Adding upstream version 14.2.21.upstream/14.2.21upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 720 insertions, 0 deletions

diff --git a/src/mds/SimpleLock.h b/src/mds/SimpleLock.h
new file mode 100644
index 00000000..2d719b27
--- /dev/null
+++ b/src/mds/SimpleLock.h
@@ -0,0 +1,720 @@
+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*- 
+// vim: ts=8 sw=2 smarttab
+/*
+ * Ceph - scalable distributed file system
+ *
+ * Copyright (C) 2004-2006 Sage Weil <sage@newdream.net>
+ *
+ * This is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License version 2.1, as published by the Free Software 
+ * Foundation.  See file COPYING.
+ * 
+ */
+
+
+#ifndef CEPH_SIMPLELOCK_H
+#define CEPH_SIMPLELOCK_H
+
+#include <boost/intrusive_ptr.hpp>
+
+#include "MDSCacheObject.h"
+#include "MDSContext.h"
+
+// -- lock types --
+// see CEPH_LOCK_*
+
+
+struct MutationImpl;
+typedef boost::intrusive_ptr<MutationImpl> MutationRef;
+
+extern "C" {
+#include "locks.h"
+}
+
+
+#define CAP_ANY     0
+#define CAP_LONER   1
+#define CAP_XLOCKER 2
+
+struct LockType {
+  int type;
+  const sm_t *sm;
+
+  explicit LockType(int t) : type(t) {
+    switch (type) {
+    case CEPH_LOCK_DN:
+    case CEPH_LOCK_IAUTH:
+    case CEPH_LOCK_ILINK:
+    case CEPH_LOCK_IXATTR:
+    case CEPH_LOCK_ISNAP:
+    case CEPH_LOCK_IFLOCK:
+    case CEPH_LOCK_IPOLICY:
+      sm = &sm_simplelock;
+      break;
+    case CEPH_LOCK_IDFT:
+    case CEPH_LOCK_INEST:
+      sm = &sm_scatterlock;
+      break;
+    case CEPH_LOCK_IFILE:
+      sm = &sm_filelock;
+      break;
+    case CEPH_LOCK_DVERSION:
+    case CEPH_LOCK_IVERSION:
+      sm = &sm_locallock;
+      break;
+    default:
+      sm = 0;
+    }
+  }
+
+};
+
+
+class SimpleLock {
+public:
+  LockType *type;
+  
+  static std::string_view get_state_name(int n) {
+    switch (n) {
+    case LOCK_UNDEF: return "UNDEF";
+    case LOCK_SYNC: return "sync";
+    case LOCK_LOCK: return "lock";
+
+    case LOCK_PREXLOCK: return "prexlock";
+    case LOCK_XLOCK: return "xlock";
+    case LOCK_XLOCKDONE: return "xlockdone";
+    case LOCK_XLOCKSNAP: return "xlocksnap";
+    case LOCK_LOCK_XLOCK: return "lock->xlock";
+
+    case LOCK_SYNC_LOCK: return "sync->lock";
+    case LOCK_LOCK_SYNC: return "lock->sync";
+    case LOCK_REMOTEXLOCK: return "remote_xlock";
+    case LOCK_EXCL: return "excl";
+    case LOCK_EXCL_SYNC: return "excl->sync";
+    case LOCK_EXCL_LOCK: return "excl->lock";
+    case LOCK_SYNC_EXCL: return "sync->excl";
+    case LOCK_LOCK_EXCL: return "lock->excl";      
+
+    case LOCK_XSYN: return "xsyn";
+    case LOCK_XSYN_EXCL: return "xsyn->excl";
+    case LOCK_EXCL_XSYN: return "excl->xsyn";
+    case LOCK_XSYN_SYNC: return "xsyn->sync";
+    case LOCK_XSYN_LOCK: return "xsyn->lock";
+    case LOCK_XSYN_MIX: return "xsyn->mix";
+
+    case LOCK_SYNC_MIX: return "sync->mix";
+    case LOCK_SYNC_MIX2: return "sync->mix(2)";
+    case LOCK_LOCK_TSYN: return "lock->tsyn";
+      
+    case LOCK_MIX_LOCK: return "mix->lock";
+    case LOCK_MIX_LOCK2: return "mix->lock(2)";
+    case LOCK_MIX: return "mix";
+    case LOCK_MIX_TSYN: return "mix->tsyn";
+      
+    case LOCK_TSYN_MIX: return "tsyn->mix";
+    case LOCK_TSYN_LOCK: return "tsyn->lock";
+    case LOCK_TSYN: return "tsyn";
+
+    case LOCK_MIX_SYNC: return "mix->sync";
+    case LOCK_MIX_SYNC2: return "mix->sync(2)";
