Commit 8c4208d5 authored by Zequan Wu's avatar Zequan Wu
Browse files

[Profile][NFC] Clean up initializeProfileForContinuousMode 

Merge two versions of `initializeProfileForContinuousMode` function into one.

Differential Revision: https://reviews.llvm.org/D107591
parent d238b602

compiler-rt/lib/profile/InstrProfilingFile.c

+153 −219
Original line number Diff line number Diff line
@@ -92,6 +92,56 @@ static lprofFilename lprofCurFilename = {0, 0, 0, {0}, NULL, 
                                         {0}, 0, 0, 0,   PNS_unknown};



static int ProfileMergeRequested = 0;



#if defined(__APPLE__)

static const int ContinuousModeSupported = 1;

static const int UseBiasVar = 0;

static const char *FileOpenMode = "a+b";

static intptr_t INSTR_PROF_PROFILE_COUNTER_BIAS_VAR;

static void *BiasAddr = NULL;

static void *BiasDefaultAddr = NULL;

#elif defined(__ELF__) || defined(_WIN32)



#define INSTR_PROF_PROFILE_COUNTER_BIAS_DEFAULT_VAR                            \

  INSTR_PROF_CONCAT(INSTR_PROF_PROFILE_COUNTER_BIAS_VAR, _default)

intptr_t INSTR_PROF_PROFILE_COUNTER_BIAS_DEFAULT_VAR = 0;



/* This variable is a weak external reference which could be used to detect

 * whether or not the compiler defined this symbol. */

#if defined(_WIN32)

COMPILER_RT_VISIBILITY extern intptr_t INSTR_PROF_PROFILE_COUNTER_BIAS_VAR;

#if defined(_M_IX86) || defined(__i386__)

#define WIN_SYM_PREFIX "_"

#else

#define WIN_SYM_PREFIX

#endif

#pragma comment(                                                               \

    linker, "/alternatename:" WIN_SYM_PREFIX INSTR_PROF_QUOTE(                 \

                INSTR_PROF_PROFILE_COUNTER_BIAS_VAR) "=" WIN_SYM_PREFIX        \

                INSTR_PROF_QUOTE(INSTR_PROF_PROFILE_COUNTER_BIAS_DEFAULT_VAR))

#else

COMPILER_RT_VISIBILITY extern intptr_t INSTR_PROF_PROFILE_COUNTER_BIAS_VAR

    __attribute__((weak, alias(INSTR_PROF_QUOTE(

                             INSTR_PROF_PROFILE_COUNTER_BIAS_DEFAULT_VAR))));

#endif

static const int ContinuousModeSupported = 1;

static const int UseBiasVar = 1;

/* TODO: If there are two DSOs, the second DSO initilization will truncate the

 * first profile file. */

static const char *FileOpenMode = "w+b";

/* This symbol is defined by the compiler when runtime counter relocation is

 * used and runtime provides a weak alias so we can check if it's defined. */

static void *BiasAddr = &INSTR_PROF_PROFILE_COUNTER_BIAS_VAR;

static void *BiasDefaultAddr = &INSTR_PROF_PROFILE_COUNTER_BIAS_DEFAULT_VAR;

#else

static const int ContinuousModeSupported = 0;

static const int UseBiasVar = 0;

static const char *FileOpenMode = "a+b";

static intptr_t INSTR_PROF_PROFILE_COUNTER_BIAS_VAR;

static void *BiasAddr = NULL;

static void *BiasDefaultAddr = NULL;

#endif



static int isProfileMergeRequested() { return ProfileMergeRequested; }

static void setProfileMergeRequested(int EnableMerge) {

  ProfileMergeRequested = EnableMerge;
@@ -426,8 +476,6 @@ static void truncateCurrentFile(void) { 
  fclose(File);

}



// TODO: Move these functions into InstrProfilingPlatform* files.

