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author | Ulrich Drepper <drepper@redhat.com> | 1997-07-11 01:19:07 +0000 |
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committer | Ulrich Drepper <drepper@redhat.com> | 1997-07-11 01:19:07 +0000 |
commit | 2d7da676f38bc00f40d2b604036c0295c156529e (patch) | |
tree | b07f60862c86c9a3cd03ec0e4bfbe600b99c0f55 /nis/lckcache.c | |
parent | 9c2322bc08c01e34c7488ef12c1d1bf26097190b (diff) | |
download | glibc-2d7da676f38bc00f40d2b604036c0295c156529e.tar.gz glibc-2d7da676f38bc00f40d2b604036c0295c156529e.tar.xz glibc-2d7da676f38bc00f40d2b604036c0295c156529e.zip |
update. cvs/libc-ud-970710
1997-07-11 03:00 Ulrich Drepper <drepper@cygnus.com> * inet/inet_ntoa.c: Prevent looking for thread data key if we found one. * signal/sigandset.c: Include stddef.h to get NULL defined. * signal/sigisempty.c: Likewise. * signal/sigorset.c: Likewise. * sysdeps/stub/if_index.h: Likewise. * wcsmbs/wcstod_l.c: Include locale.h to get __locale_t defined. * wcsmbs/wcstof_l.c: Likewise. * wcsmbs/wcstol_l.c: Likewise. * wcsmbs/wcstold_l.c: Likewise. * wcsmbs/wcstoll_l.c: Likewise. * wcsmbs/wcstoul_l.c: Likewise. * wcsmbs/wcstoull_l.c: Likewise. Reported by Marcus G. Daniels <marcus@cathcart.sysc.pdx.edu>. * stdio-common/snprintf.c: Use ISO C function definition form. * sysdeps/stub/libc-lock.h: Don't define __libc_key_create and __libc_setspecific as empty macros since they are used as function with return value. Reported by Andreas Jaeger. 1997-07-10 Marcus G. Daniels <marcus@cathcart.sysc.pdx.edu> * sysdeps/mach/hurd/select.c (__select): Need bit count for MACH_MSG_TYPE_INTEGER_T. 1997-07-08 10:12 Fila Kolodny <fila@ibi.com> * sysdeps/i370/Implies: New file for i370-ibm-mvs port. * sysdeps/mvs/Implies: Likewise. 1997-07-09 23:06 Thorsten Kukuk <kukuk@vt.uni-paderborn.de> * nis/Makefile: Add new source files. * nis/nis_intern.h: Add new internal functions. * nis/rpcsvc/nislib.h: Likewise. * nis/lckcache.c: New. * nis/nis_cache.c: New, dummy functions in the moment. * nis/nis_util.c: New. * nis/nisplus-parser.h: New. * nis/nss_nisplus/nisplus-parser.c: New. * nis/rpcsvc/nis_cache.h: New. * nis/rpcsvc/nis_cache.x: New. * nis/nss_compat/compat-grp.c: Matches Solaris behaviour now. * nis/nss_compat/compat-pwd.c: Likewise. * nis/nss_compat/compat-spwd.c: Likewise. * nis/nss_nisplus/nisplus-alias.c: Likewise. * nis/nss_nisplus/nisplus-ethers.c: Likewise. * nis/nss_nisplus/nisplus-grp.c: Likewise. * nis/nss_nisplus/nisplus-hosts.c: Likewise. * nis/nss_nisplus/nisplus-netgrp.c: Likewise. * nis/nss_nisplus/nisplus-network.c: Likewise. * nis/nss_nisplus/nisplus-proto.c: Likewise. * nis/nss_nisplus/nisplus-publickey.c: Likewise. * nis/nss_nisplus/nisplus-pwd.c: Likewise. * nis/nss_nisplus/nisplus-rpc.c: Likewise. * nis/nss_nisplus/nisplus-service.c: Likewise. * nis/nss_nisplus/nisplus-spwd.c: Likewise. * nis/nss_nis/nis-publickey.c: Remove libc-lock.h include. * nis/nis_intern.c: Removed. * nis/nis_call.c: Complete rewrite. * nis/nis_lookup.c: Likewise. * nis/nis_table.c: Likewise. * nis/libnsl.map: Add missing symbols. * nis/nis_print.c: Fix nis_print_link. * nis/nis_subr.c: Fix nis_getnames. 1997-07-09 07:19 H.J. Lu <hjl@gnu.ai.mit.edu> * posix/execvp.c (execvp): Handle ESTALE. 1997-07-10 13:54 Ulrich Drepper <drepper@cygnus.com> * posix/regex.c: Make CHAR_SET_SIZE definition always available, even if SYNTAX_TABLE is defined. Patch by Akim Demaille <demaille@inf.enst.fr>. 