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authorThe Android Open Source Project2009-03-03 21:32:55 -0600
committerThe Android Open Source Project2009-03-03 21:32:55 -0600
commitdd7bc3319deb2b77c5d07a51b7d6cd7e11b5beb0 (patch)
tree2ba8d1a0846d69b18f623515e8d9b5d9fe38b590 /liblog/fake_log_device.c
parente54eebbf1a908d65ee8cf80bab62821c05666d70 (diff)
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auto import from //depot/cupcake/@135843
Diffstat (limited to 'liblog/fake_log_device.c')
-rw-r--r--liblog/fake_log_device.c685
1 files changed, 685 insertions, 0 deletions
diff --git a/liblog/fake_log_device.c b/liblog/fake_log_device.c
new file mode 100644
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+++ b/liblog/fake_log_device.c
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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 * Intercepts log messages intended for the Android log device.
18 * When running in the context of the simulator, the messages are
19 * passed on to the underlying (fake) log device. When not in the
20 * simulator, messages are printed to stderr.
21 */
22#include "cutils/logd.h"
23
24#include <stdlib.h>
25#include <string.h>
26#include <ctype.h>
27#include <errno.h>
28#include <fcntl.h>
29
30#ifdef HAVE_PTHREADS
31#include <pthread.h>
32#endif
33
34#define kMaxTagLen 16 /* from the long-dead utils/Log.cpp */
35
36#define kTagSetSize 16 /* arbitrary */
37
38#if 0
39#define TRACE(...) printf("fake_log_device: " __VA_ARGS__)
40#else
41#define TRACE(...) ((void)0)
42#endif
43
44/* from the long-dead utils/Log.cpp */
45typedef enum {
46 FORMAT_OFF = 0,
47 FORMAT_BRIEF,
48 FORMAT_PROCESS,
49 FORMAT_TAG,
50 FORMAT_THREAD,
51 FORMAT_RAW,
52 FORMAT_TIME,
53 FORMAT_THREADTIME,
54 FORMAT_LONG
55} LogFormat;
56
57
58/*
59 * Log driver state.
60 */
61typedef struct LogState {
62 /* the fake fd that's seen by the user */
63 int fakeFd;
64
65 /* a printable name for this fake device */
66 char *debugName;
67
68 /* nonzero if this is a binary log */
69 int isBinary;
70
71 /* global minimum priority */
72 int globalMinPriority;
73
74 /* output format */
75 LogFormat outputFormat;
76
77 /* tags and priorities */
78 struct {
79 char tag[kMaxTagLen];
80 int minPriority;
81 } tagSet[kTagSetSize];
82} LogState;
83
84
85#ifdef HAVE_PTHREADS
86/*
87 * Locking. Since we're emulating a device, we need to be prepared
88 * to have multiple callers at the same time. This lock is used
89 * to both protect the fd list and to prevent LogStates from being
90 * freed out from under a user.
91 */
92static pthread_mutex_t fakeLogDeviceLock = PTHREAD_MUTEX_INITIALIZER;
93
94static void lock()
95{
96 pthread_mutex_lock(&fakeLogDeviceLock);
97}
98
99static void unlock()
100{
101 pthread_mutex_unlock(&fakeLogDeviceLock);
102}
103#else // !HAVE_PTHREADS
104#define lock() ((void)0)
105#define unlock() ((void)0)
106#endif // !HAVE_PTHREADS
107
108
109/*
110 * File descriptor management.
111 */
112#define FAKE_FD_BASE 10000
113#define MAX_OPEN_LOGS 16
114static LogState *openLogTable[MAX_OPEN_LOGS];
115
116/*
117 * Allocate an fd and associate a new LogState with it.
118 * The fd is available via the fakeFd field of the return value.
119 */
120static LogState *createLogState()
121{
122 size_t i;
123
124 for (i = 0; i < sizeof(openLogTable); i++) {
125 if (openLogTable[i] == NULL) {
126 openLogTable[i] = calloc(1, sizeof(LogState));
127 openLogTable[i]->fakeFd = FAKE_FD_BASE + i;
128 return openLogTable[i];
129 }
130 }
131 return NULL;
132}
133
134/*
135 * Translate an fd to a LogState.
136 */
137static LogState *fdToLogState(int fd)
138{
139 if (fd >= FAKE_FD_BASE && fd < FAKE_FD_BASE + MAX_OPEN_LOGS) {
140 return openLogTable[fd - FAKE_FD_BASE];
141 }
142 return NULL;
143}
144
145/*
146 * Unregister the fake fd and free the memory it pointed to.
