Stefan Hajnoczi | 26f7227 | 2010-05-22 19:24:51 +0100 | [diff] [blame] | 1 | /* |
| 2 | * Simple trace backend |
| 3 | * |
| 4 | * Copyright IBM, Corp. 2010 |
| 5 | * |
| 6 | * This work is licensed under the terms of the GNU GPL, version 2. See |
| 7 | * the COPYING file in the top-level directory. |
| 8 | * |
| 9 | */ |
| 10 | |
| 11 | #include <stdlib.h> |
| 12 | #include <stdint.h> |
| 13 | #include <stdio.h> |
| 14 | #include <time.h> |
Stefan Hajnoczi | 85aff15 | 2011-09-05 08:30:17 +0100 | [diff] [blame] | 15 | #ifndef _WIN32 |
Stefan Hajnoczi | 0b5538c | 2011-02-26 18:38:39 +0000 | [diff] [blame] | 16 | #include <signal.h> |
| 17 | #include <pthread.h> |
Stefan Hajnoczi | 85aff15 | 2011-09-05 08:30:17 +0100 | [diff] [blame] | 18 | #endif |
Paolo Bonzini | 1de7afc | 2012-12-17 18:20:00 +0100 | [diff] [blame] | 19 | #include "qemu/timer.h" |
Stefan Hajnoczi | 26f7227 | 2010-05-22 19:24:51 +0100 | [diff] [blame] | 20 | #include "trace.h" |
Lluís | e485897 | 2011-08-31 20:31:03 +0200 | [diff] [blame] | 21 | #include "trace/control.h" |
Lluís Vilanova | b618c28 | 2014-01-14 16:52:55 +0100 | [diff] [blame] | 22 | #include "trace/simple.h" |
Stefan Hajnoczi | 26f7227 | 2010-05-22 19:24:51 +0100 | [diff] [blame] | 23 | |
| 24 | /** Trace file header event ID */ |
| 25 | #define HEADER_EVENT_ID (~(uint64_t)0) /* avoids conflicting with TraceEventIDs */ |
| 26 | |
| 27 | /** Trace file magic number */ |
| 28 | #define HEADER_MAGIC 0xf2b177cb0aa429b4ULL |
| 29 | |
| 30 | /** Trace file version number, bump if format changes */ |
Lluís Vilanova | ef0bd3b | 2014-02-23 20:37:35 +0100 | [diff] [blame] | 31 | #define HEADER_VERSION 3 |
Stefan Hajnoczi | 26f7227 | 2010-05-22 19:24:51 +0100 | [diff] [blame] | 32 | |
Stefan Hajnoczi | 0b5538c | 2011-02-26 18:38:39 +0000 | [diff] [blame] | 33 | /** Records were dropped event ID */ |
| 34 | #define DROPPED_EVENT_ID (~(uint64_t)0 - 1) |
| 35 | |
| 36 | /** Trace record is valid */ |
| 37 | #define TRACE_RECORD_VALID ((uint64_t)1 << 63) |
| 38 | |
Stefan Hajnoczi | 0b5538c | 2011-02-26 18:38:39 +0000 | [diff] [blame] | 39 | /* |
| 40 | * Trace records are written out by a dedicated thread. The thread waits for |
| 41 | * records to become available, writes them out, and then waits again. |
| 42 | */ |
Michael Tokarev | 86946a2 | 2014-05-08 12:30:46 +0400 | [diff] [blame] | 43 | static CompatGMutex trace_lock; |
| 44 | static CompatGCond trace_available_cond; |
| 45 | static CompatGCond trace_empty_cond; |
Stefan Hajnoczi | 4a0e671 | 2013-02-12 14:34:05 +0100 | [diff] [blame] | 46 | |
Stefan Hajnoczi | 0b5538c | 2011-02-26 18:38:39 +0000 | [diff] [blame] | 47 | static bool trace_available; |
| 48 | static bool trace_writeout_enabled; |
| 49 | |
Harsh Prateek Bora | 62bab73 | 2012-07-18 15:15:59 +0530 | [diff] [blame] | 50 | enum { |
| 51 | TRACE_BUF_LEN = 4096 * 64, |
| 52 | TRACE_BUF_FLUSH_THRESHOLD = TRACE_BUF_LEN / 4, |
| 53 | }; |
| 54 | |
| 55 | uint8_t trace_buf[TRACE_BUF_LEN]; |
