DXR is a code search and navigation tool aimed at making sense of large projects. It supports full-text and regex searches as well as structural queries.

Header

Mercurial (b6d82b1a6b02)

VCS Links

Line Code
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601
/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "mozilla/Logging.h"

#include <algorithm>

#include "mozilla/ClearOnShutdown.h"
#include "mozilla/FileUtils.h"
#include "mozilla/Mutex.h"
#include "mozilla/StaticPtr.h"
#include "mozilla/Printf.h"
#include "mozilla/Atomics.h"
#include "mozilla/Sprintf.h"
#include "mozilla/UniquePtrExtensions.h"
#include "MainThreadUtils.h"
#include "nsClassHashtable.h"
#include "nsDebug.h"
#include "nsDebugImpl.h"
#include "NSPRLogModulesParser.h"
#include "LogCommandLineHandler.h"
#ifdef MOZ_GECKO_PROFILER
#  include "ProfilerMarkerPayload.h"
#endif

#include "prenv.h"
#ifdef XP_WIN
#  include <process.h>
#else
#  include <sys/types.h>
#  include <unistd.h>
#endif

// NB: Initial amount determined by auditing the codebase for the total amount
//     of unique module names and padding up to the next power of 2.
const uint32_t kInitialModuleCount = 256;
// When rotate option is added to the modules list, this is the hardcoded
// number of files we create and rotate.  When there is rotate:40,
// we will keep four files per process, each limited to 10MB.  Sum is 40MB,
// the given limit.
//
// (Note: When this is changed to be >= 10, SandboxBroker::LaunchApp must add
// another rule to allow logfile.?? be written by content processes.)
const uint32_t kRotateFilesNumber = 4;

namespace mozilla {

namespace detail {

void log_print(const LogModule* aModule, LogLevel aLevel, const char* aFmt,
               ...) {
  va_list ap;
  va_start(ap, aFmt);
  aModule->Printv(aLevel, aFmt, ap);
  va_end(ap);
}

}  // namespace detail

LogLevel ToLogLevel(int32_t aLevel) {
  aLevel = std::min(aLevel, static_cast<int32_t>(LogLevel::Verbose));
  aLevel = std::max(aLevel, static_cast<int32_t>(LogLevel::Disabled));
  return static_cast<LogLevel>(aLevel);
}

static const char* ToLogStr(LogLevel aLevel) {
  switch (aLevel) {
    case LogLevel::Error:
      return "E";
    case LogLevel::Warning:
      return "W";
    case LogLevel::Info:
      return "I";
    case LogLevel::Debug:
      return "D";
    case LogLevel::Verbose:
      return "V";
    case LogLevel::Disabled:
    default:
      MOZ_CRASH("Invalid log level.");
      return "";
  }
}

namespace detail {

/**
 * A helper class providing reference counting for FILE*.
 * It encapsulates the following:
 *  - the FILE handle
 *  - the order number it was created for when rotating (actual path)
 *  - number of active references
 */
class LogFile {
  FILE* mFile;
  uint32_t mFileNum;

 public:
  LogFile(FILE* aFile, uint32_t aFileNum)
      : mFile(aFile), mFileNum(aFileNum), mNextToRelease(nullptr) {}

  ~LogFile() {
    fclose(mFile);
    delete mNextToRelease;
  }

  FILE* File() const { return mFile; }
  uint32_t Num() const { return mFileNum; }

  LogFile* mNextToRelease;
};

static const char* ExpandLogFileName(const char* aFilename,
                                     char (&buffer)[2048]) {
  MOZ_ASSERT(aFilename);
  static const char kPIDToken[] = "%PID";
  static const char kMOZLOGExt[] = MOZ_LOG_FILE_EXTENSION;

  bool hasMozLogExtension = StringEndsWith(nsDependentCString(aFilename),
                                           nsLiteralCString(kMOZLOGExt));

  const char* pidTokenPtr = strstr(aFilename, kPIDToken);
  if (pidTokenPtr &&
      SprintfLiteral(buffer, "%.*s%s%d%s%s",
                     static_cast<int>(pidTokenPtr - aFilename), aFilename,
                     XRE_IsParentProcess() ? "-main." : "-child.",
                     base::GetCurrentProcId(), pidTokenPtr + strlen(kPIDToken),
                     hasMozLogExtension ? "" : kMOZLOGExt) > 0) {
    return buffer;
  }

