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Implement first instance of NOFORK applet - echo

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find: use NOFORK/NOEXEC; small -exec buglet also eliminated
vfork_daemon_rexec: honor PREFER_APPLETS
echo: small size improvements

find -exec echo {} \; with PREFER_APPLETS=y runs 4 times faster
This commit is contained in:
Denis Vlasenko 2007-04-09 13:04:50 +00:00
parent 2dfdd44d9d
commit 7e754f12d3
6 changed files with 77 additions and 50 deletions
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3
Config.in
View File

@ -244,7 +244,8 @@ config FEATURE_EXEC_PREFER_APPLETS
help
This is an experimental option which directs applets about to
call 'exec' to try and find an applicable busybox applet before
searching the executable path for a binary or symlink to execute.
searching the PATH. This may affect shell, find -exec, xargs and
similar programs.
config BUSYBOX_EXEC_PATH
string "Path to BusyBox executable"

73
coreutils/echo.c
View File

@ -20,87 +20,86 @@
* 1) In handling '\c' escape, the previous version only suppressed the
* trailing newline. SUSv3 specifies _no_ output after '\c'.
* 2) SUSv3 specifies that octal escapes are of the form \0{#{#{#}}}.
* The previous version version did not allow 4-digit octals.
* The previous version did not allow 4-digit octals.
*/
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include "busybox.h"
int bb_echo(char **argv)
{
#ifndef CONFIG_FEATURE_FANCY_ECHO
const char *arg;
#if !ENABLE_FEATURE_FANCY_ECHO
#define eflag '\\'
++argv;
#else
const char *p;
int nflag = 1;
int eflag = 0;
char nflag = 1;
char eflag = 0;
while (1) {
arg = *++argv;
if (!arg)
goto ret;
if (*arg != '-')
break;
while (*++argv && (**argv == '-')) {
/* If it appears that we are handling options, then make sure
* that all of the options specified are actually valid.
* Otherwise, the string should just be echoed.
*/
if (!*(p = *argv + 1)) { /* A single '-', so echo it. */
p = arg + 1;
if (!*p) /* A single '-', so echo it. */
goto just_echo;
}
do {
if (strrchr("neE", *p) == 0) {
if (!strrchr("neE", *p))
goto just_echo;
}
} while (*++p);
/* All of the options in this arg are valid, so handle them. */
p = *argv + 1;
p = arg + 1;
do {
if (*p == 'n') {
if (*p == 'n')
nflag = 0;
} else if (*p == 'e') {
if (*p == 'e')
eflag = '\\';
} else {
eflag = 0;
}
} while (*++p);
}
just_echo:
just_echo:
#endif
while (*argv) {
while (1) {
/* arg is already = *argv and isn't NULL */
int c;
while ((c = *(*argv)++)) {
while ((c = *arg++)) {
if (c == eflag) { /* Check for escape seq. */
if (**argv == 'c') {
if (*arg == 'c') {
/* '\c' means cancel newline and
* ignore all subsequent chars. */
return 0;
goto ret;
}
#ifndef CONFIG_FEATURE_FANCY_ECHO
#if !ENABLE_FEATURE_FANCY_ECHO
/* SUSv3 specifies that octal escapes must begin with '0'. */
if (((unsigned int)(**argv - '1')) >= 7)
if ( (((unsigned char)*arg) - '1') >= 7)
#endif
{
/* Since SUSv3 mandates a first digit of 0, 4-digit octals
* of the form \0### are accepted. */
if ((**argv == '0') && (((unsigned int)(argv[0][1] - '0')) < 8)) {
(*argv)++;
if (*arg == '0' && ((unsigned char)(arg[1]) - '0') < 8) {
arg++;
}
/* bb_process_escape_sequence can handle nul correctly */
c = bb_process_escape_sequence((const char **) argv);
c = bb_process_escape_sequence(&arg);
}
}
putchar(c);
}
if (*++argv) {
arg = *++argv;
if (!arg)
break;
putchar(' ');
}
}
#ifdef CONFIG_FEATURE_FANCY_ECHO
if (nflag) {
@ -109,14 +108,16 @@ just_echo:
#else
putchar('\n');
#endif
return 0;
ret:
return fflush(stdout);
}
/* This is a NOFORK applet. Be very careful! */
int echo_main(int argc, char** argv);
int echo_main(int argc, char** argv)
{
(void)bb_echo(argv);
fflush_stdout_and_exit(EXIT_SUCCESS);
return bb_echo(argv);
}
/*-

25
findutils/find.c
View File

@ -242,9 +242,30 @@ ACTF(exec)
for (i = 0; i < ap->exec_argc; i++)
argv[i] = subst(ap->exec_argv[i], ap->subst_count[i], fileName);
argv[i] = NULL; /* terminate the list */
rc = wait4pid(spawn(argv));
if (rc)
if (ENABLE_FEATURE_EXEC_PREFER_APPLETS) {
const struct BB_applet *a = find_applet_by_name(argv[0]);
if (a) {
if (a->nofork) {
rc = a->main(ap->exec_argc, argv);
goto f;
}
#ifndef BB_NOMMU
if (a->noexec) {
rc = fork();
if (rc) goto w;
current_applet = a;
run_current_applet_and_exit(ap->exec_argc, argv);
}
#endif
}
}
rc = spawn(argv);
w:
rc = wait4pid(rc);
if (rc < 0)
bb_perror_msg("%s", argv[0]);
f:
for (i = 0; i < ap->exec_argc; i++)
free(argv[i]);
return rc == 0; /* return 1 if success */

