->pipe_buffer.size - wpipe->pipe_buffer.cnt;
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if (space > 0) {
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int size = wpipe->pipe_buffer.size - wpipe->pipe_buffer.in;
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if (size > space)
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size = space;
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if (size > uio->uio_resid)
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size = uio->uio_resid;
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if ((error = pipelock(wpipe)) == 0) {
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error = uiomove( &wpipe->pipe_buffer.buffer[wpipe->pipe_buffer.in],
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size, uio);
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pipeunlock(wpipe);
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||||
}
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if (error)
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break;
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wpipe->pipe_buffer.in += size;
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if (wpipe->pipe_buffer.in >= wpipe->pipe_buffer.size)
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wpipe->pipe_buffer.in = 0;
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wpipe->pipe_buffer.cnt += size;
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wpipe->pipe_mtime = time;
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} else {
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/*
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* If the "read-side" has been blocked, wake it up now.
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||||
*/
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||||
if (wpipe->pipe_state & PIPE_WANTR) {
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wpipe->pipe_state &= ~PIPE_WANTR;
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wakeup(wpipe);
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||||
}
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||||
/*
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||||
* don't block on non-blocking I/O
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||||
*/
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||||
if (wpipe->pipe_state & PIPE_NBIO) {
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||||
break;
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||||
}
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||||
wpipe->pipe_state |= PIPE_WANTW;
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if (tsleep(wpipe, (PRIBIO+1)|PCATCH, "pipewr", 0)) {
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error = ERESTART;
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||||
break;
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}
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||||
/*
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||||
* If read side wants to go away, we just issue a signal
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* to ourselves.
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*/
|
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if (wpipe->pipe_state & PIPE_EOF) {
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psignal(curproc, SIGPIPE);
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break;
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||||
}
|
||||
}
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||||
}
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||||
|
||||
--wpipe->pipe_busy;
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if ((wpipe->pipe_busy == 0) &&
|
||||
(wpipe->pipe_state & PIPE_WANT)) {
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||||
wpipe->pipe_state &= ~(PIPE_WANT|PIPE_WANTR);
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||||
wakeup(wpipe);
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||||
} else if (wpipe->pipe_buffer.cnt > 0) {
|
||||
/*
|
||||
* If we have put any characters in the buffer, we wake up
|
||||
* the reader.
|
||||
*/
|
||||
if (wpipe->pipe_state & PIPE_WANTR) {
|
||||
wpipe->pipe_state &= ~PIPE_WANTR;
|
||||
wakeup(wpipe);
|
||||
}
|
||||
}
|
||||
if (wpipe->pipe_state & PIPE_SEL) {
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||||
wpipe->pipe_state &= ~PIPE_SEL;
|
||||
selwakeup(&wpipe->pipe_sel);
|
||||
}
|
||||
return error;
|
||||
}
|
||||
|
||||
/*
|
||||
* we implement a very minimal set of ioctls for compatibility with sockets.
