init.c revision 3294bbbad9494eb4ca534624b96e39f8ed15aaf2 
1/*
2 * Copyright (C) 2008 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#include <stdio.h>
18#include <stdlib.h>
19#include <string.h>
20#include <unistd.h>
21#include <fcntl.h>
22#include <ctype.h>
23#include <signal.h>
24#include <sys/wait.h>
25#include <sys/mount.h>
26#include <sys/stat.h>
27#include <sys/poll.h>
28#include <errno.h>
29#include <stdarg.h>
30#include <mtd/mtd-user.h>
31#include <sys/types.h>
32#include <sys/socket.h>
33#include <sys/un.h>
34
35#include <cutils/sockets.h>
36#include <cutils/iosched_policy.h>
37#include <termios.h>
38
39#include <sys/system_properties.h>
40
41#include "devices.h"
42#include "init.h"
43#include "list.h"
44#include "log.h"
45#include "property_service.h"
46#include "bootchart.h"
47#include "signal_handler.h"
48#include "keychords.h"
49#include "parser.h"
50#include "util.h"
51
52static int property_triggers_enabled = 0;
53
54#if BOOTCHART
55static int   bootchart_count;
56#endif
57
58static char console[32];
59static char serialno[32];
60static char bootmode[32];
61static char baseband[32];
62static char carrier[32];
63static char bootloader[32];
64static char hardware[32];
65static unsigned revision = 0;
66static char qemu[32];
67
68static struct action *cur_action = NULL;
69static struct command *cur_command = NULL;
70static struct listnode *command_queue = NULL;
71
72void notify_service_state(const char *name, const char *state)
73{
74    char pname[PROP_NAME_MAX];
75    int len = strlen(name);
76    if ((len + 10) > PROP_NAME_MAX)
77        return;
78    snprintf(pname, sizeof(pname), "init.svc.%s", name);
79    property_set(pname, state);
80}
81
82static int have_console;
83static char *console_name = "/dev/console";
84static time_t process_needs_restart;
85
86static const char *ENV[32];
87
88/* add_environment - add "key=value" to the current environment */
89int add_environment(const char *key, const char *val)
90{
91    int n;
92
93    for (n = 0; n < 31; n++) {
94        if (!ENV[n]) {
95            size_t len = strlen(key) + strlen(val) + 2;
96            char *entry = malloc(len);
97            snprintf(entry, len, "%s=%s", key, val);
98            ENV[n] = entry;
99            return 0;
100        }
101    }
102
103    return 1;
104}
105
106static void zap_stdio(void)
107{
108    int fd;
109    fd = open("/dev/null", O_RDWR);
110    dup2(fd, 0);
111    dup2(fd, 1);
112    dup2(fd, 2);
113    close(fd);
114}
115
116static void open_console()
117{
118    int fd;
119    if ((fd = open(console_name, O_RDWR)) < 0) {
120        fd = open("/dev/null", O_RDWR);
121    }
122    dup2(fd, 0);
123    dup2(fd, 1);
124    dup2(fd, 2);
125    close(fd);
126}
127
128static void publish_socket(const char *name, int fd)
129{
130    char key[64] = ANDROID_SOCKET_ENV_PREFIX;
131    char val[64];
132
133    strlcpy(key + sizeof(ANDROID_SOCKET_ENV_PREFIX) - 1,
134            name,
135            sizeof(key) - sizeof(ANDROID_SOCKET_ENV_PREFIX));
136    snprintf(val, sizeof(val), "%d", fd);
137    add_environment(key, val);
138
139    /* make sure we don't close-on-exec */
140    fcntl(fd, F_SETFD, 0);
141}
142
143void service_start(struct service *svc, const char *dynamic_args)
144{
145    struct stat s;
146    pid_t pid;
147    int needs_console;
148    int n;
149
150        /* starting a service removes it from the disabled
151         * state and immediately takes it out of the restarting
152         * state if it was in there
153         */
154    svc->flags &= (~(SVC_DISABLED|SVC_RESTARTING));
155    svc->time_started = 0;
156
157        /* running processes require no additional work -- if
158         * they're in the process of exiting, we've ensured
159         * that they will immediately restart on exit, unless
160         * they are ONESHOT
161         */
162    if (svc->flags & SVC_RUNNING) {
163        return;
164    }
165
166    needs_console = (svc->flags & SVC_CONSOLE) ? 1 : 0;
167    if (needs_console && (!have_console)) {
168        ERROR("service '%s' requires console\n", svc->name);
169        svc->flags |= SVC_DISABLED;
170        return;
171    }
