Improve the performance for pipe(2) again. Also include some
fixes for previous version of new pipes from Bruce Evans. This new version: Supports more properly the semantics of select (BDE). Supports "OLD_PIPE" correctly (kern_descrip.c, BDE). Eliminates incorrect EPIPE returns (bash 'pipe broken' messages.) Much faster yet, currently tuned relatively conservatively -- but now gives approx 50% more perf than the new pipes code did originally. (That was about 50% more perf than the original BSD pipe code.) Known bugs outstanding: No support for async io (SIGIO). Will be included soon. Next to do: Merge support for FIFOs. Submitted by: bde
This commit is contained in:
dyson
parent
da64467214
commit
276899d730
@ -36,7 +36,7 @@
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* SUCH DAMAGE.
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*
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* @(#)kern_descrip.c 8.6 (Berkeley) 4/19/94
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* $Id: kern_descrip.c,v 1.23 1995/12/14 08:31:14 phk Exp $
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* $Id: kern_descrip.c,v 1.24 1996/01/28 23:41:39 dyson Exp $
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*/
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#include <sys/param.h>
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@ -425,9 +425,11 @@ ofstat(p, uap, retval)
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error = soo_stat((struct socket *)fp->f_data, &ub);
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break;
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#ifndef OLD_PIPE
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case DTYPE_PIPE:
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error = pipe_stat((struct pipe *)fp->f_data, &ub);
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break;
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#endif
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default:
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panic("ofstat");
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@ -474,9 +476,11 @@ fstat(p, uap, retval)
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error = soo_stat((struct socket *)fp->f_data, &ub);
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break;
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#ifndef OLD_PIPE
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case DTYPE_PIPE:
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error = pipe_stat((struct pipe *)fp->f_data, &ub);
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break;
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#endif
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default:
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panic("fstat");
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@ -512,7 +516,9 @@ fpathconf(p, uap, retval)
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return (EBADF);
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switch (fp->f_type) {
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#ifndef OLD_PIPE
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case DTYPE_PIPE:
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#endif
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case DTYPE_SOCKET:
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if (uap->name != _PC_PIPE_BUF)
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return (EINVAL);
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@ -18,7 +18,7 @@
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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: sys_pipe.c,v 1.3 1996/01/31 02:05:12 dyson Exp $
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* $Id: sys_pipe.c,v 1.2 1996/01/29 02:57:33 dyson Exp $
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*/
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#ifndef OLD_PIPE
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@ -30,6 +30,29 @@
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* do.
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*/
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/*
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* This code has two modes of operation, a small write mode and a large
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* write mode. The small write mode acts like conventional pipes with
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* a kernel buffer. If the buffer is less than PIPE_MINDIRECT, then the
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* "normal" pipe buffering is done. If the buffer is between PIPE_MINDIRECT
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* and PIPE_SIZE in size, it is fully mapped and wired into the kernel, and
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* the receiving process can copy it directly from the pages in the sending
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* process.
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*
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* If the sending process receives a signal, it is possible that it will
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* go away, and certainly it's address space can change, because control
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* is returned back to the user-mode side. In that case, the pipe code
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* arranges to copy the buffer supplied by the user process, to a pageable
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* kernel buffer, and the receiving process will grab the data from the
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* pageable kernel buffer. Since signals don't happen all that often,
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* the copy operation is normally eliminated.
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*
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* The constant PIPE_MINDIRECT is chosen to make sure that buffering will
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* happen for small transfers so that the system will not spend all of
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* it's time context switching. PIPE_SIZE is constrained by the
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* amount of kernel virtual memory.
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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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@ -58,6 +81,7 @@
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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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#include <vm/vm_page.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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@ -76,15 +100,34 @@ static struct fileops pipeops =
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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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#define MINPIPESIZE (PIPE_SIZE/3)
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#define MAXPIPESIZE (2*PIPE_SIZE/3)
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/*
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* Maximum amount of kva for pipes -- this is kind-of a soft limit, but
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* is there so that on large systems, we don't exhaust it.
