d/freebsd-skq
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Replace home-grown dup2() implementation with actual dup2() calls. This

Browse Source 
should slightly reduce the number of system calls in critical portions of
the shell, and select a more efficient path through the fdalloc code.

Reviewed by:	bde
This commit is contained in:
Dag-Erling Smørgrav 2004-01-21 12:50:01 +00:00
parent 0193eb5ee9
commit 7e1c72660f
5 changed files with 13 additions and 43 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

12
bin/sh/eval.c
View File

@ -479,16 +479,14 @@ evalpipe(union node *n)
if (forkshell(jp, lp->n, n->npipe.backgnd) == 0) {
INTON;
if (prevfd > 0) {
close(0);
copyfd(prevfd, 0);
dup2(prevfd, 0);
close(prevfd);
}
if (pip[1] >= 0) {
if (!(prevfd >= 0 && pip[0] == 0))
close(pip[0]);
if (pip[1] != 1) {
close(1);
copyfd(pip[1], 1);
dup2(pip[1], 1);
close(pip[1]);
}
}
@ -545,8 +543,7 @@ evalbackcmd(union node *n, struct backcmd *result)
FORCEINTON;
close(pip[0]);
if (pip[1] != 1) {
close(1);
copyfd(pip[1], 1);
dup2(pip[1], 1);
close(pip[1]);
}
evaltree(n, EV_EXIT);
@ -742,8 +739,7 @@ evalcommand(union node *cmd, int flags, struct backcmd *backcmd)
FORCEINTON;
close(pip[0]);
if (pip[1] != 1) {
close(1);
copyfd(pip[1], 1);
dup2(pip[1], 1);
close(pip[1]);
}
}

2
bin/sh/input.c
View File

@ -388,7 +388,7 @@ setinputfile(char *fname, int push)
if ((fd = open(fname, O_RDONLY)) < 0)
error("Can't open %s: %s", fname, strerror(errno));
if (fd < 10) {
fd2 = copyfd(fd, 10);
fd2 = fcntl(fd, F_DUPFD, 10);
close(fd);
if (fd2 < 0)
error("Out of file descriptors");

1
bin/sh/parser.c
View File

@ -48,7 +48,6 @@ __FBSDID("$FreeBSD$");
#include "parser.h"
#include "nodes.h"
#include "expand.h" /* defines rmescapes() */
#include "redir.h" /* defines copyfd() */
#include "syntax.h"
#include "options.h"
#include "input.h"

40
bin/sh/redir.c
View File

@ -182,8 +182,7 @@ openredirect(union node *redir, char memory[10])
error("cannot open %s: %s", fname, strerror(errno));
movefd:
if (f != fd) {
close(fd);
copyfd(f, fd);
dup2(f, fd);
close(f);
}
break;
@ -215,12 +214,11 @@ movefd:
if (redir->ndup.dupfd >= 0) { /* if not ">&-" */
if (memory[redir->ndup.dupfd])
memory[fd] = 1;
else {
close(fd);
copyfd(redir->ndup.dupfd, fd);
}
} else
else
dup2(redir->ndup.dupfd, fd);
} else {
close(fd);
}
break;
case NHERE:
case NXHERE:
@ -288,10 +286,11 @@ popredir(void)
if (rp->renamed[i] != EMPTY) {
if (i == 0)
fd0_redirected--;
close(i);
if (rp->renamed[i] >= 0) {
copyfd(rp->renamed[i], i);
dup2(rp->renamed[i], i);
close(rp->renamed[i]);
} else {
close(i);
}
}
}
@ -346,26 +345,3 @@ clearredir(void)
}
}
}
/*
* Copy a file descriptor to be >= to. Returns -1
* if the source file descriptor is closed, EMPTY if there are no unused
* file descriptors left.
*/
int
copyfd(int from, int to)
{
int newfd;
newfd = fcntl(from, F_DUPFD, to);
if (newfd < 0) {
if (errno == EMFILE)
return EMPTY;
else
error("%d: %s", from, strerror(errno));
}
return newfd;
}

1
bin/sh/redir.h
View File

@ -46,5 +46,4 @@ void redirect(union node *, int);
void popredir(void);
int fd0_redirected_p(void);
void clearredir(void);
int copyfd(int, int);