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 <log/log.h>
25 
26 #define EVENT_LOG_TAG_dvm_lock_sample 20003
27 
28 namespace art {
29 
Set4LE(uint8_t * buf,uint32_t val)30 static 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 
EventLogWriteInt(char * dst,int value)37 static 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 
EventLogWriteString(char * dst,const char * value,size_t len)43 static 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 
LogContentionEvent(Thread * self,uint32_t wait_ms,uint32_t sample_percent,const char * owner_filename,int32_t owner_line_number)52 void Monitor::LogContentionEvent(Thread* self, uint32_t wait_ms, uint32_t sample_percent,
53                                  const char* owner_filename, int32_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, Thread::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   ArtMethod* m = self->GetCurrentMethod(&pc);
82   const char* filename;
83   int32_t line_number;
84   TranslateLocation(m, pc, &filename, &line_number);
85   cp = EventLogWriteString(cp, filename, strlen(filename));
86 
87   // Emit the source code line number, 5 bytes.
88   cp = EventLogWriteInt(cp, line_number);
89 
90   // Emit the lock owner source code file name, <= 37 bytes.
91   if (owner_filename == nullptr) {
92     owner_filename = "";
93   } else if (strcmp(filename, owner_filename) == 0) {
94     // Common case, so save on log space.
95     owner_filename = "-";
96   }
97   cp = EventLogWriteString(cp, owner_filename, strlen(owner_filename));
98 
99   // Emit the source code line number, 5 bytes.
100   cp = EventLogWriteInt(cp, owner_line_number);
101 
102   // Emit the sample percentage, 5 bytes.
103   cp = EventLogWriteInt(cp, sample_percent);
104 
105   CHECK_LE((size_t)(cp - eventBuffer), sizeof(eventBuffer));
106   android_btWriteLog(EVENT_LOG_TAG_dvm_lock_sample, EVENT_TYPE_LIST, eventBuffer,
107                      (size_t)(cp - eventBuffer));
108 }
109 
110 }  // namespace art
111