summaryrefslogtreecommitdiffstats
path: root/adb/fdevent.c
blob: 43e600cb3c8febeafaf3eeff6a23e883f5cb24a8 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
/* http://frotznet.googlecode.com/svn/trunk/utils/fdevent.c
**
** Copyright 2006, Brian Swetland <swetland@frotz.net>
**
** Licensed 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 <sys/ioctl.h>

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>

#include <fcntl.h>

#include <stdarg.h>
#include <stddef.h>

#include "adb_trace.h"
#include "fdevent.h"
#include "transport.h"
#include "sysdeps.h"

#define TRACE_TAG  TRACE_FDEVENT

/* !!! Do not enable DEBUG for the adb that will run as the server:
** both stdout and stderr are used to communicate between the client
** and server. Any extra output will cause failures.
*/
#define DEBUG 0   /* non-0 will break adb server */

// This socket is used when a subproc shell service exists.
// It wakes up the fdevent_loop() and cause the correct handling
// of the shell's pseudo-tty master. I.e. force close it.
int SHELL_EXIT_NOTIFY_FD = -1;

static void fatal(const char *fn, const char *fmt, ...)
{
    va_list ap;
    va_start(ap, fmt);
    fprintf(stderr, "%s:", fn);
    vfprintf(stderr, fmt, ap);
    va_end(ap);
    abort();
}

#define FATAL(x...) fatal(__FUNCTION__, x)

#if DEBUG
static void dump_fde(fdevent *fde, const char *info)
{
    adb_mutex_lock(&D_lock);
    fprintf(stderr,"FDE #%03d %c%c%c %s\n", fde->fd,
            fde->state & FDE_READ ? 'R' : ' ',
            fde->state & FDE_WRITE ? 'W' : ' ',
            fde->state & FDE_ERROR ? 'E' : ' ',
            info);
    adb_mutex_unlock(&D_lock);
}
#else
#define dump_fde(fde, info) do { } while(0)
#endif

#define FDE_EVENTMASK  0x00ff
#define FDE_STATEMASK  0xff00

#define FDE_ACTIVE     0x0100
#define FDE_PENDING    0x0200
#define FDE_CREATED    0x0400

static void fdevent_plist_enqueue(fdevent *node);
static void fdevent_plist_remove(fdevent *node);
static fdevent *fdevent_plist_dequeue(void);
static void fdevent_subproc_event_func(int fd, unsigned events, void *userdata);

static fdevent list_pending = {
    .next = &list_pending,
    .prev = &list_pending,
};

static fdevent **fd_table = 0;
static int fd_table_max = 0;

#ifdef CRAPTASTIC
//HAVE_EPOLL

#include <sys/epoll.h>

static int epoll_fd = -1;

static void fdevent_init()
{
        /* XXX: what's a good size for the passed in hint? */
    epoll_fd = epoll_create(256);

    if(epoll_fd < 0) {
        perror("epoll_create() failed");
        exit(1);
    }

        /* mark for close-on-exec */
    fcntl(epoll_fd, F_SETFD, FD_CLOEXEC);
}

static void fdevent_connect(fdevent *fde)
{
    struct epoll_event ev;

    memset(&ev, 0, sizeof(ev));
    ev.events = 0;
    ev.data.ptr = fde;

#if 0
    if(epoll_ctl(epoll_fd, EPOLL_CTL_ADD, fde->fd, &ev)) {
        perror("epoll_ctl() failed\n");
        exit(1);
    }
#endif
}

static void fdevent_disconnect(fdevent *fde)
{
    struct epoll_event ev;

    memset(&ev, 0, sizeof(ev));
    ev.events = 0;
    ev.data.ptr = fde;