Stefan Hajnoczi | 30d9408 | 2013-02-12 14:34:04 +0100 | [diff] [blame] | 56 | static volatile gint trace_idx; |
Harsh Prateek Bora | 62bab73 | 2012-07-18 15:15:59 +0530 | [diff] [blame] | 57 | static unsigned int writeout_idx; |
Stefan Hajnoczi | 30d9408 | 2013-02-12 14:34:04 +0100 | [diff] [blame] | 58 | static volatile gint dropped_events; |
Stefan Hajnoczi | 26896cb | 2014-05-07 19:24:10 +0200 | [diff] [blame] | 59 | static uint32_t trace_pid; |
Stefan Hajnoczi | 26f7227 | 2010-05-22 19:24:51 +0100 | [diff] [blame] | 60 | static FILE *trace_fp; |
Stefan Weil | 4552e41 | 2012-08-13 21:51:16 +0200 | [diff] [blame] | 61 | static char *trace_file_name; |
Stefan Hajnoczi | 26f7227 | 2010-05-22 19:24:51 +0100 | [diff] [blame] | 62 | |
Harsh Prateek Bora | 62bab73 | 2012-07-18 15:15:59 +0530 | [diff] [blame] | 63 | /* * Trace buffer entry */ |
| 64 | typedef struct { |
| 65 | uint64_t event; /* TraceEventID */ |
| 66 | uint64_t timestamp_ns; |
| 67 | uint32_t length; /* in bytes */ |
Stefan Hajnoczi | 26896cb | 2014-05-07 19:24:10 +0200 | [diff] [blame] | 68 | uint32_t pid; |
Markus Armbruster | fb3a508 | 2013-01-25 16:43:37 +0100 | [diff] [blame] | 69 | uint64_t arguments[]; |
Harsh Prateek Bora | 62bab73 | 2012-07-18 15:15:59 +0530 | [diff] [blame] | 70 | } TraceRecord; |
| 71 | |
| 72 | typedef struct { |
| 73 | uint64_t header_event_id; /* HEADER_EVENT_ID */ |
| 74 | uint64_t header_magic; /* HEADER_MAGIC */ |
| 75 | uint64_t header_version; /* HEADER_VERSION */ |
Harsh Prateek Bora | 8ae601e | 2012-07-20 18:52:12 +0530 | [diff] [blame] | 76 | } TraceLogHeader; |
Harsh Prateek Bora | 62bab73 | 2012-07-18 15:15:59 +0530 | [diff] [blame] | 77 | |
| 78 | |
| 79 | static void read_from_buffer(unsigned int idx, void *dataptr, size_t size); |
| 80 | static unsigned int write_to_buffer(unsigned int idx, void *dataptr, size_t size); |
| 81 | |
| 82 | static void clear_buffer_range(unsigned int idx, size_t len) |
| 83 | { |
| 84 | uint32_t num = 0; |
| 85 | while (num < len) { |
| 86 | if (idx >= TRACE_BUF_LEN) { |
| 87 | idx = idx % TRACE_BUF_LEN; |
| 88 | } |
| 89 | trace_buf[idx++] = 0; |
| 90 | num++; |
| 91 | } |
| 92 | } |
Stefan Hajnoczi | c5ceb52 | 2010-07-13 09:26:33 +0100 | [diff] [blame] | 93 | /** |
Stefan Hajnoczi | 0b5538c | 2011-02-26 18:38:39 +0000 | [diff] [blame] | 94 | * Read a trace record from the trace buffer |
| 95 | * |
| 96 | * @idx Trace buffer index |
| 97 | * @record Trace record to fill |
| 98 | * |
| 99 | * Returns false if the record is not valid. |
Stefan Hajnoczi | c5ceb52 | 2010-07-13 09:26:33 +0100 | [diff] [blame] | 100 | */ |
Harsh Prateek Bora | 62bab73 | 2012-07-18 15:15:59 +0530 | [diff] [blame] | 101 | static bool get_trace_record(unsigned int idx, TraceRecord **recordptr) |
Prerna Saxena | 9410b56 | 2010-07-13 09:26:32 +0100 | [diff] [blame] | 102 | { |
Harsh Prateek Bora | 62bab73 | 2012-07-18 15:15:59 +0530 | [diff] [blame] | 103 | uint64_t event_flag = 0; |
| 104 | TraceRecord record; |
