1 files changed, 189 insertions, 0 deletions
diff --git a/src/common/ceph_mutex.h b/src/common/ceph_mutex.h
new file mode 100644
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+++ b/src/common/ceph_mutex.h
@@ -0,0 +1,189 @@
+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
+// vim: ts=8 sw=2 smarttab
+
+#pragma once
+
+#include <utility>
+#include "common/containers.h"
+
+// What and why
+// ============
+//
+// For general code making use of mutexes, use these ceph:: types.
+// The key requirement is that you make use of the ceph::make_mutex()
+// and make_recursive_mutex() factory methods, which take a string
+// naming the mutex for the purposes of the lockdep debug variant.
+
+#if defined(WITH_SEASTAR) && !defined(WITH_ALIEN)
+
+namespace ceph {
+  // an empty class satisfying the mutex concept
+  struct dummy_mutex {
+    void lock() {}
+    bool try_lock() {
+      return true;
+    }
+    void unlock() {}
+    void lock_shared() {}
+    void unlock_shared() {}
+  };
+
+  struct dummy_shared_mutex : dummy_mutex {
+    void lock_shared() {}
+    void unlock_shared() {}
+  };
+
+  using mutex = dummy_mutex;
+  using recursive_mutex = dummy_mutex;
+  using shared_mutex = dummy_shared_mutex;
+  // in seastar, we should use a difference interface for enforcing the
+  // semantics of condition_variable
+
+  template <typename ...Args>
+  dummy_mutex make_mutex(Args&& ...args) {
+    return {};
+  }
+
+  template <typename ...Args>
+  recursive_mutex make_recursive_mutex(Args&& ...args) {
+    return {};
+  }
+
+  template <typename ...Args>
+  shared_mutex make_shared_mutex(Args&& ...args) {
+    return {};
+  }
+
+  #define ceph_mutex_is_locked(m) true
+  #define ceph_mutex_is_locked_by_me(m) true
+}
+
+#else  // defined (WITH_SEASTAR) && !defined(WITH_ALIEN)
+//
+// For legacy Mutex users that passed recursive=true, use
+// ceph::make_recursive_mutex.  For legacy Mutex users that passed
+// lockdep=false, use std::mutex directly.
+
+#ifdef CEPH_DEBUG_MUTEX
+
+// ============================================================================
+// debug (lockdep-capable, various sanity checks and asserts)
+// ============================================================================
+//
+// Note: this is known to cause deadlocks on Windows because
+// of the winpthreads shared mutex implementation.
+
+#include "common/condition_variable_debug.h"
+#include "common/mutex_debug.h"
+#include "common/shared_mutex_debug.h"
+
+namespace ceph {
+  typedef ceph::mutex_debug mutex;
+  typedef ceph::mutex_recursive_debug recursive_mutex;
+  typedef ceph::condition_variable_debug condition_variable;
+  typedef ceph::shared_mutex_debug shared_mutex;
+
+  // pass arguments to mutex_debug ctor
+  template <typename ...Args>
+  mutex make_mutex(Args&& ...args) {
+    return {std::forward<Args>(args)...};
+  }
+
+  // pass arguments to recursive_mutex_debug ctor
+  template <typename ...Args>
+  recursive_mutex make_recursive_mutex(Args&& ...args) {
+    return {std::forward<Args>(args)...};
+  }
+
+  // pass arguments to shared_mutex_debug ctor
+  template <typename ...Args>
+  shared_mutex make_shared_mutex(Args&& ...args) {
+    return {std::forward<Args>(args)...};
+  }
+
+  // debug methods
+  #define ceph_mutex_is_locked(m) ((m).is_locked())
+  #define ceph_mutex_is_not_locked(m) (!(m).is_locked())
+  #define ceph_mutex_is_rlocked(m) ((m).is_rlocked())
+  #define ceph_mutex_is_wlocked(m) ((m).is_wlocked())
+  #define ceph_mutex_is_locked_by_me(m) ((m).is_locked_by_me())
+  #define ceph_mutex_is_not_locked_by_me(m) (!(m).is_locked_by_me())
+}
+
+#else
+
+// ============================================================================
+// release (fast and minimal)
+// ============================================================================
+
+#include <condition_variable>
+#include <mutex>
+
+// The winpthreads shared mutex implementation is broken.
+// We'll use boost::shared_mutex instead.
+// https://github.com/msys2/MINGW-packages/issues/3319
+#if __MINGW32__
+#include <boost/thread/shared_mutex.hpp>
+#else
+#include <shared_mutex>
+#endif
+
+namespace ceph {
+
+  typedef std::mutex mutex;
+  typedef std::recursive_mutex recursive_mutex;
+  typedef std::condition_variable condition_variable;
+
+#if __MINGW32__
+  typedef boost::shared_mutex shared_mutex;
+#else
+  typedef std::shared_mutex shared_mutex;
+#endif
+
+  // discard arguments to make_mutex (they are for debugging only)
+  template <typename ...Args>
+  mutex make_mutex(Args&& ...args) {
+    return {};
+  }
+  template <typename ...Args>
+  recursive_mutex make_recursive_mutex(Args&& ...args) {
+    return {};
+  }
+  template <typename ...Args>
+  shared_mutex make_shared_mutex(Args&& ...args) {
+    return {};
+  }
+
+  // debug methods.  Note that these can blindly return true
+  // because any code that does anything other than assert these
+  // are true is broken.
+  #define ceph_mutex_is_locked(m) true
+  #define ceph_mutex_is_not_locked(m) true
+  #define ceph_mutex_is_rlocked(m) true
+  #define ceph_mutex_is_wlocked(m) true
+  #define ceph_mutex_is_locked_by_me(m) true
+  #define ceph_mutex_is_not_locked_by_me(m) true
+
+}
+
+#endif	// CEPH_DEBUG_MUTEX
+
+#endif	// WITH_SEASTAR
+
+namespace ceph {
+
+template <class LockT,
+          class LockFactoryT>
+ceph::containers::tiny_vector<LockT> make_lock_container(
+  const std::size_t num_instances,
+  LockFactoryT&& lock_factory)
+{
+  return {
+    num_instances, [&](const std::size_t i, auto emplacer) {
+      // this will be called `num_instances` times
+      new (emplacer.data()) LockT {lock_factory(i)};
+    }
+  };
+}
+} // namespace ceph
+