diff options
Diffstat (limited to 'src/util')
-rw-r--r-- | src/util/atomic_io.c | 60 | ||||
-rw-r--r-- | src/util/atomic_io.h | 40 | ||||
-rw-r--r-- | src/util/util.c | 38 | ||||
-rw-r--r-- | src/util/util.h | 7 |
4 files changed, 102 insertions, 43 deletions
diff --git a/src/util/atomic_io.c b/src/util/atomic_io.c new file mode 100644 index 000000000..1543af9a0 --- /dev/null +++ b/src/util/atomic_io.c @@ -0,0 +1,60 @@ +/* + Authors: + Jan Cholasta <jcholast@redhat.com> + + Copyright (C) 2012 Red Hat + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 3 of the License, or + (at your option) any later version. + + This program 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 General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see <http://www.gnu.org/licenses/>. +*/ + +#include "util/atomic_io.h" + +/* based on code from libssh <http://www.libssh.org> */ +ssize_t sss_atomic_io_s(int fd, void *buf, size_t n, bool do_read) +{ + char *b = buf; + size_t pos = 0; + ssize_t res; + struct pollfd pfd; + + pfd.fd = fd; + pfd.events = do_read ? POLLIN : POLLOUT; + + while (n > pos) { + if (do_read) { + res = read(fd, b + pos, n - pos); + } else { + res = write(fd, b + pos, n - pos); + } + switch (res) { + case -1: + if (errno == EINTR) { + continue; + } + if (errno == EAGAIN || errno == EWOULDBLOCK) { + (void) poll(&pfd, 1, -1); + continue; + } + return -1; + case 0: + /* read returns 0 on end-of-file */ + errno = do_read ? 0 : EPIPE; + return pos; + default: + pos += (size_t) res; + } + } + + return pos; +} diff --git a/src/util/atomic_io.h b/src/util/atomic_io.h new file mode 100644 index 000000000..ffae31d6c --- /dev/null +++ b/src/util/atomic_io.h @@ -0,0 +1,40 @@ +/* + Authors: + Jan Cholasta <jcholast@redhat.com> + + Copyright (C) 2012 Red Hat + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 3 of the License, or + (at your option) any later version. + + This program 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 General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see <http://www.gnu.org/licenses/>. +*/ + +#ifndef __SSSD_ATOMIC_IO_H__ +#define __SSSD_ATOMIC_IO_H__ + +#include <unistd.h> +#include <stdbool.h> +#include <poll.h> +#include <errno.h> + +/* Performs a read or write operation in an manner that is seemingly atomic + * to the caller. + * + * Please note that the function does not perform any asynchronous operation + * so the operation might potentially block + */ +ssize_t sss_atomic_io_s(int fd, void *buf, size_t n, bool do_read); + +#define sss_atomic_read_s(fd, buf, n) sss_atomic_io_s(fd, buf, n, true) +#define sss_atomic_write_s(fd, buf, n) sss_atomic_io_s(fd, buf, n, false) + +#endif /* __SSSD_ATOMIC_IO_H__ */ diff --git a/src/util/util.c b/src/util/util.c index 3a6c5d270..f1aaebc28 100644 --- a/src/util/util.c +++ b/src/util/util.c @@ -611,41 +611,3 @@ void to_sized_string(struct sized_string *out, const char *in) } } -/* based on code from libssh <http://www.libssh.org> */ -ssize_t sss_atomic_io(int fd, void *buf, size_t n, bool do_read) -{ - char *b = buf; - size_t pos = 0; - ssize_t res; - struct pollfd pfd; - - pfd.fd = fd; - pfd.events = do_read ? POLLIN : POLLOUT; - - while (n > pos) { - if (do_read) { - res = read(fd, b + pos, n - pos); - } else { - res = write(fd, b + pos, n - pos); - } - switch (res) { - case -1: - if (errno == EINTR) { - continue; - } - if (errno == EAGAIN || errno == EWOULDBLOCK) { - (void) poll(&pfd, 1, -1); - continue; - } - return -1; - case 0: - /* read returns 0 on end-of-file */ - errno = do_read ? 0 : EPIPE; - return pos; - default: - pos += (size_t) res; - } - } - - return pos; -} diff --git a/src/util/util.h b/src/util/util.h index da6db1cff..181e75166 100644 --- a/src/util/util.h +++ b/src/util/util.h @@ -42,6 +42,8 @@ #include <ldb.h> #include <dhash.h> +#include "util/atomic_io.h" + #ifndef HAVE_ERRNO_T #define HAVE_ERRNO_T typedef int errno_t; @@ -510,11 +512,6 @@ errno_t sss_filter_sanitize(TALLOC_CTX *mem_ctx, char * sss_escape_ip_address(TALLOC_CTX *mem_ctx, int family, const char *addr); -ssize_t sss_atomic_io(int fd, void *buf, size_t n, bool do_read); - -#define sss_atomic_read(fd, buf, n) sss_atomic_io(fd, buf, n, true) -#define sss_atomic_write(fd, buf, n) sss_atomic_io(fd, buf, n, false) - /* from sss_tc_utf8.c */ char * sss_tc_utf8_str_tolower(TALLOC_CTX *mem_ctx, const char *s); |