From 638621aff981fc5e9e5824d04c67ef2a7dfa4744 Mon Sep 17 00:00:00 2001 From: Ulrich Drepper Date: Fri, 14 Dec 2001 22:17:03 +0000 Subject: [PATCH] Update. * sysdeps/generic/strstr.c (strstr): Update. New optimized version. --- ChangeLog | 2 + linuxthreads/ChangeLog | 6 ++ linuxthreads/linuxthreads.texi | 11 ++-- linuxthreads/man/pthread_atfork.man | 13 ++-- sysdeps/generic/strstr.c | 121 +++++++++++++++++------------------- 5 files changed, 74 insertions(+), 79 deletions(-) diff --git a/ChangeLog b/ChangeLog index 494741f..e4a4d65 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,5 +1,7 @@ 2001-12-14 Ulrich Drepper + * sysdeps/generic/strstr.c (strstr): Update. New optimized version. + * crypt/md5.h: Define md5_uintptr. 2001-12-13 Ulrich Drepper diff --git a/linuxthreads/ChangeLog b/linuxthreads/ChangeLog index a926600..2b55b8f 100644 --- a/linuxthreads/ChangeLog +++ b/linuxthreads/ChangeLog @@ -1,3 +1,9 @@ +2001-12-14 Ulrich Drepper + + * man/pthread_atfork.man: Adjust description of mutex handling + after fork for current implementation. + * linuxthreads.texi: Likewise [PR libc/2519]. + 2001-12-13 Andreas Schwab * specific.c (pthread_key_delete): Don't contact the thread diff --git a/linuxthreads/linuxthreads.texi b/linuxthreads/linuxthreads.texi index 9513a67..b4d83c9 100644 --- a/linuxthreads/linuxthreads.texi +++ b/linuxthreads/linuxthreads.texi @@ -1395,12 +1395,10 @@ pocess image. To understand the purpose of @code{pthread_atfork}, recall that @code{fork} duplicates the whole memory space, including mutexes in their current locking state, but only the calling thread: other threads -are not running in the child process. Thus, if a mutex is locked by a -thread other than the thread calling @code{fork}, that mutex will remain -locked forever in the child process, possibly blocking the execution of -the child process. Or if some shared data, such as a linked list, was in the -middle of being updated by a thread in the parent process, the child -will get a copy of the incompletely updated data which it cannot use. +are not running in the child process. The mutexes are not usable after +the @code{fork} and must be initialized with @code{pthread_mutex_init} +in the child process. This is a limitation of the current +implementation and might or might not be present in future versions. To avoid this, install handlers with @code{pthread_atfork} as follows: have the @var{prepare} handler lock the mutexes (in locking order), and the @@ -1627,4 +1625,3 @@ of a mapping of user threads to kernel threads. It exists for source compatibility. However, it will return the value that was set by the last call to @code{pthread_setconcurrency}. @end deftypefun - diff --git a/linuxthreads/man/pthread_atfork.man b/linuxthreads/man/pthread_atfork.man index 4d06a56..b682bed 100644 --- a/linuxthreads/man/pthread_atfork.man +++ b/linuxthreads/man/pthread_atfork.man @@ -30,15 +30,10 @@ while the |parent| and |child| handlers are called in FIFO order To understand the purpose of !pthread_atfork!, recall that !fork!(2) duplicates the whole memory space, including mutexes in their current locking state, but only the calling thread: other threads are not -running in the child process. Thus, if a mutex is locked by a thread -other than the thread calling !fork!, that mutex will remain locked -forever in the child process, possibly blocking the execution of the -child process. To avoid this, install handlers with !pthread_atfork! -as follows: the |prepare| handler locks the global mutexes (in locking -order), and the |parent| and |child| handlers unlock them (in -reverse order). Alternatively, |prepare| and |parent| can be set to -!NULL! and |child| to a function that calls !pthread_mutex_init! on -the global mutexes. +running in the child process. The mutexes are not usable after the +!fork! and must be initialized with |pthread_mutex_init| in the child +process. This is a limitation of the current implementation and might +or might not be present in future versions. .SH "RETURN VALUE" diff --git a/sysdeps/generic/strstr.c b/sysdeps/generic/strstr.c index 1409fbd..ff295e0 100644 --- a/sysdeps/generic/strstr.c +++ b/sysdeps/generic/strstr.c @@ -1,5 +1,5 @@ /* Return the offset of one string within another. - Copyright (C) 1994, 1996, 1997, 2000 Free Software Foundation, Inc. + Copyright (C) 1994, 1996, 1997, 2000, 2001 Free Software Foundation, Inc. This file is part of the GNU C Library. The GNU C Library is free software; you can redistribute it and/or @@ -43,85 +43,80 @@ strstr (phaystack, pneedle) const char *phaystack; const char *pneedle; { - register const unsigned char *haystack, *needle; - register chartype b, c; + const unsigned char *haystack, *needle; + chartype b; + const unsigned char *rneedle; haystack = (const unsigned char *) phaystack; - needle = (const unsigned char *) pneedle; - b = *needle; - if (b != '\0') + if (b = *(needle = (const unsigned char *) pneedle)) { - haystack--; /* possible ANSI violation */ - do - { - c = *++haystack; - if (c == '\0') + chartype c; + haystack--; /* possible ANSI violation */ + + { + chartype a; + do + if (!(a = *++haystack)) goto ret0; - } - while (c != b); + while (a != b); + } - c = *++needle; - if (c == '\0') + if (!(c = *++needle)) goto foundneedle; ++needle; goto jin; for (;;) - { - register chartype a; - register const unsigned char *rhaystack, *rneedle; - - do - { - a = *++haystack; - if (a == '\0') - goto ret0; - if (a == b) - break; + { + { + chartype a; + if (0) + jin:{ + if ((a = *++haystack) == c) + goto crest; + } + else a = *++haystack; - if (a == '\0') - goto ret0; -shloop: - ; - } - while (a != b); - -jin: a = *++haystack; - if (a == '\0') - goto ret0; - - if (a != c) - goto shloop; - - rhaystack = haystack-- + 1; - rneedle = needle; - a = *rneedle; - - if (*rhaystack == a) do { - if (a == '\0') - goto foundneedle; - ++rhaystack; - a = *++needle; - if (*rhaystack != a) - break; - if (a == '\0') - goto foundneedle; - ++rhaystack; - a = *++needle; + for (; a != b; a = *++haystack) + { + if (!a) + goto ret0; + if ((a = *++haystack) == b) + break; + if (!a) + goto ret0; + } } - while (*rhaystack == a); - - needle = rneedle; /* took the register-poor approach */ - - if (a == '\0') - break; - } + while ((a = *++haystack) != c); + } + crest: + { + chartype a; + { + const unsigned char *rhaystack; + if (*(rhaystack = haystack-- + 1) == (a = *(rneedle = needle))) + do + { + if (!a) + goto foundneedle; + if (*++rhaystack != (a = *++needle)) + break; + if (!a) + goto foundneedle; + } + while (*++rhaystack == (a = *++needle)); + needle = rneedle; /* took the register-poor aproach */ + } + if (!a) + break; + } + } } foundneedle: - return (char*) haystack; + return (char *) haystack; ret0: return 0; } -- 2.7.4