147 */
148static void deleteFakeFd(int fd)
149{
150 LogState *ls;
151
152 lock();
153
154 ls = fdToLogState(fd);
155 if (ls != NULL) {
156 openLogTable[fd - FAKE_FD_BASE] = NULL;
157 free(ls->debugName);
158 free(ls);
159 }
160
161 unlock();
162}
163
164/*
165 * Configure logging based on ANDROID_LOG_TAGS environment variable. We
166 * need to parse a string that looks like
167 *
168 * *:v jdwp:d dalvikvm:d dalvikvm-gc:i dalvikvmi:i
169 *
170 * The tag (or '*' for the global level) comes first, followed by a colon
171 * and a letter indicating the minimum priority level we're expected to log.
172 * This can be used to reveal or conceal logs with specific tags.
173 *
174 * We also want to check ANDROID_PRINTF_LOG to determine how the output
175 * will look.
176 */
177static void configureInitialState(const char* pathName, LogState* logState)
178{
179 static const int kDevLogLen = sizeof("/dev/log/") - 1;
180
181 logState->debugName = strdup(pathName);
182
183 /* identify binary logs */
184 if (strcmp(pathName + kDevLogLen, "events") == 0) {
185 logState->isBinary = 1;
186 }
187
188 /* global min priority defaults to "info" level */
189 logState->globalMinPriority = ANDROID_LOG_INFO;
190
191 /*
192 * This is based on the the long-dead utils/Log.cpp code.
193 */
194 const char* tags = getenv("ANDROID_LOG_TAGS");
195 TRACE("Found ANDROID_LOG_TAGS='%s'\n", tags);
196 if (tags != NULL) {
197 int entry = 0;
198
199 while (*tags != '\0') {
200 char tagName[kMaxTagLen];
201 int i, minPrio;
202
203 while (isspace(*tags))
204 tags++;
205
206 i = 0;
207 while (*tags != '\0' && !isspace(*tags) && *tags != ':' &&
208 i < kMaxTagLen)
209 {
210 tagName[i++] = *tags++;
211 }
212 if (i == kMaxTagLen) {
213 TRACE("ERROR: env tag too long (%d chars max)\n", kMaxTagLen-1);
214 return;
215 }
216 tagName[i] = '\0';
217
218 /* default priority, if there's no ":" part; also zero out '*' */
219 minPrio = ANDROID_LOG_VERBOSE;
220 if (tagName[0] == '*' && tagName[1] == '\0') {
221 minPrio = ANDROID_LOG_DEBUG;
222 tagName[0] = '\0';
223 }
224
225 if (*tags == ':') {
226 tags++;
227 if (*tags >= '0' && *tags <= '9') {
228 if (*tags >= ('0' + ANDROID_LOG_SILENT))
229 minPrio = ANDROID_LOG_VERBOSE;
230 else
231 minPrio = *tags - '\0';
232 } else {
233 switch (*tags) {
234 case 'v': minPrio = ANDROID_LOG_VERBOSE; break;
235 case 'd': minPrio = ANDROID_LOG_DEBUG; break;
236 case 'i': minPrio = ANDROID_LOG_INFO; break;
237 case 'w': minPrio = ANDROID_LOG_WARN; break;
238 case 'e': minPrio = ANDROID_LOG_ERROR; break;
239 case 'f': minPrio = ANDROID_LOG_FATAL; break;
240 case 's': minPrio = ANDROID_LOG_SILENT; break;
241 default: minPrio = ANDROID_LOG_DEFAULT; break;
242 }
243 }
244
245 tags++;
246 if (*tags != '\0' && !isspace(*tags)) {
247 TRACE("ERROR: garbage in tag env; expected whitespace\n");
248 TRACE(" env='%s'\n", tags);
249 return;
250 }
251 }
252
253 if (tagName[0] == 0) {
254 logState->globalMinPriority = minPrio;
255 TRACE("+++ global min prio %d\n", logState->globalMinPriority);
256 } else {
257 logState->tagSet[entry].minPriority = minPrio;
258 strcpy(logState->tagSet[entry].tag, tagName);
259 TRACE("+++ entry %d: %s:%d\n",
260 entry,
261 logState->tagSet[entry].tag,
262 logState->tagSet[entry].minPriority);
263 entry++;
264 }
265 }
266 }
267
268
269 /*
270 * Taken from the long-dead utils/Log.cpp
271 */
272 const char* fstr = getenv("ANDROID_PRINTF_LOG");
273 LogFormat format;
274 if (fstr == NULL) {
275 format = FORMAT_BRIEF;
276 } else {
277 if (strcmp(fstr, "brief") == 0)
278 format = FORMAT_BRIEF;
279 else if (strcmp(fstr, "process") == 0)
280 format = FORMAT_PROCESS;
281 else if (strcmp(fstr, "tag") == 0)
282 format = FORMAT_PROCESS;
283 else if (strcmp(fstr, "thread") == 0)
284 format = FORMAT_PROCESS;
285 else if (strcmp(fstr, "raw") == 0)
286 format = FORMAT_PROCESS;
287 else if (strcmp(fstr, "time") == 0)
288 format = FORMAT_PROCESS;
289 else if (strcmp(fstr, "long") == 0)
290 format = FORMAT_PROCESS;
291 else
292 format = (LogFormat) atoi(fstr); // really?!