  if (!hasMozLogExtension &&
      SprintfLiteral(buffer, "%s%s", aFilename, kMOZLOGExt) > 0) {
    return buffer;
  }

  return aFilename;
}

}  // namespace detail

namespace {
// Helper method that initializes an empty va_list to be empty.
void empty_va(va_list* va, ...) {
  va_start(*va, va);
  va_end(*va);
}
}  // namespace

class LogModuleManager {
 public:
  LogModuleManager()
      // As for logging atomics, don't preserve behavior for this lock when
      // recording/replaying.
      : mModulesLock("logmodules", recordreplay::Behavior::DontPreserve),
        mModules(kInitialModuleCount),
        mPrintEntryCount(0),
        mOutFile(nullptr),
        mToReleaseFile(nullptr),
        mOutFileNum(0),
        mOutFilePath(strdup("")),
        mMainThread(PR_GetCurrentThread()),
        mSetFromEnv(false),
        mAddTimestamp(false),
        mAddProfilerMarker(false),
        mIsRaw(false),
        mIsSync(false),
        mRotate(0),
        mInitialized(false) {}

  ~LogModuleManager() {
    detail::LogFile* logFile = mOutFile.exchange(nullptr);
    delete logFile;
  }

  /**
   * Loads config from command line args or env vars if present, in
   * this specific order of priority.
   *
   * Notes:
   *
   * 1) This function is only intended to be called once per session.
   * 2) None of the functions used in Init should rely on logging.
   */
  void Init(int argc, char* argv[]) {
    MOZ_DIAGNOSTIC_ASSERT(!mInitialized);
    mInitialized = true;

    LoggingHandleCommandLineArgs(argc, static_cast<char const* const*>(argv),
                                 [](nsACString const& env) {
                                   // We deliberately set/rewrite the
                                   // environment variables so that when child
                                   // processes are spawned w/o passing the
                                   // arguments they still inherit the logging
                                   // settings as well as sandboxing can be
                                   // correctly set. Scripts can pass
                                   // -MOZ_LOG=$MOZ_LOG,modules as an argument
                                   // to merge existing settings, if required.

                                   // PR_SetEnv takes ownership of the string.
                                   PR_SetEnv(ToNewCString(env));
                                 });

    bool shouldAppend = false;
    bool addTimestamp = false;
    bool isSync = false;
    bool isRaw = false;
    bool isMarkers = false;
    int32_t rotate = 0;
    const char* modules = PR_GetEnv("MOZ_LOG");
    if (!modules || !modules[0]) {
      modules = PR_GetEnv("MOZ_LOG_MODULES");
      if (modules) {
        NS_WARNING(
            "MOZ_LOG_MODULES is deprecated."
            "\nPlease use MOZ_LOG instead.");
      }
    }
    if (!modules || !modules[0]) {
      modules = PR_GetEnv("NSPR_LOG_MODULES");
      if (modules) {
        NS_WARNING(
            "NSPR_LOG_MODULES is deprecated."
            "\nPlease use MOZ_LOG instead.");
      }
    }

    // Need to capture `this` since `sLogModuleManager` is not set until after
    // initialization is complete.
    NSPRLogModulesParser(
        modules, [this, &shouldAppend, &addTimestamp, &isSync, &isRaw, &rotate,
                  &isMarkers](const char* aName, LogLevel aLevel,
                              int32_t aValue) mutable {
          if (strcmp(aName, "append") == 0) {
            shouldAppend = true;
          } else if (strcmp(aName, "timestamp") == 0) {
            addTimestamp = true;
          } else if (strcmp(aName, "sync") == 0) {
            isSync = true;
          } else if (strcmp(aName, "raw") == 0) {
            isRaw = true;
          } else if (strcmp(aName, "rotate") == 0) {
            rotate = (aValue << 20) / kRotateFilesNumber;
          } else if (strcmp(aName, "profilermarkers") == 0) {
            isMarkers = true;
          } else {
            this->CreateOrGetModule(aName)->SetLevel(aLevel);
          }
        });

