1 files changed, 170 insertions, 0 deletions
diff --git a/ACE/ace/File_Lock.h b/ACE/ace/File_Lock.h
new file mode 100644
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--- /dev/null
+++ b/ACE/ace/File_Lock.h
@@ -0,0 +1,170 @@
+// -*- C++ -*-
+
+//=============================================================================
+/**
+ *  @file    File_Lock.h
+ *
+ *  $Id$
+ *
+ *  @author Douglas C. Schmidt <schmidt@cs.wustl.edu>
+ */
+//=============================================================================
+
+#ifndef ACE_FILE_LOCK_H
+#define ACE_FILE_LOCK_H
+#include /**/ "ace/pre.h"
+
+#include /**/ "ace/ACE_export.h"
+
+#if !defined (ACE_LACKS_PRAGMA_ONCE)
+# pragma once
+#endif /* ACE_LACKS_PRAGMA_ONCE */
+
+#include "ace/OS_NS_stdio.h"
+
+ACE_BEGIN_VERSIONED_NAMESPACE_DECL
+
+/**
+ * @class ACE_File_Lock
+ *
+ * @brief A wrapper around the UNIX file locking mechanism.
+ *
+ * Allows us to "adapt" the UNIX file locking mechanisms to work
+ * with all of our Guard stuff...
+ */
+class ACE_Export ACE_File_Lock
+{
+public:
+  /**
+   * Set the <handle_> of the File_Lock to @a handle.  Note that this
+   * constructor assumes ownership of the @a handle and will close it
+   * down in <remove>.  If you want the @a handle to stay open when
+   * <remove> is called make sure to call <dup> on the @a handle.
+   * If you don't want the file unlinked in the destructor pass a
+   * zero value for <unlink_in_destructor>.
+   */
+  ACE_File_Lock (ACE_HANDLE handle = ACE_INVALID_HANDLE,
+                 bool unlink_in_destructor = true);
+
+  /// Open the @a filename with @a flags and @a mode and set the result
+  /// to <handle_>.  If you don't want the file unlinked in the
+  /// destructor pass a false value for @a unlink_in_destructor.
+  ACE_File_Lock (const ACE_TCHAR *filename,
+                 int flags,
+                 mode_t mode = 0,
+                 bool unlink_in_destructor = true);
+
+  /// Open the @a filename with @a flags and @a mode and set the result to
+  /// <handle_>.
+  int open (const ACE_TCHAR *filename,
+            int flags,
+            mode_t mode = 0);
+
+  /// Remove a File lock by releasing it and closing down the <handle_>.
+  ~ACE_File_Lock (void);
+
+  /// Remove a File lock by releasing it and closing down the
+  /// <handle_>.  If @a unlink_file is true then we unlink the file.
+  int remove (bool unlink_file = true);
+
+  /**
+   * Note, for interface uniformity with other synchronization
+   * wrappers we include the <acquire> method.  This is implemented as
+   * a write-lock to be on the safe-side...
+   */
+  int acquire (short whence = 0, ACE_OFF_T start = 0, ACE_OFF_T len = 1);
+
+  /**
+   * Note, for interface uniformity with other synchronization
+   * wrappers we include the <tryacquire> method.  This is implemented
+   * as a write-lock to be on the safe-side...  Returns -1 on failure.
+   * If we "failed" because someone else already had the lock, @c errno
+   * is set to @c EBUSY.
+   */
+  int tryacquire (short whence = 0, ACE_OFF_T start = 0, ACE_OFF_T len = 1);
+
+  /// Unlock a readers/writer lock.
+  int release (short whence = 0, ACE_OFF_T start = 0, ACE_OFF_T len = 1);
+
+  /// Acquire a write lock, but block if any readers or a
+  /// writer hold the lock.
+  int acquire_write (short whence = 0, ACE_OFF_T start = 0, ACE_OFF_T len = 1);
+
+  /**
+   * Conditionally acquire a write lock (i.e., won't block).  Returns
+   * -1 on failure.  If we "failed" because someone else already had
+   * the lock, @c errno is set to @c EBUSY.
+   */
+  int tryacquire_write (short whence = 0, ACE_OFF_T start = 0, ACE_OFF_T len = 1);
+
+  /**
+   * Conditionally upgrade to a write lock (i.e., won't block).  Returns
+   * -1 on failure.  If we "failed" because someone else already had
+   * the lock, @c errno is set to @c EBUSY.
+   */
+  int tryacquire_write_upgrade (short whence = 0,
+                                ACE_OFF_T start = 0,
+                                ACE_OFF_T len = 1);
+
+  /**
+   * Acquire a read lock, but block if a writer hold the lock.
+   * Returns -1 on failure.  If we "failed" because someone else
+   * already had the lock, @c errno is set to @c EBUSY.
+   */
+  int acquire_read (short whence = 0, ACE_OFF_T start = 0, ACE_OFF_T len = 1);
+
+  /**
+   * Conditionally acquire a read lock (i.e., won't block).  Returns
+   * -1 on failure.  If we "failed" because someone else already had
+   * the lock, @c errno is set to @c EBUSY.
+   */
+  int tryacquire_read (short whence = 0, ACE_OFF_T start = 0, ACE_OFF_T len = 1);
+
+  /// Get underlying ACE_HANDLE for the file.
+  ACE_HANDLE get_handle (void) const;
+
+  /**
+   * Set underlying ACE_HANDLE.  Note that this method assumes
+   * ownership of the @a handle and will close it down in <remove>.  If
+   * you want the @a handle to stay open when <remove> is called make
+   * sure to call <dup> on the @a handle before closing it. You are
+   * responsible for the closing the existing @a handle before
+   * overwriting it.
+   */
+  void set_handle (ACE_HANDLE);
+
+  /// Dump state of the object.
+  void dump (void) const;
+
+  /// Declare the dynamic allocation hooks.
+  ACE_ALLOC_HOOK_DECLARE;
+
+protected:
+  /// Locking structure for OS record locks.
+  ACE_OS::ace_flock_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...
+  bool removed_;
+
+  /// Keeps track of whether to unlink the underlying file in the
+  /// destructor.
+  bool const unlink_in_destructor_;
+
+private:
+  // = Prevent assignment and initialization.
+  void operator= (const ACE_File_Lock &);
+  ACE_File_Lock (const ACE_File_Lock &);
+};
+
+ACE_END_VERSIONED_NAMESPACE_DECL
+
+#if defined (__ACE_INLINE__)
+#include "ace/File_Lock.inl"
+#endif /* __ACE_INLINE__ */
+
+#include /**/ "ace/post.h"
+#endif /* ACE_FILE_LOCK_H */