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*/
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#define MAXPIPEKVA (8*1024*1024)
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/*
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* Limit for direct transfers, we cannot, of course limit
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* the amount of kva for pipes in general though.
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*/
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#define LIMITPIPEKVA (16*1024*1024)
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int amountpipekva;
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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 int pipelock __P((struct pipe *cpipe, int catch));
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static __inline void pipeunlock __P((struct pipe *cpipe));
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static int pipe_build_write_buffer __P((struct pipe *wpipe, struct uio *uio));
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static void pipe_destroy_write_buffer __P((struct pipe *wpipe));
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static int pipe_direct_write __P((struct pipe *wpipe, struct uio *uio));
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static void pipe_clone_write_buffer __P((struct pipe *wpipe));
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static void pipe_mark_pages_clean __P((struct pipe *cpipe));
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static int pipewrite __P((struct pipe *wpipe, struct uio *uio, int nbio));
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static void pipespace __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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@ -106,8 +149,10 @@ pipe(p, uap, retval)
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rpipe = malloc( sizeof (*rpipe), M_TEMP, M_WAITOK);
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pipeinit(rpipe);
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rpipe->pipe_state |= PIPE_DIRECTOK;
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wpipe = malloc( sizeof (*wpipe), M_TEMP, M_WAITOK);
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pipeinit(wpipe);
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wpipe->pipe_state |= PIPE_DIRECTOK;
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error = falloc(p, &rf, &fd);
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if (error)
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@ -140,17 +185,13 @@ free1:
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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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pipespace(cpipe)
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struct pipe *cpipe;
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{
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int npages, error;
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npages = round_page(PIPESIZE)/PAGE_SIZE;
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npages = round_page(cpipe->pipe_buffer.size)/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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@ -163,16 +204,29 @@ pipeinit(cpipe)
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* The map entry is, by default, pageable.
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*/
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error = 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_offset_t *) &cpipe->pipe_buffer.buffer,
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cpipe->pipe_buffer.size, 1,
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VM_PROT_ALL, VM_PROT_ALL, 0);
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if (error != KERN_SUCCESS)
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panic("pipeinit: cannot allocate pipe -- out of kvm -- code = %d", error);
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amountpipekva += cpipe->pipe_buffer.size;
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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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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_buffer.size = PIPE_SIZE;
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/* Buffer kva gets dynamically allocated */
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cpipe->pipe_buffer.buffer = NULL;
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cpipe->pipe_state = 0;
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cpipe->pipe_peer = NULL;
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@ -181,6 +235,14 @@ pipeinit(cpipe)
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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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* pipe data structure initializations to support direct pipe I/O
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*/
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cpipe->pipe_map.cnt = 0;
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cpipe->pipe_map.kva = 0;
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cpipe->pipe_map.pos = 0;
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cpipe->pipe_map.npages = 0;
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}
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@ -188,13 +250,15 @@ pipeinit(cpipe)
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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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pipelock(cpipe, catch)
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struct pipe *cpipe;
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int catch;
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{
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int error;
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while (cpipe->pipe_state & PIPE_LOCK) {
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cpipe->pipe_state |= PIPE_LWANT;
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if (error = tsleep( &cpipe->pipe_state, PRIBIO|PCATCH, "pipelk", 0)) {
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if (error = tsleep( &cpipe->pipe_state,
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catch?(PRIBIO|PCATCH):PRIBIO, "pipelk", 0)) {
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return error;
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}
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}
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@ -217,6 +281,24 @@ pipeunlock(cpipe)
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return;
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}
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#if 0
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static void
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pipe_mark_pages_clean(cpipe)
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struct pipe *cpipe;
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{
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vm_size_t off;
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vm_page_t m;
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for(off = 0; off < cpipe->pipe_buffer.object->size; off += 1) {
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m = vm_page_lookup(cpipe->pipe_buffer.object, off);
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if ((m != NULL) && (m->busy == 0) && (m->flags & PG_BUSY) == 0) {
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m->dirty = 0;
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pmap_clear_modify(VM_PAGE_TO_PHYS(m));
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}
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}
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}
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#endif
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/* ARGSUSED */
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static int
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pipe_read(fp, uio, cred)
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@ -228,16 +310,20 @@ pipe_read(fp, uio, cred)
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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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int size;
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++rpipe->pipe_busy;
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while (uio->uio_resid) {
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/*
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* normal pipe buffer receive
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*/
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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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if ((error = pipelock(rpipe,1)) == 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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@ -252,6 +338,29 @@ pipe_read(fp, uio, cred)
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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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/*
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* Direct copy, bypassing a kernel buffer.