        /* technically we only need to delete if we
        ** were actively monitoring events, but let's
        ** be aggressive and do it anyway, just in case
        ** something's out of sync
        */
    epoll_ctl(epoll_fd, EPOLL_CTL_DEL, fde->fd, &ev);
}

static void fdevent_update(fdevent *fde, unsigned events)
{
    struct epoll_event ev;
    int active;

    active = (fde->state & FDE_EVENTMASK) != 0;

    memset(&ev, 0, sizeof(ev));
    ev.events = 0;
    ev.data.ptr = fde;

    if(events & FDE_READ) ev.events |= EPOLLIN;
    if(events & FDE_WRITE) ev.events |= EPOLLOUT;
    if(events & FDE_ERROR) ev.events |= (EPOLLERR | EPOLLHUP);

    fde->state = (fde->state & FDE_STATEMASK) | events;

    if(active) {
            /* we're already active. if we're changing to *no*
            ** events being monitored, we need to delete, otherwise
            ** we need to just modify
            */
        if(ev.events) {
            if(epoll_ctl(epoll_fd, EPOLL_CTL_MOD, fde->fd, &ev)) {
                perror("epoll_ctl() failed\n");
                exit(1);
            }
        } else {
            if(epoll_ctl(epoll_fd, EPOLL_CTL_DEL, fde->fd, &ev)) {
                perror("epoll_ctl() failed\n");
                exit(1);
            }
        }
    } else {
            /* we're not active.  if we're watching events, we need
            ** to add, otherwise we can just do nothing
            */
        if(ev.events) {
            if(epoll_ctl(epoll_fd, EPOLL_CTL_ADD, fde->fd, &ev)) {
                perror("epoll_ctl() failed\n");
                exit(1);
            }
        }
    }
}

static void fdevent_process()
{
    struct epoll_event events[256];
    fdevent *fde;
    int i, n;

    n = epoll_wait(epoll_fd, events, 256, -1);

    if(n < 0) {
        if(errno == EINTR) return;
        perror("epoll_wait");
        exit(1);
    }

    for(i = 0; i < n; i++) {
        struct epoll_event *ev = events + i;
        fde = ev->data.ptr;

        if(ev->events & EPOLLIN) {
            fde->events |= FDE_READ;
        }
        if(ev->events & EPOLLOUT) {
            fde->events |= FDE_WRITE;
        }
        if(ev->events & (EPOLLERR | EPOLLHUP)) {
            fde->events |= FDE_ERROR;
        }
        if(fde->events) {
            if(fde->state & FDE_PENDING) continue;
            fde->state |= FDE_PENDING;
            fdevent_plist_enqueue(fde);
        }
    }
}

#else /* USE_SELECT */

#ifdef HAVE_WINSOCK
#include <winsock2.h>
#else
#include <sys/select.h>
#endif

static fd_set read_fds;
static fd_set write_fds;
static fd_set error_fds;

static int select_n = 0;

static void fdevent_init(void)
{
    FD_ZERO(&read_fds);
    FD_ZERO(&write_fds);
    FD_ZERO(&error_fds);
}

static void fdevent_connect(fdevent *fde)
{
    if(fde->fd >= select_n) {
        select_n = fde->fd + 1;
    }
}

static void fdevent_disconnect(fdevent *fde)
{
    int i, n;

    FD_CLR(fde->fd, &read_fds);
    FD_CLR(fde->fd, &write_fds);
    FD_CLR(fde->fd, &error_fds);

    for(n = 0, i = 0; i < select_n; i++) {
        if(fd_table[i] != 0) n = i;
    }
    select_n = n + 1;
}

static void fdevent_update(fdevent *fde, unsigned events)
{
    if(events & FDE_READ) {
        FD_SET(fde->fd, &read_fds);
    } else {
        FD_CLR(fde->fd, &read_fds);
    }
    if(events & FDE_WRITE) {
        FD_SET(fde->fd, &write_fds);
    } else {
        FD_CLR(fde->fd, &write_fds);
    }
    if(events & FDE_ERROR) {
        FD_SET(fde->fd, &error_fds);
    } else {
        FD_CLR(fde->fd, &error_fds);
    }

    fde->state = (fde->state & FDE_STATEMASK) | events;
}

/* Looks at fd_table[] for bad FDs and sets bit in fds.
** Returns the number of bad FDs.
*/
static int fdevent_fd_check(fd_set *fds)
{
    int i, n = 0;
    fdevent *fde;

    for(i = 0; i < select_n; i++) {
        fde = fd_table[i];
        if(fde == 0) continue;
        if(fcntl(i, F_GETFL, NULL) < 0) {
            FD_SET(i, fds);
            n++;
            // fde->state |= FDE_DONT_CLOSE;