172
173    if (stat(svc->args[0], &s) != 0) {
174        ERROR("cannot find '%s', disabling '%s'\n", svc->args[0], svc->name);
175        svc->flags |= SVC_DISABLED;
176        return;
177    }
178
179    if ((!(svc->flags & SVC_ONESHOT)) && dynamic_args) {
180        ERROR("service '%s' must be one-shot to use dynamic args, disabling\n",
181               svc->args[0]);
182        svc->flags |= SVC_DISABLED;
183        return;
184    }
185
186    NOTICE("starting '%s'\n", svc->name);
187
188    pid = fork();
189
190    if (pid == 0) {
191        struct socketinfo *si;
192        struct svcenvinfo *ei;
193        char tmp[32];
194        int fd, sz;
195
196        if (properties_inited()) {
197            get_property_workspace(&fd, &sz);
198            sprintf(tmp, "%d,%d", dup(fd), sz);
199            add_environment("ANDROID_PROPERTY_WORKSPACE", tmp);
200        }
201
202        for (ei = svc->envvars; ei; ei = ei->next)
203            add_environment(ei->name, ei->value);
204
205        for (si = svc->sockets; si; si = si->next) {
206            int s = create_socket(si->name,
207                                  !strcmp(si->type, "dgram") ?
208                                  SOCK_DGRAM : SOCK_STREAM,
209                                  si->perm, si->uid, si->gid);
210            if (s >= 0) {
211                publish_socket(si->name, s);
212            }
213        }
214
215        if (svc->ioprio_class != IoSchedClass_NONE) {
216            if (android_set_ioprio(getpid(), svc->ioprio_class, svc->ioprio_pri)) {
217                ERROR("Failed to set pid %d ioprio = %d,%d: %s\n",
218                      getpid(), svc->ioprio_class, svc->ioprio_pri, strerror(errno));
219            }
220        }
221
222        if (needs_console) {
223            setsid();
224            open_console();
225        } else {
226            zap_stdio();
227        }
228
229#if 0
230        for (n = 0; svc->args[n]; n++) {
231            INFO("args[%d] = '%s'\n", n, svc->args[n]);
232        }
233        for (n = 0; ENV[n]; n++) {
234            INFO("env[%d] = '%s'\n", n, ENV[n]);
235        }
236#endif
237
238        setpgid(0, getpid());
239
240    /* as requested, set our gid, supplemental gids, and uid */
241        if (svc->gid) {
242            setgid(svc->gid);
243        }
244        if (svc->nr_supp_gids) {
245            setgroups(svc->nr_supp_gids, svc->supp_gids);
246        }
247        if (svc->uid) {
248            setuid(svc->uid);
249        }
250
251        if (!dynamic_args) {
252            if (execve(svc->args[0], (char**) svc->args, (char**) ENV) < 0) {
253                ERROR("cannot execve('%s'): %s\n", svc->args[0], strerror(errno));
254            }
255        } else {
256            char *arg_ptrs[SVC_MAXARGS+1];
257            int arg_idx = svc->nargs;
258            char *tmp = strdup(dynamic_args);
259            char *next = tmp;
260            char *bword;
261
262            /* Copy the static arguments */
263            memcpy(arg_ptrs, svc->args, (svc->nargs * sizeof(char *)));
264
265            while((bword = strsep(&next, " "))) {
266                arg_ptrs[arg_idx++] = bword;
267                if (arg_idx == SVC_MAXARGS)
268                    break;
269            }
270            arg_ptrs[arg_idx] = '\0';
271            execve(svc->args[0], (char**) arg_ptrs, (char**) ENV);
272        }
273        _exit(127);
274    }
275
276    if (pid < 0) {
277        ERROR("failed to start '%s'\n", svc->name);
278        svc->pid = 0;
279        return;
280    }
281
282    svc->time_started = gettime();
283    svc->pid = pid;
284    svc->flags |= SVC_RUNNING;
285
286    if (properties_inited())
287        notify_service_state(svc->name, "running");
288}
289
290void service_stop(struct service *svc)
291{
292        /* we are no longer running, nor should we
293         * attempt to restart
294         */
295    svc->flags &= (~(SVC_RUNNING|SVC_RESTARTING));
296
297        /* if the service has not yet started, prevent
298         * it from auto-starting with its class
299         */
300    svc->flags |= SVC_DISABLED;
301
302    if (svc->pid) {
