700d350d |
1 | /* LTTng user-space "fast" library |
2 | * |
3 | * This daemon is spawned by each traced thread (to share the mmap). |
4 | * |
5 | * Its job is to dump periodically this buffer to disk (when it receives a |
6 | * SIGUSR1 from its parent). |
7 | * |
8 | * It uses the control information in the shared memory area (producer/consumer |
9 | * count). |
10 | * |
11 | * When the parent thread dies (yes, those thing may happen) ;) , this daemon |
12 | * will flush the last buffer and write it to disk. |
13 | * |
14 | * Supplement note for streaming : the daemon is responsible for flushing |
15 | * periodically the buffer if it is streaming data. |
16 | * |
b09f3215 |
17 | * |
700d350d |
18 | * Notes : |
19 | * shm memory is typically limited to 4096 units (system wide limit SHMMNI in |
20 | * /proc/sys/kernel/shmmni). As it requires computation time upon creation, we |
21 | * do not use it : we will use a shared mmap() instead which is passed through |
22 | * the fork(). |
23 | * MAP_SHARED mmap segment. Updated when msync or munmap are called. |
24 | * MAP_ANONYMOUS. |
25 | * Memory mapped by mmap() is preserved across fork(2), with the same |
26 | * attributes. |
27 | * |
28 | * Eventually, there will be two mode : |
29 | * * Slow thread spawn : a fork() is done for each new thread. If the process |
30 | * dies, the data is not lost. |
31 | * * Fast thread spawn : a pthread_create() is done by the application for each |
32 | * new thread. |
a85b8f41 |
33 | * |
34 | * We use a timer to check periodically if the parent died. I think it is less |
35 | * intrusive than a ptrace() on the parent, which would get every signal. The |
36 | * side effect of this is that we won't be notified if the parent does an |
37 | * exec(). In this case, we will just sit there until the parent exits. |
38 | * |
39 | * |
b09f3215 |
40 | * Copyright 2006 Mathieu Desnoyers |
41 | * |
42 | */ |
43 | |
32f2b04a |
44 | #define _GNU_SOURCE |
b09f3215 |
45 | #include <sys/types.h> |
46 | #include <sys/wait.h> |
47 | #include <unistd.h> |
48 | #include <stdlib.h> |
49 | #include <stdio.h> |
50 | #include <signal.h> |
51 | #include <syscall.h> |
52 | #include <features.h> |
53 | #include <pthread.h> |
54 | #include <malloc.h> |
55 | #include <string.h> |
700d350d |
56 | #include <sys/mman.h> |
57 | #include <signal.h> |
77b31f39 |
58 | #include <sys/stat.h> |
59 | #include <fcntl.h> |
60 | #include <stdlib.h> |
61 | #include <sys/param.h> |
47d7d576 |
62 | #include <sys/time.h> |
77b31f39 |
63 | |
32f2b04a |
64 | #include <asm/atomic.h> |
77b31f39 |
65 | #include <asm/timex.h> //for get_cycles() |
b09f3215 |
66 | |
1c48e587 |
67 | #include "ltt-usertrace-fast.h" |
b09f3215 |
68 | |
32f2b04a |
69 | enum force_switch_mode { FORCE_ACTIVE, FORCE_FLUSH }; |
b09f3215 |
70 | |
e8efa18d |
71 | /* Writer (the traced application) */ |
b09f3215 |
72 | |
e8efa18d |
73 | __thread struct ltt_trace_info *thread_trace_info = NULL; |
700d350d |
74 | |
e8efa18d |
75 | void ltt_usertrace_fast_buffer_switch(void) |
76 | { |
a85b8f41 |
77 | struct ltt_trace_info *tmp = thread_trace_info; |
78 | if(tmp) |
79 | kill(tmp->daemon_id, SIGUSR1); |
e8efa18d |