        }
    }
    return n;
}

#if !DEBUG
static inline void dump_all_fds(const char *extra_msg) {}
#else
static void dump_all_fds(const char *extra_msg)
{
int i;
    fdevent *fde;
    // per fd: 4 digits (but really: log10(FD_SETSIZE)), 1 staus, 1 blank
    char msg_buff[FD_SETSIZE*6 + 1], *pb=msg_buff;
    size_t max_chars = FD_SETSIZE * 6 + 1;
    int printed_out;
#define SAFE_SPRINTF(...)                                                    \
    do {                                                                     \
        printed_out = snprintf(pb, max_chars, __VA_ARGS__);                  \
        if (printed_out <= 0) {                                              \
            D("... snprintf failed.\n");                                     \
            return;                                                          \
        }                                                                    \
        if (max_chars < (unsigned int)printed_out) {                         \
            D("... snprintf out of space.\n");                               \
            return;                                                          \
        }                                                                    \
        pb += printed_out;                                                   \
        max_chars -= printed_out;                                            \
    } while(0)

    for(i = 0; i < select_n; i++) {
        fde = fd_table[i];
        SAFE_SPRINTF("%d", i);
        if(fde == 0) {
            SAFE_SPRINTF("? ");
            continue;
        }
        if(fcntl(i, F_GETFL, NULL) < 0) {
            SAFE_SPRINTF("b");
        }
        SAFE_SPRINTF(" ");
    }
    D("%s fd_table[]->fd = {%s}\n", extra_msg, msg_buff);
}
#endif

static void fdevent_process()
{
    int i, n;
    fdevent *fde;
    unsigned events;
    fd_set rfd, wfd, efd;

    memcpy(&rfd, &read_fds, sizeof(fd_set));
    memcpy(&wfd, &write_fds, sizeof(fd_set));
    memcpy(&efd, &error_fds, sizeof(fd_set));

    dump_all_fds("pre select()");

    n = select(select_n, &rfd, &wfd, &efd, NULL);
    int saved_errno = errno;
    D("select() returned n=%d, errno=%d\n", n, n<0?saved_errno:0);

    dump_all_fds("post select()");

    if(n < 0) {
        switch(saved_errno) {
        case EINTR: return;
        case EBADF:
            // Can't trust the FD sets after an error.
            FD_ZERO(&wfd);
            FD_ZERO(&efd);
            FD_ZERO(&rfd);
            break;
        default:
            D("Unexpected select() error=%d\n", saved_errno);
            return;
        }
    }
    if(n <= 0) {
        // We fake a read, as the rest of the code assumes
        // that errors will be detected at that point.
        n = fdevent_fd_check(&rfd);
    }

    for(i = 0; (i < select_n) && (n > 0); i++) {
        events = 0;
        if(FD_ISSET(i, &rfd)) { events |= FDE_READ; n--; }
        if(FD_ISSET(i, &wfd)) { events |= FDE_WRITE; n--; }
        if(FD_ISSET(i, &efd)) { events |= FDE_ERROR; n--; }

        if(events) {
            fde = fd_table[i];
            if(fde == 0)
              FATAL("missing fde for fd %d\n", i);

            fde->events |= events;

            D("got events fde->fd=%d events=%04x, state=%04x\n",
                fde->fd, fde->events, fde->state);
            if(fde->state & FDE_PENDING) continue;
            fde->state |= FDE_PENDING;
            fdevent_plist_enqueue(fde);
        }
    }
}