303        NOTICE("service '%s' is being killed\n", svc->name);
304        kill(-svc->pid, SIGTERM);
305        notify_service_state(svc->name, "stopping");
306    } else {
307        notify_service_state(svc->name, "stopped");
308    }
309}
310
311void property_changed(const char *name, const char *value)
312{
313    if (property_triggers_enabled)
314        queue_property_triggers(name, value);
315}
316
317static void restart_service_if_needed(struct service *svc)
318{
319    time_t next_start_time = svc->time_started + 5;
320
321    if (next_start_time <= gettime()) {
322        svc->flags &= (~SVC_RESTARTING);
323        service_start(svc, NULL);
324        return;
325    }
326
327    if ((next_start_time < process_needs_restart) ||
328        (process_needs_restart == 0)) {
329        process_needs_restart = next_start_time;
330    }
331}
332
333static void restart_processes()
334{
335    process_needs_restart = 0;
336    service_for_each_flags(SVC_RESTARTING,
337                           restart_service_if_needed);
338}
339
340static void msg_start(const char *name)
341{
342    struct service *svc;
343    char *tmp = NULL;
344    char *args = NULL;
345
346    if (!strchr(name, ':'))
347        svc = service_find_by_name(name);
348    else {
349        tmp = strdup(name);
350        args = strchr(tmp, ':');
351        *args = '\0';
352        args++;
353
354        svc = service_find_by_name(tmp);
355    }
356
357    if (svc) {
358        service_start(svc, args);
359    } else {
360        ERROR("no such service '%s'\n", name);
361    }
362    if (tmp)
363        free(tmp);
364}
365
366static void msg_stop(const char *name)
367{
368    struct service *svc = service_find_by_name(name);
369
370    if (svc) {
371        service_stop(svc);
372    } else {
373        ERROR("no such service '%s'\n", name);
374    }
375}
376
377void handle_control_message(const char *msg, const char *arg)
378{
379    if (!strcmp(msg,"start")) {
380        msg_start(arg);
381    } else if (!strcmp(msg,"stop")) {
382        msg_stop(arg);
383    } else {
384        ERROR("unknown control msg '%s'\n", msg);
385    }
386}
387
388static void import_kernel_nv(char *name, int in_qemu)
389{
390    char *value = strchr(name, '=');
391
392    if (value == 0) return;
393    *value++ = 0;
394    if (*name == 0) return;
395
396    if (!in_qemu)
397    {
398        /* on a real device, white-list the kernel options */
399        if (!strcmp(name,"qemu")) {
400            strlcpy(qemu, value, sizeof(qemu));
401        } else if (!strcmp(name,"androidboot.console")) {
402            strlcpy(console, value, sizeof(console));
403        } else if (!strcmp(name,"androidboot.mode")) {
404            strlcpy(bootmode, value, sizeof(bootmode));
405        } else if (!strcmp(name,"androidboot.serialno")) {
406            strlcpy(serialno, value, sizeof(serialno));
407        } else if (!strcmp(name,"androidboot.baseband")) {
408            strlcpy(baseband, value, sizeof(baseband));
409        } else if (!strcmp(name,"androidboot.carrier")) {
410            strlcpy(carrier, value, sizeof(carrier));
411        } else if (!strcmp(name,"androidboot.bootloader")) {
412            strlcpy(bootloader, value, sizeof(bootloader));
413        } else if (!strcmp(name,"androidboot.hardware")) {
414            strlcpy(hardware, value, sizeof(hardware));
415        } else {
416            qemu_cmdline(name, value);
417        }
418    } else {
419        /* in the emulator, export any kernel option with the
420         * ro.kernel. prefix */
421        char  buff[32];
422        int   len = snprintf( buff, sizeof(buff), "ro.kernel.%s", name );
423        if (len < (int)sizeof(buff)) {
424            property_set( buff, value );
425        }
426    }
427}
428
429static void import_kernel_cmdline(int in_qemu)
430{
431    char cmdline[1024];
432    char *ptr;
433    int fd;
434
435    fd = open("/proc/cmdline", O_RDONLY);
436    if (fd >= 0) {
437        int n = read(fd, cmdline, 1023);
438        if (n < 0) n = 0;
439
440        /* get rid of trailing newline, it happens */
441        if (n > 0 && cmdline[n-1] == '\n') n--;