+    case LOCK_EXCL_MIX: return "excl->mix";
+    case LOCK_MIX_EXCL: return "mix->excl";
+
+    case LOCK_PRE_SCAN: return "*->scan";
+    case LOCK_SCAN: return "scan";
+
+    case LOCK_SNAP_SYNC: return "snap->sync";
+
+    default: ceph_abort(); return std::string_view();
+    }
+  }
+
+  static std::string_view get_lock_type_name(int t) {
+    switch (t) {
+      case CEPH_LOCK_DN: return "dn";
+      case CEPH_LOCK_DVERSION: return "dversion";
+      case CEPH_LOCK_IVERSION: return "iversion";
+      case CEPH_LOCK_IFILE: return "ifile";
+      case CEPH_LOCK_IAUTH: return "iauth";
+      case CEPH_LOCK_ILINK: return "ilink";
+      case CEPH_LOCK_IDFT: return "idft";
+      case CEPH_LOCK_INEST: return "inest";
+      case CEPH_LOCK_IXATTR: return "ixattr";
+      case CEPH_LOCK_ISNAP: return "isnap";
+      case CEPH_LOCK_INO: return "ino";
+      case CEPH_LOCK_IFLOCK: return "iflock";
+      case CEPH_LOCK_IPOLICY: return "ipolicy";
+      default: ceph_abort(); return std::string_view();
+    }
+  }
+
+  static std::string_view get_lock_action_name(int a) {
+    switch (a) {
+      case LOCK_AC_SYNC: return "sync";
+      case LOCK_AC_MIX: return "mix";
+      case LOCK_AC_LOCK: return "lock";
+      case LOCK_AC_LOCKFLUSHED: return "lockflushed";
+
+      case LOCK_AC_SYNCACK: return "syncack";
+      case LOCK_AC_MIXACK: return "mixack";
+      case LOCK_AC_LOCKACK: return "lockack";
+
+      case LOCK_AC_REQSCATTER: return "reqscatter";
+      case LOCK_AC_REQUNSCATTER: return "requnscatter";
+      case LOCK_AC_NUDGE: return "nudge";
+      case LOCK_AC_REQRDLOCK: return "reqrdlock";
+      default: return "???";
+    }
+  }
+
+  // waiting
+  static const uint64_t WAIT_RD          = (1<<0);  // to read
+  static const uint64_t WAIT_WR          = (1<<1);  // to write
+  static const uint64_t WAIT_XLOCK       = (1<<2);  // to xlock   (** dup)
+  static const uint64_t WAIT_STABLE      = (1<<2);  // for a stable state
+  static const uint64_t WAIT_REMOTEXLOCK = (1<<3);  // for a remote xlock
+  static const int WAIT_BITS        = 4;
+  static const uint64_t WAIT_ALL         = ((1<<WAIT_BITS)-1);
+
+
+protected:
+  // parent (what i lock)
+  MDSCacheObject *parent;
+
+  // lock state
+  __s16 state;
+  __s16 state_flags;
+
+  enum {
+    LEASED		= 1 << 0,
+    NEED_RECOVER	= 1 << 1,
+  };
+
+private:
+  int num_rdlock;
+
+  // XXX not in mempool
+  struct unstable_bits_t {
+    set<__s32> gather_set;  // auth+rep.  >= 0 is mds, < 0 is client
+
+    // local state
+    int num_wrlock = 0, num_xlock = 0;
+    MutationRef xlock_by;
+    client_t xlock_by_client = -1;
+    client_t excl_client = -1;
+
+    bool empty() {
+      return
+	gather_set.empty() &&
+	num_wrlock == 0 &&
+	num_xlock == 0 &&
+	xlock_by.get() == NULL &&
+	xlock_by_client == -1 &&
+	excl_client == -1;
+    }
+
+    unstable_bits_t() {}
+  };
+
+  mutable std::unique_ptr<unstable_bits_t> _unstable;
+
+  bool have_more() const { return _unstable ? true : false; }
+  unstable_bits_t *more() const {
+    if (!_unstable)
+      _unstable.reset(new unstable_bits_t);
+    return _unstable.get();
+  }
+  void try_clear_more() {
+    if (_unstable && _unstable->empty()) {
+      _unstable.reset();
+    }
+  }
+
+public:
+
+  client_t get_excl_client() const {
+    return have_more() ? more()->excl_client : -1;
+  }
+  void set_excl_client(client_t c) {