#endif

static void fdevent_register(fdevent *fde)
{
    if(fde->fd < 0) {
        FATAL("bogus negative fd (%d)\n", fde->fd);
    }

    if(fde->fd >= fd_table_max) {
        int oldmax = fd_table_max;
        if(fde->fd > 32000) {
            FATAL("bogus huuuuge fd (%d)\n", fde->fd);
        }
        if(fd_table_max == 0) {
            fdevent_init();
            fd_table_max = 256;
        }
        while(fd_table_max <= fde->fd) {
            fd_table_max *= 2;
        }
        fd_table = realloc(fd_table, sizeof(fdevent*) * fd_table_max);
        if(fd_table == 0) {
            FATAL("could not expand fd_table to %d entries\n", fd_table_max);
        }
        memset(fd_table + oldmax, 0, sizeof(int) * (fd_table_max - oldmax));
    }

    fd_table[fde->fd] = fde;
}

static void fdevent_unregister(fdevent *fde)
{
    if((fde->fd < 0) || (fde->fd >= fd_table_max)) {
        FATAL("fd out of range (%d)\n", fde->fd);
    }

    if(fd_table[fde->fd] != fde) {
        FATAL("fd_table out of sync [%d]\n", fde->fd);
    }

    fd_table[fde->fd] = 0;

    if(!(fde->state & FDE_DONT_CLOSE)) {
        dump_fde(fde, "close");
        adb_close(fde->fd);
    }
}

static void fdevent_plist_enqueue(fdevent *node)
{
    fdevent *list = &list_pending;

    node->next = list;
    node->prev = list->prev;
    node->prev->next = node;
    list->prev = node;
}

static void fdevent_plist_remove(fdevent *node)
{
    node->prev->next = node->next;
    node->next->prev = node->prev;
    node->next = 0;
    node->prev = 0;
}

static fdevent *fdevent_plist_dequeue(void)
{
    fdevent *list = &list_pending;
    fdevent *node = list->next;

    if(node == list) return 0;

    list->next = node->next;
    list->next->prev = list;
    node->next = 0;
    node->prev = 0;

    return node;
}

static void fdevent_call_fdfunc(fdevent* fde)
{
    unsigned events = fde->events;
    fde->events = 0;
    if(!(fde->state & FDE_PENDING)) return;
    fde->state &= (~FDE_PENDING);
    dump_fde(fde, "callback");
    fde->func(fde->fd, events, fde->arg);
}

static void fdevent_subproc_event_func(int fd, unsigned ev, void *userdata)
{

    D("subproc handling on fd=%d ev=%04x\n", fd, ev);

    // Hook oneself back into the fde's suitable for select() on read.
    if((fd < 0) || (fd >= fd_table_max)) {
        FATAL("fd %d out of range for fd_table \n", fd);
    }
    fdevent *fde = fd_table[fd];
    fdevent_add(fde, FDE_READ);

    if(ev & FDE_READ){
      int subproc_fd;

      if(readx(fd, &subproc_fd, sizeof(subproc_fd))) {
          FATAL("Failed to read the subproc's fd from fd=%d\n", fd);
      }
      if((subproc_fd < 0) || (subproc_fd >= fd_table_max)) {
          D("subproc_fd %d out of range 0, fd_table_max=%d\n",
            subproc_fd, fd_table_max);
          return;
      }
      fdevent *subproc_fde = fd_table[subproc_fd];
      if(!subproc_fde) {
          D("subproc_fd %d cleared from fd_table\n", subproc_fd);
          return;
      }
      if(subproc_fde->fd != subproc_fd) {
          // Already reallocated?
          D("subproc_fd %d != fd_table[].fd %d\n", subproc_fd, subproc_fde->fd);
          return;
      }

      subproc_fde->force_eof = 1;

      int rcount = 0;
      ioctl(subproc_fd, FIONREAD, &rcount);
      D("subproc with fd=%d  has rcount=%d err=%d\n",
        subproc_fd, rcount, errno);

      if(rcount) {
        // If there is data left, it will show up in the select().
        // This works because there is no other thread reading that
        // data when in this fd_func().
        return;
      }

