/*

 * Copyright (c) 2012, 2019, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 *

 */

#include "precompiled.hpp"

#include "jfr/jfrEvents.hpp"

#include "jfr/jni/jfrJavaSupport.hpp"

#include "jfr/leakprofiler/leakProfiler.hpp"

#include "jfr/recorder/repository/jfrEmergencyDump.hpp"

#include "jfr/recorder/service/jfrPostBox.hpp"

#include "jfr/recorder/service/jfrRecorderService.hpp"

#include "jfr/utilities/jfrTypes.hpp"

#include "logging/log.hpp"

#include "memory/resourceArea.hpp"

#include "runtime/atomic.hpp"

#include "runtime/handles.inline.hpp"

#include "runtime/globals.hpp"

#include "runtime/mutexLocker.hpp"

#include "runtime/os.hpp"

#include "runtime/thread.inline.hpp"

#include "utilities/growableArray.hpp"

static const char vm_error_filename_fmt[] = "hs_err_pid%p.jfr";

static const char vm_oom_filename_fmt[] = "hs_oom_pid%p.jfr";

static const char vm_soe_filename_fmt[] = "hs_soe_pid%p.jfr";

static const char chunk_file_jfr_ext[] = ".jfr";

static const size_t iso8601_len = 19; // "YYYY-MM-DDTHH:MM:SS"

static fio_fd open_exclusivly(const char* path) {

  return os::open(path, O_CREAT | O_RDWR, S_IREAD | S_IWRITE);

}

static int file_sort(const char** const file1, const char** file2) {

  assert(NULL != *file1 && NULL != *file2, "invariant");

  int cmp = strncmp(*file1, *file2, iso8601_len);

  if (0 == cmp) {

    const char* const dot1 = strchr(*file1, '.');

    assert(NULL != dot1, "invariant");

    const char* const dot2 = strchr(*file2, '.');

    assert(NULL != dot2, "invariant");

    ptrdiff_t file1_len = dot1 - *file1;

    ptrdiff_t file2_len = dot2 - *file2;

    if (file1_len < file2_len) {

      return -1;

    }

    if (file1_len > file2_len) {

      return 1;

    }

    assert(file1_len == file2_len, "invariant");

    cmp = strncmp(*file1, *file2, file1_len);

  }

  assert(cmp != 0, "invariant");

  return cmp;

}

static void iso8601_to_date_time(char* iso8601_str) {

  assert(iso8601_str != NULL, "invariant");

  assert(strlen(iso8601_str) == iso8601_len, "invariant");

  // "YYYY-MM-DDTHH:MM:SS"

  for (size_t i = 0; i < iso8601_len; ++i) {

    switch (iso8601_str[i]) {

    case 'T':

    case '-':

    case ':':

      iso8601_str[i] = '_';

      break;

    }

  }

  // "YYYY_MM_DD_HH_MM_SS"

}

static void date_time(char* buffer, size_t buffer_len) {

  assert(buffer != NULL, "invariant");

  assert(buffer_len >= iso8601_len, "buffer too small");

  os::iso8601_time(buffer, buffer_len);

  assert(strlen(buffer) >= iso8601_len + 1, "invariant");

  // "YYYY-MM-DDTHH:MM:SS"

  buffer[iso8601_len] = '\0';

  iso8601_to_date_time(buffer);

}

static int64_t file_size(fio_fd fd) {

  assert(fd != invalid_fd, "invariant");

  const int64_t current_offset = os::current_file_offset(fd);

  const int64_t size = os::lseek(fd, 0, SEEK_END);

  os::seek_to_file_offset(fd, current_offset);

  return size;

}

class RepositoryIterator : public StackObj {

 private:

  const char* const _repo;

  const size_t _repository_len;

  GrowableArray<const char*>* _files;

  const char* const fully_qualified(const char* entry) const;

  mutable int _iterator;

 public:

  RepositoryIterator(const char* repository, size_t repository_len);

  ~RepositoryIterator() {}

  const char* const filter(const char* entry) const;

  bool has_next() const;

  const char* const next() const;

};

const char* const RepositoryIterator::fully_qualified(const char* entry) const {

  assert(NULL != entry, "invariant");

  char* file_path_entry = NULL;

  // only use files that have content, not placeholders

  const char* const file_separator = os::file_separator();

  if (NULL != file_separator) {

    const size_t entry_len = strlen(entry);

    const size_t file_separator_length = strlen(file_separator);

    const size_t file_path_entry_length = _repository_len + file_separator_length + entry_len;

    file_path_entry = NEW_RESOURCE_ARRAY_RETURN_NULL(char, file_path_entry_length + 1);

    if (NULL == file_path_entry) {

      return NULL;

    }

    int position = 0;

    position += jio_snprintf(&file_path_entry[position], _repository_len + 1, "%s", _repo);

    position += jio_snprintf(&file_path_entry[position], file_separator_length + 1, "%s", os::file_separator());

    position += jio_snprintf(&file_path_entry[position], entry_len + 1, "%s", entry);

    file_path_entry[position] = '\0';

    assert((size_t)position == file_path_entry_length, "invariant");

    assert(strlen(file_path_entry) == (size_t)position, "invariant");

