ut0mutex.h

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/** @file include/ut0mutex.h
 Policy based mutexes.
 
 Created 2012-03-24 Sunny Bains.
 ***********************************************************************/
 
#ifndef ut0mutex_h
#define ut0mutex_h
 
#include "my_inttypes.h"
 
extern ulong srv_spin_wait_delay;
extern ulong srv_n_spin_wait_rounds;
 
#ifdef UNIV_LIBRARY
/* Mutexes are disabled under UNIV_LIBRARY */
#define mutex_create(I, M) (void)M
#define mutex_enter(M) (void)M
#define mutex_enter_nospin(M) (void)M
#define mutex_enter_nowait(M) (void)M
#define mutex_exit(M) (void)M
#define mutex_free(M) (void)M
 
#ifdef UNIV_DEBUG
#define mutex_validate(M) (M)
/* Since mutexes are disabled under UNIV_LIBRARY, the following is OK. */
#define mutex_own(m) ((m) != nullptr)
#endif /* UNIV_DEBUG */
typedef OSMutex SysMutex;
typedef OSMutex ib_mutex_t;
typedef OSMutex ib_bpmutex_t;
 
#else /* UNIV_LIBRARY */
 
#include <set>
#include "ib0mutex.h"
#include "os0atomic.h"
#include "sync0policy.h"
 
/** Create a typedef using the MutexType<PolicyType>
@param[in]      M               Mutex type
@param[in]      P               Policy type
@param[in]      T               The resulting typedef alias */
#define UT_MUTEX_TYPE(M, P, T) typedef PolicyMutex<M<P>> T;
 
typedef OSMutex EventMutex;
 
#ifdef HAVE_IB_LINUX_FUTEX
UT_MUTEX_TYPE(TTASFutexMutex, GenericPolicy, FutexMutex)
UT_MUTEX_TYPE(TTASFutexMutex, BlockMutexPolicy, BlockFutexMutex)
#endif /* HAVE_IB_LINUX_FUTEX */
 
UT_MUTEX_TYPE(OSTrackMutex, GenericPolicy, SysMutex)
UT_MUTEX_TYPE(OSTrackMutex, BlockMutexPolicy, BlockSysMutex)
 
UT_MUTEX_TYPE(TTASEventMutex, GenericPolicy, SyncArrayMutex)
UT_MUTEX_TYPE(TTASEventMutex, BlockMutexPolicy, BlockSyncArrayMutex)
 
#ifndef UNIV_HOTBACKUP
#ifdef MUTEX_FUTEX
/** The default mutex type. */
typedef FutexMutex ib_mutex_t;
typedef BlockFutexMutex ib_bpmutex_t;
#define MUTEX_TYPE "Uses futexes"
#elif defined(MUTEX_SYS)
typedef SysMutex ib_mutex_t;
typedef BlockSysMutex ib_bpmutex_t;
#define MUTEX_TYPE "Uses system mutexes"
#elif defined(MUTEX_EVENT)
typedef SyncArrayMutex ib_mutex_t;
typedef BlockSyncArrayMutex ib_bpmutex_t;
#define MUTEX_TYPE "Uses event mutexes"
#else
#error "ib_mutex_t type is unknown"
#endif /* MUTEX_FUTEX */
 
#include "ut0mutex.ic"
 
extern ulong srv_spin_wait_delay;
extern ulong srv_n_spin_wait_rounds;
 
#define mutex_create(I, M) mutex_init((M), (I), __FILE__, __LINE__)
 
template <typename Mutex>
void mutex_enter_inline(Mutex *m, ut::Location loc) {
  m->enter(srv_n_spin_wait_rounds, srv_spin_wait_delay, loc.filename, loc.line);
}
 
#define mutex_enter(M) mutex_enter_inline(M, UT_LOCATION_HERE)
 
#define mutex_enter_nospin(M) (M)->enter(0, 0, __FILE__, __LINE__)
 
#define mutex_enter_nowait(M) (M)->trylock(__FILE__, __LINE__)
 
#define mutex_exit(M) (M)->exit()
 
#define mutex_free(M) mutex_destroy(M)
 