#if defined(__APPLE__)

/* Write a partial profile to \p Filename, which is required to be backed by

 * the open file object \p File. */

static int writeProfileWithFileObject(const char *Filename, FILE *File) {
@@ -439,19 +487,17 @@ static int writeProfileWithFileObject(const char *Filename, FILE *File) { 
  return rc;

}



/* Unlock the profile \p File and clear the unlock flag. */

static void unlockProfile(int *ProfileRequiresUnlock, FILE *File) {

  if (!*ProfileRequiresUnlock) {

    PROF_WARN("%s", "Expected to require profile unlock\n");

  }



  lprofUnlockFileHandle(File);

  *ProfileRequiresUnlock = 0;

}



static void initializeProfileForContinuousMode(void) {

  if (!__llvm_profile_is_continuous_mode_enabled())

    return;

  if (!ContinuousModeSupported) {

    PROF_ERR("%s\n", "continuous mode is unsupported on this platform");

    return;

  }

  if (UseBiasVar && BiasAddr == BiasDefaultAddr) {

    PROF_ERR("%s\n", "__llvm_profile_counter_bias is undefined");

    return;

  }



  /* Get the sizes of various profile data sections. Taken from

   * __llvm_profile_get_size_for_buffer(). */
@@ -465,19 +511,6 @@ static void initializeProfileForContinuousMode(void) { 
  uint64_t DataSize = __llvm_profile_get_data_size(DataBegin, DataEnd);

  uint64_t CountersSize = CountersEnd - CountersBegin;



  /* Check that the counter and data sections in this image are page-aligned. */

  unsigned PageSize = getpagesize();

  if ((intptr_t)CountersBegin % PageSize != 0) {

    PROF_ERR("Counters section not page-aligned (start = %p, pagesz = %u).\n",

             CountersBegin, PageSize);

    return;

  }

  if ((intptr_t)DataBegin % PageSize != 0) {

    PROF_ERR("Data section not page-aligned (start = %p, pagesz = %u).\n",

             DataBegin, PageSize);

    return;

  }



  int Length = getCurFilenameLength();

  char *FilenameBuf = (char *)COMPILER_RT_ALLOCA(Length + 1);

  const char *Filename = getCurFilename(FilenameBuf, 0);
@@ -486,33 +519,7 @@ static void initializeProfileForContinuousMode(void) { 


  FILE *File = NULL;

  off_t CurrentFileOffset = 0;

  off_t OffsetModPage = 0;



  /* Whether an exclusive lock on the profile must be dropped after init.

   * Use a cleanup to warn if the unlock does not occur. */

  COMPILER_RT_CLEANUP(warnIfNonZero) int ProfileRequiresUnlock = 0;



  if (!doMerging()) {

    /* We are not merging profiles, so open the raw profile in append mode. */

    File = fopen(Filename, "a+b");

    if (!File)

      return;



    /* Check that the offset within the file is page-aligned. */

    CurrentFileOffset = ftello(File);

    OffsetModPage = CurrentFileOffset % PageSize;

    if (OffsetModPage != 0) {

      PROF_ERR("Continuous counter sync mode is enabled, but raw profile is not"

               "page-aligned. CurrentFileOffset = %" PRIu64 ", pagesz = %u.\n",

               (uint64_t)CurrentFileOffset, PageSize);

      return;

    }



    /* Grow the profile so that mmap() can succeed.  Leak the file handle, as

     * the file should stay open. */

    if (writeProfileWithFileObject(Filename, File) != 0)

      return;

  } else {

  if (doMerging()) {

    /* We are merging profiles. Map the counter section as shared memory into

     * the profile, i.e. into each participating process. An increment in one

     * process should be visible to every other process with the same counter
@@ -521,24 +528,47 @@ static void initializeProfileForContinuousMode(void) { 
    if (!File)

      return;



    ProfileRequiresUnlock = 1;



    uint64_t ProfileFileSize;

    if (getProfileFileSizeForMerging(File, &ProfileFileSize) == -1)

      return unlockProfile(&ProfileRequiresUnlock, File);



    uint64_t ProfileFileSize = 0;

    if (getProfileFileSizeForMerging(File, &ProfileFileSize) == -1) {

      lprofUnlockFileHandle(File);

      fclose(File);

      return;

