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Systemd/src/cgls/cgls.c
Lennart Poettering 4afd3348c7 tree-wide: expose "p"-suffix unref calls in public APIs to make gcc cleanup easy 
GLIB has recently started to officially support the gcc cleanup
attribute in its public API, hence let's do the same for our APIs.

With this patch we'll define an xyz_unrefp() call for each public
xyz_unref() call, to make it easy to use inside a
__attribute__((cleanup())) expression. Then, all code is ported over to
make use of this.

The new calls are also documented in the man pages, with examples how to
use them (well, I only added docs where the _unref() call itself already
had docs, and the examples, only cover sd_bus_unrefp() and
sd_event_unrefp()).

This also renames sd_lldp_free() to sd_lldp_unref(), since that's how we
tend to call our destructors these days.

Note that this defines no public macro that wraps gcc's attribute and
makes it easier to use. While I think it's our duty in the library to
make our stuff easy to use, I figure it's not our duty to make gcc's own
features easy to use on its own. Most likely, client code which wants to
make use of this should define its own:

       #define _cleanup_(function) __attribute__((cleanup(function)))

Or similar, to make the gcc feature easier to use.

Making this logic public has the benefit that we can remove three header
files whose only purpose was to define these functions internally.

See #2008.
2015-11-27 19:19:36 +01:00

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/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
/***
This file is part of systemd.
Copyright 2010 Lennart Poettering
systemd is free software; you can redistribute it and/or modify it
under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 of the License, or
(at your option) any later version.
systemd 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with systemd; If not, see <http://www.gnu.org/licenses/>.
***/
#include <errno.h>
#include <getopt.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include "sd-bus.h"
#include "alloc-util.h"
#include "bus-error.h"
#include "bus-util.h"
#include "cgroup-show.h"
#include "cgroup-util.h"
#include "fileio.h"
#include "log.h"
#include "output-mode.h"
#include "pager.h"
#include "path-util.h"
#include "unit-name.h"
#include "util.h"
static bool arg_no_pager = false;
static bool arg_kernel_threads = false;
static bool arg_all = false;
static int arg_full = -1;
static char* arg_machine = NULL;
static void help(void) {
printf("%s [OPTIONS...] [CGROUP...]\n\n"
"Recursively show control group contents.\n\n"
" -h --help Show this help\n"
" --version Show package version\n"
" --no-pager Do not pipe output into a pager\n"
" -a --all Show all groups, including empty\n"
" -l --full Do not ellipsize output\n"
" -k Include kernel threads in output\n"
" -M --machine= Show container\n"
, program_invocation_short_name);
}
static int parse_argv(int argc, char *argv[]) {
enum {
ARG_NO_PAGER = 0x100,
ARG_VERSION,
};
static const struct option options[] = {
{ "help", no_argument, NULL, 'h' },
{ "version", no_argument, NULL, ARG_VERSION },
{ "no-pager", no_argument, NULL, ARG_NO_PAGER },
{ "all", no_argument, NULL, 'a' },
{ "full", no_argument, NULL, 'l' },
{ "machine", required_argument, NULL, 'M' },
{}
};
int c;
assert(argc >= 1);
assert(argv);
while ((c = getopt_long(argc, argv, "hkalM:", options, NULL)) >= 0)
switch (c) {
case 'h':
help();
return 0;
case ARG_VERSION:
return version();
case ARG_NO_PAGER:
arg_no_pager = true;
break;
case 'a':
arg_all = true;
