log0test.h

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/**************************************************/ /**
 @file include/log0test.h
 
 Redo log - helper for unit tests.
 
 *******************************************************/
 
#ifndef log0test_h
#define log0test_h
 
#include <memory>
 
/* lsn_t */
#include "log0types.h"
 
#ifdef UNIV_DEBUG
 
/* DBUG_EXECUTE_IF */
#include "my_dbug.h"
 
/* DEBUG_SYNC_C */
#include "my_sys.h"
 
/* current_thd */
#include "sql/current_thd.h"
 
/* debug_sync_set_action */
#include "sql/debug_sync.h"
 
#endif /* UNIV_DEBUG */
 
#ifndef UNIV_HOTBACKUP
 
/** It is a environment for tests of redo log. It contains a mock, which
replaces real buffer pool during the test. */
class Log_test {
 public:
  typedef page_no_t Key;
  typedef int64_t Value;
 
  struct Page {
    Key key;
    Value value;
    lsn_t oldest_modification;
    lsn_t newest_modification;
  };
 
  typedef std::map<Key, Page> Pages;
 
  class Sync_point {
   public:
    virtual void sync() = 0;
 
    virtual ~Sync_point() = default;
  };
 
  enum class Options {
    VALIDATE_RECENT_CLOSED = 1,
    VALIDATE_RECENT_WRITTEN = 2
  };
 
  typedef std::map<std::string, std::unique_ptr<Sync_point>> Sync_points;
 
  /** Calculates oldest_modification of the earliest added dirty page
  during the test in log0log-t. It is basically a replacement for the
  log_buf_get_oldest_modification_approx() during the test.
  @return oldest_modification lsn */
  lsn_t oldest_modification_approx() const;
 
  void add_dirty_page(const Page &page);
 
  void fsync_written_pages();
 
  void purge(lsn_t max_dirty_page_age);
 
  static byte *create_mlog_rec(byte *rec, Key key, Value value, size_t payload);
 
  static byte *create_mlog_rec(byte *rec, Key key, Value value);
 
  static byte *parse_mlog_rec(byte *begin, byte *end, Key &key, Value &value,
                              lsn_t &start_lsn, lsn_t &end_lsn);
 
  byte *parse_mlog_rec(byte *begin, byte *end);
 
  const Pages &flushed() const;
 
  const Pages &recovered() const;
 
  void sync_point(const std::string &sync_point_name);
 
  void register_sync_point_handler(
      const std::string &sync_point_name,
      std::unique_ptr<Sync_point> &&sync_point_handler);
 
  bool enabled(Options option) const;
 
  void set_enabled(Options option, bool enabled);
 
  int flush_every() const;
 
  void set_flush_every(int flush_every);
 
  int verbosity() const;
 
  void set_verbosity(int level);
 
 private:
  void recovered_reset(Key key, lsn_t oldest_modification,
                       lsn_t newest_modification);
 
  void recovered_add(Key key, Value value, lsn_t oldest_modification,
                     lsn_t newest_modification);
 
  mutable std::mutex m_mutex;
  mutable std::mutex m_purge_mutex;
  std::map<lsn_t, Page> m_buf;
  Pages m_written;
  Pages m_flushed;
  Pages m_recovered;
  Sync_points m_sync_points;
  uint64_t m_options_enabled = 0;
  int m_verbosity = 0;
  int m_flush_every = 10;
};
 
/** Represents currently running test of redo log, nullptr otherwise. */
extern std::unique_ptr<Log_test> log_test;
 
/** This function is responsible for three actions:
 
1. Defines a conditional sync point with name = sync_point_name
   (@see CONDITIONAL_SYNC_POINT).
 
2. Crashes MySQL if debug variable with name = "crash_" + sync_poit_name is
   defined. You could use following approach to crash it:
      SET GLOBAL DEBUG = '+d,crash_foo' (if sync_point_name='foo')
 
3. Notifies log_test (unless it's nullptr) about the sync point.
 
@param[in]  sync_point_name  name of syncpoint, must be a string literal */
template <size_t N>
static void log_sync_point(const char (&sync_point_name)[N]) {
#ifdef UNIV_DEBUG
  CONDITIONAL_SYNC_POINT(sync_point_name);
  const std::string crash_var_name = std::string{"crash_"} + sync_point_name;
  DBUG_EXECUTE_IF(crash_var_name.c_str(), DBUG_SUICIDE(););
#endif /* UNIV_DEBUG */
  if (log_test != nullptr) {
    log_test->sync_point(sync_point_name);
  }
}
 
#endif /* !UNIV_HOTBACKUP */
 
#endif /* log0test_h */