/* $OpenBSD: sys_pipe.c,v 1.18 1999/10/27 07:38:19 niklas Exp $ */ /* * 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. Modifications may be freely made to this file if the above conditions * are met. */ #ifndef OLD_PIPE /* * This file contains a high-performance replacement for the socket-based * pipes scheme originally used in FreeBSD/4.4Lite. It does not support * all features of sockets, but does do everything that pipes normally * do. */ /* * This code has two modes of operation, a small write mode and a large * write mode. The small write mode acts like conventional pipes with * a kernel buffer. If the buffer is less than PIPE_MINDIRECT, then the * "normal" pipe buffering is done. If the buffer is between PIPE_MINDIRECT * and PIPE_SIZE in size, it is fully mapped and wired into the kernel, and * the receiving process can copy it directly from the pages in the sending * process. * * If the sending process receives a signal, it is possible that it will * go away, and certainly its address space can change, because control * is returned back to the user-mode side. In that case, the pipe code * arranges to copy the buffer supplied by the user process, to a pageable * kernel buffer, and the receiving process will grab the data from the * pageable kernel buffer. Since signals don't happen all that often, * the copy operation is normally eliminated. * * The constant PIPE_MINDIRECT is chosen to make sure that buffering will * happen for small transfers so that the system will not spend all of * its time context switching. PIPE_SIZE is constrained by the * amount of kernel virtual memory. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #if defined(__FreeBSD__) #include #else /* defined(__NetBSD__) || defined(__OpenBSD__) */ #include #include #endif #include #include #include #include #include #include #include #include #include #include #include /* * interfaces to the outside world */ int pipe_read __P((struct file *, struct uio *, struct ucred *)); int pipe_write __P((struct file *, struct uio *, struct ucred *)); int pipe_close __P((struct file *, struct proc *)); int pipe_select __P((struct file *, int which, struct proc *)); #if defined(__FreeBSD__) int pipe_ioctl __P((struct file *, int, caddr_t, struct proc *)); #else /* defined(__NetBSD__) || defined(__OpenBSD__) */ int pipe_ioctl __P((struct file *, u_long, caddr_t, struct proc *)); #endif static struct fileops pipeops = { pipe_read, pipe_write, pipe_ioctl, pipe_select, pipe_close }; /* * Default pipe buffer size(s), this can be kind-of large now because pipe * space is pageable. The pipe code will try to maintain locality of * reference for performance reasons, so small amounts of outstanding I/O * will not wipe the cache. */ #define MINPIPESIZE (PIPE_SIZE/3) #define MAXPIPESIZE (2*PIPE_SIZE/3) /* * Maximum amount of kva for pipes -- this is kind-of a soft limit, but * is there so that on large systems, we don't exhaust it. */ #define MAXPIPEKVA (8*1024*1024) /* * Limit for direct transfers, we cannot, of course limit * the amount of kva for pipes in general though. */ #define LIMITPIPEKVA (16*1024*1024) /* * Limit the number of "big" pipes */ #define LIMITBIGPIPES 32 int nbigpipe; static int amountpipekva; void pipeclose __P((struct pipe *)); void pipeinit __P((struct pipe *)); int pipe_stat __P((struct pipe *, struct stat *)); static __inline int pipelock __P((struct pipe *, int)); static __inline void pipeunlock __P((struct pipe *)); static __inline void pipeselwakeup __P((struct