7
include/applets.h
View File

@ -28,24 +28,28 @@ s - suid type:
# define APPLET_NOUSAGE(name,main,l,s) int main##_main(int argc, char **argv);
# define APPLET_ODDNAME(name,main,l,s,name2) int main##_main(int argc, char **argv);
# define APPLET_NOEXEC(name,main,l,s,name2) int main##_main(int argc, char **argv);
# define APPLET_NOFORK(name,main,l,s,name2) int main##_main(int argc, char **argv);
#elif defined(MAKE_USAGE) && ENABLE_FEATURE_VERBOSE_USAGE
# define APPLET(name,l,s) name##_trivial_usage "\n\n" name##_full_usage "\0"
# define APPLET_NOUSAGE(name,main,l,s) "\b\0"
# define APPLET_ODDNAME(name,main,l,s,name2) name2##_trivial_usage "\n\n" name2##_full_usage "\0"
# define APPLET_NOEXEC(name,main,l,s,name2) name2##_trivial_usage "\n\n" name2##_full_usage "\0"
# define APPLET_NOFORK(name,main,l,s,name2) name2##_trivial_usage "\n\n" name2##_full_usage "\0"
#elif defined(MAKE_USAGE) && !ENABLE_FEATURE_VERBOSE_USAGE
# define APPLET(name,l,s) name##_trivial_usage "\0"
# define APPLET_NOUSAGE(name,main,l,s) "\b\0"
# define APPLET_ODDNAME(name,main,l,s,name2) name2##_trivial_usage "\0"
# define APPLET_NOEXEC(name,main,l,s,name2) name2##_trivial_usage "\0"
# define APPLET_NOFORK(name,main,l,s,name2) name2##_trivial_usage "\0"
#elif defined(MAKE_LINKS)
# define APPLET(name,l,c) LINK l name
# define APPLET_NOUSAGE(name,main,l,s) LINK l name
# define APPLET_ODDNAME(name,main,l,s,name2) LINK l name
# define APPLET_NOEXEC(name,main,l,s,name2) LINK l name
# define APPLET_NOFORK(name,main,l,s,name2) LINK l name
#else
const struct BB_applet applets[] = { /* name,main,location,need_suid */
@ -53,6 +57,7 @@ s - suid type:
# define APPLET_NOUSAGE(name,main,l,s) {#name,main##_main,l,s},
# define APPLET_ODDNAME(name,main,l,s,name2) {#name,main##_main,l,s},
# define APPLET_NOEXEC(name,main,l,s,name2) {#name,main##_main,l,s,1},
# define APPLET_NOFORK(name,main,l,s,name2) {#name,main##_main,l,s,1,1},
#endif
#if ENABLE_INSTALL_NO_USR
@ -118,7 +123,7 @@ USE_DUMPKMAP(APPLET(dumpkmap, _BB_DIR_BIN, _BB_SUID_NEVER))
USE_APP_DUMPLEASES(APPLET(dumpleases, _BB_DIR_USR_BIN, _BB_SUID_NEVER))
//USE_E2FSCK(APPLET(e2fsck, _BB_DIR_SBIN, _BB_SUID_NEVER))
//USE_E2LABEL(APPLET_NOUSAGE(e2label, tune2fs, _BB_DIR_SBIN, _BB_SUID_NEVER))
USE_ECHO(APPLET_NOEXEC(echo, echo, _BB_DIR_BIN, _BB_SUID_NEVER, echo))
USE_ECHO(APPLET_NOFORK(echo, echo, _BB_DIR_BIN, _BB_SUID_NEVER, echo))
USE_ED(APPLET(ed, _BB_DIR_BIN, _BB_SUID_NEVER))
USE_FEATURE_GREP_EGREP_ALIAS(APPLET_NOUSAGE(egrep, grep, _BB_DIR_BIN, _BB_SUID_NEVER))
USE_EJECT(APPLET(eject, _BB_DIR_USR_BIN, _BB_SUID_NEVER))

9
libbb/process_escape_sequence.c
View File

@ -8,9 +8,6 @@
* Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
*/
#include <stdio.h>
#include <limits.h>
#include <ctype.h>
#include "libbb.h"
#define WANT_HEX_ESCAPES 1
@ -46,10 +43,10 @@ char bb_process_escape_sequence(const char **ptr)
#endif
do {
d = (unsigned int)(*q - '0');
d = (unsigned char)(*q) - '0';
#ifdef WANT_HEX_ESCAPES
if (d >= 10) {
d = ((unsigned int)(_tolower(*q) - 'a')) + 10;
d = (unsigned char)(_tolower(*q)) - 'a' + 10;
}
#endif
@ -80,7 +77,7 @@ char bb_process_escape_sequence(const char **ptr)
break;
}
} while (*++p);
n = *(p+(sizeof(charmap)/2));
n = *(p + (sizeof(charmap)/2));
}
*ptr = q;

8
libbb/vfork_daemon_rexec.c
View File

@ -26,14 +26,16 @@ pid_t spawn(char **argv)
volatile int failed;
pid_t pid;
// Be nice to nommu machines.
// Ain't it a good place to fflush(NULL)?
/* Be nice to nommu machines. */
failed = 0;
pid = vfork();
if (pid < 0) /* error */
return pid;
if (!pid) { /* child */
/* Don't use BB_EXECVP tricks here! */
execvp(argv[0], argv);
/* This macro is ok - it doesn't do NOEXEC/NOFORK tricks */
BB_EXECVP(argv[0], argv);
/* We are (maybe) sharing a stack with blocked parent,
* let parent know we failed and then exit to unblock parent