+    if (c < 0 && !have_more())
+      return;  // default is -1
+    more()->excl_client = c;
+  }
+
+  SimpleLock(MDSCacheObject *o, LockType *lt) :
+    type(lt),
+    parent(o), 
+    state(LOCK_SYNC),
+    state_flags(0),
+    num_rdlock(0)
+  {}
+  virtual ~SimpleLock() {}
+
+  virtual bool is_scatterlock() const {
+    return false;
+  }
+  virtual bool is_locallock() const {
+    return false;
+  }
+
+  // parent
+  MDSCacheObject *get_parent() { return parent; }
+  int get_type() const { return type->type; }
+  const sm_t* get_sm() const { return type->sm; }
+
+  int get_wait_shift() const {
+    switch (get_type()) {
+    case CEPH_LOCK_DN:       return 8;
+    case CEPH_LOCK_DVERSION: return 8 + 1*SimpleLock::WAIT_BITS;
+    case CEPH_LOCK_IAUTH:    return 8 + 2*SimpleLock::WAIT_BITS;
+    case CEPH_LOCK_ILINK:    return 8 + 3*SimpleLock::WAIT_BITS;
+    case CEPH_LOCK_IDFT:     return 8 + 4*SimpleLock::WAIT_BITS;
+    case CEPH_LOCK_IFILE:    return 8 + 5*SimpleLock::WAIT_BITS;
+    case CEPH_LOCK_IVERSION: return 8 + 6*SimpleLock::WAIT_BITS;
+    case CEPH_LOCK_IXATTR:   return 8 + 7*SimpleLock::WAIT_BITS;
+    case CEPH_LOCK_ISNAP:    return 8 + 8*SimpleLock::WAIT_BITS;
+    case CEPH_LOCK_INEST:    return 8 + 9*SimpleLock::WAIT_BITS;
+    case CEPH_LOCK_IFLOCK:   return 8 +10*SimpleLock::WAIT_BITS;
+    case CEPH_LOCK_IPOLICY:  return 8 +11*SimpleLock::WAIT_BITS;
+    default:
+      ceph_abort();
+    }
+  }
+
+  int get_cap_shift() const {
+    switch (get_type()) {
+    case CEPH_LOCK_IAUTH: return CEPH_CAP_SAUTH;
+    case CEPH_LOCK_ILINK: return CEPH_CAP_SLINK;
+    case CEPH_LOCK_IFILE: return CEPH_CAP_SFILE;
+    case CEPH_LOCK_IXATTR: return CEPH_CAP_SXATTR;
+    default: return 0;
+    }
+  }
+  int get_cap_mask() const {
+    switch (get_type()) {
+    case CEPH_LOCK_IFILE: return (1 << CEPH_CAP_FILE_BITS) - 1;
+    default: return (1 << CEPH_CAP_SIMPLE_BITS) - 1;
+    }
+  }
+
+  struct ptr_lt {
+    bool operator()(const SimpleLock* l, const SimpleLock* r) const {
+      // first sort by object type (dn < inode)
+      if (!(l->type->type > CEPH_LOCK_DN) && (r->type->type > CEPH_LOCK_DN)) return true;
+      if ((l->type->type > CEPH_LOCK_DN) == (r->type->type > CEPH_LOCK_DN)) {
+	// then sort by object
+	if (l->parent->is_lt(r->parent)) return true;
+	if (l->parent == r->parent) {
+	  // then sort by (inode) lock type
+	  if (l->type->type < r->type->type) return true;
+	}
+      }
+      return false;
+    }
+  };
+
+  void decode_locked_state(const bufferlist& bl) {
+    parent->decode_lock_state(type->type, bl);
+  }
+  void encode_locked_state(bufferlist& bl) {
+    parent->encode_lock_state(type->type, bl);
+  }
+  void finish_waiters(uint64_t mask, int r=0) {
+    parent->finish_waiting(mask << get_wait_shift(), r);
+  }
+  void take_waiting(uint64_t mask, MDSContext::vec& ls) {
+    parent->take_waiting(mask << get_wait_shift(), ls);
+  }
+  void add_waiter(uint64_t mask, MDSContext *c) {
+    parent->add_waiter((mask << get_wait_shift()) | MDSCacheObject::WAIT_ORDERED, c);
+  }
+  bool is_waiter_for(uint64_t mask) const {
+    return parent->is_waiter_for(mask << get_wait_shift());
+  }
+  
+  
+
+  // state
+  int get_state() const { return state; }
+  int set_state(int s) { 
+    state = s; 
+    //assert(!is_stable() || gather_set.size() == 0);  // gather should be empty in stable states.