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*/
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} else if ((size = rpipe->pipe_map.cnt) &&
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(rpipe->pipe_state & PIPE_DIRECTW)) {
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caddr_t va;
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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,1)) == 0) {
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va = (caddr_t) rpipe->pipe_map.kva + rpipe->pipe_map.pos;
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error = uiomove(va, 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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nread += size;
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rpipe->pipe_atime = time;
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rpipe->pipe_map.pos += size;
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rpipe->pipe_map.cnt -= size;
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if (rpipe->pipe_map.cnt == 0) {
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rpipe->pipe_state &= ~PIPE_DIRECTW;
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wakeup(rpipe);
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}
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} else {
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/*
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* detect EOF condition
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@ -272,8 +381,6 @@ pipe_read(fp, uio, cred)
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error = EAGAIN;
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break;
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}
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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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@ -281,7 +388,7 @@ pipe_read(fp, uio, cred)
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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 ((error = pipelock(rpipe,1)) == 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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@ -307,8 +414,11 @@ pipe_read(fp, uio, cred)
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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) {
|
||||
if ((error == 0) && (error = pipelock(rpipe,1)) == 0) {
|
||||
if (rpipe->pipe_buffer.cnt == 0) {
|
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#if 0
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pipe_mark_pages_clean(rpipe);
|
||||
#endif
|
||||
rpipe->pipe_buffer.in = 0;
|
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rpipe->pipe_buffer.out = 0;
|
||||
}
|
||||
@ -330,35 +440,273 @@ pipe_read(fp, uio, cred)
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return error;
|
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}
|
||||
|
||||
/* ARGSUSED */
|
||||
/*
|
||||
* Map the sending processes' buffer into kernel space and wire it.
|
||||
* This is similar to a physical write operation.
|
||||
*/
|
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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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pipe_build_write_buffer(wpipe, uio)
|
||||
struct pipe *wpipe;
|
||||
struct uio *uio;
|
||||
struct ucred *cred;
|
||||
{
|
||||
struct pipe *rpipe = (struct pipe *) fp->f_data;
|
||||
struct pipe *wpipe = rpipe->pipe_peer;