80 | } |
700d350d |
81 | |
77b31f39 |
82 | /* The cleanup should never be called from a signal handler */ |
e8efa18d |
83 | static void ltt_usertrace_fast_cleanup(void *arg) |
b09f3215 |
84 | { |
a85b8f41 |
85 | struct ltt_trace_info *tmp = thread_trace_info; |
86 | if(tmp) { |
87 | thread_trace_info = NULL; |
88 | kill(tmp->daemon_id, SIGUSR2); |
89 | munmap(tmp, sizeof(*tmp)); |
90 | } |
700d350d |
91 | } |
b09f3215 |
92 | |
e8efa18d |
93 | /* Reader (the disk dumper daemon) */ |
700d350d |
94 | |
a85b8f41 |
95 | static pid_t traced_pid = 0; |
77b31f39 |
96 | static pthread_t traced_thread = 0; |
e8efa18d |
97 | static int parent_exited = 0; |
700d350d |
98 | |
e8efa18d |
99 | /* signal handling */ |
100 | static void handler_sigusr1(int signo) |
700d350d |
101 | { |
a35eaa9c |
102 | printf("LTT Signal %d received : parent buffer switch.\n", signo); |
e8efa18d |
103 | } |
104 | |
105 | static void handler_sigusr2(int signo) |
106 | { |
a35eaa9c |
107 | printf("LTT Signal %d received : parent exited.\n", signo); |
e8efa18d |
108 | parent_exited = 1; |
109 | } |
110 | |
111 | static void handler_sigalarm(int signo) |
112 | { |
a35eaa9c |
113 | printf("LTT Signal %d received\n", signo); |
e8efa18d |
114 | |
a85b8f41 |
115 | if(getppid() != traced_pid) { |
e8efa18d |
116 | /* Parent died */ |
a85b8f41 |
117 | printf("LTT Parent %lu died, cleaning up\n", traced_pid); |
118 | traced_pid = 0; |
e8efa18d |
119 | } |
120 | alarm(3); |
b09f3215 |
121 | } |
122 | |
47d7d576 |
123 | /* Do a buffer switch. Don't switch if buffer is completely empty */ |
32f2b04a |
124 | static void flush_buffer(struct ltt_buf *ltt_buf, enum force_switch_mode mode) |
47d7d576 |
125 | { |
32f2b04a |
126 | uint64_t tsc; |
127 | int offset_begin, offset_end, offset_old; |
128 | int reserve_commit_diff; |
129 | int consumed_old, consumed_new; |
130 | int commit_count, reserve_count; |
131 | int end_switch_old; |
47d7d576 |
132 | |
32f2b04a |
133 | do { |
134 | offset_old = atomic_read(<t_buf->offset); |
135 | offset_begin = offset_old; |
136 | end_switch_old = 0; |
137 | tsc = ltt_get_timestamp(); |
138 | if(tsc == 0) { |
139 | /* Error in getting the timestamp : should not happen : it would |
140 | * mean we are called from an NMI during a write seqlock on xtime. */ |
141 | return; |
142 | } |
143 | |
144 | if(SUBBUF_OFFSET(offset_begin, ltt_buf) != 0) { |
145 | offset_begin = SUBBUF_ALIGN(offset_begin, ltt_buf); |
146 | end_switch_old = 1; |
147 | } else { |
148 | /* we do not have to switch : buffer is empty */ |
149 | return; |
150 | } |
151 | if(mode == FORCE_ACTIVE) |
152 | offset_begin += ltt_subbuf_header_len(ltt_buf); |
153 | /* Always begin_switch in FORCE_ACTIVE mode */ |
154 | |
155 | /* Test new buffer integrity */ |
156 | reserve_commit_diff = |
157 | atomic_read( |
158 | <t_buf->reserve_count[SUBBUF_INDEX(offset_begin, ltt_buf)]) |
159 | - atomic_read( |
160 | <t_buf->commit_count[SUBBUF_INDEX(offset_begin, ltt_buf)]); |
161 | if(reserve_commit_diff == 0) { |
162 | /* Next buffer not corrupted. */ |
163 | if(mode == FORCE_ACTIVE |
164 | && (offset_begin-atomic_read(<t_buf->consumed)) |
165 | >= ltt_buf->alloc_size) { |
