ChangeLogTag:Mon Aug 4 03:26:30 UTC 2003 Don Hinton <dhinton@dresystems.com>

1 files changed, 235 insertions, 0 deletions

diff --git a/ace/Thread_Mutex.h b/ace/Thread_Mutex.h
new file mode 100644
index 00000000000..774a1bcb318
--- /dev/null
+++ b/ace/Thread_Mutex.h
@@ -0,0 +1,235 @@
+// -*- C++ -*-
+
+//==========================================================================
+/**
+ *  @file    Thread_Mutex.h
+ *
+ *  $Id$
+ *
+ *   Moved from Synch.h.
+ *
+ *  @author Douglas C. Schmidt <schmidt@cs.wustl.edu>
+ */
+//==========================================================================
+
+#ifndef ACE_THREAD_MUTEX_H
+#define ACE_THREAD_MUTEX_H
+#include /**/ "ace/pre.h"
+
+#include "ace/config-all.h"
+
+#if !defined (ACE_LACKS_PRAGMA_ONCE)
+# pragma once
+#endif /* ACE_LACKS_PRAGMA_ONCE */
+
+#if !defined (ACE_HAS_THREADS)
+#  include "ace/Null_Thread.h"
+#else /* ACE_HAS_THREAD */
+// ACE platform supports some form of threading.
+
+#include "ace/ACE_export.h"
+#include "ace/OS.h"
+
+  /**
+   * @class ACE_Thread_Mutex
+   *
+   * @brief ACE_Thread_Mutex wrapper (only valid for threads in the same
+   * process).
+   *
+   * This implementation is optimized for locking threads that are
+   * in the same process.  It maps to <CRITICAL_SECTION>s on NT
+   * and <ACE_mutex_t> with <type> set to <USYNC_THREAD> on UNIX.
+   * ACE_Thread_Mutex is recursive on some platforms (like
+   * Win32). However, on most platforms (like Solaris) it is not
+   * recursive.  To be totally safe and portable, developers
+   * should use <ACE_Recursive_Thread_Mutex> when they need a
+   * recursive mutex.
+   */
+class ACE_Export ACE_Thread_Mutex
+{
+  friend class ACE_Condition_Thread_Mutex;
+public:
+  /// Constructor.
+  ACE_Thread_Mutex (const ACE_TCHAR *name = 0,
+                    ACE_mutexattr_t *attributes = 0);
+
+  /// Implicitly destroy the mutex.
+  ~ACE_Thread_Mutex (void);
+
+  /**
+   * Explicitly destroy the mutex.  Note that only one thread should
+   * call this method since it doesn't protect against race
+   * conditions.
+   */
+  int remove (void);
+
+  /// Acquire lock ownership (wait on queue if necessary).
+  int acquire (void);
+
+  /**
+   * Block the thread until we acquire the mutex or until <tv> times
+   * out, in which case -1 is returned with <errno> == <ETIME>.  Note
+   * that <tv> is assumed to be in "absolute" rather than "relative"
+   * time.  The value of <tv> is updated upon return to show the
+   * actual (absolute) acquisition time.
+   */
+  int acquire (ACE_Time_Value &tv);
+
+  /**
+   * If <tv> == 0 the call <acquire()> directly.  Otherwise, Block the
+   * thread until we acquire the mutex or until <tv> times out, in
+   * which case -1 is returned with <errno> == <ETIME>.  Note that
+   * <*tv> is assumed to be in "absolute" rather than "relative" time.
+   * The value of <*tv> is updated upon return to show the actual
+   * (absolute) acquisition time.
+   */
+  int acquire (ACE_Time_Value *tv);
+
+  /**
+   * Conditionally acquire lock (i.e., don't wait on queue).  Returns
+   * -1 on failure.  If we "failed" because someone else already had
+   * the lock, <errno> is set to <EBUSY>.
+   */
+  int tryacquire (void);
+
+  /// Release lock and unblock a thread at head of queue.
+  int release (void);
+
+  /**
+   * Acquire mutex ownership.  This calls <acquire> and is only here
+   * to make the <ACE_Thread_Mutex> interface consistent with the
+   * other synchronization APIs.
+   */
+  int acquire_read (void);
+
+  /**
+   * Acquire mutex ownership.  This calls <acquire> and is only here
+   * to make the <ACE_Thread_Mutex> interface consistent with the
+   * other synchronization APIs.