+    return s;
+  }
+  void set_state_rejoin(int s, MDSContext::vec& waiters, bool survivor) {
+    ceph_assert(!get_parent()->is_auth());
+
+    // If lock in the replica object was not in SYNC state when auth mds of the object failed.
+    // Auth mds of the object may take xlock on the lock and change the object when replaying
+    // unsafe requests.
+    if (!survivor || state != LOCK_SYNC)
+      mark_need_recover();
+
+    state = s;
+
+    if (is_stable())
+      take_waiting(SimpleLock::WAIT_ALL, waiters);
+  }
+
+  bool is_stable() const {
+    return get_sm()->states[state].next == 0;
+  }
+  bool is_unstable_and_locked() const {
+    if (is_stable())
+      return false;
+    return is_rdlocked() || is_wrlocked() || is_xlocked();
+  }
+  int get_next_state() {
+    return get_sm()->states[state].next;
+  }
+
+
+  bool is_sync_and_unlocked() const {
+    return
+      get_state() == LOCK_SYNC &&
+      !is_rdlocked() &&
+      !is_leased() &&
+      !is_wrlocked() &&
+      !is_xlocked();
+  }
+
+
+  /*
+  bool fw_rdlock_to_auth() {
+    return get_sm()->states[state].can_rdlock == FW;
+  }
+  */
+  bool req_rdlock_from_auth() {
+    return get_sm()->states[state].can_rdlock == REQ;
+  }
+
+  // gather set
+  static set<int32_t> empty_gather_set;
+
+  // int32_t: <0 is client, >=0 is MDS rank
+  const set<int32_t>& get_gather_set() const {
+    return have_more() ? more()->gather_set : empty_gather_set;
+  }
+
+  void init_gather() {
+    for (const auto p : parent->get_replicas()) {
+      more()->gather_set.insert(p.first);
+    }
+  }
+  bool is_gathering() const {
+    return have_more() && !more()->gather_set.empty();
+  }
+  bool is_gathering(int32_t i) const {
+    return have_more() && more()->gather_set.count(i);
+  }
+  void clear_gather() {
+    if (have_more())
+      more()->gather_set.clear();
+  }
+  void remove_gather(int32_t i) {
+    if (have_more())
+      more()->gather_set.erase(i);
+  }
+
+
+
+  virtual bool is_dirty() const { return false; }
+  virtual bool is_stale() const { return false; }
+  virtual bool is_flushing() const { return false; }
+  virtual bool is_flushed() const { return false; }
+  virtual void clear_flushed() { }
+
+  // can_*
+  bool can_lease(client_t client) const {
+    return get_sm()->states[state].can_lease == ANY ||
+      (get_sm()->states[state].can_lease == AUTH && parent->is_auth()) ||
+      (get_sm()->states[state].can_lease == XCL && client >= 0 && get_xlock_by_client() == client);
+  }
+  bool can_read(client_t client) const {
+    return get_sm()->states[state].can_read == ANY ||
+      (get_sm()->states[state].can_read == AUTH && parent->is_auth()) ||
+      (get_sm()->states[state].can_read == XCL && client >= 0 && get_xlock_by_client() == client);
+  }
+  bool can_read_projected(client_t client) const {
+    return get_sm()->states[state].can_read_projected == ANY ||
+      (get_sm()->states[state].can_read_projected == AUTH && parent->is_auth()) ||
+      (get_sm()->states[state].can_read_projected == XCL && client >= 0 && get_xlock_by_client() == client);
+  }
+  bool can_rdlock(client_t client) const {
+    return get_sm()->states[state].can_rdlock == ANY ||
+      (get_sm()->states[state].can_rdlock == AUTH && parent->is_auth()) ||
+      (get_sm()->states[state].can_rdlock == XCL && client >= 0 && get_xlock_by_client() == client);
+  }
+  bool can_wrlock(client_t client) const {
+    return get_sm()->states[state].can_wrlock == ANY ||
+      (get_sm()->states[state].can_wrlock == AUTH && parent->is_auth()) ||
+      (get_sm()->states[state].can_wrlock == XCL && client >= 0 && (get_xlock_by_client() == client ||
+								    get_excl_client() == client));
+  }