1997-07-09 08:16 H.J. Lu <hjl@gnu.ai.mit.edu> * libio/fileops.c (_IO_file_underflow): Adjust pointers before calling _IO_SYSREAD (). 1997-07-07 22:54 Zack Weinberg <zack@rabi.phys.columbia.edu> * sysdeps/sparc/divrem.m4: Eliminate use of "DEFS.h" (sysdep.h does the same job). * sysdeps/sparc/alloca.S: Likewise. * sysdeps/sparc/dotmul.S: Likewise. * sysdeps/sparc/udiv_qrnnd.S: Likewise. * sysdeps/sparc/rem.S: Regenerated. * sysdeps/sparc/sdiv.S: Regenerated. * sysdeps/sparc/udiv.S: Regenerated. * sysdeps/sparc/urem.S: Regenerated. * sysdeps/sparc/DEFS.h: Removed. * sysdeps/sparc/elf/DEFS.h: Removed. * sysdeps/sparc/Dist: Don't distribute DEFS.h. * sysdeps/unix/sparc/sysdep.h: Use 4 byte alignment. Add .type directive #ifdef HAVE_ELF. Minor format changes. * sysdeps/alpha/DEFS.h: Removed. * sysdeps/alpha/Dist: Don't distribute DEFS.h. 1997-07-07 19:03 H.J. Lu <hjl@gnu.ai.mit.edu> * math/test-fenv.c (feenv_nomask_test): Move fesetenv (FE_NOMASK_ENV) after fork () to work with SMP. * sysdeps/i386/fpu_control.h (_FPU_IEEE): Fix comment. 1997-07-08 Andreas Schwab <schwab@issan.informatik.uni-dortmund.de> * libc.map: Add _IO_peekc_locked. 1997-07-07 15:45 Fila Kolodny <fila@ibi.com> * Makeconfig: Add dbobjdir to rpath-link analogous to nssobjdir. 1997-07-08 Andreas Schwab <schwab@issan.informatik.uni-dortmund.de> * sysdeps/m68k/fpu/feholdexcpt.c: Shift the exception mask in the right position. * sysdeps/m68k/fpu/fesetenv.c (fesetenv): Likewise. 1997-07-08 13:59 Ulrich Drepper <drepper@cygnus.com> * time/strftime.c (spaces, zeroes): Handle broken SGI compiler. Patch by Richard Stallman <rms@gnu.ai.mit.edu>.
Diffstat (limited to 'nis/lckcache.c')
-rw-r--r-- | nis/lckcache.c | 181 |
1 files changed, 181 insertions, 0 deletions
diff --git a/nis/lckcache.c b/nis/lckcache.c new file mode 100644 index 0000000000..ead577372e --- /dev/null +++ b/nis/lckcache.c @@ -0,0 +1,181 @@ +/* Handle locking of NIS+ cache file. + Copyright (C) 1996 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 + modify it under the terms of the GNU Library General Public License as + published by the Free Software Foundation; either version 2 of the + License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Library General Public License for more details. + + You should have received a copy of the GNU Library General Public + License along with the GNU C Library; see the file COPYING.LIB. If not, + write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, + Boston, MA 02111-1307, USA. */ + +#include <fcntl.h> +#include <bits/libc-lock.h> +#include <shadow.h> +#include <signal.h> +#include <string.h> +#include <unistd.h> +#include <sys/file.h> +#include <rpcsvc/nis.h> +#include <rpcsvc/nislib.h> +#include <rpcsvc/nis_cache.h> + +/* How long to wait for getting the lock before returning with an + error. */ +#define TIMEOUT 15 /* sec */ + + +/* File descriptor for lock file. */ +static int lock_fd = -1; + +/* Prevent problems in multithreaded program by using mutex. */ +__libc_lock_define_initialized (static, lock) + + +/* Prototypes for local functions. */ +static void noop_handler __P ((int __sig)); + + +/* We cannot simply return in error cases. We have to close the file + and perhaps restore the signal handler. */ +#define RETURN_CLOSE_FD(code) \ + do { \ + if ((code) < 0 && lock_fd >= 0) \ + { \ + close (lock_fd); \ + lock_fd = -1; \ + } \ + __libc_lock_unlock (lock); \ + return (code); \ + } while (0) + +#define RETURN_RESTORE_HANDLER(code) \ + do { \ + /* Restore old action handler for alarm. We don't need to know \ + about the current one. */ \ + sigaction (SIGALRM, &saved_act, NULL); \ + RETURN_CLOSE_FD (code); \ + } while (0) + +#define RETURN_CLEAR_ALARM(code) \ + do { \ + /* Clear alarm. */ \ + alarm (0); \ + /* Restore old set of handled signals. We don't need to know \ + about the current one.*/ \ + sigprocmask (SIG_SETMASK, &saved_set, NULL); \ + RETURN_RESTORE_HANDLER (code); \ + } while (0) + + +int +__nis_lock_cache (void) +{ + int flags; + sigset_t saved_set; /* Saved set of caught signals. */ + struct sigaction saved_act; /* Saved signal action. */ + sigset_t new_set; /* New set of caught signals. */ + struct sigaction new_act; /* New signal action. */ + struct flock fl; /* Information struct for locking. */ + int result; + + if (lock_fd != -1) + /* Still locked by own process. */ + return -1; + + /* Prevent problems caused by multiple threads. */ + __libc_lock_lock (lock); + + lock_fd = open (CACHELOCK, O_RDONLY|O_CREAT, 0666); + if (lock_fd == -1) + /* Cannot create lock file. */ + RETURN_CLOSE_FD (-1); + + /* Make sure file gets correctly closed when process finished. */ + flags = fcntl (lock_fd, F_GETFD, 0); + if (flags == -1) + /* Cannot get file flags. */ + RETURN_CLOSE_FD (-1); + flags |= FD_CLOEXEC; /* Close on exit. */ + if (fcntl (lock_fd, F_SETFD, flags) < 0) + /* Cannot set new flags. */ + RETURN_CLOSE_FD (-1); + + /* Now we have to get exclusive write access. Since multiple + process could try this we won't stop when it first fails. + Instead we set a timeout for the system call. Once the timer + expires it is likely that there are some problems which cannot be + resolved by waiting. + + It is important that we don't change the signal state. We must + restore the old signal behaviour. */ + memset (&new_act, '\0', sizeof (struct sigaction)); + new_act.sa_handler = noop_handler; + sigfillset (&new_act.sa_mask); + new_act.sa_flags = 0ul; + + /* Install new action handler for alarm and save old. */ + if (sigaction (SIGALRM, &new_act, &saved_act) < 0) + /* Cannot install signal handler. */ + RETURN_CLOSE_FD (-1); + + /* Now make sure the alarm signal is not blocked. */ + sigemptyset (&new_set); + sigaddset (&new_set, SIGALRM); + if (sigprocmask (SIG_UNBLOCK, &new_set, &saved_set) < 0) + RETURN_RESTORE_HANDLER (-1); + + /* Start timer. If we cannot get the lock in the specified time we + get a signal. */ + alarm (TIMEOUT); + + /* Try to get the lock. */ + memset (&fl, '\0', sizeof (struct flock)); + fl.l_type = F_RDLCK; + fl.l_whence = SEEK_SET; + result = fcntl (lock_fd, F_SETLK, &fl); + + RETURN_CLEAR_ALARM (result); +} + + +int +__nis_unlock_cache () +{ + int result; + + if (lock_fd == -1) + /* There is no lock set. */ + result = -1; + else + { + /* Prevent problems caused by multiple threads. */ + __libc_lock_lock (lock); + + result = close (lock_fd); + + /* Mark descriptor as unused. */ + lock_fd = -1; + + /* Clear mutex. */ + __libc_lock_unlock (lock); + } + + return result; +} + + +static void +noop_handler (sig) + int sig; +{ + /* We simply return which makes the `fcntl' call return with an error. */ +} |