monitor_android.cc revision 4a8c3fa4bd8d95fac5671ab778dd00b6dc3ec0e4 
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 "monitor.h"
18#include "thread.h"
19
20#include <fcntl.h>
21#include <sys/stat.h>
22#include <sys/types.h>
23
24#include "cutils/log.h"
25
26#define EVENT_LOG_TAG_dvm_lock_sample 20003
27
28namespace art {
29
30static void Set4LE(uint8_t* buf, uint32_t val) {
31  *buf++ = (uint8_t)(val);
32  *buf++ = (uint8_t)(val >> 8);
33  *buf++ = (uint8_t)(val >> 16);
34  *buf = (uint8_t)(val >> 24);
35}
36
37static char* EventLogWriteInt(char* dst, int value) {
38  *dst++ = EVENT_TYPE_INT;
39  Set4LE(reinterpret_cast<uint8_t*>(dst), value);
40  return dst + 4;
41}
42
43static char* EventLogWriteString(char* dst, const char* value, size_t len) {
44  *dst++ = EVENT_TYPE_STRING;
45  len = len < 32 ? len : 32;
46  Set4LE(reinterpret_cast<uint8_t*>(dst), len);
47  dst += 4;
48  memcpy(dst, value, len);
49  return dst + len;
50}
51
52void Monitor::LogContentionEvent(Thread* self, uint32_t wait_ms, uint32_t sample_percent,
53                                 const char* owner_filename, uint32_t owner_line_number) {
54  // Emit the event list length, 1 byte.
55  char eventBuffer[174];
56  char* cp = eventBuffer;
57  *cp++ = 9;
58
59  // Emit the process name, <= 37 bytes.
60  int fd = open("/proc/self/cmdline", O_RDONLY);
61  char procName[33];
62  memset(procName, 0, sizeof(procName));
63  read(fd, procName, sizeof(procName) - 1);
64  close(fd);
65  size_t len = strlen(procName);
66  cp = EventLogWriteString(cp, procName, len);
67
68  // Emit the sensitive thread ("main thread") status, 5 bytes.
69  cp = EventLogWriteInt(cp, Monitor::IsSensitiveThread());
70
71  // Emit self thread name string, <= 37 bytes.
72  std::string thread_name;
73  self->GetThreadName(thread_name);
74  cp = EventLogWriteString(cp, thread_name.c_str(), thread_name.size());
75
76  // Emit the wait time, 5 bytes.
77  cp = EventLogWriteInt(cp, wait_ms);
78
79  // Emit the source code file name, <= 37 bytes.
80  uint32_t pc;
81  mirror::ArtMethod* m = self->GetCurrentMethod(&pc);
82  CHECK_NE(pc, DexFile::kDexNoIndex);  // TODO: Can we relax this check?
83  const char* filename;
84  uint32_t line_number;
85  TranslateLocation(m, pc, &filename, &line_number);
86  cp = EventLogWriteString(cp, filename, strlen(filename));
87
88  // Emit the source code line number, 5 bytes.
89  cp = EventLogWriteInt(cp, line_number);
90
91  // Emit the lock owner source code file name, <= 37 bytes.
92  if (owner_filename == NULL) {
93    owner_filename = "";
94  } else if (strcmp(filename, owner_filename) == 0) {
95    // Common case, so save on log space.
96    owner_filename = "-";
97  }
98  cp = EventLogWriteString(cp, owner_filename, strlen(owner_filename));
99
100  // Emit the source code line number, 5 bytes.
101  cp = EventLogWriteInt(cp, owner_line_number);
102
103  // Emit the sample percentage, 5 bytes.
104  cp = EventLogWriteInt(cp, sample_percent);
105
106  CHECK_LE((size_t)(cp - eventBuffer), sizeof(eventBuffer));
107  android_btWriteLog(EVENT_LOG_TAG_dvm_lock_sample, EVENT_TYPE_LIST, eventBuffer,
108                     (size_t)(cp - eventBuffer));
109}
110
111}  // namespace art
112