    // Rotate implies timestamp to make the files readable
    mAddTimestamp = addTimestamp || rotate > 0;
    mIsSync = isSync;
    mIsRaw = isRaw;
    mRotate = rotate;
    mAddProfilerMarker = isMarkers;

    if (rotate > 0 && shouldAppend) {
      NS_WARNING("MOZ_LOG: when you rotate the log, you cannot use append!");
    }

    const char* logFile = PR_GetEnv("MOZ_LOG_FILE");
    if (!logFile || !logFile[0]) {
      logFile = PR_GetEnv("NSPR_LOG_FILE");
    }

    if (logFile && logFile[0]) {
      char buf[2048];
      logFile = detail::ExpandLogFileName(logFile, buf);
      mOutFilePath.reset(strdup(logFile));

      if (mRotate > 0) {
        // Delete all the previously captured files, including non-rotated
        // log files, so that users don't complain our logs eat space even
        // after the rotate option has been added and don't happen to send
        // us old large logs along with the rotated files.
        remove(mOutFilePath.get());
        for (uint32_t i = 0; i < kRotateFilesNumber; ++i) {
          RemoveFile(i);
        }
      }

      mOutFile = OpenFile(shouldAppend, mOutFileNum);
      mSetFromEnv = true;
    }
  }

  void SetLogFile(const char* aFilename) {
    // For now we don't allow you to change the file at runtime.
    if (mSetFromEnv) {
      NS_WARNING(
          "LogModuleManager::SetLogFile - Log file was set from the "
          "MOZ_LOG_FILE environment variable.");
      return;
    }

    const char* filename = aFilename ? aFilename : "";
    char buf[2048];
    filename = detail::ExpandLogFileName(filename, buf);

    // Can't use rotate at runtime yet.
    MOZ_ASSERT(mRotate == 0,
               "We don't allow rotate for runtime logfile changes");
    mOutFilePath.reset(strdup(filename));

    // Exchange mOutFile and set it to be released once all the writes are done.
    detail::LogFile* newFile = OpenFile(false, 0);
    detail::LogFile* oldFile = mOutFile.exchange(newFile);

    // Since we don't allow changing the logfile if MOZ_LOG_FILE is already set,
    // and we don't allow log rotation when setting it at runtime,
    // mToReleaseFile will be null, so we're not leaking.
    DebugOnly<detail::LogFile*> prevFile = mToReleaseFile.exchange(oldFile);
    MOZ_ASSERT(!prevFile, "Should be null because rotation is not allowed");

    // If we just need to release a file, we must force print, in order to
    // trigger the closing and release of mToReleaseFile.
    if (oldFile) {
      va_list va;
      empty_va(&va);
      Print("Logger", LogLevel::Info, "Flushing old log files\n", va);
    }
  }

  uint32_t GetLogFile(char* aBuffer, size_t aLength) {
    uint32_t len = strlen(mOutFilePath.get());
    if (len + 1 > aLength) {
      return 0;
    }
    snprintf(aBuffer, aLength, "%s", mOutFilePath.get());
    return len;
  }

  void SetIsSync(bool aIsSync) { mIsSync = aIsSync; }

  void SetAddTimestamp(bool aAddTimestamp) { mAddTimestamp = aAddTimestamp; }

  detail::LogFile* OpenFile(bool aShouldAppend, uint32_t aFileNum) {
    FILE* file;

    if (mRotate > 0) {
      char buf[2048];
      SprintfLiteral(buf, "%s.%d", mOutFilePath.get(), aFileNum);

      // rotate doesn't support append.
      file = fopen(buf, "w");
    } else {
      file = fopen(mOutFilePath.get(), aShouldAppend ? "a" : "w");
    }

    if (!file) {
      return nullptr;
    }

    return new detail::LogFile(file, aFileNum);
  }

  void RemoveFile(uint32_t aFileNum) {
    char buf[2048];
    SprintfLiteral(buf, "%s.%d", mOutFilePath.get(), aFileNum);
    remove(buf);
  }