pipe *)); #ifndef PIPE_NODIRECT int pipe_build_write_buffer __P((struct pipe *, struct uio *)); void pipe_destroy_write_buffer __P((struct pipe *)); int pipe_direct_write __P((struct pipe *, struct uio *)); void pipe_clone_write_buffer __P((struct pipe *)); #endif void pipespace __P((struct pipe *)); /* * The pipe system call for the DTYPE_PIPE type of pipes */ /* ARGSUSED */ int #if defined(__FreeBSD__) pipe(p, uap, retval) #else /* (__NetBSD__) || (__OpenBSD__) */ sys_opipe(p, v, retval) #endif struct proc *p; void *v; #if defined(__FreeBSD__) int retval[]; #else /* (__NetBSD__) || (__OpenBSD__) */ register_t *retval; #endif { register struct filedesc *fdp = p->p_fd; struct file *rf, *wf; struct pipe *rpipe, *wpipe; int fd, error; rpipe = malloc( sizeof (*rpipe), M_TEMP, M_WAITOK); pipeinit(rpipe); rpipe->pipe_state |= PIPE_DIRECTOK; wpipe = malloc( sizeof (*wpipe), M_TEMP, M_WAITOK); pipeinit(wpipe); wpipe->pipe_state |= PIPE_DIRECTOK; error = falloc(p, &rf, &fd); if (error) goto free2; retval[0] = fd; rf->f_flag = FREAD | FWRITE; rf->f_type = DTYPE_PIPE; rf->f_ops = &pipeops; rf->f_data = (caddr_t)rpipe; error = falloc(p, &wf, &fd); if (error) goto free3; wf->f_flag = FREAD | FWRITE; wf->f_type = DTYPE_PIPE; wf->f_ops = &pipeops; wf->f_data = (caddr_t)wpipe; retval[1] = fd; rpipe->pipe_peer = wpipe; wpipe->pipe_peer = rpipe; return (0); free3: ffree(rf); fdremove(fdp, retval[0]); free2: (void)pipeclose(wpipe); (void)pipeclose(rpipe); return (error); } /* * Allocate kva for pipe circular buffer, the space is pageable */ void pipespace(cpipe) struct pipe *cpipe; { #if defined(UVM) cpipe->pipe_buffer.buffer = (caddr_t) uvm_km_valloc(kernel_map, cpipe->pipe_buffer.size); if (cpipe->pipe_buffer.buffer == NULL) panic("pipespace: out of kvm"); #else int npages, error; npages = round_page(cpipe->pipe_buffer.size)/PAGE_SIZE; /* * Create an object, I don't like the idea of paging to/from * kernel_object. * XXX -- minor change needed here for NetBSD/OpenBSD VM systems. */ #if defined(__FreeBSD__) cpipe->pipe_buffer.object = vm_object_allocate(OBJT_DEFAULT, npages); #else /* (__NetBSD__) || (__OpenBSD__) */ cpipe->pipe_buffer.object = vm_object_allocate(npages); #endif cpipe->pipe_buffer.buffer = (caddr_t) vm_map_min(kernel_map); /* * Insert the object into the kernel map, and allocate kva for it. * The map entry is, by default, pageable. * XXX -- minor change needed here for NetBSD/OpenBSD VM systems. */ #if defined(__FreeBSD__) error = vm_map_find(kernel_map, cpipe->pipe_buffer.object, 0, (vaddr_t *) &cpipe->pipe_buffer.buffer, cpipe->pipe_buffer.size, 1, VM_PROT_ALL, VM_PROT_ALL, 0); #else /* (__NetBSD__) || (__OpenBSD__) */ error = vm_map_find(kernel_map, cpipe->pipe_buffer.object, 0, (vaddr_t *) &cpipe->pipe_buffer.buffer, cpipe->pipe_buffer.size, 1); #endif if (error != KERN_SUCCESS) panic("pipeinit: cannot allocate pipe -- out of kvm -- code = %d", error); #endif amountpipekva += cpipe->pipe_buffer.size; } /* * initialize and allocate VM and memory for pipe */ void pipeinit(cpipe) struct pipe *cpipe; { int s; cpipe->pipe_buffer.in = 0; cpipe->pipe_buffer.out = 0; cpipe->pipe_buffer.cnt = 0; cpipe->pipe_buffer.size = PIPE_SIZE; /* Buffer kva gets dynamically allocated */ cpipe->pipe_buffer.buffer = NULL; /* cpipe->pipe_buffer.object = invalid */ cpipe->pipe_state = 0; cpipe->pipe_peer = NULL; cpipe->pipe_busy = 0; s = splhigh(); cpipe->pipe_ctime = time; cpipe->pipe_atime = time; cpipe->pipe_mtime = time; splx(s); bzero(&cpipe->pipe_sel, sizeof