293 }
294
295 logState->outputFormat = format;
296}
297
298/*
299 * Return a human-readable string for the priority level. Always returns
300 * a valid string.
301 */
302static const char* getPriorityString(int priority)
303{
304 /* the first character of each string should be unique */
305 static const char* priorityStrings[] = {
306 "Verbose", "Debug", "Info", "Warn", "Error", "Assert"
307 };
308 int idx;
309
310 idx = (int) priority - (int) ANDROID_LOG_VERBOSE;
311 if (idx < 0 ||
312 idx >= (int) (sizeof(priorityStrings) / sizeof(priorityStrings[0])))
313 return "?unknown?";
314 return priorityStrings[idx];
315}
316
317#ifndef HAVE_WRITEV
318/*
319 * Some platforms like WIN32 do not have writev().
320 * Make up something to replace it.
321 */
322static ssize_t fake_writev(int fd, const struct iovec *iov, int iovcnt) {
323 int result = 0;
324 struct iovec* end = iov + iovcnt;
325 for (; iov < end; iov++) {
326 int w = write(fd, iov->iov_base, iov->iov_len);
327 if (w != iov->iov_len) {
328 if (w < 0)
329 return w;
330 return result + w;
331 }
332 result += w;
333 }
334 return result;
335}
336
337#define writev fake_writev
338#endif
339
340
341/*
342 * Write a filtered log message to stderr.
343 *
344 * Log format parsing taken from the long-dead utils/Log.cpp.
345 */
346static void showLog(LogState *state,
347 int logPrio, const char* tag, const char* msg)
348{
349#if defined(HAVE_LOCALTIME_R)
350 struct tm tmBuf;
351#endif
352 struct tm* ptm;
353 char timeBuf[32];
354 char prefixBuf[128], suffixBuf[128];
355 char priChar;
356 time_t when;
357 pid_t pid, tid;
358
359 TRACE("LOG %d: %s %s", logPrio, tag, msg);
360
361 priChar = getPriorityString(logPrio)[0];
362 when = time(NULL);
363 pid = tid = getpid(); // find gettid()?
364
365 /*
366 * Get the current date/time in pretty form
367 *
368 * It's often useful when examining a log with "less" to jump to
369 * a specific point in the file by searching for the date/time stamp.
370 * For this reason it's very annoying to have regexp meta characters
371 * in the time stamp. Don't use forward slashes, parenthesis,
372 * brackets, asterisks, or other special chars here.
373 */
374#if defined(HAVE_LOCALTIME_R)
375 ptm = localtime_r(&when, &tmBuf);
376#else
377 ptm = localtime(&when);
378#endif
379 //strftime(timeBuf, sizeof(timeBuf), "%Y-%m-%d %H:%M:%S", ptm);
380 strftime(timeBuf, sizeof(timeBuf), "%m-%d %H:%M:%S", ptm);
381
382 /*
383 * Construct a buffer containing the log header and log message.