166 | /* We do not overwrite non consumed buffers and we are full : ignore |
167 | switch while tracing is active. */ |
168 | return; |
169 | } |
170 | } else { |
171 | /* Next subbuffer corrupted. Force pushing reader even in normal mode */ |
172 | } |
173 | |
174 | offset_end = offset_begin; |
175 | } while(atomic_cmpxchg(<t_buf->offset, offset_old, offset_end) |
176 | != offset_old); |
177 | |
178 | |
179 | if(mode == FORCE_ACTIVE) { |
180 | /* Push the reader if necessary */ |
181 | do { |
182 | consumed_old = atomic_read(<t_buf->consumed); |
183 | /* If buffer is in overwrite mode, push the reader consumed count if |
184 | the write position has reached it and we are not at the first |
185 | iteration (don't push the reader farther than the writer). |
186 | This operation can be done concurrently by many writers in the |
187 | same buffer, the writer being at the fartest write position sub-buffer |
188 | index in the buffer being the one which will win this loop. */ |
189 | /* If the buffer is not in overwrite mode, pushing the reader only |
190 | happen if a sub-buffer is corrupted */ |
191 | if((SUBBUF_TRUNC(offset_end, ltt_buf) |
192 | - SUBBUF_TRUNC(consumed_old, ltt_buf)) |
193 | >= ltt_buf->alloc_size) |
194 | consumed_new = SUBBUF_ALIGN(consumed_old, ltt_buf); |
195 | else { |
196 | consumed_new = consumed_old; |
197 | break; |
198 | } |
199 | } while(atomic_cmpxchg(<t_buf->consumed, consumed_old, consumed_new) |
200 | != consumed_old); |
201 | |
202 | if(consumed_old != consumed_new) { |
203 | /* Reader pushed : we are the winner of the push, we can therefore |
204 | reequilibrate reserve and commit. Atomic increment of the commit |
205 | count permits other writers to play around with this variable |
206 | before us. We keep track of corrupted_subbuffers even in overwrite |
207 | mode : |
208 | we never want to write over a non completely committed sub-buffer : |
209 | possible causes : the buffer size is too low compared to the unordered |
210 | data input, or there is a writer who died between the reserve and the |
211 | commit. */ |
212 | if(reserve_commit_diff) { |
213 | /* We have to alter the sub-buffer commit count : a sub-buffer is |
214 | corrupted */ |
215 | atomic_add(reserve_commit_diff, |
216 | <t_buf->commit_count[SUBBUF_INDEX(offset_begin, ltt_buf)]); |
217 | atomic_inc(<t_buf->corrupted_subbuffers); |
218 | } |
219 | } |
220 | } |
221 | |
222 | /* Always switch */ |
223 | |
224 | if(end_switch_old) { |
225 | /* old subbuffer */ |
226 | /* Concurrency safe because we are the last and only thread to alter this |
227 | sub-buffer. As long as it is not delivered and read, no other thread can |
228 | alter the offset, alter the reserve_count or call the |
229 | client_buffer_end_callback on this sub-buffer. |
230 | The only remaining threads could be the ones with pending commits. They |
231 | will have to do the deliver themself. |
232 | Not concurrency safe in overwrite mode. We detect corrupted subbuffers with |
233 | commit and reserve counts. We keep a corrupted sub-buffers count and push |
234 | the readers across these sub-buffers. |
235 | Not concurrency safe if a writer is stalled in a subbuffer and |