|
||||
int size;
|
||||
int i;
|
||||
vm_offset_t addr, endaddr, paddr;
|
||||
|
||||
size = uio->uio_iov->iov_len;
|
||||
if (size > wpipe->pipe_buffer.size)
|
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size = wpipe->pipe_buffer.size;
|
||||
|
||||
endaddr = round_page(uio->uio_iov->iov_base + size);
|
||||
for(i = 0, addr = trunc_page(uio->uio_iov->iov_base);
|
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addr < endaddr;
|
||||
addr += PAGE_SIZE, i+=1) {
|
||||
|
||||
vm_page_t m;
|
||||
|
||||
vm_fault_quick( addr, VM_PROT_READ);
|
||||
paddr = pmap_kextract(addr);
|
||||
if (!paddr) {
|
||||
int j;
|
||||
for(j=0;j<i;j++)
|
||||
vm_page_unwire(wpipe->pipe_map.ms[j]);
|
||||
return EFAULT;
|
||||
}
|
||||
|
||||
m = PHYS_TO_VM_PAGE(paddr);
|
||||
vm_page_wire(m);
|
||||
wpipe->pipe_map.ms[i] = m;
|
||||
}
|
||||
|
||||
/*
|
||||
* set up the control block
|
||||
*/
|
||||
wpipe->pipe_map.npages = i;
|
||||
wpipe->pipe_map.pos = ((vm_offset_t) uio->uio_iov->iov_base) & PAGE_MASK;
|
||||
wpipe->pipe_map.cnt = size;
|
||||
|
||||
/*
|
||||
* and map the buffer
|
||||
*/
|
||||
if (wpipe->pipe_map.kva == 0) {
|
||||
wpipe->pipe_map.kva = kmem_alloc_pageable(kernel_map,
|
||||
wpipe->pipe_buffer.size);
|
||||
amountpipekva += wpipe->pipe_buffer.size;
|
||||
}
|
||||
pmap_qenter(wpipe->pipe_map.kva, wpipe->pipe_map.ms,
|
||||
wpipe->pipe_map.npages);
|
||||
|
||||
/*
|
||||
* and update the uio data
|
||||
*/
|
||||
|
||||
uio->uio_iov->iov_len -= size;
|
||||
uio->uio_iov->iov_base += size;
|
||||
if (uio->uio_iov->iov_len == 0)
|
||||
uio->uio_iov++;
|
||||
uio->uio_resid -= size;
|
||||
uio->uio_offset += size;
|
||||
return 0;
|
||||
}
|
||||
|
||||
/*
|
||||
* unmap and unwire the process buffer
|
||||
*/
|
||||
static void
|
||||
pipe_destroy_write_buffer(wpipe)
|
||||
struct pipe *wpipe;
|
||||
{
|
||||
int i;
|
||||
pmap_qremove(wpipe->pipe_map.kva, wpipe->pipe_map.npages);
|
||||
|
||||
if (wpipe->pipe_map.kva) {
|
||||
if (amountpipekva > MAXPIPEKVA) {
|
||||
vm_offset_t kva = wpipe->pipe_map.kva;
|
||||
wpipe->pipe_map.kva = 0;
|
||||
kmem_free(kernel_map, kva,
|
||||
wpipe->pipe_buffer.size);
|
||||
amountpipekva -= wpipe->pipe_buffer.size;
|
||||
}
|
||||
}
|
||||
for (i=0;i<wpipe->pipe_map.npages;i++)
|
||||
vm_page_unwire(wpipe->pipe_map.ms[i]);
|
||||
}
|
||||
|
||||
/*
|
||||
* In the case of a signal, the writing process might go away. This
|
||||
* code copies the data into the circular buffer so that the source
|
||||
* pages can be freed without loss of data.
|
||||
*/
|
||||
static void
|
||||
pipe_clone_write_buffer(wpipe)
|
||||
struct pipe *wpipe;
|
||||
{
|
||||
int size;
|
||||
int pos;
|
||||
|
||||
size = wpipe->pipe_map.cnt;
|
||||
pos = wpipe->pipe_map.pos;
|
||||
bcopy((caddr_t) wpipe->pipe_map.kva+pos,
|
||||
(caddr_t) wpipe->pipe_buffer.buffer,
|
||||
size);
|
||||
|
||||
wpipe->pipe_buffer.in = size;
|
||||
wpipe->pipe_buffer.out = 0;
|
||||
wpipe->pipe_buffer.cnt = size;
|
||||
wpipe->pipe_state &= ~PIPE_DIRECTW;
|
||||
|
||||
pipe_destroy_write_buffer(wpipe);
|
||||
}
|
||||
|
||||
/*
|
||||
* This implements the pipe buffer write mechanism. Note that only
|
||||
* a direct write OR a normal pipe write can be pending at any given time.
|
||||
* If there are any characters in the pipe buffer, the direct write will
|
||||
* be deferred until the receiving process grabs all of the bytes from
|
||||
* the pipe buffer. Then the direct mapping write is set-up.