    }

    if (ProfileFileSize == 0) {

      /* Grow the profile so that mmap() can succeed.  Leak the file handle, as

       * the file should stay open. */

      if (writeProfileWithFileObject(Filename, File) != 0)

        return unlockProfile(&ProfileRequiresUnlock, File);

      if (writeProfileWithFileObject(Filename, File) != 0) {

        lprofUnlockFileHandle(File);

        fclose(File);

        return;

      }

    } else {

      /* The merged profile has a non-zero length. Check that it is compatible

       * with the data in this process. */

      char *ProfileBuffer;

      if (mmapProfileForMerging(File, ProfileFileSize, &ProfileBuffer) == -1 ||

          munmap(ProfileBuffer, ProfileFileSize) == -1)

        return unlockProfile(&ProfileRequiresUnlock, File);

          munmap(ProfileBuffer, ProfileFileSize)) {

        lprofUnlockFileHandle(File);

        fclose(File);

        return;

      }

    }

  } else {

    File = fopen(Filename, FileOpenMode);

    if (!File)

      return;

    /* Check that the offset within the file is page-aligned. */

    CurrentFileOffset = ftello(File);

    unsigned PageSize = getpagesize();

    if (CurrentFileOffset % PageSize != 0) {

      PROF_ERR("Continuous counter sync mode is enabled, but raw profile is not"

               "page-aligned. CurrentFileOffset = %" PRIu64 ", pagesz = %u.\n",

               (uint64_t)CurrentFileOffset, PageSize);

      return;

    }

    if (writeProfileWithFileObject(Filename, File) != 0) {

      fclose(File);

      return;

    }

  }
@@ -546,9 +576,45 @@ static void initializeProfileForContinuousMode(void) { 
   * If there aren't any counters, mmap() would fail with EINVAL. */

  if (CountersSize > 0) {

    int Fileno = fileno(File);

    if (UseBiasVar) {

      /* Get the file size. */

      uint64_t FileSize = ftell(File);



      /* Map the profile. */

      char *Profile = (char *)mmap(NULL, FileSize, PROT_READ | PROT_WRITE,

                                   MAP_SHARED, Fileno, 0);

      if (Profile == MAP_FAILED) {

        PROF_ERR("Unable to mmap profile: %s\n", strerror(errno));

        return;

      }

      const uint64_t CountersOffsetInBiasMode =

          sizeof(__llvm_profile_header) +

          (DataSize * sizeof(__llvm_profile_data));

      /* Update the profile fields based on the current mapping. */

      INSTR_PROF_PROFILE_COUNTER_BIAS_VAR = (intptr_t)Profile -

                                            (uintptr_t)CountersBegin +

                                            CountersOffsetInBiasMode;



    /* Determine how much padding is needed before/after the counters and after

     * the names. */

      /* Return the memory allocated for counters to OS. */

      lprofReleaseMemoryPagesToOS((uintptr_t)CountersBegin,

                                  (uintptr_t)CountersEnd);

    } else {

      /* Check that the counter and data sections in this image are

       * page-aligned. */

      unsigned PageSize = getpagesize();

      if ((intptr_t)CountersBegin % PageSize != 0) {

        PROF_ERR(

            "Counters section not page-aligned (start = %p, pagesz = %u).\n",

            CountersBegin, PageSize);

        return;

      }

      if ((intptr_t)DataBegin % PageSize != 0) {

        PROF_ERR("Data section not page-aligned (start = %p, pagesz = %u).\n",

                 DataBegin, PageSize);

        return;

      }

      /* Determine how much padding is needed before/after the counters and

       * after the names. */

      uint64_t PaddingBytesBeforeCounters, PaddingBytesAfterCounters,

          PaddingBytesAfterNames;