cpipe->pipe_sel); cpipe->pipe_pgid = NO_PID; #ifndef PIPE_NODIRECT /* * pipe data structure initializations to support direct pipe I/O */ cpipe->pipe_map.cnt = 0; cpipe->pipe_map.kva = 0; cpipe->pipe_map.pos = 0; cpipe->pipe_map.npages = 0; /* cpipe->pipe_map.ms[] = invalid */ #endif } /* * lock a pipe for I/O, blocking other access */ static __inline int pipelock(cpipe, catch) struct pipe *cpipe; int catch; { int error; while (cpipe->pipe_state & PIPE_LOCK) { cpipe->pipe_state |= PIPE_LWANT; error = tsleep(cpipe, catch ? PRIBIO|PCATCH : PRIBIO, "pipelk", 0); if (error) return error; } cpipe->pipe_state |= PIPE_LOCK; return 0; } /* * unlock a pipe I/O lock */ static __inline void pipeunlock(cpipe) struct pipe *cpipe; { cpipe->pipe_state &= ~PIPE_LOCK; if (cpipe->pipe_state & PIPE_LWANT) { cpipe->pipe_state &= ~PIPE_LWANT; wakeup(cpipe); } } static __inline void pipeselwakeup(cpipe) struct pipe *cpipe; { if (cpipe->pipe_state & PIPE_SEL) { cpipe->pipe_state &= ~PIPE_SEL; selwakeup(&cpipe->pipe_sel); } if ((cpipe->pipe_state & PIPE_ASYNC) && cpipe->pipe_pgid != NO_PID) gsignal(cpipe->pipe_pgid, SIGIO); } /* ARGSUSED */ int pipe_read(fp, uio, cred) struct file *fp; struct uio *uio; struct ucred *cred; { struct pipe *rpipe = (struct pipe *) fp->f_data; int error = 0; int nread = 0; int size; ++rpipe->pipe_busy; while (uio->uio_resid) { /* * normal pipe buffer receive */ if (rpipe->pipe_buffer.cnt > 0) { size = rpipe->pipe_buffer.size - rpipe->pipe_buffer.out; if (size > rpipe->pipe_buffer.cnt) size = rpipe->pipe_buffer.cnt; if (size > uio->uio_resid) size = uio->uio_resid; if ((error = pipelock(rpipe,1)) == 0) { error = uiomove( &rpipe->pipe_buffer.buffer[rpipe->pipe_buffer.out], size, uio); pipeunlock(rpipe); } if (error) { break; } rpipe->pipe_buffer.out += size; if (rpipe->pipe_buffer.out >= rpipe->pipe_buffer.size) rpipe->pipe_buffer.out = 0; rpipe->pipe_buffer.cnt -= size; nread += size; #ifndef PIPE_NODIRECT /* * Direct copy, bypassing a kernel buffer. */ } else if ((size = rpipe->pipe_map.cnt) && (rpipe->pipe_state & PIPE_DIRECTW)) { caddr_t va; if (size > uio->uio_resid) size = uio->uio_resid; if ((error = pipelock(rpipe,1)) == 0) { va = (caddr_t) rpipe->pipe_map.kva + rpipe->pipe_map.pos; error = uiomove(va, size, uio); pipeunlock(rpipe); } if (error) break; nread += size; rpipe->pipe_map.pos += size; rpipe->pipe_map.cnt -= size; if (rpipe->pipe_map.cnt == 0) { rpipe->pipe_state &= ~PIPE_DIRECTW; wakeup(rpipe); } #endif } else { /* * detect EOF condition */ if (rpipe->pipe_state & PIPE_EOF) { /* XXX error = ? */ break; } /* * If the "write-side" has been blocked, wake it up now. */ if (rpipe->pipe_state & PIPE_WANTW) { rpipe->pipe_state &= ~PIPE_WANTW; wakeup(rpipe); } if (nread > 0) break; if (fp->f_flag & FNONBLOCK) { error = EAGAIN; break; } /* * If there is no more to read in the pipe, reset * its pointers to the beginning. This improves * cache hit stats. */ if ((error = pipelock(rpipe,1)) == 0) { if (rpipe->pipe_buffer.cnt == 0) { rpipe->pipe_buffer.in = 0; rpipe->pipe_buffer.out = 0; } pipeunlock(rpipe); } else { break; } if (rpipe->pipe_state & PIPE_WANTW) { rpipe->pipe_state &= ~PIPE_WANTW; wakeup(rpipe); } rpipe->pipe_state |= PIPE_WANTR; error = tsleep(rpipe, PRIBIO|PCATCH, "piperd", 0); if (error) break; } } if (error == 0) { int s = splhigh(); rpipe->pipe_atime = time; splx(s); } --rpipe->pipe_busy; if ((rpipe->pipe_busy == 0) && (rpipe->pipe_state & PIPE_WANT)) { rpipe->pipe_state &= ~(PIPE_WANT|PIPE_WANTW); wakeup(rpipe); } else if (rpipe->pipe_buffer.cnt < MINPIPESIZE) { /* * If there is no more to read in the pipe, reset * its pointers to the beginning. This improves * cache hit stats. */ if (rpipe->pipe_buffer.cnt == 0) { if ((error == 0) && (error = pipelock(rpipe,1)) == 0) { rpipe->pipe_buffer.in = 0; rpipe->pipe_buffer.out = 0; pipeunlock(rpipe); } } /* * If the "write-side" has been blocked, wake it up now. */ if (rpipe->pipe_state & PIPE_WANTW) { rpipe->pipe_state &= ~PIPE_WANTW; wakeup(rpipe); } } if ((rpipe->pipe_buffer.size - rpipe->pipe_buffer.cnt) >= PIPE_BUF) pipeselwakeup(rpipe); return error; } #ifndef PIPE_NODIRECT /* * Map the sending processes' buffer into kernel space and wire it. * This is similar to a physical write operation. */ int pipe_build_write_buffer(wpipe, uio) struct pipe *wpipe; struct uio *uio; { int size; int i; vaddr_t addr, endaddr, paddr; size = uio->uio_iov->iov_len; if (size > wpipe->pipe_buffer.size) 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); addr < endaddr; addr += PAGE_SIZE, i+=1) { vm_page_t m; vm_fault_quick( (caddr_t) addr, VM_PROT_READ); paddr = pmap_kextract(addr); if (!paddr) { int j; for(j=0;jpipe_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 = ((vaddr_t) uio->uio_iov->iov_base) & PAGE_MASK; wpipe->pipe_map.cnt = size; /* * and map the buffer */ if (wpipe->pipe_map.kva == 0) { /* * We need to allocate space for an extra page because the * address range might (will) span pages at times. */ wpipe->pipe_map.kva = kmem_alloc_pageable(kernel_map, wpipe->pipe_buffer.size + PAGE_SIZE); amountpipekva += wpipe->pipe_buffer.size + PAGE_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 */ void pipe_destroy_write_buffer(wpipe) struct pipe *wpipe; { int i; if (wpipe->pipe_map.kva) { pmap_qremove(wpipe->pipe_map.kva, wpipe->pipe_map.npages); if (amountpipekva > MAXPIPEKVA) { vaddr_t kva = wpipe->pipe_map.kva; wpipe->pipe_map.kva = 0; kmem_free(kernel_map, kva, wpipe->pipe_buffer.size + PAGE_SIZE); amountpipekva -= wpipe->pipe_buffer.size + PAGE_SIZE; } } for (i=0;ipipe_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. */ 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. */ int pipe_direct_write(wpipe, uio) struct pipe *wpipe; struct uio *uio; { int error; retry: while (wpipe->pipe_state & PIPE_DIRECTW) { if ( wpipe->pipe_state & PIPE_WANTR) { wpipe->pipe_state &= ~PIPE_WANTR; wakeup(wpipe); } wpipe->pipe_state |= PIPE_WANTW; error = tsleep(wpipe, PRIBIO|PCATCH, "pipdww", 0); if (error) goto error1; if (wpipe->pipe_state & PIPE_EOF) { error = EPIPE; goto error1; } } wpipe->pipe_map.cnt = 0; /* transfer not ready yet */ if (wpipe->pipe_buffer.cnt > 0) { if ( wpipe->pipe_state & PIPE_WANTR) { wpipe->pipe_state &= ~PIPE_WANTR; wakeup(wpipe); } wpipe->pipe_state |= PIPE_WANTW; error = tsleep(wpipe, PRIBIO|PCATCH, "pipdwc", 0); if (error) goto error1; if (wpipe->pipe_state & PIPE_EOF) { error = EPIPE; goto error1; } goto retry; } wpipe->pipe_state |= PIPE_DIRECTW; error = pipe_build_write_buffer(wpipe, uio); if (error) { wpipe->pipe_state &= ~PIPE_DIRECTW; goto error1; } 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); pipeselwakeup(wpipe); error = EPIPE; goto error1; } if (wpipe->pipe_state & PIPE_WANTR) { wpipe->pipe_state &= ~PIPE_WANTR; wakeup(wpipe); } pipeselwakeup(wpipe); 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; } #endif int pipe_write(fp, uio, cred) struct file *fp; struct uio *uio; struct ucred *cred; { int error = 0; int orig_resid; struct pipe *wpipe, *rpipe; rpipe = (struct pipe *) fp->f_data; wpipe = rpipe->pipe_peer; /* * detect loss of pipe read side, issue SIGPIPE if lost. */ if ((wpipe == NULL) || (wpipe->pipe_state & PIPE_EOF)) { return EPIPE; } /* * If it is advantageous to resize the pipe buffer, do * so. */ if ((uio->uio_resid > PIPE_SIZE) && (nbigpipe < LIMITBIGPIPES) && (wpipe->pipe_state & PIPE_DIRECTW) == 0 && (wpipe->pipe_buffer.size <= PIPE_SIZE) && (wpipe->pipe_buffer.cnt == 0)) { if (wpipe->pipe_buffer.buffer) { amountpipekva -= wpipe->pipe_buffer.size; #if defined(UVM) uvm_km_free(kernel_map, (vaddr_t)wpipe->pipe_buffer.buffer, wpipe->pipe_buffer.size); #else kmem_free(kernel_map, (vaddr_t)wpipe->pipe_buffer.buffer, wpipe->pipe_buffer.size); #endif } #ifndef PIPE_NODIRECT if (wpipe->pipe_map.kva) { amountpipekva -= wpipe->pipe_buffer.size + PAGE_SIZE; kmem_free(kernel_map, wpipe->pipe_map.kva, wpipe->pipe_buffer.size + PAGE_SIZE); } #endif wpipe->pipe_buffer.in = 0; wpipe->pipe_buffer.out = 0; wpipe->pipe_buffer.cnt = 0; wpipe->pipe_buffer.size = BIG_PIPE_SIZE; wpipe->pipe_buffer.buffer = NULL; ++nbigpipe; #ifndef PIPE_NODIRECT wpipe->pipe_map.cnt = 0; wpipe->pipe_map.kva = 0; wpipe->pipe_map.pos = 0; wpipe->pipe_map.npages = 0; #endif } if (wpipe->pipe_buffer.buffer == NULL) { if ((error = pipelock(wpipe,1)) == 0) { pipespace(wpipe); pipeunlock(wpipe); } else { return error; } } ++wpipe->pipe_busy; orig_resid = uio->uio_resid; while (uio->uio_resid) { int space; #ifndef PIPE_NODIRECT /* * If the transfer is large, we can gain performance if * we do process-to-process copies directly. * If the write is non-blocking, we don't use the * direct write mechanism. */ if ((uio->uio_iov->iov_len >= PIPE_MINDIRECT) && (fp->f_flag & FNONBLOCK) == 0 && (wpipe->pipe_map.kva || (amountpipekva < LIMITPIPEKVA)) && (uio->uio_iov->iov_len >= PIPE_MINDIRECT)) { error = pipe_direct_write( wpipe, uio); if (error) { break; } continue; } #endif /* * 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) { if (wpipe->pipe_state & PIPE_WANTR) { wpipe->pipe_state &= ~PIPE_WANTR; wakeup(wpipe); } error = tsleep(wpipe, PRIBIO|PCATCH, "pipbww", 0); if (error) break; } space = wpipe->pipe_buffer.size - wpipe->pipe_buffer.cnt; /* Writes of size <= PIPE_BUF must be atomic. */ /* XXX perhaps they need to be contiguous to be atomic? */ if ((space < uio->uio_resid) && (orig_resid <= PIPE_BUF)) space = 0; if (space > 0 && (wpipe->pipe_buffer.cnt < PIPE_SIZE)) { /* * This set the maximum transfer as a segment of * the buffer. */ int size = wpipe->pipe_buffer.size - wpipe->pipe_buffer.in; /* * space is the size left in the buffer */ if (size > space) size = space; /* * now limit it to the size of the uio transfer */ if (size > uio->uio_resid) size = uio->uio_resid; 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); } if (error) break; wpipe->pipe_buffer.in += size; if (wpipe->pipe_buffer.in >= wpipe->pipe_buffer.size) wpipe->pipe_buffer.in = 0; wpipe->pipe_buffer.cnt += size; } else { /* * If the "read-side" has been blocked, wake it up now. */ if (wpipe->pipe_state & PIPE_WANTR) { wpipe->pipe_state &= ~PIPE_WANTR; wakeup(wpipe); } /* * don't block on non-blocking I/O */ if (fp->f_flag & FNONBLOCK) { error = EAGAIN; break; } /* * We have no more space and have something to offer, * wake up selects. */ pipeselwakeup(wpipe); wpipe->pipe_state |= PIPE_WANTW; error = tsleep(wpipe, (PRIBIO + 1)|PCATCH, "pipewr", 0); if (error) break; /* * If read side wants to go away, we just issue a * signal to ourselves. */ if (wpipe->pipe_state & PIPE_EOF) { error = EPIPE; break; } } } --wpipe->pipe_busy; if ((wpipe->pipe_busy == 0) && (wpipe->pipe_state & PIPE_WANT)) { wpipe->pipe_state &= ~(PIPE_WANT|PIPE_WANTR); wakeup(wpipe); } 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); } } /* * Don't return EPIPE if I/O was successful */ if ((wpipe->pipe_buffer.cnt == 0) && (uio->uio_resid == 0) && (error == EPIPE)) error = 0; if (error == 0) { int s = splhigh(); wpipe->pipe_mtime = time; splx(s); } /* * We have something to offer, * wake up select. */ if (wpipe->pipe_buffer.cnt) pipeselwakeup(wpipe); return error; } /* * we implement a very minimal set of ioctls for compatibility with sockets. */ int pipe_ioctl(fp, cmd, data, p) struct file *fp; #if defined(__FreeBSD__) int cmd; #else u_long cmd; #endif register caddr_t data; struct proc *p; { register struct pipe *mpipe = (struct pipe *)fp->f_data; switch (cmd) { case FIONBIO: return (0); case FIOASYNC: if (*(int *)data) { mpipe->pipe_state |= PIPE_ASYNC; } else { mpipe->pipe_state &= ~PIPE_ASYNC; } return (0); case FIONREAD: #ifndef PIPE_NODIRECT if (mpipe->pipe_state & PIPE_DIRECTW) *(int *)data = mpipe->pipe_map.cnt; else #endif *(int *)data = mpipe->pipe_buffer.cnt; return (0); case SIOCSPGRP: mpipe->pipe_pgid = *(int *)data; return (0); case SIOCGPGRP: *(int *)data = mpipe->pipe_pgid; return (0); } return (ENOTTY); } 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; wpipe = rpipe->pipe_peer; switch (which) { case FREAD: if ( (rpipe->pipe_state & PIPE_DIRECTW) || (rpipe->pipe_buffer.cnt > 0) || (rpipe->pipe_state & PIPE_EOF)) { return (1); } selrecord(p, &rpipe->pipe_sel); rpipe->pipe_state |= PIPE_SEL; break; case FWRITE: if ((wpipe == NULL) || (wpipe->pipe_state & PIPE_EOF) || (((wpipe->pipe_state & PIPE_DIRECTW) == 0) && (wpipe->pipe_buffer.size - wpipe->pipe_buffer.cnt) >= PIPE_BUF)) { return (1); } selrecord(p, &wpipe->pipe_sel); wpipe->pipe_state |= PIPE_SEL; break; case 0: if ((rpipe->pipe_state & PIPE_EOF) || (wpipe == NULL) || (wpipe->pipe_state & PIPE_EOF)) { return (1); } selrecord(p, &rpipe->pipe_sel); rpipe->pipe_state |= PIPE_SEL; break; } 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_IFIFO; 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); TIMEVAL_TO_TIMESPEC(&pipe->pipe_mtime, &ub->st_mtimespec); TIMEVAL_TO_TIMESPEC(&pipe->pipe_ctime, &ub->st_ctimespec); /* * Left as 0: st_dev, st_ino, st_nlink, st_uid, st_gid, st_rdev, * st_flags, st_gen. * XXX (st_dev, st_ino) should be unique. */ return 0; } /* ARGSUSED */ int pipe_close(fp, p) struct file *fp; struct proc *p; { struct pipe *cpipe = (struct pipe *)fp->f_data; pipeclose(cpipe); fp->f_data = NULL; return 0; } /* * shutdown the pipe */ void pipeclose(cpipe) struct pipe *cpipe; { struct pipe *ppipe; if (cpipe) { pipeselwakeup(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 ((ppipe = cpipe->pipe_peer) != NULL) { pipeselwakeup(ppipe); ppipe->pipe_state |= PIPE_EOF; wakeup(ppipe); ppipe->pipe_peer = NULL; } /* * free resources */ if (cpipe->pipe_buffer.buffer) { if (cpipe->pipe_buffer.size > PIPE_SIZE) --nbigpipe; amountpipekva -= cpipe->pipe_buffer.size; #if defined(UVM) uvm_km_free(kernel_map, (vaddr_t)cpipe->pipe_buffer.buffer, cpipe->pipe_buffer.size); #else kmem_free(kernel_map, (vaddr_t)cpipe->pipe_buffer.buffer, cpipe->pipe_buffer.size); #endif } #ifndef PIPE_NODIRECT if (cpipe->pipe_map.kva) { amountpipekva -= cpipe->pipe_buffer.size + PAGE_SIZE; kmem_free(kernel_map, cpipe->pipe_map.kva, cpipe->pipe_buffer.size + PAGE_SIZE); } #endif free(cpipe, M_TEMP); } } #endif