|
||||
*/
|
||||
static int
|
||||
pipe_direct_write(wpipe, uio)
|
||||
struct pipe *wpipe;
|
||||
struct uio *uio;
|
||||
{
|
||||
int error;
|
||||
while (wpipe->pipe_state & PIPE_DIRECTW) {
|
||||
error = tsleep(wpipe,
|
||||
PRIBIO|PCATCH, "pipdww", 0);
|
||||
if (error || (wpipe->pipe_state & PIPE_EOF))
|
||||
goto error1;
|
||||
}
|
||||
wpipe->pipe_map.cnt = 0; /* transfer not ready yet */
|
||||
wpipe->pipe_state |= PIPE_DIRECTW;
|
||||
while (wpipe->pipe_buffer.cnt > 0) {
|
||||
error = tsleep(wpipe,
|
||||
PRIBIO|PCATCH, "pipdwc", 0);
|
||||
if (error || (wpipe->pipe_state & PIPE_EOF)) {
|
||||
wpipe->pipe_state &= ~PIPE_DIRECTW;
|
||||
if (error == 0)
|
||||
error = EPIPE;
|
||||
goto error1;
|
||||
}
|
||||
}
|
||||
|
||||
error = pipe_build_write_buffer(wpipe, uio);
|
||||
if (error) {
|
||||
wpipe->pipe_state &= ~PIPE_DIRECTW;
|
||||
goto error1;
|
||||
}
|
||||
|
||||
if (wpipe->pipe_state & PIPE_WANTR) {
|
||||
wpipe->pipe_state &= ~PIPE_WANTR;
|
||||
wakeup(wpipe);
|
||||
}
|
||||
|
||||
error = 0;
|
||||
while (!error && (wpipe->pipe_state & PIPE_DIRECTW)) {
|
||||
if (wpipe->pipe_state & PIPE_EOF) {
|
||||
pipelock(wpipe, 0);
|
||||
pipe_destroy_write_buffer(wpipe);
|
||||
pipeunlock(wpipe);
|
||||
wakeup(wpipe);
|
||||
return EPIPE;
|
||||
}
|
||||
error = tsleep(wpipe, PRIBIO|PCATCH, "pipdwt", 0);
|
||||
}
|
||||
|
||||
pipelock(wpipe,0);
|
||||
if (wpipe->pipe_state & PIPE_DIRECTW) {
|
||||
/*
|
||||
* this bit of trickery substitutes a kernel buffer for
|
||||
* the process that might be going away.
|
||||
*/
|
||||
pipe_clone_write_buffer(wpipe);
|
||||
} else {
|
||||
pipe_destroy_write_buffer(wpipe);
|
||||
}
|
||||
pipeunlock(wpipe);
|
||||
return error;
|
||||
|
||||
error1:
|
||||
wakeup(wpipe);
|
||||
return error;
|
||||
}
|
||||
|
||||
static __inline int
|
||||
pipewrite(wpipe, uio, nbio)
|
||||
struct pipe *wpipe;
|
||||
struct uio *uio;
|
||||
int nbio;
|
||||
{
|
||||
int error = 0;
|
||||
|
||||
/*
|
||||
* detect loss of pipe read side, issue SIGPIPE if lost.
|
||||
*/
|
||||
if (wpipe == NULL || (wpipe->pipe_state & PIPE_EOF)) {
|
||||
psignal(curproc, SIGPIPE);
|
||||
return EPIPE;
|
||||
}
|
||||
|
||||
if( wpipe->pipe_buffer.buffer == NULL) {
|
||||
if ((error = pipelock(wpipe,1)) == 0) {
|
||||
pipespace(wpipe);
|
||||
pipeunlock(wpipe);
|
||||
} else {
|
||||
return error;
|
||||
}
|
||||
}
|
||||
|
||||
++wpipe->pipe_busy;
|
||||
while (uio->uio_resid) {
|
||||
int space = wpipe->pipe_buffer.size - wpipe->pipe_buffer.cnt;
|
||||
if (space > 0) {
|
||||
int space;
|
||||
/*
|
||||
* If the transfer is large, we can gain performance if
|
||||
* we do process-to-process copies directly.