| 105 | /* read the event flag to see if its a valid record */ |
| 106 | read_from_buffer(idx, &record, sizeof(event_flag)); |
| 107 | |
| 108 | if (!(record.event & TRACE_RECORD_VALID)) { |
Stefan Hajnoczi | 0b5538c | 2011-02-26 18:38:39 +0000 | [diff] [blame] | 109 | return false; |
Prerna Saxena | 9410b56 | 2010-07-13 09:26:32 +0100 | [diff] [blame] | 110 | } |
| 111 | |
Harsh Prateek Bora | 62bab73 | 2012-07-18 15:15:59 +0530 | [diff] [blame] | 112 | smp_rmb(); /* read memory barrier before accessing record */ |
| 113 | /* read the record header to know record length */ |
| 114 | read_from_buffer(idx, &record, sizeof(TraceRecord)); |
| 115 | *recordptr = malloc(record.length); /* dont use g_malloc, can deadlock when traced */ |
| 116 | /* make a copy of record to avoid being overwritten */ |
| 117 | read_from_buffer(idx, *recordptr, record.length); |
| 118 | smp_rmb(); /* memory barrier before clearing valid flag */ |
| 119 | (*recordptr)->event &= ~TRACE_RECORD_VALID; |
| 120 | /* clear the trace buffer range for consumed record otherwise any byte |
| 121 | * with its MSB set may be considered as a valid event id when the writer |
| 122 | * thread crosses this range of buffer again. |
| 123 | */ |
| 124 | clear_buffer_range(idx, record.length); |
Stefan Hajnoczi | c5ceb52 | 2010-07-13 09:26:33 +0100 | [diff] [blame] | 125 | return true; |
Prerna Saxena | 9410b56 | 2010-07-13 09:26:32 +0100 | [diff] [blame] | 126 | } |
| 127 | |
Stefan Hajnoczi | 0b5538c | 2011-02-26 18:38:39 +0000 | [diff] [blame] | 128 | /** |
| 129 | * Kick writeout thread |
| 130 | * |
| 131 | * @wait Whether to wait for writeout thread to complete |
| 132 | */ |
| 133 | static void flush_trace_file(bool wait) |
Stefan Hajnoczi | 26f7227 | 2010-05-22 19:24:51 +0100 | [diff] [blame] | 134 | { |
Michael Tokarev | 86946a2 | 2014-05-08 12:30:46 +0400 | [diff] [blame] | 135 | g_mutex_lock(&trace_lock); |
Stefan Hajnoczi | 0b5538c | 2011-02-26 18:38:39 +0000 | [diff] [blame] | 136 | trace_available = true; |
Michael Tokarev | 86946a2 | 2014-05-08 12:30:46 +0400 | [diff] [blame] | 137 | g_cond_signal(&trace_available_cond); |
Stefan Hajnoczi | 0b5538c | 2011-02-26 18:38:39 +0000 | [diff] [blame] | 138 | |
| 139 | if (wait) { |
Michael Tokarev | 86946a2 | 2014-05-08 12:30:46 +0400 | [diff] [blame] | 140 | g_cond_wait(&trace_empty_cond, &trace_lock); |
Stefan Hajnoczi | 0b5538c | 2011-02-26 18:38:39 +0000 | [diff] [blame] | 141 | } |
| 142 | |
Michael Tokarev | 86946a2 | 2014-05-08 12:30:46 +0400 | [diff] [blame] | 143 | g_mutex_unlock(&trace_lock); |
Stefan Hajnoczi | 0b5538c | 2011-02-26 18:38:39 +0000 | [diff] [blame] | 144 | } |
| 145 | |
| 146 | static void wait_for_trace_records_available(void) |
| 147 | { |
Michael Tokarev | 86946a2 | 2014-05-08 12:30:46 +0400 | [diff] [blame] | 148 | g_mutex_lock(&trace_lock); |
Stefan Hajnoczi | 0b5538c | 2011-02-26 18:38:39 +0000 | [diff] [blame] | 149 | while (!(trace_available && trace_writeout_enabled)) { |