236 | another writer switches in, finding out it's corrupted. The result will be |
237 | than the old (uncommited) subbuffer will be declared corrupted, and that |
238 | the new subbuffer will be declared corrupted too because of the commit |
239 | count adjustment. |
240 | Offset old should never be 0. */ |
241 | ltt_buffer_end_callback(ltt_buf, tsc, offset_old, |
242 | SUBBUF_INDEX((offset_old), ltt_buf)); |
243 | /* Setting this reserve_count will allow the sub-buffer to be delivered by |
244 | the last committer. */ |
245 | reserve_count = atomic_add_return((SUBBUF_OFFSET((offset_old-1), |
246 | ltt_buf) + 1), |
247 | <t_buf->reserve_count[SUBBUF_INDEX((offset_old), |
248 | ltt_buf)]); |
249 | if(reserve_count == atomic_read( |
250 | <t_buf->commit_count[SUBBUF_INDEX((offset_old), ltt_buf)])) { |
251 | ltt_deliver_callback(ltt_buf, SUBBUF_INDEX((offset_old), ltt_buf), NULL); |
252 | } |
253 | } |
254 | |
255 | if(mode == FORCE_ACTIVE) { |
256 | /* New sub-buffer */ |
257 | /* This code can be executed unordered : writers may already have written |
258 | to the sub-buffer before this code gets executed, caution. */ |
259 | /* The commit makes sure that this code is executed before the deliver |
260 | of this sub-buffer */ |
261 | ltt_buffer_begin_callback(ltt_buf, tsc, SUBBUF_INDEX(offset_begin, ltt_buf)); |
262 | commit_count = atomic_add_return(ltt_subbuf_header_len(ltt_buf), |
263 | <t_buf->commit_count[SUBBUF_INDEX(offset_begin, ltt_buf)]); |
264 | /* Check if the written buffer has to be delivered */ |
265 | if(commit_count == atomic_read( |
266 | <t_buf->reserve_count[SUBBUF_INDEX(offset_begin, ltt_buf)])) { |
267 | ltt_deliver_callback(ltt_buf, SUBBUF_INDEX(offset_begin, ltt_buf), NULL); |
268 | } |
269 | } |
47d7d576 |
270 | |
271 | } |
272 | |
273 | static inline int ltt_buffer_get(struct ltt_buf *ltt_buf, |
274 | unsigned int *offset) |
275 | { |
276 | unsigned int consumed_old, consumed_idx; |
277 | consumed_old = atomic_read(<t_buf->consumed); |
278 | consumed_idx = SUBBUF_INDEX(consumed_old, ltt_buf); |
279 | |
280 | if(atomic_read(<t_buf->commit_count[consumed_idx]) |
281 | != atomic_read(<t_buf->reserve_count[consumed_idx])) { |
282 | return -EAGAIN; |
283 | } |
284 | if((SUBBUF_TRUNC(atomic_read(<t_buf->offset), ltt_buf) |
285 | -SUBBUF_TRUNC(consumed_old, ltt_buf)) == 0) { |
286 | return -EAGAIN; |
287 | } |
288 | |
289 | *offset = consumed_old; |
290 | |
291 | return 0; |
292 | } |
293 | |
294 | static inline int ltt_buffer_put(struct ltt_buf *ltt_buf, |
295 | unsigned int offset) |
296 | { |
297 | unsigned int consumed_old, consumed_new; |
298 | int ret; |
299 | |
300 | consumed_old = offset; |
301 | consumed_new = SUBBUF_ALIGN(consumed_old, ltt_buf); |
302 | if(atomic_cmpxchg(<t_buf->consumed, consumed_old, consumed_new) |
303 | != consumed_old) { |
304 | /* We have been pushed by the writer : the last buffer read _is_ |
305 | * corrupted! |
306 | * It can also happen if this is a buffer we never got. */ |
307 | return -EIO; |
308 | } else { |
309 | if(atomic_read(<t_buf->full) == 1) { |
310 | /* tell the client that buffer is now unfull */ |
32f2b04a |