+   */
+  int acquire_write (void);
+
+  /**
+   * Conditionally acquire mutex (i.e., won't block).  This calls
+   * <tryacquire> and is only here to make the <ACE_Thread_Mutex>
+   * interface consistent with the other synchronization APIs.
+   * Returns -1 on failure.  If we "failed" because someone else
+   * already had the lock, <errno> is set to <EBUSY>.
+   */
+  int tryacquire_read (void);
+
+  /**
+   * Conditionally acquire mutex (i.e., won't block).  This calls
+   * <tryacquire> and is only here to make the <ACE_Thread_Mutex>
+   * interface consistent with the other synchronization APIs.
+   * Returns -1 on failure.  If we "failed" because someone else
+   * already had the lock, <errno> is set to <EBUSY>.
+   */
+  int tryacquire_write (void);
+
+  /**
+   * This is only here to make the <ACE_Thread_Mutex>
+   * interface consistent with the other synchronization APIs.
+   * Assumes the caller has already acquired the mutex using one of
+   * the above calls, and returns 0 (success) always.
+   */
+  int tryacquire_write_upgrade (void);
+
+  /// Return the underlying mutex.
+  const ACE_thread_mutex_t &lock (void) const;
+
+  /// Dump the state of an object.
+  void dump (void) const;
+
+  /// Declare the dynamic allocation hooks.
+  ACE_ALLOC_HOOK_DECLARE;
+
+  // protected:
+  /// Mutex type that supports single-process locking efficiently.
+  ACE_thread_mutex_t lock_;
+
+  /// Keeps track of whether <remove> has been called yet to avoid
+  /// multiple <remove> calls, e.g., explicitly and implicitly in the
+  /// destructor.  This flag isn't protected by a lock, so make sure
+  /// that you don't have multiple threads simultaneously calling
+  /// <remove> on the same object, which is a bad idea anyway...
+  int removed_;
+
+private:
+  // = Prevent assignment and initialization.
+  void operator= (const ACE_Thread_Mutex &);
+  ACE_Thread_Mutex (const ACE_Thread_Mutex &);
+};
+
+#if defined (ACE_USES_OBSOLETE_GUARD_CLASSES)
+/**
+ * @class ACE_Thread_Mutex_Guard
+ *
+ * @brief This data structure is meant to be used within a method or
+ * function...  It performs automatic aquisition and release of
+ * an <ACE_Thread_Mutex>.
+ *
+ * This class is obsolete and should be replaced by
+ * ACE_Guard<ACE_Thread_Mutex>.
+ */
+class ACE_Export ACE_Thread_Mutex_Guard
+{
+public:
+  /// Implicitly and automatically acquire the lock.
+  ACE_Thread_Mutex_Guard (ACE_Thread_Mutex &m, int block = 1);
+
+  /// Implicitly release the lock.
+  ~ACE_Thread_Mutex_Guard (void);
+
+  /// 1 if locked, 0 if couldn't acquire the lock (errno will contain
+  /// the reason for this).
+  int locked (void);
+
+  /**
+   * Explicitly release the lock.  Note that only one thread should
+   * call this method since it doesn't protect against race
+   * conditions.
+   */
+  int remove (void);
+
+  /// Explicitly acquire the lock.
+  int acquire (void);
+
+  /**
+   * Conditionally acquire the lock (i.e., won't block).  Returns -1
+   * on failure.  If we "failed" because someone else already had the
+   * lock, <errno> is set to <EBUSY>.
+   */
+  int tryacquire (void);
+
+  /// Explicitly release the lock.
+  int release (void);
+
+  /// Dump the state of an object.
+  void dump (void) const;
+
+  /// Declare the dynamic allocation hooks.
+  ACE_ALLOC_HOOK_DECLARE;
+
+protected:
+  /// Reference to the mutex.
+  ACE_Thread_Mutex &lock_;
+
+  /// Keeps track of whether we acquired the lock or failed.
+  int owner_;
+
+private:
+  // = Prevent assignment and initialization.
+  void operator= (const ACE_Thread_Mutex_Guard &);
+  ACE_Thread_Mutex_Guard (const ACE_Thread_Mutex_Guard &);
+};
+#endif /* ACE_USES_OBSOLETE_GUARD_CLASSES */
+
+#if defined (__ACE_INLINE__)
+#include "ace/Thread_Mutex.inl"
+#endif /* __ACE_INLINE__ */
+
+#endif /* !ACE_HAS_THREADS */
+
+#include /**/ "ace/post.h"
+#endif /* ACE_THREAD_MUTEX_H */