Michael Tokarev | 86946a2 | 2014-05-08 12:30:46 +0400 | [diff] [blame] | 150 | g_cond_signal(&trace_empty_cond); |
| 151 | g_cond_wait(&trace_available_cond, &trace_lock); |
Stefan Hajnoczi | 0b5538c | 2011-02-26 18:38:39 +0000 | [diff] [blame] | 152 | } |
| 153 | trace_available = false; |
Michael Tokarev | 86946a2 | 2014-05-08 12:30:46 +0400 | [diff] [blame] | 154 | g_mutex_unlock(&trace_lock); |
Stefan Hajnoczi | 0b5538c | 2011-02-26 18:38:39 +0000 | [diff] [blame] | 155 | } |
| 156 | |
Stefan Hajnoczi | 85aff15 | 2011-09-05 08:30:17 +0100 | [diff] [blame] | 157 | static gpointer writeout_thread(gpointer opaque) |
Stefan Hajnoczi | 0b5538c | 2011-02-26 18:38:39 +0000 | [diff] [blame] | 158 | { |
Harsh Prateek Bora | 62bab73 | 2012-07-18 15:15:59 +0530 | [diff] [blame] | 159 | TraceRecord *recordptr; |
| 160 | union { |
| 161 | TraceRecord rec; |
| 162 | uint8_t bytes[sizeof(TraceRecord) + sizeof(uint64_t)]; |
| 163 | } dropped; |
| 164 | unsigned int idx = 0; |
Markus Armbruster | fb3a508 | 2013-01-25 16:43:37 +0100 | [diff] [blame] | 165 | int dropped_count; |
Blue Swirl | 0caf448 | 2011-07-23 21:21:14 +0000 | [diff] [blame] | 166 | size_t unused __attribute__ ((unused)); |
Stefan Hajnoczi | 0b5538c | 2011-02-26 18:38:39 +0000 | [diff] [blame] | 167 | |
| 168 | for (;;) { |
| 169 | wait_for_trace_records_available(); |
| 170 | |
Markus Armbruster | e722d70 | 2013-01-25 16:43:38 +0100 | [diff] [blame] | 171 | if (g_atomic_int_get(&dropped_events)) { |
Harsh Prateek Bora | 62bab73 | 2012-07-18 15:15:59 +0530 | [diff] [blame] | 172 | dropped.rec.event = DROPPED_EVENT_ID, |
| 173 | dropped.rec.timestamp_ns = get_clock(); |
Markus Armbruster | fb3a508 | 2013-01-25 16:43:37 +0100 | [diff] [blame] | 174 | dropped.rec.length = sizeof(TraceRecord) + sizeof(uint64_t), |
Stefan Hajnoczi | 26896cb | 2014-05-07 19:24:10 +0200 | [diff] [blame] | 175 | dropped.rec.pid = trace_pid; |
Markus Armbruster | b6b2c96 | 2013-01-25 16:43:39 +0100 | [diff] [blame] | 176 | do { |
Markus Armbruster | e722d70 | 2013-01-25 16:43:38 +0100 | [diff] [blame] | 177 | dropped_count = g_atomic_int_get(&dropped_events); |
Markus Armbruster | b6b2c96 | 2013-01-25 16:43:39 +0100 | [diff] [blame] | 178 | } while (!g_atomic_int_compare_and_exchange(&dropped_events, |
| 179 | dropped_count, 0)); |
Markus Armbruster | fb3a508 | 2013-01-25 16:43:37 +0100 | [diff] [blame] | 180 | dropped.rec.arguments[0] = dropped_count; |
Harsh Prateek Bora | 62bab73 | 2012-07-18 15:15:59 +0530 | [diff] [blame] | 181 | unused = fwrite(&dropped.rec, dropped.rec.length, 1, trace_fp); |
Stefan Hajnoczi | c5ceb52 | 2010-07-13 09:26:33 +0100 | [diff] [blame] | 182 | } |
Stefan Hajnoczi | 0b5538c | 2011-02-26 18:38:39 +0000 | [diff] [blame] | 183 | |
Harsh Prateek Bora | 62bab73 | 2012-07-18 15:15:59 +0530 | [diff] [blame] | 184 | while (get_trace_record(idx, &recordptr)) { |
| 185 | unused = fwrite(recordptr, recordptr->length, 1, trace_fp); |
| 186 | writeout_idx += recordptr->length; |