311 | ret = futex((unsigned long)<t_buf->full, |
312 | FUTEX_WAKE, 1, 0, 0, 0); |
47d7d576 |
313 | if(ret != 1) { |
314 | printf("LTT warning : race condition : writer not waiting or too many writers\n"); |
315 | } |
316 | atomic_set(<t_buf->full, 0); |
317 | } |
318 | } |
319 | } |
320 | |
321 | /* In the writer : |
322 | * |
323 | * if(buffer full condition) { |
324 | * put myself in the wait queue |
325 | * ltt_buf->full = 1; |
326 | * schedule |
327 | * } |
328 | *{ |
329 | if(buffer_is_full) { |
330 | atomic_set(<t_buf->full, 1); |
32f2b04a |
331 | ret = do_futex((unsigned long)<t_buf->full, 1, 0, 0, 0); |
47d7d576 |
332 | } |
333 | } |
334 | |
335 | */ |
336 | |
337 | static int read_subbuffer(struct ltt_buf *ltt_buf, int fd) |
338 | { |
32f2b04a |
339 | unsigned int consumed_old; |
47d7d576 |
340 | int err; |
341 | printf("LTT read buffer\n"); |
342 | |
343 | |
32f2b04a |
344 | err = ltt_buffer_get(ltt_buf, &consumed_old); |
47d7d576 |
345 | if(err != -EAGAIN && err != 0) { |
346 | printf("LTT Reserving sub buffer failed\n"); |
347 | goto get_error; |
348 | } |
349 | |
350 | err = TEMP_FAILURE_RETRY(write(fd, |
351 | ltt_buf->start |
352 | + (consumed_old & ((ltt_buf->alloc_size)-1)), |
353 | ltt_buf->subbuf_size)); |
354 | |
355 | if(err < 0) { |
356 | perror("Error in writing to file"); |
357 | goto write_error; |
358 | } |
359 | #if 0 |
360 | err = fsync(pair->trace); |
361 | if(err < 0) { |
362 | ret = errno; |
363 | perror("Error in writing to file"); |
364 | goto write_error; |
365 | } |
366 | #endif //0 |
367 | write_error: |
32f2b04a |
368 | err = ltt_buffer_put(ltt_buf, consumed_old); |
47d7d576 |
369 | |
370 | if(err != 0) { |
371 | if(err == -EIO) { |
32f2b04a |
372 | printf("Reader has been pushed by the writer, last subbuffer corrupted.\n"); |
47d7d576 |
373 | /* FIXME : we may delete the last written buffer if we wish. */ |
374 | } |
375 | goto get_error; |
376 | } |
377 | |
378 | get_error: |
379 | return err; |
380 | } |
e8efa18d |
381 | |
a85b8f41 |
382 | /* This function is called by ltt_rw_init which has signals blocked */ |
700d350d |
383 | static void ltt_usertrace_fast_daemon(struct ltt_trace_info *shared_trace_info, |
77b31f39 |
384 | sigset_t oldset, pid_t l_traced_pid, pthread_t l_traced_thread) |
700d350d |
385 | { |
386 | struct sigaction act; |
387 | int ret; |
77b31f39 |
388 | int fd_fac; |
389 | int fd_cpu; |
390 | char outfile_name[PATH_MAX]; |
391 | char identifier_name[PATH_MAX]; |
392 | |
700d350d |
393 | |
a85b8f41 |
394 | traced_pid = l_traced_pid; |
77b31f39 |
395 | traced_thread = l_traced_thread; |
e8efa18d |
396 | |
a85b8f41 |
397 | printf("LTT ltt_usertrace_fast_daemon : init is %d, pid is %lu, traced_pid is %lu\n", |
398 | shared_trace_info->init, getpid(), traced_pid); |
700d350d |
399 | |
e8efa18d |
400 | act.sa_handler = handler_sigusr1; |
700d350d |
401 | act.sa_flags = 0; |
402 | sigemptyset(&(act.sa_mask)); |
403 | sigaddset(&(act.sa_mask), SIGUSR1); |
404 | sigaction(SIGUSR1, &act, NULL); |
e8efa18d |
405 | |
406 | act.sa_handler = handler_sigusr2; |
407 | act.sa_flags = 0; |
408 | sigemptyset(&(act.sa_mask)); |
409 | sigaddset(&(act.sa_mask), SIGUSR2); |