442
443        cmdline[n] = 0;
444        close(fd);
445    } else {
446        cmdline[0] = 0;
447    }
448
449    ptr = cmdline;
450    while (ptr && *ptr) {
451        char *x = strchr(ptr, ' ');
452        if (x != 0) *x++ = 0;
453        import_kernel_nv(ptr, in_qemu);
454        ptr = x;
455    }
456
457        /* don't expose the raw commandline to nonpriv processes */
458    chmod("/proc/cmdline", 0440);
459}
460
461static void get_hardware_name(void)
462{
463    char data[1024];
464    int fd, n;
465    char *x, *hw, *rev;
466
467    /* Hardware string was provided on kernel command line */
468    if (hardware[0])
469        return;
470
471    fd = open("/proc/cpuinfo", O_RDONLY);
472    if (fd < 0) return;
473
474    n = read(fd, data, 1023);
475    close(fd);
476    if (n < 0) return;
477
478    data[n] = 0;
479    hw = strstr(data, "\nHardware");
480    rev = strstr(data, "\nRevision");
481
482    if (hw) {
483        x = strstr(hw, ": ");
484        if (x) {
485            x += 2;
486            n = 0;
487            while (*x && !isspace(*x)) {
488                hardware[n++] = tolower(*x);
489                x++;
490                if (n == 31) break;
491            }
492            hardware[n] = 0;
493        }
494    }
495
496    if (rev) {
497        x = strstr(rev, ": ");
498        if (x) {
499            revision = strtoul(x + 2, 0, 16);
500        }
501    }
502}
503
504static struct command *get_first_command(struct action *act)
505{
506    struct listnode *node;
507    node = list_head(&act->commands);
508    if (!node)
509        return NULL;
510
511    return node_to_item(node, struct command, clist);
512}
513
514static struct command *get_next_command(struct action *act, struct command *cmd)
515{
516    struct listnode *node;
517    node = cmd->clist.next;
518    if (!node)
519        return NULL;
520    if (node == &act->commands)
521        return NULL;
522
523    return node_to_item(node, struct command, clist);
524}
525
526static int is_last_command(struct action *act, struct command *cmd)
527{
528    return (list_tail(&act->commands) == &cmd->clist);
529}
530
531void execute_one_command(void)
532{
533    int ret;
534
535    if (!cur_action || !cur_command || is_last_command(cur_action, cur_command)) {
536        cur_action = action_remove_queue_head();
537        if (!cur_action)
538            return;
539        INFO("processing action %p (%s)\n", cur_action, cur_action->name);
540        cur_command = get_first_command(cur_action);
541    } else {
542        cur_command = get_next_command(cur_action, cur_command);
543    }
544
545    if (!cur_command)
546        return;
547
548    ret = cur_command->func(cur_command->nargs, cur_command->args);
549    INFO("command '%s' r=%d\n", cur_command->args[0], ret);
550}
551
552void open_devnull_stdio(void)
553{
554    int fd;
555    static const char *name = "/dev/__null__";
556    if (mknod(name, S_IFCHR | 0600, (1 << 8) | 3) == 0) {
557        fd = open(name, O_RDWR);
558        unlink(name);
559        if (fd >= 0) {
560            dup2(fd, 0);
561            dup2(fd, 1);
562            dup2(fd, 2);
563            if (fd > 2) {
564                close(fd);
565            }
566            return;
567        }
568    }
569
570    exit(1);
571}
572
573static int device_init_action(int nargs, char **args)
574{
575    INFO("device init\n");
576    device_init();
577    return 0;
578}
579
580static int property_init_action(int nargs, char **args)
581{
582    INFO("property init\n");
583    property_init();
584    return 0;
585}
586
587static int keychord_init_action(int nargs, char **args)
588{
589    keychord_init();
590    return 0;
591}
592
593static int console_init_action(int nargs, char **args)
594{
595    int fd;
596    char tmp[PROP_VALUE_MAX];
597
598    if (console[0]) {
599        snprintf(tmp, sizeof(tmp), "/dev/%s", console);
600        console_name = strdup(tmp);
601    }
602
603    fd = open(console_name, O_RDWR);
604    if (fd >= 0)
605        have_console = 1;
606    close(fd);
607
608    if( load_565rle_image(INIT_IMAGE_FILE) ) {
609        fd = open("/dev/tty0", O_WRONLY);