      __llvm_profile_get_padding_sizes_for_counters(
@@ -561,9 +627,10 @@ static void initializeProfileForContinuousMode(void) { 
          CurrentFileOffset + sizeof(__llvm_profile_header) +

          (DataSize * sizeof(__llvm_profile_data)) + PaddingBytesBeforeCounters;



    uint64_t *CounterMmap = (uint64_t *)mmap(

        (void *)CountersBegin, PageAlignedCountersLength, PROT_READ | PROT_WRITE,

        MAP_FIXED | MAP_SHARED, Fileno, FileOffsetToCounters);

      uint64_t *CounterMmap =

          (uint64_t *)mmap((void *)CountersBegin, PageAlignedCountersLength,

                           PROT_READ | PROT_WRITE, MAP_FIXED | MAP_SHARED,

                           Fileno, FileOffsetToCounters);

      if (CounterMmap != CountersBegin) {

        PROF_ERR(

            "Continuous counter sync mode is enabled, but mmap() failed (%s).\n"
@@ -575,146 +642,13 @@ static void initializeProfileForContinuousMode(void) { 
            FileOffsetToCounters);

      }

    }



  if (ProfileRequiresUnlock)

    unlockProfile(&ProfileRequiresUnlock, File);

}

#elif defined(__ELF__) || defined(_WIN32)



#define INSTR_PROF_PROFILE_COUNTER_BIAS_DEFAULT_VAR                            \

  INSTR_PROF_CONCAT(INSTR_PROF_PROFILE_COUNTER_BIAS_VAR, _default)

intptr_t INSTR_PROF_PROFILE_COUNTER_BIAS_DEFAULT_VAR = 0;



/* This variable is a weak external reference which could be used to detect

 * whether or not the compiler defined this symbol. */

#if defined(_WIN32)

COMPILER_RT_VISIBILITY extern intptr_t INSTR_PROF_PROFILE_COUNTER_BIAS_VAR;

#if defined(_M_IX86) || defined(__i386__)

#define WIN_SYM_PREFIX "_"

#else

#define WIN_SYM_PREFIX

#endif

#pragma comment(                                                               \

    linker, "/alternatename:" WIN_SYM_PREFIX INSTR_PROF_QUOTE(                 \

                INSTR_PROF_PROFILE_COUNTER_BIAS_VAR) "=" WIN_SYM_PREFIX        \

                INSTR_PROF_QUOTE(INSTR_PROF_PROFILE_COUNTER_BIAS_DEFAULT_VAR))

#else

COMPILER_RT_VISIBILITY extern intptr_t INSTR_PROF_PROFILE_COUNTER_BIAS_VAR

    __attribute__((weak, alias(INSTR_PROF_QUOTE(

                             INSTR_PROF_PROFILE_COUNTER_BIAS_DEFAULT_VAR))));

#endif



static int writeMMappedFile(FILE *OutputFile, char **Profile) {

  if (!OutputFile)

    return -1;



  /* Write the data into a file. */

  setupIOBuffer();

  ProfDataWriter fileWriter;

  initFileWriter(&fileWriter, OutputFile);

  if (lprofWriteData(&fileWriter, NULL, 0)) {

    PROF_ERR("Failed to write profile: %s\n", strerror(errno));

    return -1;

  }

  fflush(OutputFile);



  /* Get the file size. */

  uint64_t FileSize = ftell(OutputFile);



  /* Map the profile. */

  *Profile = (char *)mmap(

      NULL, FileSize, PROT_READ | PROT_WRITE, MAP_SHARED, fileno(OutputFile), 0);

  if (*Profile == MAP_FAILED) {

    PROF_ERR("Unable to mmap profile: %s\n", strerror(errno));

    return -1;

  }



  return 0;

}



static void initializeProfileForContinuousMode(void) {

  if (!__llvm_profile_is_continuous_mode_enabled())

    return;