  }

  return file_path_entry;

}

const char* const RepositoryIterator::filter(const char* entry) const {

  if (entry == NULL) {

    return NULL;

  }

  const size_t entry_len = strlen(entry);

  if (entry_len <= 2) {

    // for "." and ".."

    return NULL;

  }

  char* entry_name = NEW_RESOURCE_ARRAY_RETURN_NULL(char, entry_len + 1);

  if (entry_name == NULL) {

    return NULL;

  }

  strncpy(entry_name, entry, entry_len + 1);

  const char* const fully_qualified_path_entry = fully_qualified(entry_name);

  if (NULL == fully_qualified_path_entry) {

    return NULL;

  }

  const fio_fd entry_fd = open_exclusivly(fully_qualified_path_entry);

  if (invalid_fd == entry_fd) {

    return NULL;

  }

  const int64_t entry_size = file_size(entry_fd);

  os::close(entry_fd);

  if (0 == entry_size) {

    return NULL;

  }

  return entry_name;

}

RepositoryIterator::RepositoryIterator(const char* repository, size_t repository_len) :

  _repo(repository),

  _repository_len(repository_len),

  _files(NULL),

  _iterator(0) {

  if (NULL != _repo) {

    assert(strlen(_repo) == _repository_len, "invariant");

    _files = new GrowableArray<const char*>(10);

    DIR* dirp = os::opendir(_repo);

    if (dirp == NULL) {

      log_error(jfr, system)("Unable to open repository %s", _repo);

      return;

    }

    struct dirent* dentry;

    while ((dentry = os::readdir(dirp)) != NULL) {

      const char* const entry_path = filter(dentry->d_name);

      if (NULL != entry_path) {

        _files->append(entry_path);

      }

    }

    os::closedir(dirp);

    if (_files->length() > 1) {

      _files->sort(file_sort);

    }

  }

}

bool RepositoryIterator::has_next() const {

  return (_files != NULL && _iterator < _files->length());

}

const char* const RepositoryIterator::next() const {

  return _iterator >= _files->length() ? NULL : fully_qualified(_files->at(_iterator++));

}

static void write_emergency_file(fio_fd emergency_fd, const RepositoryIterator& iterator) {

  assert(emergency_fd != invalid_fd, "invariant");

  const size_t size_of_file_copy_block = 1 * M; // 1 mb

  jbyte* const file_copy_block = NEW_RESOURCE_ARRAY_RETURN_NULL(jbyte, size_of_file_copy_block);

  if (file_copy_block == NULL) {

    return;

  }

  while (iterator.has_next()) {

    fio_fd current_fd = invalid_fd;

    const char* const fqn = iterator.next();

    if (fqn != NULL) {

      current_fd = open_exclusivly(fqn);

      if (current_fd != invalid_fd) {

        const int64_t current_filesize = file_size(current_fd);

        assert(current_filesize > 0, "invariant");

        int64_t bytes_read = 0;

        int64_t bytes_written = 0;

        while (bytes_read < current_filesize) {

          const ssize_t read_result = os::read_at(current_fd, file_copy_block, size_of_file_copy_block, bytes_read);

          if (-1 == read_result) {

            log_info(jfr)( // For user, should not be "jfr, system"

              "Unable to recover JFR data");

            break;

          }

          bytes_read += (int64_t)read_result;

          assert(bytes_read - bytes_written <= (int64_t)size_of_file_copy_block, "invariant");

          bytes_written += (int64_t)os::write(emergency_fd, file_copy_block, bytes_read - bytes_written);

          assert(bytes_read == bytes_written, "invariant");

        }

        os::close(current_fd);

      }

    }

  }

}

static const char* create_emergency_dump_path() {

  char* buffer = NEW_RESOURCE_ARRAY_RETURN_NULL(char, JVM_MAXPATHLEN);

  if (NULL == buffer) {

    return NULL;

  }

  const char* const cwd = os::get_current_directory(buffer, JVM_MAXPATHLEN);

  if (NULL == cwd) {

    return NULL;

  }

  size_t pos = strlen(cwd);

  const int fsep_len = jio_snprintf(&buffer[pos], JVM_MAXPATHLEN - pos, "%s", os::file_separator());

  const char* filename_fmt = NULL;

  // fetch specific error cause

  switch (JfrJavaSupport::cause()) {

    case JfrJavaSupport::OUT_OF_MEMORY:

      filename_fmt = vm_oom_filename_fmt;

      break;

    case JfrJavaSupport::STACK_OVERFLOW:

      filename_fmt = vm_soe_filename_fmt;

      break;

    default:

      filename_fmt = vm_error_filename_fmt;

  }

  char* emergency_dump_path = NULL;

  pos += fsep_len;

  if (Arguments::copy_expand_pid(filename_fmt, strlen(filename_fmt), &buffer[pos], JVM_MAXPATHLEN - pos)) {

    const size_t emergency_filename_length = strlen(buffer);

    emergency_dump_path = NEW_RESOURCE_ARRAY_RETURN_NULL(char, emergency_filename_length + 1);

    if (NULL == emergency_dump_path) {

      return NULL;

