From 32389c925760f3dadf9091390e039075c99470c5 Mon Sep 17 00:00:00 2001 From: Adam Dickmeiss Date: Mon, 3 Jul 2006 09:50:51 +0000 Subject: [PATCH] Use confstr(_CS_GNU_LIBPTHREAD_VERSION ..) to determine whether fcntl locks is conforming to POSIX or not. In POSIX mode, locks are shared for all threads in a process. In the other (linuxthreads) mode , it isn't. --- configure.ac | 6 +-- util/.cvsignore | 2 +- util/flock.c | 112 ++++++++++++++++++++++++++++++++++--------------------- 3 files changed, 73 insertions(+), 47 deletions(-) diff --git a/configure.ac b/configure.ac index e0d6789..31aa332 100644 --- a/configure.ac +++ b/configure.ac @@ -1,5 +1,5 @@ dnl Zebra, Index Data ApS, 1995-2006 -dnl $Id: configure.ac,v 1.21 2006-06-29 14:10:33 adam Exp $ +dnl $Id: configure.ac,v 1.22 2006-07-03 09:50:51 adam Exp $ dnl AC_PREREQ(2.59) AC_INIT([idzebra],[2.0.0],[adam@indexdata.dk]) @@ -129,8 +129,8 @@ else AC_DEFINE(HAVE_TCL_H,0) fi dnl -dnl ------ mkstemp -AC_CHECK_FUNCS(mkstemp) +dnl ------ various functions +AC_CHECK_FUNCS(mkstemp confstr) dnl dnl ------ GNU Readline READLINE_SHARED_LIBADD="" diff --git a/util/.cvsignore b/util/.cvsignore index 1612649..17f54fa 100644 --- a/util/.cvsignore +++ b/util/.cvsignore @@ -11,4 +11,4 @@ idzebra-config my.LCK tstflock tstflock.out -tstflockscope +tstlockscope diff --git a/util/flock.c b/util/flock.c index 42dd067..009c971 100644 --- a/util/flock.c +++ b/util/flock.c @@ -1,4 +1,4 @@ -/* $Id: flock.c,v 1.13 2006-06-30 15:10:20 adam Exp $ +/* $Id: flock.c,v 1.14 2006-07-03 09:50:51 adam Exp $ Copyright (C) 1995-2006 Index Data ApS @@ -40,21 +40,15 @@ Free Software Foundation, 59 Temple Place - Suite 330, Boston, MA #include #include -/** whether lock file desciptors are shared within one process' threads */ -#define ZEBRA_FLOCK_SHARE_FD_IN_THREADS 1 - -/** whether we always lock on the file - even if rd/wr locks should do */ -#define ZEBRA_FLOCK_FILE_LOCK_ALWAYS 1 - -/** whether we should also use pthreads locking to do "extra" rd/wr locks */ -#define ZEBRA_FLOCK_EXTRA_RDWR_LOCKS 1 - /** whether this module should debug */ -#define DEBUG_FLOCK 0 +#define DEBUG_FLOCK 1 /** have this module (mutex) been initialized? */ static int initialized = 0; +/** whether fcntl locks are shared for all threads in a process */ +static int posix_locks = 1; + /** mutex for lock_list below */ Zebra_mutex lock_list_mutex; @@ -81,9 +75,7 @@ struct zebra_lock_info { /** number of file write locks/read locks */ int no_file_write_lock; int no_file_read_lock; -#if ZEBRA_FLOCK_EXTRA_RDWR_LOCKS Zebra_lock_rdwr rdwr_lock; -#endif Zebra_mutex file_mutex; #endif /** next in lock list */ @@ -136,11 +128,12 @@ ZebraLockHandle zebra_lock_create(const char *dir, const char *name) zebra_mutex_lock(&lock_list_mutex); /* see if we have the same filename in a global list of "lock files" */ #ifndef WIN32 -#if ZEBRA_FLOCK_SHARE_FD_IN_THREADS - for (p = lock_list; p ; p = p->next) - if (!strcmp(p->fname, fname)) - break; -#endif + if (posix_locks) + { + for (p = lock_list; p ; p = p->next) + if (!strcmp(p->fname, fname)) + break; + } #endif if (!p) { /* didn't match (or we didn't want it to match! */ @@ -166,9 +159,9 @@ ZebraLockHandle zebra_lock_create(const char *dir, const char *name) p->fname = fname; fname = 0; /* fname buffer now owned by p->fname */ #ifndef WIN32 -#if ZEBRA_FLOCK_EXTRA_RDWR_LOCKS - zebra_lock_rdwr_init(&p->rdwr_lock); -#endif + if (posix_locks) + zebra_lock_rdwr_init(&p->rdwr_lock); + zebra_mutex_init(&p->file_mutex); p->no_file_write_lock = 0; p->no_file_read_lock = 0; @@ -225,9 +218,8 @@ void zebra_lock_destroy(ZebraLockHandle h) h->p->fd, h, h->p->fname); #ifndef WIN32 -#if ZEBRA_FLOCK_EXTRA_RDWR_LOCKS - zebra_lock_rdwr_destroy(&h->p->rdwr_lock); -#endif + if (posix_locks) + zebra_lock_rdwr_destroy(&h->p->rdwr_lock); zebra_mutex_destroy(&h->p->file_mutex); #endif if (h->p->fd != -1) @@ -262,7 +254,7 @@ static int unixLock(int fd, int type, int cmd) int zebra_lock_w(ZebraLockHandle h) { int r; - int do_lock = ZEBRA_FLOCK_FILE_LOCK_ALWAYS; + int do_lock = 0; yaz_log(log_level, "zebra_lock_w fd=%d p=%p fname=%s begin", h->p->fd, h, h->p->fname); @@ -270,9 +262,8 @@ int zebra_lock_w(ZebraLockHandle h) while ((r = _locking(h->p->fd, _LK_LOCK, 1))) ; #else -#if ZEBRA_FLOCK_EXTRA_RDWR_LOCKS - zebra_lock_rdwr_wlock(&h->p->rdwr_lock); -#endif + if (posix_locks) + zebra_lock_rdwr_wlock(&h->p->rdwr_lock); zebra_mutex_lock(&h->p->file_mutex); if (h->p->no_file_write_lock == 0) @@ -283,12 +274,16 @@ int zebra_lock_w(ZebraLockHandle h) /* if there is already a read lock.. upgrade to write lock */ r = unixLock(h->p->fd, F_WRLCK, F_SETLKW); } + else + { + assert(posix_locks); + } zebra_mutex_unlock(&h->p->file_mutex); h->write_flag = 1; +#endif yaz_log(log_level, "zebra_lock_w fd=%d p=%p fname=%s end", h->p->fd, h, h->p->fname); -#endif return r; } @@ -296,17 +291,16 @@ int zebra_lock_w(ZebraLockHandle h) int zebra_lock_r(ZebraLockHandle h) { int r; - int do_lock = ZEBRA_FLOCK_FILE_LOCK_ALWAYS; + int do_lock = 0; - yaz_log(log_level, "zebra_lock_r fd=%d p=%p fname=%s", + yaz_log(log_level, "zebra_lock_r fd=%d p=%p fname=%s begin", h->p->fd, h, h->p->fname); #ifdef WIN32 while ((r = _locking(h->p->fd, _LK_LOCK, 1))) ; #else -#if ZEBRA_FLOCK_EXTRA_RDWR_LOCKS - zebra_lock_rdwr_rlock(&h->p->rdwr_lock); -#endif + if (posix_locks) + zebra_lock_rdwr_rlock(&h->p->rdwr_lock); zebra_mutex_lock(&h->p->file_mutex); if (h->p->no_file_read_lock == 0 && h->p->no_file_write_lock == 0) @@ -317,17 +311,23 @@ int zebra_lock_r(ZebraLockHandle h) /* only read lock if no write locks already */ r = unixLock(h->p->fd, F_RDLCK, F_SETLKW); } + else + { + assert(posix_locks); + } zebra_mutex_unlock(&h->p->file_mutex); h->write_flag = 0; #endif + yaz_log(log_level, "zebra_lock_r fd=%d p=%p fname=%s end", + h->p->fd, h, h->p->fname); return r; } int zebra_unlock(ZebraLockHandle h) { int r = 0; - int do_unlock = ZEBRA_FLOCK_FILE_LOCK_ALWAYS; + int do_unlock = 0; yaz_log(log_level, "zebra_unlock fd=%d p=%p fname=%s begin", h->p->fd, h, h->p->fname); #ifdef WIN32 @@ -342,31 +342,57 @@ int zebra_unlock(ZebraLockHandle h) do_unlock = 1; if (do_unlock) r = unixLock(h->p->fd, F_UNLCK, F_SETLKW); + else + { + assert(posix_locks); + } zebra_mutex_unlock(&h->p->file_mutex); -#if ZEBRA_FLOCK_EXTRA_RDWR_LOCKS - if (h->write_flag) - zebra_lock_rdwr_wunlock(&h->p->rdwr_lock); - else - zebra_lock_rdwr_runlock(&h->p->rdwr_lock); + if (posix_locks) + { + if (h->write_flag) + zebra_lock_rdwr_wunlock(&h->p->rdwr_lock); + else + zebra_lock_rdwr_runlock(&h->p->rdwr_lock); + } #endif - yaz_log(log_level, "zebra_unlock fd=%d p=%p fname=%s end", h->p->fd, h, h->p->fname); -#endif return r; } +#if HAVE_CONFSTR +static int test_for_linuxthreads() +{ + char conf_buf[512]; + size_t r; + + r = confstr(_CS_GNU_LIBPTHREAD_VERSION, conf_buf, sizeof(conf_buf)); + if (r == 0) + { + yaz_log(YLOG_WARN|YLOG_ERRNO, "confstr failed"); + return -1; + } + if (strncmp(conf_buf, "linuxthreads", 12) == 0) + posix_locks = 0; + return 0; +} +#endif + void zebra_flock_init() { if (!initialized) { + initialized = 1; log_level = yaz_log_module_level("flock"); #if DEBUG_FLOCK log_level = YLOG_LOG|YLOG_FLUSH; #endif - initialized = 1; +#if HAVE_CONFSTR + test_for_linuxthreads(); +#endif zebra_mutex_init(&lock_list_mutex); + yaz_log(log_level, "posix_locks: %d", posix_locks); } yaz_log(log_level, "zebra_flock_init"); } -- 1.7.10.4