break;
case 'l':
arg_full = true;
break;
case 'k':
arg_kernel_threads = true;
break;
case 'M':
arg_machine = optarg;
break;
case '?':
return -EINVAL;
default:
assert_not_reached("Unhandled option");
}
return 1;
}
static int get_cgroup_root(char **ret) {
_cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
_cleanup_(sd_bus_flush_close_unrefp) sd_bus *bus = NULL;
_cleanup_free_ char *unit = NULL, *path = NULL;
const char *m;
int r;
if (!arg_machine) {
r = cg_get_root_path(ret);
if (r < 0)
return log_error_errno(r, "Failed to get root control group path: %m");
return 0;
}
m = strjoina("/run/systemd/machines/", arg_machine);
r = parse_env_file(m, NEWLINE, "SCOPE", &unit, NULL);
if (r < 0)
return log_error_errno(r, "Failed to load machine data: %m");
path = unit_dbus_path_from_name(unit);
if (!path)
return log_oom();
r = bus_connect_transport_systemd(BUS_TRANSPORT_LOCAL, NULL, false, &bus);
if (r < 0)
return log_error_errno(r, "Failed to create bus connection: %m");
r = sd_bus_get_property_string(
bus,
"org.freedesktop.systemd1",
path,
unit_dbus_interface_from_name(unit),
"ControlGroup",
&error,
ret);
if (r < 0)
return log_error_errno(r, "Failed to query unit control group path: %s", bus_error_message(&error, r));
return 0;
}
static void show_cg_info(const char *controller, const char *path) {
if (cg_unified() <= 0 && controller && !streq(controller, SYSTEMD_CGROUP_CONTROLLER))
printf("Controller %s; ", controller);
printf("Control group %s:\n", isempty(path) ? "/" : path);
fflush(stdout);
}
int main(int argc, char *argv[]) {
int r, output_flags;
log_parse_environment();
log_open();
r = parse_argv(argc, argv);
if (r <= 0)
goto finish;
if (!arg_no_pager) {
r = pager_open(false);
if (r > 0 && arg_full < 0)
arg_full = true;
}
output_flags =
arg_all * OUTPUT_SHOW_ALL |
(arg_full > 0) * OUTPUT_FULL_WIDTH;
if (optind < argc) {
_cleanup_free_ char *root = NULL;
int i;
r = get_cgroup_root(&root);
if (r < 0)
goto finish;
for (i = optind; i < argc; i++) {
int q;
if (path_startswith(argv[i], "/sys/fs/cgroup")) {
printf("Directory %s:\n", argv[i]);
fflush(stdout);
q = show_cgroup_by_path(argv[i], NULL, 0, arg_kernel_threads, output_flags);
} else {
_cleanup_free_ char *c = NULL, *p = NULL, *j = NULL;
const char *controller, *path;
r = cg_split_spec(argv[i], &c, &p);
if (r < 0) {
log_error_errno(r, "Failed to split argument %s: %m", argv[i]);
goto finish;
}
controller = c ?: SYSTEMD_CGROUP_CONTROLLER;
if (p) {
j = strjoin(root, "/", p, NULL);
if (!j) {
r = log_oom();
goto finish;
}
path_kill_slashes(j);
path = j;
} else
path = root;
show_cg_info(controller, path);
q = show_cgroup(controller, path, NULL, 0, arg_kernel_threads, output_flags);
}
if (q < 0)
r = q;
}
} else {
bool done = false;
if (!arg_machine) {
_cleanup_free_ char *cwd = NULL;
cwd = get_current_dir_name();
if (!cwd) {
r = log_error_errno(errno, "Cannot determine current working directory: %m");
goto finish;
}
if (path_startswith(cwd, "/sys/fs/cgroup")) {
printf("Working directory %s:\n", cwd);
fflush(stdout);
r = show_cgroup_by_path(cwd, NULL, 0, arg_kernel_threads, output_flags);
done = true;
}
}
if (!done) {
_cleanup_free_ char *root = NULL;
r = get_cgroup_root(&root);
if (r < 0)
goto finish;
show_cg_info(SYSTEMD_CGROUP_CONTROLLER, root);
printf("-.slice\n");
r = show_cgroup(SYSTEMD_CGROUP_CONTROLLER, root, NULL, 0, arg_kernel_threads, output_flags);
}
}
if (r < 0)
log_error_errno(r, "Failed to list cgroup tree: %m");
finish:
pager_close();
return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS;
}
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