| 187 | free(recordptr); /* dont use g_free, can deadlock when traced */ |
| 188 | idx = writeout_idx % TRACE_BUF_LEN; |
Stefan Hajnoczi | 0b5538c | 2011-02-26 18:38:39 +0000 | [diff] [blame] | 189 | } |
| 190 | |
| 191 | fflush(trace_fp); |
Stefan Hajnoczi | 26f7227 | 2010-05-22 19:24:51 +0100 | [diff] [blame] | 192 | } |
Stefan Hajnoczi | 0b5538c | 2011-02-26 18:38:39 +0000 | [diff] [blame] | 193 | return NULL; |
Stefan Hajnoczi | 26f7227 | 2010-05-22 19:24:51 +0100 | [diff] [blame] | 194 | } |
| 195 | |
Harsh Prateek Bora | 62bab73 | 2012-07-18 15:15:59 +0530 | [diff] [blame] | 196 | void trace_record_write_u64(TraceBufferRecord *rec, uint64_t val) |
Stefan Hajnoczi | 26f7227 | 2010-05-22 19:24:51 +0100 | [diff] [blame] | 197 | { |
Harsh Prateek Bora | 62bab73 | 2012-07-18 15:15:59 +0530 | [diff] [blame] | 198 | rec->rec_off = write_to_buffer(rec->rec_off, &val, sizeof(uint64_t)); |
| 199 | } |
Stefan Hajnoczi | 26f7227 | 2010-05-22 19:24:51 +0100 | [diff] [blame] | 200 | |
Harsh Prateek Bora | 62bab73 | 2012-07-18 15:15:59 +0530 | [diff] [blame] | 201 | void trace_record_write_str(TraceBufferRecord *rec, const char *s, uint32_t slen) |
| 202 | { |
| 203 | /* Write string length first */ |
| 204 | rec->rec_off = write_to_buffer(rec->rec_off, &slen, sizeof(slen)); |
| 205 | /* Write actual string now */ |
| 206 | rec->rec_off = write_to_buffer(rec->rec_off, (void*)s, slen); |
| 207 | } |
| 208 | |
| 209 | int trace_record_start(TraceBufferRecord *rec, TraceEventID event, size_t datasize) |
| 210 | { |
| 211 | unsigned int idx, rec_off, old_idx, new_idx; |
| 212 | uint32_t rec_len = sizeof(TraceRecord) + datasize; |
Lluís Vilanova | 60481e2 | 2013-03-05 14:47:55 +0100 | [diff] [blame] | 213 | uint64_t event_u64 = event; |
Harsh Prateek Bora | 62bab73 | 2012-07-18 15:15:59 +0530 | [diff] [blame] | 214 | uint64_t timestamp_ns = get_clock(); |
| 215 | |
Markus Armbruster | b6b2c96 | 2013-01-25 16:43:39 +0100 | [diff] [blame] | 216 | do { |
Markus Armbruster | e722d70 | 2013-01-25 16:43:38 +0100 | [diff] [blame] | 217 | old_idx = g_atomic_int_get(&trace_idx); |
Harsh Prateek Bora | 62bab73 | 2012-07-18 15:15:59 +0530 | [diff] [blame] | 218 | smp_rmb(); |
| 219 | new_idx = old_idx + rec_len; |
| 220 | |
| 221 | if (new_idx - writeout_idx > TRACE_BUF_LEN) { |
| 222 | /* Trace Buffer Full, Event dropped ! */ |
Markus Armbruster | fb3a508 | 2013-01-25 16:43:37 +0100 | [diff] [blame] | 223 | g_atomic_int_inc(&dropped_events); |
Harsh Prateek Bora | 62bab73 | 2012-07-18 15:15:59 +0530 | [diff] [blame] | 224 | return -ENOSPC; |
| 225 | } |
Markus Armbruster | b6b2c96 | 2013-01-25 16:43:39 +0100 | [diff] [blame] | 226 | } while (!g_atomic_int_compare_and_exchange(&trace_idx, old_idx, new_idx)); |
Prerna Saxena | 22890ab | 2010-06-24 17:04:53 +0530 | [diff] [blame] | 227 | |
Harsh Prateek Bora | 62bab73 | 2012-07-18 15:15:59 +0530 | [diff] [blame] | 228 | idx = old_idx % TRACE_BUF_LEN; |