610        if (fd >= 0) {
611            const char *msg;
612                msg = "\n"
613            "\n"
614            "\n"
615            "\n"
616            "\n"
617            "\n"
618            "\n"  // console is 40 cols x 30 lines
619            "\n"
620            "\n"
621            "\n"
622            "\n"
623            "\n"
624            "\n"
625            "\n"
626            "             A N D R O I D ";
627            write(fd, msg, strlen(msg));
628            close(fd);
629        }
630    }
631    return 0;
632}
633
634static int set_init_properties_action(int nargs, char **args)
635{
636    char tmp[PROP_VALUE_MAX];
637
638    if (qemu[0])
639        import_kernel_cmdline(1);
640
641    if (!strcmp(bootmode,"factory"))
642        property_set("ro.factorytest", "1");
643    else if (!strcmp(bootmode,"factory2"))
644        property_set("ro.factorytest", "2");
645    else
646        property_set("ro.factorytest", "0");
647
648    property_set("ro.serialno", serialno[0] ? serialno : "");
649    property_set("ro.bootmode", bootmode[0] ? bootmode : "unknown");
650    property_set("ro.baseband", baseband[0] ? baseband : "unknown");
651    property_set("ro.carrier", carrier[0] ? carrier : "unknown");
652    property_set("ro.bootloader", bootloader[0] ? bootloader : "unknown");
653
654    property_set("ro.hardware", hardware);
655    snprintf(tmp, PROP_VALUE_MAX, "%d", revision);
656    property_set("ro.revision", tmp);
657    return 0;
658}
659
660static int property_service_init_action(int nargs, char **args)
661{
662    /* read any property files on system or data and
663     * fire up the property service.  This must happen
664     * after the ro.foo properties are set above so
665     * that /data/local.prop cannot interfere with them.
666     */
667    start_property_service();
668    return 0;
669}
670
671static int signal_init_action(int nargs, char **args)
672{
673    signal_init();
674    return 0;
675}
676
677static int check_startup_action(int nargs, char **args)
678{
679    /* make sure we actually have all the pieces we need */
680    if ((get_device_fd() < 0) ||
681        (get_property_set_fd() < 0) ||
682        (get_signal_fd() < 0)) {
683        ERROR("init startup failure\n");
684        exit(1);
685    }
686    return 0;
687}
688
689static int queue_property_triggers_action(int nargs, char **args)
690{
691    queue_all_property_triggers();
692    /* enable property triggers */
693    property_triggers_enabled = 1;
694    return 0;
695}
696
697#if BOOTCHART
698static int bootchart_init_action(int nargs, char **args)
699{
700    bootchart_count = bootchart_init();
701    if (bootchart_count < 0) {
702        ERROR("bootcharting init failure\n");
703    } else if (bootchart_count > 0) {
704        NOTICE("bootcharting started (period=%d ms)\n", bootchart_count*BOOTCHART_POLLING_MS);
705    } else {
706        NOTICE("bootcharting ignored\n");
707    }
708}
709#endif
710
711int main(int argc, char **argv)
712{
713    int fd_count = 0;
714    struct pollfd ufds[4];
715    char *tmpdev;
716    char* debuggable;
717    char tmp[32];
718    int device_fd_init = 0;
719    int property_set_fd_init = 0;
720    int signal_fd_init = 0;
721    int keychord_fd_init = 0;
722
723    /* clear the umask */
724    umask(0);
725
726        /* Get the basic filesystem setup we need put
727         * together in the initramdisk on / and then we'll
728         * let the rc file figure out the rest.
729         */
730    mkdir("/dev", 0755);
731    mkdir("/proc", 0755);
732    mkdir("/sys", 0755);
733
734    mount("tmpfs", "/dev", "tmpfs", 0, "mode=0755");
735    mkdir("/dev/pts", 0755);
736    mkdir("/dev/socket", 0755);
737    mount("devpts", "/dev/pts", "devpts", 0, NULL);
738    mount("proc", "/proc", "proc", 0, NULL);
739    mount("sysfs", "/sys", "sysfs", 0, NULL);
740
741        /* We must have some place other than / to create the
742         * device nodes for kmsg and null, otherwise we won't
743         * be able to remount / read-only later on.
744         * Now that tmpfs is mounted on /dev, we can actually
745         * talk to the outside world.