      D("subproc_fde.state=%04x\n", subproc_fde->state);
      subproc_fde->events |= FDE_READ;
      if(subproc_fde->state & FDE_PENDING) {
        return;
      }
      subproc_fde->state |= FDE_PENDING;
      fdevent_call_fdfunc(subproc_fde);
    }
}

fdevent *fdevent_create(int fd, fd_func func, void *arg)
{
    fdevent *fde = (fdevent*) malloc(sizeof(fdevent));
    if(fde == 0) return 0;
    fdevent_install(fde, fd, func, arg);
    fde->state |= FDE_CREATED;
    return fde;
}

void fdevent_destroy(fdevent *fde)
{
    if(fde == 0) return;
    if(!(fde->state & FDE_CREATED)) {
        FATAL("fde %p not created by fdevent_create()\n", fde);
    }
    fdevent_remove(fde);
}

void fdevent_install(fdevent *fde, int fd, fd_func func, void *arg)
{
    memset(fde, 0, sizeof(fdevent));
    fde->state = FDE_ACTIVE;
    fde->fd = fd;
    fde->force_eof = 0;
    fde->func = func;
    fde->arg = arg;

#ifndef HAVE_WINSOCK
    fcntl(fd, F_SETFL, O_NONBLOCK);
#endif
    fdevent_register(fde);
    dump_fde(fde, "connect");
    fdevent_connect(fde);
    fde->state |= FDE_ACTIVE;
}

void fdevent_remove(fdevent *fde)
{
    if(fde->state & FDE_PENDING) {
        fdevent_plist_remove(fde);
    }

    if(fde->state & FDE_ACTIVE) {
        fdevent_disconnect(fde);
        dump_fde(fde, "disconnect");
        fdevent_unregister(fde);
    }

    fde->state = 0;
    fde->events = 0;
}


void fdevent_set(fdevent *fde, unsigned events)
{
    events &= FDE_EVENTMASK;

    if((fde->state & FDE_EVENTMASK) == events) return;

    if(fde->state & FDE_ACTIVE) {
        fdevent_update(fde, events);
        dump_fde(fde, "update");
    }

    fde->state = (fde->state & FDE_STATEMASK) | events;

    if(fde->state & FDE_PENDING) {
            /* if we're pending, make sure
            ** we don't signal an event that
            ** is no longer wanted.
            */
        fde->events &= (~events);
        if(fde->events == 0) {
            fdevent_plist_remove(fde);
            fde->state &= (~FDE_PENDING);
        }
    }
}

void fdevent_add(fdevent *fde, unsigned events)
{
    fdevent_set(
        fde, (fde->state & FDE_EVENTMASK) | (events & FDE_EVENTMASK));
}

void fdevent_del(fdevent *fde, unsigned events)
{
    fdevent_set(
        fde, (fde->state & FDE_EVENTMASK) & (~(events & FDE_EVENTMASK)));
}

void fdevent_subproc_setup()
{
    int s[2];

    if(adb_socketpair(s)) {
        FATAL("cannot create shell-exit socket-pair\n");
    }
    SHELL_EXIT_NOTIFY_FD = s[0];
    fdevent *fde;
    fde = fdevent_create(s[1], fdevent_subproc_event_func, NULL);
    if(!fde)
      FATAL("cannot create fdevent for shell-exit handler\n");
    fdevent_add(fde, FDE_READ);
}

void fdevent_loop()
{
    fdevent *fde;
    fdevent_subproc_setup();

    for(;;) {
        D("--- ---- waiting for events\n");

        fdevent_process();

        while((fde = fdevent_plist_dequeue())) {
            fdevent_call_fdfunc(fde);
        }
    }
}