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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-17 06:23:09 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-17 06:23:09 +0000 |
commit | 30d479c28c831a0d4f1fdb54a9e346b0fc176be1 (patch) | |
tree | aa35d7414ce9f1326abf6f723f6dfa5b0aa08b1d /file_io/unix/flock.c | |
parent | Initial commit. (diff) | |
download | apr-0796b9c8dc2d3ccba70e2228520d621065e3fb90.tar.xz apr-0796b9c8dc2d3ccba70e2228520d621065e3fb90.zip |
Adding upstream version 1.7.2.upstream/1.7.2
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'file_io/unix/flock.c')
-rw-r--r-- | file_io/unix/flock.c | 120 |
1 files changed, 120 insertions, 0 deletions
diff --git a/file_io/unix/flock.c b/file_io/unix/flock.c new file mode 100644 index 0000000..01e8a63 --- /dev/null +++ b/file_io/unix/flock.c @@ -0,0 +1,120 @@ +/* Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed with + * this work for additional information regarding copyright ownership. + * The ASF licenses this file to You under the Apache License, Version 2.0 + * (the "License"); you may not use this file except in compliance with + * the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +#include "apr_arch_file_io.h" + +#if APR_HAVE_FCNTL_H +#include <fcntl.h> +#endif +#ifdef HAVE_SYS_FILE_H +#include <sys/file.h> +#endif + +APR_DECLARE(apr_status_t) apr_file_lock(apr_file_t *thefile, int type) +{ + int rc; + +#if defined(HAVE_FCNTL_H) + { + struct flock l = { 0 }; + int fc; + + l.l_whence = SEEK_SET; /* count l_start from start of file */ + l.l_start = 0; /* lock from start of file */ + l.l_len = 0; /* lock to end of file */ + if ((type & APR_FLOCK_TYPEMASK) == APR_FLOCK_SHARED) + l.l_type = F_RDLCK; + else + l.l_type = F_WRLCK; + + fc = (type & APR_FLOCK_NONBLOCK) ? F_SETLK : F_SETLKW; + + /* keep trying if fcntl() gets interrupted (by a signal) */ + while ((rc = fcntl(thefile->filedes, fc, &l)) < 0 && errno == EINTR) + continue; + + if (rc == -1) { + /* on some Unix boxes (e.g., Tru64), we get EACCES instead + * of EAGAIN; we don't want APR_STATUS_IS_EAGAIN() matching EACCES + * since that breaks other things, so fix up the retcode here + */ + if (errno == EACCES) { + return EAGAIN; + } + return errno; + } + } +#elif defined(HAVE_SYS_FILE_H) + { + int ltype; + + if ((type & APR_FLOCK_TYPEMASK) == APR_FLOCK_SHARED) + ltype = LOCK_SH; + else + ltype = LOCK_EX; + if ((type & APR_FLOCK_NONBLOCK) != 0) + ltype |= LOCK_NB; + + /* keep trying if flock() gets interrupted (by a signal) */ + while ((rc = flock(thefile->filedes, ltype)) < 0 && errno == EINTR) + continue; + + if (rc == -1) + return errno; + } +#else +#error No file locking mechanism is available. +#endif + + return APR_SUCCESS; +} + +APR_DECLARE(apr_status_t) apr_file_unlock(apr_file_t *thefile) +{ + int rc; + +#if defined(HAVE_FCNTL_H) + { + struct flock l = { 0 }; + + l.l_whence = SEEK_SET; /* count l_start from start of file */ + l.l_start = 0; /* lock from start of file */ + l.l_len = 0; /* lock to end of file */ + l.l_type = F_UNLCK; + + /* keep trying if fcntl() gets interrupted (by a signal) */ + while ((rc = fcntl(thefile->filedes, F_SETLKW, &l)) < 0 + && errno == EINTR) + continue; + + if (rc == -1) + return errno; + } +#elif defined(HAVE_SYS_FILE_H) + { + /* keep trying if flock() gets interrupted (by a signal) */ + while ((rc = flock(thefile->filedes, LOCK_UN)) < 0 && errno == EINTR) + continue; + + if (rc == -1) + return errno; + } +#else +#error No file locking mechanism is available. +#endif + + return APR_SUCCESS; +} |