diff options
author | smpatel <smpatel@FreeBSD.org> | 1996-08-20 07:18:10 +0000 |
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committer | smpatel <smpatel@FreeBSD.org> | 1996-08-20 07:18:10 +0000 |
commit | c61e4bcfdb1e5ae975e1d75cbeb8a7ed1ceebe97 (patch) | |
tree | ab6497bc38f907dc6bb88c6b38fd4b7e32a584ee /sys/kern/sys_generic.c | |
parent | 076318a498c311c3ddbad40c9ce240e63ae19657 (diff) | |
download | FreeBSD-src-c61e4bcfdb1e5ae975e1d75cbeb8a7ed1ceebe97.zip FreeBSD-src-c61e4bcfdb1e5ae975e1d75cbeb8a7ed1ceebe97.tar.gz |
Remove the kernel FD_SETSIZE limit for select().
Make select()'s first argument 'int' not 'u_int'.
Reviewed by: bde
Diffstat (limited to 'sys/kern/sys_generic.c')
-rw-r--r-- | sys/kern/sys_generic.c | 58 |
1 files changed, 43 insertions, 15 deletions
diff --git a/sys/kern/sys_generic.c b/sys/kern/sys_generic.c index acf407b..27b9910 100644 --- a/sys/kern/sys_generic.c +++ b/sys/kern/sys_generic.c @@ -36,7 +36,7 @@ * SUCH DAMAGE. * * @(#)sys_generic.c 8.5 (Berkeley) 1/21/94 - * $Id: sys_generic.c,v 1.17 1995/12/14 08:31:48 phk Exp $ + * $Id: sys_generic.c,v 1.18 1996/01/03 21:42:17 wollman Exp $ */ #include "opt_ktrace.h" @@ -61,7 +61,7 @@ #endif #include <vm/vm.h> -static int selscan __P((struct proc *, fd_set *, fd_set *, int, int *)); +static int selscan __P((struct proc *, fd_mask **, fd_mask **, int, int *)); /* * Read system call. @@ -516,7 +516,7 @@ int selwait; */ #ifndef _SYS_SYSPROTO_H_ struct select_args { - u_int nd; + int nd; fd_set *in, *ou, *ex; struct timeval *tv; }; @@ -527,22 +527,49 @@ select(p, uap, retval) register struct select_args *uap; int *retval; { - fd_set ibits[3], obits[3]; + fd_mask *ibits[3], *obits[3]; struct timeval atv; - int s, ncoll, error = 0, timo; + int s, ncoll, error = 0, timo, i; u_int ni; - bzero((caddr_t)ibits, sizeof(ibits)); - bzero((caddr_t)obits, sizeof(obits)); - if (uap->nd > FD_SETSIZE) - return (EINVAL); + if (uap->nd < 0) + return EINVAL; + if (uap->nd > p->p_fd->fd_nfiles) - uap->nd = p->p_fd->fd_nfiles; /* forgiving; slightly wrong */ + uap->nd = p->p_fd->fd_nfiles; /* forgiving; slightly wrong */ + + /* The amount of space we need to allocate */ + ni = howmany(roundup2 (uap->nd, FD_SETSIZE), NFDBITS) * + sizeof(fd_mask); + + if (ni > p->p_selbits_size) { + if (p->p_selbits_size) + free (p->p_selbits, M_SELECT); + + while (p->p_selbits_size < ni) + p->p_selbits_size += 32; /* Increase by 256 bits */ + + p->p_selbits = malloc(p->p_selbits_size * 6, M_SELECT, + M_WAITOK); + } + for (i = 0; i < 3; i++) { + ibits[i] = (fd_mask *)(p->p_selbits + i * p->p_selbits_size); + obits[i] = (fd_mask *)(p->p_selbits + (i + 3) * + p->p_selbits_size); + } + + /* + * This buffer is usually very small therefore it's probably faster + * to just zero it, rather than calculate what needs to be zeroed. + */ + bzero (p->p_selbits, p->p_selbits_size * 6); + + /* The amount of space we need to copyin/copyout */ ni = howmany(uap->nd, NFDBITS) * sizeof(fd_mask); #define getbits(name, x) \ if (uap->name && \ - (error = copyin((caddr_t)uap->name, (caddr_t)&ibits[x], ni))) \ + (error = copyin((caddr_t)uap->name, (caddr_t)ibits[x], ni))) \ goto done; getbits(in, 0); getbits(ou, 1); @@ -600,7 +627,7 @@ done: error = 0; #define putbits(name, x) \ if (uap->name && \ - (error2 = copyout((caddr_t)&obits[x], (caddr_t)uap->name, ni))) \ + (error2 = copyout((caddr_t)obits[x], (caddr_t)uap->name, ni))) \ error = error2; if (error == 0) { int error2; @@ -616,7 +643,7 @@ done: static int selscan(p, ibits, obits, nfd, retval) struct proc *p; - fd_set *ibits, *obits; + fd_mask **ibits, **obits; int nfd, *retval; { register struct filedesc *fdp = p->p_fd; @@ -628,14 +655,15 @@ selscan(p, ibits, obits, nfd, retval) for (msk = 0; msk < 3; msk++) { for (i = 0; i < nfd; i += NFDBITS) { - bits = ibits[msk].fds_bits[i/NFDBITS]; + bits = ibits[msk][i/NFDBITS]; while ((j = ffs(bits)) && (fd = i + --j) < nfd) { bits &= ~(1 << j); fp = fdp->fd_ofiles[fd]; if (fp == NULL) return (EBADF); if ((*fp->f_ops->fo_select)(fp, flag[msk], p)) { - FD_SET(fd, &obits[msk]); + obits[msk][(fd)/NFDBITS] |= + (1 << ((fd) % NFDBITS)); n++; } } |