  LogModule* CreateOrGetModule(const char* aName) {
    OffTheBooksMutexAutoLock guard(mModulesLock);
    LogModule* module = nullptr;
    if (!mModules.Get(aName, &module)) {
      module = new LogModule(aName, LogLevel::Disabled);
      mModules.Put(aName, module);
    }

    return module;
  }

  void Print(const char* aName, LogLevel aLevel, const char* aFmt,
             va_list aArgs) MOZ_FORMAT_PRINTF(4, 0) {
    // We don't do nuwa-style forking anymore, so our pid can't change.
    static long pid = static_cast<long>(base::GetCurrentProcId());
    const size_t kBuffSize = 1024;
    char buff[kBuffSize];

    char* buffToWrite = buff;
    SmprintfPointer allocatedBuff;

    va_list argsCopy;
    va_copy(argsCopy, aArgs);
    int charsWritten = VsprintfLiteral(buff, aFmt, argsCopy);
    va_end(argsCopy);

    if (charsWritten < 0) {
      // Print out at least something.  We must copy to the local buff,
      // can't just assign aFmt to buffToWrite, since when
      // buffToWrite != buff, we try to release it.
      MOZ_ASSERT(false, "Probably incorrect format string in LOG?");
      strncpy(buff, aFmt, kBuffSize - 1);
      buff[kBuffSize - 1] = '\0';
      charsWritten = strlen(buff);
    } else if (static_cast<size_t>(charsWritten) >= kBuffSize - 1) {
      // We may have maxed out, allocate a buffer instead.
      allocatedBuff = mozilla::Vsmprintf(aFmt, aArgs);
      buffToWrite = allocatedBuff.get();
      charsWritten = strlen(buffToWrite);
    }

#ifdef MOZ_GECKO_PROFILER
    if (mAddProfilerMarker && profiler_is_active()) {
      profiler_add_marker(
          "LogMessages", JS::ProfilingCategoryPair::OTHER,
          MakeUnique<LogMarkerPayload>(aName, buffToWrite, TimeStamp::Now()));
    }
#endif

    // Determine if a newline needs to be appended to the message.
    const char* newline = "";
    if (charsWritten == 0 || buffToWrite[charsWritten - 1] != '\n') {
      newline = "\n";
    }

    FILE* out = stderr;

    // In case we use rotate, this ensures the FILE is kept alive during
    // its use.  Increased before we load mOutFile.
    ++mPrintEntryCount;

    detail::LogFile* outFile = mOutFile;
    if (outFile) {
      out = outFile->File();
    }

    // This differs from the NSPR format in that we do not output the
    // opaque system specific thread pointer (ie pthread_t) cast
    // to a long. The address of the current PR_Thread continues to be
    // prefixed.
    //
    // Additionally we prefix the output with the abbreviated log level
    // and the module name.
    PRThread* currentThread = PR_GetCurrentThread();
    const char* currentThreadName = (mMainThread == currentThread)
                                        ? "Main Thread"
                                        : PR_GetThreadName(currentThread);

    char noNameThread[40];
    if (!currentThreadName) {
      SprintfLiteral(noNameThread, "Unnamed thread %p", currentThread);
      currentThreadName = noNameThread;
    }

    if (!mAddTimestamp) {
      if (!mIsRaw) {
        fprintf_stderr(out, "[%s %ld: %s]: %s/%s %s%s",
                       nsDebugImpl::GetMultiprocessMode(), pid,
                       currentThreadName, ToLogStr(aLevel), aName, buffToWrite,
                       newline);
      } else {
        fprintf_stderr(out, "%s%s", buffToWrite, newline);
      }
    } else {
      PRExplodedTime now;
      PR_ExplodeTime(PR_Now(), PR_GMTParameters, &now);
      fprintf_stderr(
          out,
          "%04d-%02d-%02d %02d:%02d:%02d.%06d UTC - [%s %ld: %s]: %s/%s %s%s",
          now.tm_year, now.tm_month + 1, now.tm_mday, now.tm_hour, now.tm_min,
          now.tm_sec, now.tm_usec, nsDebugImpl::GetMultiprocessMode(), pid,
          currentThreadName, ToLogStr(aLevel), aName, buffToWrite, newline);
    }

    if (mIsSync) {
      fflush(out);
    }

    if (mRotate > 0 && outFile) {
      int32_t fileSize = ftell(out);
      if (fileSize > mRotate) {
        uint32_t fileNum = outFile->Num();

        uint32_t nextFileNum = fileNum + 1;
        if (nextFileNum >= kRotateFilesNumber) {
          nextFileNum = 0;
        }