384 */
385 size_t prefixLen, suffixLen;
386
387 switch (state->outputFormat) {
388 case FORMAT_TAG:
389 prefixLen = snprintf(prefixBuf, sizeof(prefixBuf),
390 "%c/%-8s: ", priChar, tag);
391 strcpy(suffixBuf, "\n"); suffixLen = 1;
392 break;
393 case FORMAT_PROCESS:
394 prefixLen = snprintf(prefixBuf, sizeof(prefixBuf),
395 "%c(%5d) ", priChar, pid);
396 suffixLen = snprintf(suffixBuf, sizeof(suffixBuf),
397 " (%s)\n", tag);
398 break;
399 case FORMAT_THREAD:
400 prefixLen = snprintf(prefixBuf, sizeof(prefixBuf),
401 "%c(%5d:%p) ", priChar, pid, (void*)tid);
402 strcpy(suffixBuf, "\n"); suffixLen = 1;
403 break;
404 case FORMAT_RAW:
405 prefixBuf[0] = 0; prefixLen = 0;
406 strcpy(suffixBuf, "\n"); suffixLen = 1;
407 break;
408 case FORMAT_TIME:
409 prefixLen = snprintf(prefixBuf, sizeof(prefixBuf),
410 "%s %-8s\n\t", timeBuf, tag);
411 strcpy(suffixBuf, "\n"); suffixLen = 1;
412 break;
413 case FORMAT_THREADTIME:
414 prefixLen = snprintf(prefixBuf, sizeof(prefixBuf),
415 "%s %5d %5d %c %-8s \n\t", timeBuf, pid, tid, priChar, tag);
416 strcpy(suffixBuf, "\n"); suffixLen = 1;
417 break;
418 case FORMAT_LONG:
419 prefixLen = snprintf(prefixBuf, sizeof(prefixBuf),
420 "[ %s %5d:%p %c/%-8s ]\n",
421 timeBuf, pid, (void*)tid, priChar, tag);
422 strcpy(suffixBuf, "\n\n"); suffixLen = 2;
423 break;
424 default:
425 prefixLen = snprintf(prefixBuf, sizeof(prefixBuf),
426 "%c/%-8s(%5d): ", priChar, tag, pid);
427 strcpy(suffixBuf, "\n"); suffixLen = 1;
428 break;
429 }
430
431 /*
432 * Figure out how many lines there will be.
433 */
434 const char* end = msg + strlen(msg);
435 size_t numLines = 0;
436 const char* p = msg;
437 while (p < end) {
438 if (*p++ == '\n') numLines++;
439 }
440 if (p > msg && *(p-1) != '\n') numLines++;
441
442 /*
443 * Create an array of iovecs large enough to write all of
444 * the lines with a prefix and a suffix.
445 */
446 const size_t INLINE_VECS = 6;
447 const size_t MAX_LINES = ((size_t)~0)/(3*sizeof(struct iovec*));
448 struct iovec stackVec[INLINE_VECS];
449 struct iovec* vec = stackVec;
450 size_t numVecs;
451
452 if (numLines > MAX_LINES)
453 numLines = MAX_LINES;
454
455 numVecs = numLines*3; // 3 iovecs per line.
456 if (numVecs > INLINE_VECS) {
457 vec = (struct iovec*)malloc(sizeof(struct iovec)*numLines);
458 if (vec == NULL) {
459 msg = "LOG: write failed, no memory";
460 numVecs = 3;
461 numLines = 1;
462 vec = stackVec;
463 }
464 }
465
466 /*
467 * Fill in the iovec pointers.
468 */
469 p = msg;
470 struct iovec* v = vec;
471 int totalLen = 0;
472 while (numLines > 0 && p < end) {
473 if (prefixLen > 0) {
474 v->iov_base = prefixBuf;
475 v->iov_len = prefixLen;
476 totalLen += prefixLen;
477 v++;
478 }
479 const char* start = p;
480 while (p < end && *p != '\n') p++;
481 if ((p-start) > 0) {
482 v->iov_base = (void*)start;
483 v->iov_len = p-start;
484 totalLen += p-start;
485 v++;
486 }
487 if (*p == '\n') p++;
488 if (suffixLen > 0) {
489 v->iov_base = suffixBuf;
490 v->iov_len = suffixLen;
491 totalLen += suffixLen;
492 v++;
493 }
494 numLines -= 1;
495 }
496
497 /*
498 * Write the entire message to the log file with a single writev() call.
499 * We need to use this rather than a collection of printf()s on a FILE*
500 * because of multi-threading and multi-process issues.
501 *
502 * If the file was not opened with O_APPEND, this will produce interleaved
503 * output when called on the same file from multiple processes.
504 *
505 * If the file descriptor is actually a network socket, the writev()
506 * call may return with a partial write. Putting the writev() call in
507 * a loop can result in interleaved data. This can be alleviated
508 * somewhat by wrapping the writev call in the Mutex.