|
||||
*/
|
||||
int
|
||||
pipe_ioctl(fp, cmd, data, p)
|
||||
struct file *fp;
|
||||
int cmd;
|
||||
register caddr_t data;
|
||||
struct proc *p;
|
||||
{
|
||||
register struct pipe *mpipe = (struct pipe *)fp->f_data;
|
||||
|
||||
switch (cmd) {
|
||||
|
||||
case FIONBIO:
|
||||
if (*(int *)data)
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||||
mpipe->pipe_state |= PIPE_NBIO;
|
||||
else
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||||
mpipe->pipe_state &= ~PIPE_NBIO;
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||||
return (0);
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||||
|
||||
case FIOASYNC:
|
||||
if (*(int *)data) {
|
||||
mpipe->pipe_state |= PIPE_ASYNC;
|
||||
} else {
|
||||
mpipe->pipe_state &= ~PIPE_ASYNC;
|
||||
}
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||||
return (0);
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||||
|
||||
case FIONREAD:
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||||
*(int *)data = mpipe->pipe_buffer.cnt;
|
||||
return (0);
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||||
|
||||
case SIOCSPGRP:
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||||
mpipe->pipe_pgid = *(int *)data;
|
||||
return (0);
|
||||
|
||||
case SIOCGPGRP:
|
||||
*(int *)data = mpipe->pipe_pgid;
|
||||
return (0);
|
||||
|
||||
}
|
||||
return ENOSYS;
|
||||
}
|
||||
|
||||
int
|
||||
pipe_select(fp, which, p)
|
||||
struct file *fp;
|
||||
int which;
|
||||
struct proc *p;
|
||||
{
|
||||
register struct pipe *rpipe = (struct pipe *)fp->f_data;
|
||||
struct pipe *wpipe;
|
||||
register int s = splnet();
|
||||
|
||||
wpipe = rpipe->pipe_peer;
|
||||
switch (which) {
|
||||
|
||||
case FREAD:
|
||||
if (rpipe->pipe_buffer.cnt > 0) {
|
||||
splx(s);
|
||||
return (1);
|
||||
}
|
||||
selrecord(p, &rpipe->pipe_sel);
|
||||
rpipe->pipe_state |= PIPE_SEL;
|
||||
break;
|
||||
|
||||
case FWRITE:
|
||||
if (wpipe == 0) {
|
||||
splx(s);
|
||||
return (1);
|
||||
}
|
||||
if (wpipe->pipe_buffer.cnt < wpipe->pipe_buffer.size) {
|
||||
splx(s);
|
||||
return (1);
|
||||
}
|
||||
selrecord(p, &wpipe->pipe_sel);
|
||||
wpipe->pipe_state |= PIPE_SEL;
|
||||
break;
|
||||
|
||||
case 0:
|
||||
selrecord(p, &rpipe->pipe_sel);
|
||||
rpipe->pipe_state |= PIPE_SEL;
|
||||
break;
|
||||
}
|
||||
splx(s);
|
||||
return (0);
|
||||
}
|
||||
|
||||
int
|
||||
pipe_stat(pipe, ub)
|
||||
register struct pipe *pipe;
|
||||
register struct stat *ub;
|
||||
{
|
||||
bzero((caddr_t)ub, sizeof (*ub));
|
||||
ub->st_mode = S_IFSOCK;
|
||||
ub->st_blksize = pipe->pipe_buffer.size / 2;
|
||||
ub->st_size = pipe->pipe_buffer.cnt;
|
||||
ub->st_blocks = (ub->st_size + ub->st_blksize - 1) / ub->st_blksize;
|
||||
TIMEVAL_TO_TIMESPEC(&pipe->pipe_atime, &ub->st_atimespec);
|
||||
TIMEVAL_TO_TIMESPEC(&pipe->pipe_mtime, &ub->st_mtimespec);
|
||||
TIMEVAL_TO_TIMESPEC(&pipe->pipe_ctime, &ub->st_ctimespec);
|
||||
return 0;
|
||||
}
|
||||
|
||||
/* ARGSUSED */
|
||||
static int
|
||||
pipe_close(fp, p)
|
||||
struct file *fp;
|
||||
struct proc *p;
|
||||
{
|
||||
int error = 0;
|
||||
struct pipe *cpipe = (struct pipe *)fp->f_data;
|
||||
pipeclose(cpipe);
|
||||
fp->f_data = NULL;
|
||||
return 0;
|
||||
}
|
||||
|
||||
/*
|
||||
* shutdown the pipe
|
||||
*/
|
||||
static void
|
||||
pipeclose(cpipe)
|
||||
struct pipe *cpipe;
|
||||
{
|
||||
if (cpipe) {
|
||||
/*
|
||||
* If the other side is blocked, wake it up saying that
|
||||
* we want to close it down.