|
||||
*/
|
||||
if ((amountpipekva < LIMITPIPEKVA) &&
|
||||
(uio->uio_iov->iov_len >= PIPE_MINDIRECT)) {
|
||||
error = pipe_direct_write( wpipe, uio);
|
||||
if (error) {
|
||||
break;
|
||||
}
|
||||
continue;
|
||||
}
|
||||
|
||||
/*
|
||||
* Pipe buffered writes cannot be coincidental with
|
||||
* direct writes. We wait until the currently executing
|
||||
* direct write is completed before we start filling the
|
||||
* pipe buffer.
|
||||
*/
|
||||
retrywrite:
|
||||
while (wpipe->pipe_state & PIPE_DIRECTW) {
|
||||
error = tsleep(wpipe,
|
||||
PRIBIO|PCATCH, "pipbww", 0);
|
||||
if (error)
|
||||
break;
|
||||
}
|
||||
|
||||
space = wpipe->pipe_buffer.size - wpipe->pipe_buffer.cnt;
|
||||
|
||||
/*
|
||||
* We must afford contiguous writes on buffers of size
|
||||
* PIPE_BUF or less.
|
||||
*/
|
||||
if ((space > 0) &&
|
||||
((uio->uio_resid > PIPE_BUF) || (uio->uio_resid <= space))) {
|
||||
int size = wpipe->pipe_buffer.size - wpipe->pipe_buffer.in;
|
||||
if (size > space)
|
||||
size = space;
|
||||
if (size > uio->uio_resid)
|
||||
size = uio->uio_resid;
|
||||
if ((error = pipelock(wpipe)) == 0) {
|
||||
if ((error = pipelock(wpipe,1)) == 0) {
|
||||
/*
|
||||
* It is possible for a direct write to
|
||||
* slip in on us... handle it here...
|
||||
*/
|
||||
if (wpipe->pipe_state & PIPE_DIRECTW) {
|
||||
pipeunlock(wpipe);
|
||||
goto retrywrite;
|
||||
}
|
||||
error = uiomove( &wpipe->pipe_buffer.buffer[wpipe->pipe_buffer.in],
|
||||
size, uio);
|
||||
pipeunlock(wpipe);
|
||||
@ -383,9 +731,11 @@ pipe_write(fp, uio, cred)
|
||||
/*
|
||||
* don't block on non-blocking I/O
|
||||
*/
|
||||
if (wpipe->pipe_state & PIPE_NBIO) {
|
||||
if (nbio) {
|
||||
error = EAGAIN;
|
||||
break;
|
||||
}
|
||||
|
||||
wpipe->pipe_state |= PIPE_WANTW;
|
||||
if (error = tsleep(wpipe, (PRIBIO+1)|PCATCH, "pipewr", 0)) {
|
||||
break;
|
||||
@ -395,13 +745,12 @@ pipe_write(fp, uio, cred)
|
||||
* to ourselves.
|
||||
*/
|
||||
if (wpipe->pipe_state & PIPE_EOF) {
|
||||
psignal(curproc, SIGPIPE);
|
||||
error = EPIPE;
|
||||
break;
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
--wpipe->pipe_busy;
|
||||
if ((wpipe->pipe_busy == 0) &&
|
||||
(wpipe->pipe_state & PIPE_WANT)) {
|
||||
wpipe->pipe_state &= ~(PIPE_WANT|PIPE_WANTR);
|
||||
@ -416,13 +765,32 @@ pipe_write(fp, uio, cred)
|
||||
wakeup(wpipe);
|
||||
}
|
||||
}
|
||||
if ((wpipe->pipe_buffer.cnt == 0) &&
|
||||
(uio->uio_resid == 0) &&
|
||||
(error == EPIPE))
|
||||
error = 0;
|
||||
|
||||
if (wpipe->pipe_state & PIPE_SEL) {
|
||||
wpipe->pipe_state &= ~PIPE_SEL;
|
||||
selwakeup(&wpipe->pipe_sel);
|
||||
}
|
||||
|
||||
--wpipe->pipe_busy;
|
||||
return error;
|
||||
}
|
||||
|
||||
/* ARGSUSED */
|
||||
static int
|
||||
pipe_write(fp, uio, cred)
|
||||
struct file *fp;
|
||||
struct uio *uio;
|
||||
struct ucred *cred;
|
||||
{
|
||||
struct pipe *rpipe = (struct pipe *) fp->f_data;
|
||||
struct pipe *wpipe = rpipe->pipe_peer;
|
||||
return pipewrite(wpipe, uio, (rpipe->pipe_state & PIPE_NBIO)?1:0);
|
||||
}
|
||||
|
||||
/*
|
||||
* we implement a very minimal set of ioctls for compatibility with sockets.