+  bool can_force_wrlock(client_t client) const {
+    return get_sm()->states[state].can_force_wrlock == ANY ||
+      (get_sm()->states[state].can_force_wrlock == AUTH && parent->is_auth()) ||
+      (get_sm()->states[state].can_force_wrlock == XCL && client >= 0 && (get_xlock_by_client() == client ||
+									  get_excl_client() == client));
+  }
+  bool can_xlock(client_t client) const {
+    return get_sm()->states[state].can_xlock == ANY ||
+      (get_sm()->states[state].can_xlock == AUTH && parent->is_auth()) ||
+      (get_sm()->states[state].can_xlock == XCL && client >= 0 && get_xlock_by_client() == client);
+  }
+
+  // rdlock
+  bool is_rdlocked() const { return num_rdlock > 0; }
+  int get_rdlock() { 
+    if (!num_rdlock)
+      parent->get(MDSCacheObject::PIN_LOCK);
+    return ++num_rdlock; 
+  }
+  int put_rdlock() {
+    ceph_assert(num_rdlock>0);
+    --num_rdlock;
+    if (num_rdlock == 0)
+      parent->put(MDSCacheObject::PIN_LOCK);
+    return num_rdlock;
+  }
+  int get_num_rdlocks() const {
+    return num_rdlock;
+  }
+
+  // wrlock
+  void get_wrlock(bool force=false) {
+    //assert(can_wrlock() || force);
+    if (more()->num_wrlock == 0)
+      parent->get(MDSCacheObject::PIN_LOCK);
+    ++more()->num_wrlock;
+  }
+  void put_wrlock() {
+    --more()->num_wrlock;
+    if (more()->num_wrlock == 0) {
+      parent->put(MDSCacheObject::PIN_LOCK);
+      try_clear_more();
+    }
+  }
+  bool is_wrlocked() const {
+    return have_more() && more()->num_wrlock > 0;
+  }
+  int get_num_wrlocks() const {
+    return have_more() ? more()->num_wrlock : 0;
+  }
+
+  // xlock
+  void get_xlock(MutationRef who, client_t client) { 
+    ceph_assert(get_xlock_by() == MutationRef());
+    ceph_assert(state == LOCK_XLOCK || is_locallock() ||
+	   state == LOCK_LOCK /* if we are a slave */);
+    parent->get(MDSCacheObject::PIN_LOCK);
+    more()->num_xlock++;
+    more()->xlock_by = who; 
+    more()->xlock_by_client = client;
+  }
+  void set_xlock_done() {
+    ceph_assert(more()->xlock_by);
+    ceph_assert(state == LOCK_XLOCK || is_locallock() ||
+	   state == LOCK_LOCK /* if we are a slave */);
+    if (!is_locallock())
+      state = LOCK_XLOCKDONE;
+    more()->xlock_by.reset();
+  }
+  void put_xlock() {
+    ceph_assert(state == LOCK_XLOCK || state == LOCK_XLOCKDONE ||
+	   state == LOCK_XLOCKSNAP || state == LOCK_LOCK_XLOCK ||
+	   state == LOCK_LOCK  || /* if we are a master of a slave */
+	   is_locallock());
+    --more()->num_xlock;
+    parent->put(MDSCacheObject::PIN_LOCK);
+    if (more()->num_xlock == 0) {
+      more()->xlock_by.reset();
+      more()->xlock_by_client = -1;
+      try_clear_more();
+    }
+  }
+  bool is_xlocked() const {
+    return have_more() && more()->num_xlock > 0;
+  }
+  int get_num_xlocks() const {
+    return have_more() ? more()->num_xlock : 0;
+  }
+  client_t get_xlock_by_client() const {
+    return have_more() ? more()->xlock_by_client : -1;
+  }
+  bool is_xlocked_by_client(client_t c) const {
+    return have_more() ? more()->xlock_by_client == c : false;
+  }
+  MutationRef get_xlock_by() const {
+    return have_more() ? more()->xlock_by : MutationRef();
+  }
+  
+  // lease
+  bool is_leased() const {
+    return state_flags & LEASED;
+  }
+  void get_client_lease() {
+    ceph_assert(!is_leased());
+    state_flags |= LEASED;
+  }
+  void put_client_lease() {
+    ceph_assert(is_leased());
+    state_flags &= ~LEASED;
+  }
+
+  bool needs_recover() const {
+    return state_flags & NEED_RECOVER;
+  }
+  void mark_need_recover() {
+    state_flags |= NEED_RECOVER;
+  }
+  void clear_need_recover() {
+    state_flags &= ~NEED_RECOVER;
+  }
+
+  // encode/decode