410 | sigaction(SIGUSR2, &act, NULL); |
411 | |
412 | act.sa_handler = handler_sigalarm; |
413 | act.sa_flags = 0; |
414 | sigemptyset(&(act.sa_mask)); |
415 | sigaddset(&(act.sa_mask), SIGALRM); |
416 | sigaction(SIGALRM, &act, NULL); |
417 | |
700d350d |
418 | /* Enable signals */ |
419 | ret = pthread_sigmask(SIG_SETMASK, &oldset, NULL); |
420 | if(ret) { |
a35eaa9c |
421 | printf("LTT Error in pthread_sigmask\n"); |
700d350d |
422 | } |
423 | |
e8efa18d |
424 | alarm(3); |
425 | |
77b31f39 |
426 | /* Open output files */ |
427 | umask(00000); |
428 | ret = mkdir(LTT_USERTRACE_ROOT, 0777); |
429 | if(ret < 0 && errno != EEXIST) { |
430 | perror("LTT Error in creating output (mkdir)"); |
431 | exit(-1); |
432 | } |
433 | ret = chdir(LTT_USERTRACE_ROOT); |
434 | if(ret < 0) { |
435 | perror("LTT Error in creating output (chdir)"); |
436 | exit(-1); |
437 | } |
438 | snprintf(identifier_name, PATH_MAX-1, "%lu.%lu.%llu", |
439 | traced_pid, traced_thread, get_cycles()); |
440 | snprintf(outfile_name, PATH_MAX-1, "facilities-%s", identifier_name); |
5efa73ea |
441 | fd_fac = creat(outfile_name, 0644); |
77b31f39 |
442 | |
443 | snprintf(outfile_name, PATH_MAX-1, "cpu-%s", identifier_name); |
5efa73ea |
444 | fd_cpu = creat(outfile_name, 0644); |
77b31f39 |
445 | |
446 | |
700d350d |
447 | while(1) { |
448 | pause(); |
a85b8f41 |
449 | if(traced_pid == 0) break; /* parent died */ |
e8efa18d |
450 | if(parent_exited) break; |
a35eaa9c |
451 | printf("LTT Doing a buffer switch read. pid is : %lu\n", getpid()); |
47d7d576 |
452 | |
453 | do { |
32f2b04a |
454 | ret = read_subbuffer(&shared_trace_info->channel.cpu, fd_cpu); |
47d7d576 |
455 | } while(ret == 0); |
456 | |
457 | do { |
32f2b04a |
458 | ret = read_subbuffer(&shared_trace_info->channel.facilities, fd_fac); |
47d7d576 |
459 | } while(ret == 0); |
700d350d |
460 | } |
461 | |
32f2b04a |
462 | /* The parent thread is dead and we have finished with the buffer */ |
463 | |
464 | /* Buffer force switch (flush). Using FLUSH instead of ACTIVE because we know |
465 | * there is no writer. */ |
466 | flush_buffer(&shared_trace_info->channel.cpu, FORCE_FLUSH); |
47d7d576 |
467 | do { |
32f2b04a |
468 | ret = read_subbuffer(&shared_trace_info->channel.cpu, fd_cpu); |
47d7d576 |
469 | } while(ret == 0); |
470 | |
471 | |
32f2b04a |
472 | flush_buffer(&shared_trace_info->channel.facilities, FORCE_FLUSH); |
47d7d576 |
473 | do { |
32f2b04a |
474 | ret = read_subbuffer(&shared_trace_info->channel.facilities, fd_fac); |
47d7d576 |
475 | } while(ret == 0); |
476 | |
77b31f39 |
477 | close(fd_fac); |
478 | close(fd_cpu); |
479 | |
e8efa18d |
480 | munmap(shared_trace_info, sizeof(*shared_trace_info)); |
481 | |
482 | exit(0); |
700d350d |
483 | } |
b09f3215 |
484 | |
e8efa18d |
485 | |
486 | /* Reader-writer initialization */ |
487 | |
488 | static enum ltt_process_role { LTT_ROLE_WRITER, LTT_ROLE_READER } |
489 | role = LTT_ROLE_WRITER; |
490 | |
491 | |
492 | void ltt_rw_init(void) |
b09f3215 |
493 | { |
700d350d |
494 | pid_t pid; |
495 | struct ltt_trace_info *shared_trace_info; |
496 | int ret; |
497 | sigset_t set, oldset; |
a85b8f41 |
498 | pid_t l_traced_pid = getpid(); |