Stefan Hajnoczi | 0b5538c | 2011-02-26 18:38:39 +0000 | [diff] [blame] | 229 | |
Harsh Prateek Bora | 62bab73 | 2012-07-18 15:15:59 +0530 | [diff] [blame] | 230 | rec_off = idx; |
Lluís Vilanova | 60481e2 | 2013-03-05 14:47:55 +0100 | [diff] [blame] | 231 | rec_off = write_to_buffer(rec_off, &event_u64, sizeof(event_u64)); |
Harsh Prateek Bora | 83d35d3 | 2012-07-20 18:52:13 +0530 | [diff] [blame] | 232 | rec_off = write_to_buffer(rec_off, ×tamp_ns, sizeof(timestamp_ns)); |
| 233 | rec_off = write_to_buffer(rec_off, &rec_len, sizeof(rec_len)); |
Stefan Hajnoczi | 26896cb | 2014-05-07 19:24:10 +0200 | [diff] [blame] | 234 | rec_off = write_to_buffer(rec_off, &trace_pid, sizeof(trace_pid)); |
Harsh Prateek Bora | 62bab73 | 2012-07-18 15:15:59 +0530 | [diff] [blame] | 235 | |
| 236 | rec->tbuf_idx = idx; |
| 237 | rec->rec_off = (idx + sizeof(TraceRecord)) % TRACE_BUF_LEN; |
| 238 | return 0; |
| 239 | } |
| 240 | |
| 241 | static void read_from_buffer(unsigned int idx, void *dataptr, size_t size) |
| 242 | { |
| 243 | uint8_t *data_ptr = dataptr; |
| 244 | uint32_t x = 0; |
| 245 | while (x < size) { |
| 246 | if (idx >= TRACE_BUF_LEN) { |
| 247 | idx = idx % TRACE_BUF_LEN; |
| 248 | } |
| 249 | data_ptr[x++] = trace_buf[idx++]; |
| 250 | } |
| 251 | } |
| 252 | |
| 253 | static unsigned int write_to_buffer(unsigned int idx, void *dataptr, size_t size) |
| 254 | { |
| 255 | uint8_t *data_ptr = dataptr; |
| 256 | uint32_t x = 0; |
| 257 | while (x < size) { |
| 258 | if (idx >= TRACE_BUF_LEN) { |
| 259 | idx = idx % TRACE_BUF_LEN; |
| 260 | } |
| 261 | trace_buf[idx++] = data_ptr[x++]; |
| 262 | } |
| 263 | return idx; /* most callers wants to know where to write next */ |
| 264 | } |
| 265 | |
| 266 | void trace_record_finish(TraceBufferRecord *rec) |
| 267 | { |
Harsh Prateek Bora | db8894f | 2012-07-20 18:52:15 +0530 | [diff] [blame] | 268 | TraceRecord record; |
| 269 | read_from_buffer(rec->tbuf_idx, &record, sizeof(TraceRecord)); |
Harsh Prateek Bora | 62bab73 | 2012-07-18 15:15:59 +0530 | [diff] [blame] | 270 | smp_wmb(); /* write barrier before marking as valid */ |
Harsh Prateek Bora | db8894f | 2012-07-20 18:52:15 +0530 | [diff] [blame] | 271 | record.event |= TRACE_RECORD_VALID; |
| 272 | write_to_buffer(rec->tbuf_idx, &record, sizeof(TraceRecord)); |
Harsh Prateek Bora | 62bab73 | 2012-07-18 15:15:59 +0530 | [diff] [blame] | 273 | |
Stefan Hajnoczi | 30d9408 | 2013-02-12 14:34:04 +0100 | [diff] [blame] | 274 | if (((unsigned int)g_atomic_int_get(&trace_idx) - writeout_idx) |
Markus Armbruster | e722d70 | 2013-01-25 16:43:38 +0100 | [diff] [blame] | 275 | > TRACE_BUF_FLUSH_THRESHOLD) { |
Stefan Hajnoczi | 0b5538c | 2011-02-26 18:38:39 +0000 | [diff] [blame] | 276 | flush_trace_file(false); |
Stefan Hajnoczi | 26f7227 | 2010-05-22 19:24:51 +0100 | [diff] [blame] | 277 | } |
| 278 | } |
| 279 | |
Stefan Hajnoczi | 0b5538c | 2011-02-26 18:38:39 +0000 | [diff] [blame] | 280 | void st_set_trace_file_enabled(bool enable) |