    }

    strncpy(emergency_dump_path, buffer, emergency_filename_length + 1);

  }

  if (emergency_dump_path != NULL) {

    log_info(jfr)( // For user, should not be "jfr, system"

      "Attempting to recover JFR data, emergency jfr file: %s", emergency_dump_path);

  }

  return emergency_dump_path;

}

// Caller needs ResourceMark

static const char* create_emergency_chunk_path(const char* repository_path) {

  assert(repository_path != NULL, "invariant");

  const size_t repository_path_len = strlen(repository_path);

  // date time

  char date_time_buffer[32] = { 0 };

  date_time(date_time_buffer, sizeof(date_time_buffer));

  size_t date_time_len = strlen(date_time_buffer);

  size_t chunkname_max_len = repository_path_len          // repository_base_path

                             + 1                          // "/"

                             + date_time_len              // date_time

                             + strlen(chunk_file_jfr_ext) // .jfr

                             + 1;

  char* chunk_path = NEW_RESOURCE_ARRAY_RETURN_NULL(char, chunkname_max_len);

  if (chunk_path == NULL) {

    return NULL;

  }

  // append the individual substrings

  return chunk_path;

}

static fio_fd emergency_dump_file_descriptor() {

  ResourceMark rm;

  const char* const emergency_dump_path = create_emergency_dump_path();

  return emergency_dump_path != NULL ? open_exclusivly(emergency_dump_path) : invalid_fd;

}

const char* JfrEmergencyDump::build_dump_path(const char* repository_path) {

  return repository_path == NULL ? create_emergency_dump_path() : create_emergency_chunk_path(repository_path);

}

void JfrEmergencyDump::on_vm_error(const char* repository_path) {

  assert(repository_path != NULL, "invariant");

  ResourceMark rm;

  const fio_fd emergency_fd = emergency_dump_file_descriptor();

  if (emergency_fd != invalid_fd) {

    RepositoryIterator iterator(repository_path, strlen(repository_path));

    write_emergency_file(emergency_fd, iterator);

    os::close(emergency_fd);

  }

}

/*

* We are just about to exit the VM, so we will be very aggressive

* at this point in order to increase overall success of dumping jfr data:

*

* 1. if the thread state is not "_thread_in_vm", we will quick transition

*    it to "_thread_in_vm".

*

* If we end up deadlocking in the attempt of dumping out jfr data,

* we rely on the WatcherThread task "is_error_reported()",

* This "safety net" somewhat explains the aggressiveness in this attempt.

*

*/

  if (thread->is_Java_thread()) {

    ((JavaThread*)thread)->set_thread_state(_thread_in_vm);

  }

#ifdef ASSERT

  Mutex* owned_lock = thread->owned_locks();

  while (owned_lock != NULL) {

    Mutex* next = owned_lock->next();

    owned_lock->unlock();

    owned_lock = next;

  }

#endif // ASSERT

  if (Threads_lock->owned_by_self()) {

    Threads_lock->unlock();

  }

  if (Module_lock->owned_by_self()) {

    Module_lock->unlock();

  }

  if (ClassLoaderDataGraph_lock->owned_by_self()) {

    ClassLoaderDataGraph_lock->unlock();

  }

  if (Heap_lock->owned_by_self()) {

    Heap_lock->unlock();

  }

  if (VMOperationQueue_lock->owned_by_self()) {

    VMOperationQueue_lock->unlock();

  }

  if (VMOperationRequest_lock->owned_by_self()) {

    VMOperationRequest_lock->unlock();

  }

  if (Service_lock->owned_by_self()) {

    Service_lock->unlock();

  }

  if (UseNotificationThread && Notification_lock->owned_by_self()) {

    Notification_lock->unlock();

  }

  if (CodeCache_lock->owned_by_self()) {

    CodeCache_lock->unlock();

  }

  if (PeriodicTask_lock->owned_by_self()) {

    PeriodicTask_lock->unlock();

  }

  if (JfrMsg_lock->owned_by_self()) {

    JfrMsg_lock->unlock();

  }

  if (JfrBuffer_lock->owned_by_self()) {

    JfrBuffer_lock->unlock();

  }

  if (JfrStacktrace_lock->owned_by_self()) {

    JfrStacktrace_lock->unlock();

  }

}

static volatile int jfr_shutdown_lock = 0;

static bool guard_reentrancy() {

  return Atomic::cmpxchg(1, &jfr_shutdown_lock, 0) == 0;

}

void JfrEmergencyDump::on_vm_shutdown(bool exception_handler) {

    return;

  }

  EventDumpReason event;

  if (event.should_commit()) {

    event.set_reason(exception_handler ? "Crash" : "Out of Memory");

    event.set_recordingId(-1);

    event.commit();

  }

  if (!exception_handler) {

    // OOM

    LeakProfiler::emit_events(max_jlong, false);

  }

  const int messages = MSGBIT(MSG_VM_ERROR);

  JfrRecorderService service;

  service.rotate(messages);

}