|
||||
*/
|
||||
while (cpipe->pipe_busy) {
|
||||
wakeup(cpipe);
|
||||
cpipe->pipe_state |= PIPE_WANT|PIPE_EOF;
|
||||
tsleep(cpipe, PRIBIO, "pipecl", 0);
|
||||
}
|
||||
|
||||
/*
|
||||
* Disconnect from peer
|
||||
*/
|
||||
if (cpipe->pipe_peer) {
|
||||
cpipe->pipe_peer->pipe_state |= PIPE_EOF;
|
||||
wakeup(cpipe->pipe_peer);
|
||||
cpipe->pipe_peer->pipe_peer = NULL;
|
||||
}
|
||||
|
||||
/*
|
||||
* free resources
|
||||
*/
|
||||
kmem_free(kernel_map, (vm_offset_t)cpipe->pipe_buffer.buffer,
|
||||
cpipe->pipe_buffer.size);
|
||||
free(cpipe, M_TEMP);
|
||||
}
|
||||
}
|
||||
#endif
|
||||
73
sys/sys/pipe.h
Normal file
73
sys/sys/pipe.h
Normal file
@ -0,0 +1,73 @@
|
||||
/*
|
||||
* Copyright (c) 1996 John S. Dyson
|
||||
* 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 immediately at the beginning of the file, without modification,
|
||||
* 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.
|
||||
* 3. Absolutely no warranty of function or purpose is made by the author
|
||||
* John S. Dyson.
|
||||
* 4. This work was done expressly for inclusion into FreeBSD. Other use
|
||||
* is allowed if this notation is included.
|
||||
* 5. Modifications may be freely made to this file if the above conditions
|
||||
* are met.
|
||||
*
|
||||
* $Id$
|
||||
*/
|
||||
|
||||
#ifndef OLD_PIPE
|
||||
|
||||
struct vm_object;
|
||||
|
||||
/*
|
||||
* pipe buffer information
|
||||
* Seperate in, out, cnt is used to simplify calculations.
|
||||
*/
|
||||
struct pipebuf {
|
||||
u_int cnt; /* number of chars currently in buffer */
|
||||
u_int in; /* in pointer */
|
||||
u_int out; /* out pointer */
|
||||
u_int size; /* size of buffer */
|
||||
caddr_t buffer; /* kva of buffer */
|
||||
struct vm_object *object; /* VM object containing buffer */
|
||||
};
|
||||
|
||||
/*
|
||||
* pipe_state bits
|
||||
*/
|
||||
#define PIPE_NBIO 0x1 /* non-blocking I/O */
|
||||
#define PIPE_ASYNC 0x4 /* Async? I/O */
|
||||
#define PIPE_WANTR 0x8 /* Reader wants some characters */
|
||||
#define PIPE_WANTW 0x10 /* Writer wants space to put characters */
|
||||
#define PIPE_WANT 0x20 /* Pipe is wanted to be run-down */
|
||||
#define PIPE_SEL 0x40 /* Pipe has a select active */
|
||||
#define PIPE_EOF 0x80 /* Pipe is in EOF condition */
|
||||
#define PIPE_LOCK 0x100 /* Process has exclusive access to pointers/data */
|
||||
#define PIPE_LWANT 0x200 /* Process wants exclusive access to pointers/data */
|
||||
|
||||
/*
|
||||
* Per-pipe data structure
|
||||
* Two of these are linked together to produce bi-directional
|
||||
* pipes.
|
||||
*/
|
||||
struct pipe {
|
||||
struct pipebuf pipe_buffer; /* data storage */
|
||||
struct selinfo pipe_sel; /* for compat with select */
|
||||
struct timeval pipe_atime; /* time of last access */
|
||||
struct timeval pipe_mtime; /* time of last modify */
|
||||
struct timeval pipe_ctime; /* time of status change */
|
||||
int pipe_pgid;
|
||||
struct pipe *pipe_peer; /* link with other direction */
|
||||
u_int pipe_state; /* pipe status info */
|
||||
int pipe_busy; /* busy flag, mostly to handle rundown sanely */
|
||||
};
|
||||
|
||||
int pipe_stat __P((struct pipe *pipe, struct stat *ub));
|
||||
|
||||
#endif
|
||||
Loading…
Reference in New Issue
Block a user