Stefan Hajnoczi | 26f7227 | 2010-05-22 19:24:51 +0100 | [diff] [blame] | 281 | { |
Stefan Hajnoczi | 0b5538c | 2011-02-26 18:38:39 +0000 | [diff] [blame] | 282 | if (enable == !!trace_fp) { |
| 283 | return; /* no change */ |
| 284 | } |
| 285 | |
| 286 | /* Halt trace writeout */ |
| 287 | flush_trace_file(true); |
| 288 | trace_writeout_enabled = false; |
| 289 | flush_trace_file(true); |
| 290 | |
| 291 | if (enable) { |
Harsh Prateek Bora | 8ae601e | 2012-07-20 18:52:12 +0530 | [diff] [blame] | 292 | static const TraceLogHeader header = { |
Harsh Prateek Bora | 62bab73 | 2012-07-18 15:15:59 +0530 | [diff] [blame] | 293 | .header_event_id = HEADER_EVENT_ID, |
| 294 | .header_magic = HEADER_MAGIC, |
| 295 | /* Older log readers will check for version at next location */ |
| 296 | .header_version = HEADER_VERSION, |
Stefan Hajnoczi | 0b5538c | 2011-02-26 18:38:39 +0000 | [diff] [blame] | 297 | }; |
| 298 | |
Stefan Hajnoczi | 6c2a407 | 2011-09-05 18:31:21 +0100 | [diff] [blame] | 299 | trace_fp = fopen(trace_file_name, "wb"); |
Stefan Hajnoczi | 0b5538c | 2011-02-26 18:38:39 +0000 | [diff] [blame] | 300 | if (!trace_fp) { |
| 301 | return; |
| 302 | } |
| 303 | |
| 304 | if (fwrite(&header, sizeof header, 1, trace_fp) != 1) { |
| 305 | fclose(trace_fp); |
| 306 | trace_fp = NULL; |
| 307 | return; |
| 308 | } |
| 309 | |
| 310 | /* Resume trace writeout */ |
| 311 | trace_writeout_enabled = true; |
| 312 | flush_trace_file(false); |
| 313 | } else { |
| 314 | fclose(trace_fp); |
| 315 | trace_fp = NULL; |
| 316 | } |
| 317 | } |
| 318 | |
| 319 | /** |
| 320 | * Set the name of a trace file |
| 321 | * |
| 322 | * @file The trace file name or NULL for the default name-<pid> set at |
| 323 | * config time |
| 324 | */ |
| 325 | bool st_set_trace_file(const char *file) |
| 326 | { |
| 327 | st_set_trace_file_enabled(false); |
| 328 | |
Stefan Weil | 4552e41 | 2012-08-13 21:51:16 +0200 | [diff] [blame] | 329 | g_free(trace_file_name); |
Stefan Hajnoczi | 0b5538c | 2011-02-26 18:38:39 +0000 | [diff] [blame] | 330 | |
| 331 | if (!file) { |
Stefan Weil | 4552e41 | 2012-08-13 21:51:16 +0200 | [diff] [blame] | 332 | trace_file_name = g_strdup_printf(CONFIG_TRACE_FILE, getpid()); |
Stefan Hajnoczi | 0b5538c | 2011-02-26 18:38:39 +0000 | [diff] [blame] | 333 | } else { |
Stefan Weil | 4552e41 | 2012-08-13 21:51:16 +0200 | [diff] [blame] | 334 | trace_file_name = g_strdup_printf("%s", file); |
Stefan Hajnoczi | 0b5538c | 2011-02-26 18:38:39 +0000 | [diff] [blame] | 335 | } |
| 336 | |
| 337 | st_set_trace_file_enabled(true); |
| 338 | return true; |
| 339 | } |
| 340 | |
| 341 | void st_print_trace_file_status(FILE *stream, int (*stream_printf)(FILE *stream, const char *fmt, ...)) |
| 342 | { |
| 343 | stream_printf(stream, "Trace file \"%s\" %s.\n", |
| 344 | trace_file_name, trace_fp ? "on" : "off"); |
Stefan Hajnoczi | 26f7227 | 2010-05-22 19:24:51 +0100 | [diff] [blame] | 345 | } |
Prerna Saxena | 22890ab | 2010-06-24 17:04:53 +0530 | [diff] [blame] | 346 | |