|
||||
*/
|
||||
@ -482,7 +850,8 @@ pipe_select(fp, which, p)
|
||||
switch (which) {
|
||||
|
||||
case FREAD:
|
||||
if (rpipe->pipe_buffer.cnt > 0) {
|
||||
if (rpipe->pipe_buffer.cnt > 0 ||
|
||||
(rpipe->pipe_state & PIPE_EOF)) {
|
||||
splx(s);
|
||||
return (1);
|
||||
}
|
||||
@ -491,11 +860,9 @@ pipe_select(fp, which, p)
|
||||
break;
|
||||
|
||||
case FWRITE:
|
||||
if (wpipe == 0) {
|
||||
splx(s);
|
||||
return (1);
|
||||
}
|
||||
if (wpipe->pipe_buffer.cnt < wpipe->pipe_buffer.size) {
|
||||
if ((wpipe == NULL) ||
|
||||
(wpipe->pipe_state & PIPE_EOF) ||
|
||||
((wpipe->pipe_buffer.size - wpipe->pipe_buffer.cnt) >= PIPE_BUF)) {
|
||||
splx(s);
|
||||
return (1);
|
||||
}
|
||||
@ -504,6 +871,13 @@ pipe_select(fp, which, p)
|
||||
break;
|
||||
|
||||
case 0:
|
||||
if ((rpipe->pipe_state & PIPE_EOF) ||
|
||||
(wpipe == NULL) ||
|
||||
(wpipe->pipe_state & PIPE_EOF)) {
|
||||
splx(s);
|
||||
return (1);
|
||||
}
|
||||
|
||||
selrecord(p, &rpipe->pipe_sel);
|
||||
rpipe->pipe_state |= PIPE_SEL;
|
||||
break;
|
||||
@ -519,7 +893,7 @@ pipe_stat(pipe, ub)
|
||||
{
|
||||
bzero((caddr_t)ub, sizeof (*ub));
|
||||
ub->st_mode = S_IFSOCK;
|
||||
ub->st_blksize = pipe->pipe_buffer.size / 2;
|
||||
ub->st_blksize = pipe->pipe_buffer.size;
|
||||
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);
|
||||
@ -548,7 +922,14 @@ static void
|
||||
pipeclose(cpipe)
|
||||
struct pipe *cpipe;
|
||||
{
|
||||
struct pipe *ppipe;
|
||||
if (cpipe) {
|
||||
|
||||
if (cpipe->pipe_state & PIPE_SEL) {
|
||||
cpipe->pipe_state &= ~PIPE_SEL;
|
||||
selwakeup(&cpipe->pipe_sel);
|
||||
}
|
||||
|
||||
/*
|
||||
* If the other side is blocked, wake it up saying that
|
||||
* we want to close it down.