77b31f39 |
499 | pthread_t l_traced_thread = pthread_self(); |
700d350d |
500 | |
501 | /* parent : create the shared memory map */ |
a85b8f41 |
502 | shared_trace_info = mmap(0, sizeof(*thread_trace_info), |
700d350d |
503 | PROT_READ|PROT_WRITE, MAP_SHARED|MAP_ANONYMOUS, 0, 0); |
a85b8f41 |
504 | memset(shared_trace_info, 0, sizeof(*shared_trace_info)); |
47d7d576 |
505 | /* Tricky semaphore : is in a shared memory space, so it's ok for a fast |
506 | * mutex (futex). */ |
507 | atomic_set(&shared_trace_info->channel.facilities.full, 0); |
508 | shared_trace_info->channel.facilities.alloc_size = LTT_BUF_SIZE_FACILITIES; |
509 | shared_trace_info->channel.facilities.subbuf_size = LTT_SUBBUF_SIZE_FACILITIES; |
32f2b04a |
510 | shared_trace_info->channel.facilities.start = |
511 | shared_trace_info->channel.facilities_buf; |
512 | |
47d7d576 |
513 | atomic_set(&shared_trace_info->channel.cpu.full, 0); |
514 | shared_trace_info->channel.cpu.alloc_size = LTT_BUF_SIZE_CPU; |
515 | shared_trace_info->channel.cpu.subbuf_size = LTT_SUBBUF_SIZE_CPU; |
32f2b04a |
516 | shared_trace_info->channel.cpu.start = shared_trace_info->channel.cpu_buf; |
a85b8f41 |
517 | shared_trace_info->init = 1; |
700d350d |
518 | |
519 | /* Disable signals */ |
520 | ret = sigfillset(&set); |
521 | if(ret) { |
a35eaa9c |
522 | printf("LTT Error in sigfillset\n"); |
700d350d |
523 | } |
524 | |
525 | |
526 | ret = pthread_sigmask(SIG_BLOCK, &set, &oldset); |
527 | if(ret) { |
a35eaa9c |
528 | printf("LTT Error in pthread_sigmask\n"); |
700d350d |
529 | } |
a85b8f41 |
530 | |
700d350d |
531 | pid = fork(); |
532 | if(pid > 0) { |
533 | /* Parent */ |
a85b8f41 |
534 | shared_trace_info->daemon_id = pid; |
535 | thread_trace_info = shared_trace_info; |
700d350d |
536 | |
537 | /* Enable signals */ |
538 | ret = pthread_sigmask(SIG_SETMASK, &oldset, NULL); |
539 | if(ret) { |
a35eaa9c |
540 | printf("LTT Error in pthread_sigmask\n"); |
700d350d |
541 | } |
542 | } else if(pid == 0) { |
543 | /* Child */ |
e8efa18d |
544 | role = LTT_ROLE_READER; |
77b31f39 |
545 | ltt_usertrace_fast_daemon(shared_trace_info, oldset, l_traced_pid, |
546 | l_traced_thread); |
700d350d |
547 | /* Should never return */ |
548 | exit(-1); |
549 | } else if(pid < 0) { |
550 | /* fork error */ |
a35eaa9c |
551 | perror("LTT Error in forking ltt-usertrace-fast"); |
700d350d |
552 | } |
b09f3215 |
553 | } |
554 | |
e8efa18d |
555 | static __thread struct _pthread_cleanup_buffer cleanup_buffer; |
556 | |
557 | void ltt_thread_init(void) |
558 | { |
559 | _pthread_cleanup_push(&cleanup_buffer, ltt_usertrace_fast_cleanup, NULL); |
560 | ltt_rw_init(); |
561 | } |
562 | |
04180f7f |
563 | void __attribute__((constructor)) __ltt_usertrace_fast_init(void) |
b09f3215 |
564 | { |
700d350d |
565 | printf("LTT usertrace-fast init\n"); |
b09f3215 |
566 | |
e8efa18d |
567 | ltt_rw_init(); |
700d350d |
568 | } |
569 | |
570 | void __attribute__((destructor)) __ltt_usertrace_fast_fini(void) |
571 | { |
e8efa18d |
572 | if(role == LTT_ROLE_WRITER) { |
573 | printf("LTT usertrace-fast fini\n"); |
574 | ltt_usertrace_fast_cleanup(NULL); |
575 | } |
b09f3215 |
576 | } |
577 | |