Lluís | fc76410 | 2011-08-31 20:31:18 +0200 | [diff] [blame] | 347 | void st_flush_trace_buffer(void) |
| 348 | { |
| 349 | flush_trace_file(true); |
| 350 | } |
| 351 | |
Stefan Hajnoczi | 85aff15 | 2011-09-05 08:30:17 +0100 | [diff] [blame] | 352 | /* Helper function to create a thread with signals blocked. Use glib's |
| 353 | * portable threads since QEMU abstractions cannot be used due to reentrancy in |
| 354 | * the tracer. Also note the signal masking on POSIX hosts so that the thread |
| 355 | * does not steal signals when the rest of the program wants them blocked. |
| 356 | */ |
| 357 | static GThread *trace_thread_create(GThreadFunc fn) |
Stefan Hajnoczi | 0b5538c | 2011-02-26 18:38:39 +0000 | [diff] [blame] | 358 | { |
Stefan Hajnoczi | 85aff15 | 2011-09-05 08:30:17 +0100 | [diff] [blame] | 359 | GThread *thread; |
| 360 | #ifndef _WIN32 |
Stefan Hajnoczi | 0b5538c | 2011-02-26 18:38:39 +0000 | [diff] [blame] | 361 | sigset_t set, oldset; |
Stefan Hajnoczi | 0b5538c | 2011-02-26 18:38:39 +0000 | [diff] [blame] | 362 | |
| 363 | sigfillset(&set); |
| 364 | pthread_sigmask(SIG_SETMASK, &set, &oldset); |
Stefan Hajnoczi | 85aff15 | 2011-09-05 08:30:17 +0100 | [diff] [blame] | 365 | #endif |
Stefan Hajnoczi | 4a0e671 | 2013-02-12 14:34:05 +0100 | [diff] [blame] | 366 | |
Stefan Hajnoczi | 4a0e671 | 2013-02-12 14:34:05 +0100 | [diff] [blame] | 367 | thread = g_thread_new("trace-thread", fn, NULL); |
Stefan Hajnoczi | 4a0e671 | 2013-02-12 14:34:05 +0100 | [diff] [blame] | 368 | |
Stefan Hajnoczi | 85aff15 | 2011-09-05 08:30:17 +0100 | [diff] [blame] | 369 | #ifndef _WIN32 |
Stefan Hajnoczi | 0b5538c | 2011-02-26 18:38:39 +0000 | [diff] [blame] | 370 | pthread_sigmask(SIG_SETMASK, &oldset, NULL); |
Stefan Hajnoczi | 85aff15 | 2011-09-05 08:30:17 +0100 | [diff] [blame] | 371 | #endif |
Stefan Hajnoczi | 0b5538c | 2011-02-26 18:38:39 +0000 | [diff] [blame] | 372 | |
Stefan Hajnoczi | 85aff15 | 2011-09-05 08:30:17 +0100 | [diff] [blame] | 373 | return thread; |
| 374 | } |
| 375 | |
Lluís Vilanova | 5b80827 | 2014-05-27 15:02:14 +0200 | [diff] [blame] | 376 | bool st_init(const char *file) |
Stefan Hajnoczi | 85aff15 | 2011-09-05 08:30:17 +0100 | [diff] [blame] | 377 | { |
| 378 | GThread *thread; |
| 379 | |
Stefan Hajnoczi | 26896cb | 2014-05-07 19:24:10 +0200 | [diff] [blame] | 380 | trace_pid = getpid(); |
| 381 | |
Stefan Hajnoczi | 85aff15 | 2011-09-05 08:30:17 +0100 | [diff] [blame] | 382 | thread = trace_thread_create(writeout_thread); |
| 383 | if (!thread) { |
| 384 | fprintf(stderr, "warning: unable to initialize simple trace backend\n"); |
| 385 | return false; |
| 386 | } |
| 387 | |
| 388 | atexit(st_flush_trace_buffer); |
Stefan Hajnoczi | 85aff15 | 2011-09-05 08:30:17 +0100 | [diff] [blame] | 389 | st_set_trace_file(file); |
Stefan Hajnoczi | 31d3c9b | 2011-03-13 20:14:30 +0000 | [diff] [blame] | 390 | return true; |
Prerna Saxena | 22890ab | 2010-06-24 17:04:53 +0530 | [diff] [blame] | 391 | } |