initial code repo

[stor4nfv.git] / src / ceph / src / common / Mutex.cc

diff --git a/src/ceph/src/common/Mutex.cc b/src/ceph/src/common/Mutex.cc
new file mode 100644 (file)
index 0000000..1bb5889
--- /dev/null
+++ b/src/ceph/src/common/Mutex.cc
@@ -0,0 +1,123 @@
+// -*- 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.
+ *
+ */
+
+#include "common/Mutex.h"
+#include "common/perf_counters.h"
+#include "common/config.h"
+#include "common/Clock.h"
+#include "common/valgrind.h"
+
+Mutex::Mutex(const std::string &n, bool r, bool ld,
+            bool bt,
+            CephContext *cct) :
+  name(n), id(-1), recursive(r), lockdep(ld), backtrace(bt), nlock(0),
+  locked_by(0), cct(cct), logger(0)
+{
+  ANNOTATE_BENIGN_RACE_SIZED(&id, sizeof(id), "Mutex lockdep id");
+  ANNOTATE_BENIGN_RACE_SIZED(&nlock, sizeof(nlock), "Mutex nlock");
+  ANNOTATE_BENIGN_RACE_SIZED(&locked_by, sizeof(locked_by), "Mutex locked_by");
+  if (cct) {
+    PerfCountersBuilder b(cct, string("mutex-") + name,
+                         l_mutex_first, l_mutex_last);
+    b.add_time_avg(l_mutex_wait, "wait", "Average time of mutex in locked state");
+    logger = b.create_perf_counters();
+    cct->get_perfcounters_collection()->add(logger);
+    logger->set(l_mutex_wait, 0);
+  }
+  if (recursive) {
+    // Mutexes of type PTHREAD_MUTEX_RECURSIVE do all the same checks as
+    // mutexes of type PTHREAD_MUTEX_ERRORCHECK.
+    pthread_mutexattr_t attr;
+    pthread_mutexattr_init(&attr);
+    pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_RECURSIVE);
+    pthread_mutex_init(&_m,&attr);
+    pthread_mutexattr_destroy(&attr);
+    if (lockdep && g_lockdep)
+      _register();
+  }
+  else if (lockdep) {
+    // If the mutex type is PTHREAD_MUTEX_ERRORCHECK, then error checking
+    // shall be provided. If a thread attempts to relock a mutex that it
+    // has already locked, an error shall be returned. If a thread
+    // attempts to unlock a mutex that it has not locked or a mutex which
+    // is unlocked, an error shall be returned.
+    pthread_mutexattr_t attr;
+    pthread_mutexattr_init(&attr);
+    pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_ERRORCHECK);
+    pthread_mutex_init(&_m, &attr);
+    pthread_mutexattr_destroy(&attr);
+    if (g_lockdep)
+      _register();
+  }
+  else {
+    // If the mutex type is PTHREAD_MUTEX_DEFAULT, attempting to recursively
+    // lock the mutex results in undefined behavior. Attempting to unlock the
+    // mutex if it was not locked by the calling thread results in undefined
+    // behavior. Attempting to unlock the mutex if it is not locked results in
+    // undefined behavior.
+    pthread_mutex_init(&_m, NULL);
+  }
+}
+
+Mutex::~Mutex() {
+  assert(nlock == 0);
+
+  // helgrind gets confused by condition wakeups leading to mutex destruction
+  ANNOTATE_BENIGN_RACE_SIZED(&_m, sizeof(_m), "Mutex primitive");
+  pthread_mutex_destroy(&_m);
+
+  if (cct && logger) {
+    cct->get_perfcounters_collection()->remove(logger);
+    delete logger;
+  }
+  if (lockdep && g_lockdep) {
+    lockdep_unregister(id);
+  }
+}
+
+void Mutex::Lock(bool no_lockdep) {
+  int r;
+
+  if (lockdep && g_lockdep && !no_lockdep && !recursive) _will_lock();
+
+  if (logger && cct && cct->_conf->mutex_perf_counter) {
+    utime_t start;
+    // instrumented mutex enabled
+    start = ceph_clock_now();
+    if (TryLock()) {
+      goto out;
+    }
+
+    r = pthread_mutex_lock(&_m);
+
+    logger->tinc(l_mutex_wait,
+                ceph_clock_now() - start);
+  } else {
+    r = pthread_mutex_lock(&_m);
+  }
+
+  assert(r == 0);
+  if (lockdep && g_lockdep) _locked();
+  _post_lock();
+
+out:
+  ;
+}
+
+void Mutex::Unlock() {
+  _pre_unlock();
+  if (lockdep && g_lockdep) _will_unlock();
+  int r = pthread_mutex_unlock(&_m);
+  assert(r == 0);
+}