  /* This symbol is defined by the compiler when runtime counter relocation is

   * used and runtime provides a weak alias so we can check if it's defined. */

  void *BiasAddr = &INSTR_PROF_PROFILE_COUNTER_BIAS_VAR;

  void *BiasDefaultAddr = &INSTR_PROF_PROFILE_COUNTER_BIAS_DEFAULT_VAR;

  if (BiasAddr == BiasDefaultAddr) {

    PROF_ERR("%s\n", "__llvm_profile_counter_bias is undefined");

    return;

  }



  /* Get the sizes of various profile data sections. Taken from

   * __llvm_profile_get_size_for_buffer(). */

  const __llvm_profile_data *DataBegin = __llvm_profile_begin_data();

  const __llvm_profile_data *DataEnd = __llvm_profile_end_data();

  const uint64_t *CountersBegin = __llvm_profile_begin_counters();

  const uint64_t *CountersEnd = __llvm_profile_end_counters();

  uint64_t DataSize = __llvm_profile_get_data_size(DataBegin, DataEnd);

  const uint64_t CountersOffset =

      sizeof(__llvm_profile_header) + (DataSize * sizeof(__llvm_profile_data));



  int Length = getCurFilenameLength();

  char *FilenameBuf = (char *)COMPILER_RT_ALLOCA(Length + 1);

  const char *Filename = getCurFilename(FilenameBuf, 0);

  if (!Filename)

    return;



  FILE *File = NULL;

  char *Profile = NULL;



  if (!doMerging()) {

    File = fopen(Filename, "w+b");

    if (!File)

      return;



    if (writeMMappedFile(File, &Profile) == -1) {

      fclose(File);

      return;

  }

  } else {

    File = lprofOpenFileEx(Filename);

    if (!File)

      return;



    uint64_t ProfileFileSize = 0;

    if (getProfileFileSizeForMerging(File, &ProfileFileSize) == -1) {

  if (doMerging()) {

    lprofUnlockFileHandle(File);

    fclose(File);

      return;

  }



    if (!ProfileFileSize) {

      if (writeMMappedFile(File, &Profile) == -1) {

        fclose(File);

        return;

      }

    } else {

      /* The merged profile has a non-zero length. Check that it is compatible

       * with the data in this process. */

      if (mmapProfileForMerging(File, ProfileFileSize, &Profile) == -1) {

        fclose(File);

        return;

}

    }



    lprofUnlockFileHandle(File);

  }



  /* Update the profile fields based on the current mapping. */

  INSTR_PROF_PROFILE_COUNTER_BIAS_VAR =

      (intptr_t)Profile - (uintptr_t)CountersBegin +

      CountersOffset;



  /* Return the memory allocated for counters to OS. */

  lprofReleaseMemoryPagesToOS((uintptr_t)CountersBegin, (uintptr_t)CountersEnd);

}

#else

static void initializeProfileForContinuousMode(void) {

  PROF_ERR("%s\n", "continuous mode is unsupported on this platform");

}

#endif



static const char *DefaultProfileName = "default.profraw";

static void resetFilenameToDefault(void) {

compiler-rt/lib/profile/InstrProfilingUtil.c

+0 −5
Original line number Diff line number Diff line
@@ -353,8 +353,3 @@ COMPILER_RT_VISIBILITY int lprofReleaseMemoryPagesToOS(uintptr_t Begin, 
  }

  return 0;

}
 


COMPILER_RT_VISIBILITY void warnIfNonZero(int *i) {

  if (*i)

    PROF_WARN("Expected flag to be 0, but got: %d\n", *i);

}

compiler-rt/lib/profile/InstrProfilingUtil.h

+0 −3
Original line number Diff line number Diff line
@@ -84,7 +84,4 @@ static inline size_t lprofRoundDownTo(size_t x, size_t boundary) { 


int lprofReleaseMemoryPagesToOS(uintptr_t Begin, uintptr_t End);



/// Noisly warn if *i is non-zero. Intended for use with COMPILER_RT_CLEANUP.

void warnIfNonZero(int *i);



#endif /* PROFILE_INSTRPROFILINGUTIL_H */