/* RAII guard for ib mutex */
struct IB_mutex_guard {
  /** Constructor to acquire mutex
  @param[in]   in_mutex        input mutex
  @param[in]   location        defines source file and line in code where the
                               constructor of IB_mutex_guard is called */
  IB_mutex_guard(ib_mutex_t *in_mutex, const ut::Location &location)
      : m_mutex(in_mutex) {
    ut_ad(!in_mutex->is_owned());
    mutex_enter_inline(in_mutex, location);
  }
 
  /** Destructor to release mutex */
  ~IB_mutex_guard() { clear(); }
 
  /** Disable copy construction */
  IB_mutex_guard(IB_mutex_guard const &) = delete;
 
  /** Disable assignment */
  IB_mutex_guard &operator=(IB_mutex_guard const &) = delete;
 
 private:
  /** Current mutex for RAII */
  ib_mutex_t *m_mutex;
 
  void clear() {
    ut_ad(m_mutex->is_owned());
    mutex_exit(m_mutex);
    m_mutex = nullptr;
  }
};
 
#ifdef UNIV_DEBUG
/**
Checks that the mutex has been initialized. */
#define mutex_validate(M) (M)->validate()
 
/**
Checks that the current thread owns the mutex. Works only
in the debug version. */
#define mutex_own(M) (M)->is_owned()
#else
#define mutex_own(M)      /* No op */
#define mutex_validate(M) /* No op */
#endif                    /* UNIV_DEBUG */
#else                     /* !UNIV_HOTBACKUP */
#include "../meb/mutex.h"
typedef meb::Mutex ib_mutex_t;
typedef meb::Mutex ib_bpmutex_t;
#endif /* !UNIV_HOTBACKUP */
 
/** Iterate over the mutex meta data */
class MutexMonitor {
 public:
  /** Constructor */
  MutexMonitor() = default;
 
  /** Destructor */
  ~MutexMonitor() = default;
 
  /** Enable the mutex monitoring */
  void enable();
 
  /** Disable the mutex monitoring */
  void disable();
 
  /** Reset the mutex monitoring values */
  void reset();
 
  /** Invoke the callback for each active mutex collection
  @param[in,out]        callback        Functor to call
  @return false if callback returned false */
  template <typename Callback>
  bool iterate(Callback &callback) const UNIV_NOTHROW {
    LatchMetaData::iterator end = latch_meta.end();
 
    for (LatchMetaData::iterator it = latch_meta.begin(); it != end; ++it) {
      /* Some of the slots will be null in non-debug mode */
 
      if (*it == nullptr) {
        continue;
      }
 
      latch_meta_t *latch_meta = *it;
 
      bool ret = callback(*latch_meta);
 
      if (!ret) {
        return (ret);
      }
    }
 
    return (true);
  }
};
 
/** Defined in sync0sync.cc */
extern MutexMonitor *mutex_monitor;
 
#ifndef UNIV_HOTBACKUP
/**
Creates, or rather, initializes a mutex object in a specified memory
location (which must be appropriately aligned). The mutex is initialized
in the reset state. Explicit freeing of the mutex with mutex_free is
necessary only if the memory block containing it is freed.
Add the mutex instance to the global mutex list.
@param[in,out]  mutex           mutex to initialise
@param[in]      id              The mutex ID (Latch ID)
@param[in]      file_name       Filename from where it was called
@param[in]      line            Line number in filename from where called */
template <typename Mutex>
void mutex_init(Mutex *mutex, latch_id_t id, const char *file_name,
                uint32_t line) {
  new (mutex) Mutex();
 
  mutex->init(id, file_name, line);
}
 
/**
Removes a mutex instance from the mutex list. The mutex is checked to
be in the reset state.
@param[in,out]   mutex          mutex instance to destroy */
template <typename Mutex>
void mutex_destroy(Mutex *mutex) {
  mutex->destroy();
}
 
class IB_mutex : public ib_mutex_t {
 public:
  explicit IB_mutex(latch_id_t latch_id) {
    mutex_create(latch_id, static_cast<ib_mutex_t *>(this));
  }
  ~IB_mutex() { mutex_free(static_cast<ib_mutex_t *>(this)); }
  void lock(const ut::Location &loc) {
    mutex_enter_inline(static_cast<ib_mutex_t *>(this), loc);
  }
  void unlock() { exit(); }
};
 
#endif /* !UNIV_HOTBACKUP */
#endif /* UNIV_LIBRARY */
 
#endif /* ut0mutex_h */