|
||||
@ -562,17 +943,32 @@ pipeclose(cpipe)
|
||||
/*
|
||||
* Disconnect from peer
|
||||
*/
|
||||
if (cpipe->pipe_peer) {
|
||||
cpipe->pipe_peer->pipe_state |= PIPE_EOF;
|
||||
wakeup(cpipe->pipe_peer);
|
||||
cpipe->pipe_peer->pipe_peer = NULL;
|
||||
if (ppipe = cpipe->pipe_peer) {
|
||||
if (ppipe->pipe_state & PIPE_SEL) {
|
||||
ppipe->pipe_state &= ~PIPE_SEL;
|
||||
selwakeup(&ppipe->pipe_sel);
|
||||
}
|
||||
|
||||
ppipe->pipe_state |= PIPE_EOF;
|
||||
wakeup(ppipe);
|
||||
ppipe->pipe_peer = NULL;
|
||||
}
|
||||
|
||||
/*
|
||||
* free resources
|
||||
*/
|
||||
kmem_free(kernel_map, (vm_offset_t)cpipe->pipe_buffer.buffer,
|
||||
cpipe->pipe_buffer.size);
|
||||
if (cpipe->pipe_buffer.buffer) {
|
||||
amountpipekva -= cpipe->pipe_buffer.size;
|
||||
kmem_free(kernel_map,
|
||||
(vm_offset_t)cpipe->pipe_buffer.buffer,
|
||||
cpipe->pipe_buffer.size);
|
||||
}
|
||||
if (cpipe->pipe_map.kva) {
|
||||
amountpipekva -= cpipe->pipe_buffer.size;
|
||||
kmem_free(kernel_map,
|
||||
cpipe->pipe_map.kva,
|
||||
cpipe->pipe_buffer.size);
|
||||
}
|
||||
free(cpipe, M_TEMP);
|
||||
}
|
||||
}
|
||||
|
||||
@ -25,9 +25,25 @@
|
||||
|
||||
struct vm_object;
|
||||
|
||||
/*
|
||||
* Pipe buffer size, keep moderate in value, pipes take kva space.
|
||||
*/
|
||||
#ifndef PIPE_SIZE
|
||||
#define PIPE_SIZE (16384)
|
||||
#endif
|
||||
|
||||
/*
|
||||
* PIPE_MINDIRECT MUST be smaller than PIPE_SIZE and MUST be bigger
|
||||
* than PIPE_BUF
|
||||
*/
|
||||
#ifndef PIPE_MINDIRECT
|
||||
#define PIPE_MINDIRECT (8192)
|
||||
#endif
|
||||
|
||||
#define PIPENPAGES (PIPE_SIZE/PAGE_SIZE + 1)
|
||||
/*
|
||||
* pipe buffer information
|
||||
* Separate in, out, cnt is used to simplify calculations.
|
||||
* Seperate in, out, cnt is used to simplify calculations.
|
||||
*/
|
||||
struct pipebuf {
|
||||
u_int cnt; /* number of chars currently in buffer */
|
||||
@ -38,6 +54,17 @@ struct pipebuf {
|
||||
struct vm_object *object; /* VM object containing buffer */
|
||||
};
|
||||
|
||||
/*
|
||||
* information to support direct transfers between processes for pipes
|
||||
*/
|
||||
struct pipemapping {
|
||||
vm_offset_t kva; /* kernel virtual address */
|
||||
vm_size_t cnt; /* number of chars in buffer */
|
||||
vm_size_t pos; /* current position of transfer */
|
||||
int npages; /* number of pages */
|
||||
vm_page_t ms[PIPENPAGES]; /* pages in source process */
|
||||
};
|
||||
|
||||
/*
|
||||
* pipe_state bits
|
||||
*/
|
||||
@ -50,6 +77,13 @@ struct pipebuf {
|
||||
#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 */
|
||||
#define PIPE_DIRECTW 0x400 /* Pipe direct write active */
|
||||
#define PIPE_DIRECTOK 0x800 /* Direct mode ok */
|
||||
|
||||
/*
|
||||
* Buffered write is active when buffer.cnt
|
||||
* field is set.
|
||||
*/
|
||||
|
||||
/*
|
||||
* Per-pipe data structure
|
||||
@ -58,6 +92,7 @@ struct pipebuf {
|
||||
*/
|
||||
struct pipe {
|
||||
struct pipebuf pipe_buffer; /* data storage */
|
||||
struct pipemapping pipe_map; /* pipe mapping for dir I/O */
|
||||
struct selinfo pipe_sel; /* for compat with select */
|
||||
struct timeval pipe_atime; /* time of last access */
|
||||
struct timeval pipe_mtime; /* time of last modify */
|
||||
|
||||
Loading…
x
Reference in New Issue
Block a user