+  void encode(bufferlist& bl) const {
+    ENCODE_START(2, 2, bl);
+    encode(state, bl);
+    if (have_more())
+      encode(more()->gather_set, bl);
+    else
+      encode(empty_gather_set, bl);
+    ENCODE_FINISH(bl);
+  }
+  void decode(bufferlist::const_iterator& p) {
+    DECODE_START(2, p);
+    decode(state, p);
+    set<__s32> g;
+    decode(g, p);
+    if (!g.empty())
+      more()->gather_set.swap(g);
+    DECODE_FINISH(p);
+  }
+  void encode_state_for_replica(bufferlist& bl) const {
+    __s16 s = get_replica_state();
+    using ceph::encode;
+    encode(s, bl);
+  }
+  void decode_state(bufferlist::const_iterator& p, bool is_new=true) {
+    using ceph::decode;
+    __s16 s;
+    decode(s, p);
+    if (is_new)
+      state = s;
+  }
+  void decode_state_rejoin(bufferlist::const_iterator& p, MDSContext::vec& waiters, bool survivor) {
+    __s16 s;
+    using ceph::decode;
+    decode(s, p);
+    set_state_rejoin(s, waiters, survivor);
+  }
+
+
+  // caps
+  bool is_loner_mode() const {
+    return get_sm()->states[state].loner;
+  }
+  int gcaps_allowed_ever() const {
+    return parent->is_auth() ? get_sm()->allowed_ever_auth : get_sm()->allowed_ever_replica;
+  }
+  int gcaps_allowed(int who, int s=-1) const {
+    if (s < 0) s = state;
+    if (parent->is_auth()) {
+      if (get_xlock_by_client() >= 0 && who == CAP_XLOCKER)
+	return get_sm()->states[s].xlocker_caps | get_sm()->states[s].caps; // xlocker always gets more
+      else if (is_loner_mode() && who == CAP_ANY)
+	return get_sm()->states[s].caps;
+      else 
+	return get_sm()->states[s].loner_caps | get_sm()->states[s].caps;  // loner always gets more
+    } else 
+      return get_sm()->states[s].replica_caps;
+  }
+  int gcaps_careful() const {
+    if (get_num_wrlocks())
+      return get_sm()->careful;
+    return 0;
+  }
+
+
+  int gcaps_xlocker_mask(client_t client) const {
+    if (client == get_xlock_by_client())
+      return type->type == CEPH_LOCK_IFILE ? 0xf : (CEPH_CAP_GSHARED|CEPH_CAP_GEXCL);
+    return 0;
+  }
+
+  // simplelock specifics
+  int get_replica_state() const {
+    return get_sm()->states[state].replica_state;
+  }
+  void export_twiddle() {
+    clear_gather();
+    state = get_replica_state();
+  }
+
+  bool remove_replica(int from) {
+    if (is_gathering(from)) {
+      remove_gather(from);
+      if (!is_gathering())
+	return true;
+    }
+    return false;
+  }
+  bool do_import(int from, int to) {
+    if (!is_stable()) {
+      remove_gather(from);
+      remove_gather(to);
+      if (!is_gathering())
+	return true;
+    }
+    if (!is_stable() && !is_gathering())
+      return true;
+    return false;
+  }
+
+  void _print(ostream& out) const {
+    out << get_lock_type_name(get_type()) << " ";
+    out << get_state_name(get_state());
+    if (!get_gather_set().empty())
+      out << " g=" << get_gather_set();
+    if (is_leased())
+      out << " l";
+    if (is_rdlocked()) 
+      out << " r=" << get_num_rdlocks();
+    if (is_wrlocked()) 
+      out << " w=" << get_num_wrlocks();
+    if (is_xlocked()) {
+      out << " x=" << get_num_xlocks();
+      if (get_xlock_by())
+	out << " by " << get_xlock_by();
+    }
+    /*if (is_stable())
+      out << " stable";
+    else
+      out << " unstable";
+    */
+  }
+
+  /**
+   * Write bare values (caller must be in an object section)
+   * to formatter, or nothing if is_sync_and_unlocked.
+   */
+  void dump(Formatter *f) const;
+
+  virtual void print(ostream& out) const {
+    out << "(";
+    _print(out);
+    out << ")";
+  }
+};
+WRITE_CLASS_ENCODER(SimpleLock)
+
+inline ostream& operator<<(ostream& out, const SimpleLock& l) 
+{
+  l.print(out);
+  return out;
+}
+
+
+#endif