746         */
747    open_devnull_stdio();
748    log_init();
749
750    INFO("reading config file\n");
751    parse_config_file("/init.rc");
752
753    /* pull the kernel commandline and ramdisk properties file in */
754    qemu_init();
755    import_kernel_cmdline(0);
756
757    get_hardware_name();
758    snprintf(tmp, sizeof(tmp), "/init.%s.rc", hardware);
759    parse_config_file(tmp);
760
761    action_for_each_trigger("early-init", action_add_queue_tail);
762
763    queue_builtin_action(device_init_action, "device_init");
764    queue_builtin_action(property_init_action, "property_init");
765    queue_builtin_action(keychord_init_action, "keychord_init");
766    queue_builtin_action(console_init_action, "console_init");
767    queue_builtin_action(set_init_properties_action, "set_init_properties");
768
769        /* execute all the boot actions to get us started */
770    action_for_each_trigger("init", action_add_queue_tail);
771    action_for_each_trigger("early-fs", action_add_queue_tail);
772    action_for_each_trigger("fs", action_add_queue_tail);
773    action_for_each_trigger("post-fs", action_add_queue_tail);
774
775    queue_builtin_action(property_service_init_action, "property_service_init");
776    queue_builtin_action(signal_init_action, "signal_init");
777    queue_builtin_action(check_startup_action, "check_startup");
778
779    /* execute all the boot actions to get us started */
780    action_for_each_trigger("early-boot", action_add_queue_tail);
781    action_for_each_trigger("boot", action_add_queue_tail);
782
783        /* run all property triggers based on current state of the properties */
784    queue_builtin_action(queue_property_triggers_action, "queue_propety_triggers");
785
786
787#if BOOTCHART
788    queue_builtin_action(bootchart_init_action, "bootchart_init");
789#endif
790
791    for(;;) {
792        int nr, i, timeout = -1;
793
794        execute_one_command();
795        restart_processes();
796
797        if (!device_fd_init && get_device_fd() > 0) {
798            ufds[fd_count].fd = get_device_fd();
799            ufds[fd_count].events = POLLIN;
800            ufds[fd_count].revents = 0;
801            fd_count++;
802            device_fd_init = 1;
803        }
804        if (!property_set_fd_init && get_property_set_fd() > 0) {
805            ufds[fd_count].fd = get_property_set_fd();
806            ufds[fd_count].events = POLLIN;
807            ufds[fd_count].revents = 0;
808            fd_count++;
809            property_set_fd_init = 1;
810        }
811        if (!signal_fd_init && get_signal_fd() > 0) {
812            ufds[fd_count].fd = get_signal_fd();
813            ufds[fd_count].events = POLLIN;
814            ufds[fd_count].revents = 0;
815            fd_count++;
816            signal_fd_init = 1;
817        }
818        if (!keychord_fd_init && get_keychord_fd() > 0) {
819            ufds[fd_count].fd = get_keychord_fd();
820            ufds[fd_count].events = POLLIN;
821            ufds[fd_count].revents = 0;
822            fd_count++;
823            keychord_fd_init = 1;
824        }
825
826        if (process_needs_restart) {
827            timeout = (process_needs_restart - gettime()) * 1000;
828            if (timeout < 0)
829                timeout = 0;
830        }
831
832        if (!action_queue_empty() || cur_command)
833            timeout = 0;
834
835#if BOOTCHART
836        if (bootchart_count > 0) {
837            if (timeout < 0 || timeout > BOOTCHART_POLLING_MS)
838                timeout = BOOTCHART_POLLING_MS;
839            if (bootchart_step() < 0 || --bootchart_count == 0) {
840                bootchart_finish();
841                bootchart_count = 0;
842            }
843        }
844#endif
845
846        nr = poll(ufds, fd_count, timeout);
847        if (nr <= 0)
848            continue;
849
850        for (i = 0; i < fd_count; i++) {
851            if (ufds[i].revents == POLLIN) {
852                if (ufds[i].fd == get_device_fd())
853                    handle_device_fd();
854                else if (ufds[i].fd == get_property_set_fd())
855                    handle_property_set_fd();
856                else if (ufds[i].fd == get_keychord_fd())
857                    handle_keychord();
858                else if (ufds[i].fd == get_signal_fd())
859                    handle_signal();
860            }
861        }
862    }
863
864    return 0;
865}
866