OProfileWrapper.cpp revision 234353 
1//===-- OProfileWrapper.cpp - OProfile JIT API Wrapper implementation -----===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This file implements the interface in OProfileWrapper.h. It is responsible
11// for loading the opagent dynamic library when the first call to an op_
12// function occurs.
13//
14//===----------------------------------------------------------------------===//
15
16#include "llvm/ExecutionEngine/OProfileWrapper.h"
17
18#define DEBUG_TYPE "oprofile-wrapper"
19#include "llvm/Support/Debug.h"
20#include "llvm/Support/raw_ostream.h"
21#include "llvm/Support/DynamicLibrary.h"
22#include "llvm/Support/Mutex.h"
23#include "llvm/Support/MutexGuard.h"
24#include "llvm/ADT/SmallString.h"
25
26#include <sstream>
27#include <cstring>
28#include <stddef.h>
29#include <dirent.h>
30#include <sys/stat.h>
31#include <fcntl.h>
32
33namespace {
34
35// Global mutex to ensure a single thread initializes oprofile agent.
36llvm::sys::Mutex OProfileInitializationMutex;
37
38} // anonymous namespace
39
40namespace llvm {
41
42OProfileWrapper::OProfileWrapper()
43: Agent(0),
44  OpenAgentFunc(0),
45  CloseAgentFunc(0),
46  WriteNativeCodeFunc(0),
47  WriteDebugLineInfoFunc(0),
48  UnloadNativeCodeFunc(0),
49  MajorVersionFunc(0),
50  MinorVersionFunc(0),
51  IsOProfileRunningFunc(0),
52  Initialized(false) {
53}
54
55bool OProfileWrapper::initialize() {
56  using namespace llvm;
57  using namespace llvm::sys;
58
59  MutexGuard Guard(OProfileInitializationMutex);
60
61  if (Initialized)
62    return OpenAgentFunc != 0;
63
64  Initialized = true;
65
66  // If the oprofile daemon is not running, don't load the opagent library
67  if (!isOProfileRunning()) {
68    DEBUG(dbgs() << "OProfile daemon is not detected.\n");
69    return false;
70  }
71
72  std::string error;
73  if(!DynamicLibrary::LoadLibraryPermanently("libopagent.so", &error)) {
74    DEBUG(dbgs()
75            << "OProfile connector library libopagent.so could not be loaded: "
76            << error << "\n");
77  }
78
79  // Get the addresses of the opagent functions
80  OpenAgentFunc = (op_open_agent_ptr_t)(intptr_t)
81          DynamicLibrary::SearchForAddressOfSymbol("op_open_agent");
82  CloseAgentFunc = (op_close_agent_ptr_t)(intptr_t)
83          DynamicLibrary::SearchForAddressOfSymbol("op_close_agent");
84  WriteNativeCodeFunc = (op_write_native_code_ptr_t)(intptr_t)
85          DynamicLibrary::SearchForAddressOfSymbol("op_write_native_code");
86  WriteDebugLineInfoFunc = (op_write_debug_line_info_ptr_t)(intptr_t)
87          DynamicLibrary::SearchForAddressOfSymbol("op_write_debug_line_info");
88  UnloadNativeCodeFunc = (op_unload_native_code_ptr_t)(intptr_t)
89          DynamicLibrary::SearchForAddressOfSymbol("op_unload_native_code");
90  MajorVersionFunc = (op_major_version_ptr_t)(intptr_t)
91          DynamicLibrary::SearchForAddressOfSymbol("op_major_version");
92  MinorVersionFunc = (op_major_version_ptr_t)(intptr_t)
93          DynamicLibrary::SearchForAddressOfSymbol("op_minor_version");
94
95  // With missing functions, we can do nothing
96  if (!OpenAgentFunc
97      || !CloseAgentFunc
98      || !WriteNativeCodeFunc
99      || !WriteDebugLineInfoFunc
100      || !UnloadNativeCodeFunc) {
101    OpenAgentFunc = 0;
102    CloseAgentFunc = 0;
103    WriteNativeCodeFunc = 0;
104    WriteDebugLineInfoFunc = 0;
105    UnloadNativeCodeFunc = 0;
106    return false;
107  }
108
109  return true;
110}
111
112bool OProfileWrapper::isOProfileRunning() {
113  if (IsOProfileRunningFunc != 0)
114    return IsOProfileRunningFunc();
115  return checkForOProfileProcEntry();
116}
117
118bool OProfileWrapper::checkForOProfileProcEntry() {
