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+// -*- C++ -*-
+
+//=============================================================================
+/**
+ * @file Process_Semaphore.h
+ *
+ * $Id$
+ *
+ * Wrapper for Dijkstra style general semaphores that work
+ * across processes.
+ *
+ * @author Douglas C. Schmidt <schmidt@cs.wustl.edu>
+ */
+//=============================================================================
+
+#ifndef ACE_PROCESS_SEMAPHORE_H
+#define ACE_PROCESS_SEMAPHORE_H
+
+#include /**/ "ace/pre.h"
+
+#include /**/ "ace/ACE_export.h"
+
+#if !defined (ACE_LACKS_PRAGMA_ONCE)
+# pragma once
+#endif /* ACE_LACKS_PRAGMA_ONCE */
+
+#if !(defined (ACE_WIN32) || defined (ACE_HAS_POSIX_SEM))
+# include "ace/SV_Semaphore_Complex.h"
+#else
+# include "ace/Semaphore.h"
+#endif /* !(ACE_WIN32 || ACE_HAS_POSIX_SEM) */
+
+ACE_BEGIN_VERSIONED_NAMESPACE_DECL
+
+/**
+ * @class ACE_Process_Semaphore
+ *
+ * @brief Wrapper for Dijkstra style general semaphores that work
+ * across processes.
+ */
+class ACE_Export ACE_Process_Semaphore
+{
+public:
+ /// Initialize the semaphore, with an initial value of @a count and a
+ /// maximum value of @a max.
+ ACE_Process_Semaphore (u_int count = 1, // By default make this unlocked.
+ const ACE_TCHAR *name = 0,
+ void * = 0,
+ int max = 0x7FFFFFFF);
+
+ /**
+ * This method is a no-op, i.e., it doesn't remove the semaphore.
+ * If you want to remove the semaphore, you must call the <remove>
+ * method explicitly.
+ */
+ // ~ACE_Process_Semaphore (void);
+
+ /**
+ * Explicitly destroy the semaphore. Note that only one thread
+ * should call this method since it doesn't protect against race
+ * conditions.
+ */
+ int remove (void);
+
+ /// Block the thread until the semaphore count becomes greater than
+ /// 0, then decrement it.
+ int acquire (void);
+
+ /**
+ * Conditionally decrement the semaphore if count is greater than 0
+ * (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 (void);
+
+ /// Increment the semaphore, potentially unblocking a waiting thread.
+ int release (void);
+
+ /**
+ * Acquire semaphore ownership. This calls <acquire> and is only
+ * here to make the <ACE_Process_Semaphore> interface consistent
+ * with the other synchronization APIs.
+ */
+ int acquire_read (void);
+
+ /**
+ * Acquire semaphore ownership. This calls <acquire> and is only
+ * here to make the <ACE_Process_Semaphore> interface consistent
+ * with the other synchronization APIs.
+ */
+ int acquire_write (void);
+
+ /**
+ * Conditionally acquire semaphore (i.e., won't block). This calls
+ * <tryacquire> and is only here to make the <ACE_Process_Semaphore>
+ * 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 semaphore (i.e., won't block). This calls
+ * <tryacquire> and is only here to make the ACE_Process_Semaphore
+ * 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_Process_Semaphore
+ * interface consistent with the other synchronization APIs.
+ * Assumes the caller has already acquired the semaphore using one of
+ * the above calls, and returns 0 (success) always.
+ */
+ int tryacquire_write_upgrade (void);
+
+#if defined (ACE_WIN32) || defined (ACE_HAS_POSIX_SEM)
+ /// Return the underlying lock.
+ const ACE_sema_t &lock (void) const;
+#endif /* ACE_WIN32 || ACE_HAS_POSIX_SEM */
+
+ /// Dump the state of an object.
+ void dump (void) const;
+
+ /// Declare the dynamic allocation hooks.
+ ACE_ALLOC_HOOK_DECLARE;
+
+protected:
+#if defined (ACE_WIN32) || defined (ACE_HAS_POSIX_SEM)
+ ACE_Semaphore lock_;
+#else
+ /// We need this to get the right semantics...
+ ACE_SV_Semaphore_Complex lock_;
+#endif /* ACE_WIN32 || ACE_HAS_POSIX_SEM */
+};
+
+/*****************************************************************************/
+
+template <class T> class ACE_Malloc_Lock_Adapter_T;
+
+/**
+ * @class ACE_Malloc_Lock_Adapter_T<ACE_Process_Semaphore>
+ *
+ * @brief Template specialization of ACE_Malloc_Lock_Adapter_T for
+ * ACE_Process_Semaphore.
+ *
+ * This is needed since the ctor for ACE_Process_Semaphore doesn't match
+ * the standard form used by other lock strategy classes.
+ */
+template<>
+class ACE_Export ACE_Malloc_Lock_Adapter_T<ACE_Process_Semaphore>
+{
+public:
+ ACE_Process_Semaphore * operator () (const ACE_TCHAR *name);
+};
+
+ACE_END_VERSIONED_NAMESPACE_DECL
+
+
+#if defined (__ACE_INLINE__)
+#include "ace/Process_Semaphore.inl"
+#endif /* __ACE_INLINE__ */
+
+#include /**/ "ace/post.h"
+#endif /* ACE_PROCESS_SEMAPHORE_H */