        // And here is the trick.  The current out-file remembers its order
        // number.  When no other thread shifted the global file number yet,
        // we are the thread to open the next file.
        if (mOutFileNum.compareExchange(fileNum, nextFileNum)) {
          // We can work with mToReleaseFile because we are sure the
          // mPrintEntryCount can't drop to zero now - the condition
          // to actually delete what's stored in that member.
          // And also, no other thread can enter this piece of code
          // because mOutFile is still holding the current file with
          // the non-shifted number.  The compareExchange() above is
          // a no-op for other threads.
          outFile->mNextToRelease = mToReleaseFile;
          mToReleaseFile = outFile;

          mOutFile = OpenFile(false, nextFileNum);
        }
      }
    }

    if (--mPrintEntryCount == 0 && mToReleaseFile) {
      // We were the last Print() entered, if there is a file to release
      // do it now.  exchange() is atomic and makes sure we release the file
      // only once on one thread.
      detail::LogFile* release = mToReleaseFile.exchange(nullptr);
      delete release;
    }
  }

 private:
  OffTheBooksMutex mModulesLock;
  nsClassHashtable<nsCharPtrHashKey, LogModule> mModules;

  // Print() entry counter, actually reflects concurrent use of the current
  // output file.  ReleaseAcquire ensures that manipulation with mOutFile
  // and mToReleaseFile is synchronized by manipulation with this value.
  Atomic<uint32_t, ReleaseAcquire> mPrintEntryCount;
  // File to write to.  ReleaseAcquire because we need to sync mToReleaseFile
  // with this.
  Atomic<detail::LogFile*, ReleaseAcquire> mOutFile;
  // File to be released when reference counter drops to zero.  This member
  // is assigned mOutFile when the current file has reached the limit.
  // It can be Relaxed, since it's synchronized with mPrintEntryCount
  // manipulation and we do atomic exchange() on it.
  Atomic<detail::LogFile*, Relaxed> mToReleaseFile;
  // The next file number.  This is mostly only for synchronization sake.
  // Can have relaxed ordering, since we only do compareExchange on it which
  // is atomic regardless ordering.
  Atomic<uint32_t, Relaxed> mOutFileNum;
  // Just keeps the actual file path for further use.
  UniqueFreePtr<char[]> mOutFilePath;

  PRThread* mMainThread;
  bool mSetFromEnv;
  Atomic<bool, Relaxed> mAddTimestamp;
  Atomic<bool, Relaxed> mAddProfilerMarker;
  Atomic<bool, Relaxed> mIsRaw;
  Atomic<bool, Relaxed> mIsSync;
  int32_t mRotate;
  bool mInitialized;
};

StaticAutoPtr<LogModuleManager> sLogModuleManager;

LogModule* LogModule::Get(const char* aName) {
  // This is just a pass through to the LogModuleManager so
  // that the LogModuleManager implementation can be kept internal.
  MOZ_ASSERT(sLogModuleManager != nullptr);
  return sLogModuleManager->CreateOrGetModule(aName);
}

void LogModule::SetLogFile(const char* aFilename) {
  MOZ_ASSERT(sLogModuleManager);
  sLogModuleManager->SetLogFile(aFilename);
}

uint32_t LogModule::GetLogFile(char* aBuffer, size_t aLength) {
  MOZ_ASSERT(sLogModuleManager);
  return sLogModuleManager->GetLogFile(aBuffer, aLength);
}

void LogModule::SetAddTimestamp(bool aAddTimestamp) {
  sLogModuleManager->SetAddTimestamp(aAddTimestamp);
}

void LogModule::SetIsSync(bool aIsSync) {
  sLogModuleManager->SetIsSync(aIsSync);
}

void LogModule::Init(int argc, char* argv[]) {
  // NB: This method is not threadsafe; it is expected to be called very early
  //     in startup prior to any other threads being run.
  MOZ_DIAGNOSTIC_ASSERT(NS_IsMainThread());

  if (sLogModuleManager) {
    // Already initialized.
    return;
  }

  // NB: We intentionally do not register for ClearOnShutdown as that happens
  //     before all logging is complete. And, yes, that means we leak, but
  //     we're doing that intentionally.

  // Don't assign the pointer until after Init is called. This should help us
  // detect if any of the functions called by Init somehow rely on logging.
  auto mgr = new LogModuleManager();
  mgr->Init(argc, argv);
  sLogModuleManager = mgr;
}

void LogModule::Printv(LogLevel aLevel, const char* aFmt, va_list aArgs) const {
  MOZ_ASSERT(sLogModuleManager != nullptr);

  // Forward to LogModule manager w/ level and name
  sLogModuleManager->Print(Name(), aLevel, aFmt, aArgs);
}

}  // namespace mozilla