119  DIR* ProcDir;
120
121  ProcDir = opendir("/proc");
122  if (!ProcDir)
123    return false;
124
125  // Walk the /proc tree looking for the oprofile daemon
126  struct dirent* Entry;
127  while (0 != (Entry = readdir(ProcDir))) {
128    if (Entry->d_type == DT_DIR) {
129      // Build a path from the current entry name
130      SmallString<256> CmdLineFName;
131      raw_svector_ostream(CmdLineFName) << "/proc/" << Entry->d_name
132                                        << "/cmdline";
133
134      // Open the cmdline file
135      int CmdLineFD = open(CmdLineFName.c_str(), S_IRUSR);
136      if (CmdLineFD != -1) {
137        char    ExeName[PATH_MAX+1];
138        char*   BaseName = 0;
139
140        // Read the cmdline file
141        ssize_t NumRead = read(CmdLineFD, ExeName, PATH_MAX+1);
142        close(CmdLineFD);
143        ssize_t Idx = 0;
144
145        // Find the terminator for the first string
146        while (Idx < NumRead-1 && ExeName[Idx] != 0) {
147          Idx++;
148        }
149
150        // Go back to the last non-null character
151        Idx--;
152
153        // Find the last path separator in the first string
154        while (Idx > 0) {
155          if (ExeName[Idx] == '/') {
156            BaseName = ExeName + Idx + 1;
157            break;
158          }
159          Idx--;
160        }
161
162        // Test this to see if it is the oprofile daemon
163        if (BaseName != 0 && !strcmp("oprofiled", BaseName)) {
164          // If it is, we're done
165          closedir(ProcDir);
166          return true;
167        }
168      }
169    }
170  }
171
172  // We've looked through all the files and didn't find the daemon
173  closedir(ProcDir);
174  return false;
175}
176
177bool OProfileWrapper::op_open_agent() {
178  if (!Initialized)
179    initialize();
180
181  if (OpenAgentFunc != 0) {
182    Agent = OpenAgentFunc();
183    return Agent != 0;
184  }
185
186  return false;
187}
188
189int OProfileWrapper::op_close_agent() {
190  if (!Initialized)
191    initialize();
192
193  int ret = -1;
194  if (Agent && CloseAgentFunc) {
195    ret = CloseAgentFunc(Agent);
196    if (ret == 0) {
197      Agent = 0;
198    }
199  }
200  return ret;
201}
202
203bool OProfileWrapper::isAgentAvailable() {
204  return Agent != 0;
205}
206
207int OProfileWrapper::op_write_native_code(const char* Name,
208                                          uint64_t Addr,
209                                          void const* Code,
210                                          const unsigned int Size) {
211  if (!Initialized)
212    initialize();
213
214  if (Agent && WriteNativeCodeFunc)
215    return WriteNativeCodeFunc(Agent, Name, Addr, Code, Size);
216
217  return -1;
218}
219
220int OProfileWrapper::op_write_debug_line_info(
221  void const* Code,
222  size_t NumEntries,
223  struct debug_line_info const* Info) {
224  if (!Initialized)
225    initialize();
226
227  if (Agent && WriteDebugLineInfoFunc)
228    return WriteDebugLineInfoFunc(Agent, Code, NumEntries, Info);
229
230  return -1;
231}
232
233int OProfileWrapper::op_major_version() {
234  if (!Initialized)
235    initialize();
236
237  if (Agent && MajorVersionFunc)
238    return MajorVersionFunc();
239
240  return -1;
241}
242
243int OProfileWrapper::op_minor_version() {
244  if (!Initialized)
245    initialize();
246
247  if (Agent && MinorVersionFunc)
248    return MinorVersionFunc();
249
250  return -1;
251}
252
253int  OProfileWrapper::op_unload_native_code(uint64_t Addr) {
254  if (!Initialized)
255    initialize();
256
257  if (Agent && UnloadNativeCodeFunc)
258    return UnloadNativeCodeFunc(Agent, Addr);
259
260  return -1;
261}
262
263} // namespace llvm
264