509 */
510
511 for(;;) {
512 int cc = writev(fileno(stderr), vec, v-vec);
513
514 if (cc == totalLen) break;
515
516 if (cc < 0) {
517 if(errno == EINTR) continue;
518
519 /* can't really log the failure; for now, throw out a stderr */
520 fprintf(stderr, "+++ LOG: write failed (errno=%d)\n", errno);
521 break;
522 } else {
523 /* shouldn't happen when writing to file or tty */
524 fprintf(stderr, "+++ LOG: write partial (%d of %d)\n", cc, totalLen);
525 break;
526 }
527 }
528
529 /* if we allocated storage for the iovecs, free it */
530 if (vec != stackVec)
531 free(vec);
532}
533
534
535/*
536 * Receive a log message. We happen to know that "vector" has three parts:
537 *
538 * priority (1 byte)
539 * tag (N bytes -- null-terminated ASCII string)
540 * message (N bytes -- null-terminated ASCII string)
541 */
542static ssize_t logWritev(int fd, const struct iovec* vector, int count)
543{
544 LogState* state;
545
546 /* Make sure that no-one frees the LogState while we're using it.
547 * Also guarantees that only one thread is in showLog() at a given
548 * time (if it matters).
549 */
550 lock();
551
552 state = fdToLogState(fd);
553 if (state == NULL) {
554 errno = EBADF;
555 goto error;
556 }
557
558 if (state->isBinary) {
559 TRACE("%s: ignoring binary log\n", state->debugName);
560 goto bail;
561 }
562
563 if (count != 3) {
564 TRACE("%s: writevLog with count=%d not expected\n",
565 state->debugName, count);
566 goto error;
567 }
568
569 /* pull out the three fields */
570 int logPrio = *(const char*)vector[0].iov_base;
571 const char* tag = (const char*) vector[1].iov_base;
572 const char* msg = (const char*) vector[2].iov_base;
573
574 /* see if this log tag is configured */
575 int i;
576 int minPrio = state->globalMinPriority;
577 for (i = 0; i < kTagSetSize; i++) {
578 if (state->tagSet[i].minPriority == ANDROID_LOG_UNKNOWN)
579 break; /* reached end of configured values */
580
581 if (strcmp(state->tagSet[i].tag, tag) == 0) {
582 //TRACE("MATCH tag '%s'\n", tag);
583 minPrio = state->tagSet[i].minPriority;
584 break;
585 }
586 }
587
588 if (logPrio >= minPrio) {
589 showLog(state, logPrio, tag, msg);
590 } else {
591 //TRACE("+++ NOLOG(%d): %s %s", logPrio, tag, msg);
592 }
593
594bail:
595 unlock();
596 return vector[0].iov_len + vector[1].iov_len + vector[2].iov_len;
597error:
598 unlock();
599 return -1;
600}
601
602/*
603 * Free up our state and close the fake descriptor.
604 */
605static int logClose(int fd)
606{
607 deleteFakeFd(fd);
608 return 0;
609}
610
611/*
612 * Open a log output device and return a fake fd.
613 */
614static int logOpen(const char* pathName, int flags)
615{
616 LogState *logState;
617 int fd = -1;
618
619 lock();
620
621 logState = createLogState();
622 if (logState != NULL) {
623 configureInitialState(pathName, logState);
624 fd = logState->fakeFd;
625 } else {
626 errno = ENFILE;
627 }
628
629 unlock();
630
631 return fd;
632}
633
634
635/*
636 * Runtime redirection. If this binary is running in the simulator,
637 * just pass log messages to the emulated device. If it's running
638 * outside of the simulator, write the log messages to stderr.
639 */
640
641static int (*redirectOpen)(const char *pathName, int flags) = NULL;
642static int (*redirectClose)(int fd) = NULL;
643static ssize_t (*redirectWritev)(int fd, const struct iovec* vector, int count)
644 = NULL;
645
646static void setRedirects()
647{
648 const char *ws;
649
650 /* Wrapsim sets this environment variable on children that it's
651 * created using its LD_PRELOAD wrapper.
652 */
653 ws = getenv("ANDROID_WRAPSIM");
654 if (ws != NULL && strcmp(ws, "1") == 0) {
655 /* We're running inside wrapsim, so we can just write to the device. */
656 redirectOpen = (int (*)(const char *pathName, int flags))open;
657 redirectClose = close;
658 redirectWritev = writev;
659 } else {
660 /* There's no device to delegate to; handle the logging ourselves. */
661 redirectOpen = logOpen;
662 redirectClose = logClose;
663 redirectWritev = logWritev;
664 }
665}
666
667int fakeLogOpen(const char *pathName, int flags)
668{
669 if (redirectOpen == NULL) {
670 setRedirects();
671 }
672 return redirectOpen(pathName, flags);
673}
674
675int fakeLogClose(int fd)
676{
677 /* Assume that open() was called first. */
678 return redirectClose(fd);
679}
680
681ssize_t fakeLogWritev(int fd, const struct iovec* vector, int count)
682{
683 /* Assume that open() was called first. */
684 return redirectWritev(fd, vector, count);
685}