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#ifndef CYGONCE_KERNEL_MUTEX_HXX
#define CYGONCE_KERNEL_MUTEX_HXX
//==========================================================================
//
// mutex.hxx
//
// Mutex class declarations
//
//==========================================================================
// ####ECOSGPLCOPYRIGHTBEGIN####
// -------------------------------------------
// This file is part of eCos, the Embedded Configurable Operating System.
// Copyright (C) 1998, 1999, 2000, 2001, 2002 Free Software Foundation, Inc.
//
// eCos is free software; you can redistribute it and/or modify it under
// the terms of the GNU General Public License as published by the Free
// Software Foundation; either version 2 or (at your option) any later
// version.
//
// eCos is distributed in the hope that it will be useful, but WITHOUT
// ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
// FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
// for more details.
//
// You should have received a copy of the GNU General Public License
// along with eCos; if not, write to the Free Software Foundation, Inc.,
// 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
//
// As a special exception, if other files instantiate templates or use
// macros or inline functions from this file, or you compile this file
// and link it with other works to produce a work based on this file,
// this file does not by itself cause the resulting work to be covered by
// the GNU General Public License. However the source code for this file
// must still be made available in accordance with section (3) of the GNU
// General Public License v2.
//
// This exception does not invalidate any other reasons why a work based
// on this file might be covered by the GNU General Public License.
// -------------------------------------------
// ####ECOSGPLCOPYRIGHTEND####
//==========================================================================
//#####DESCRIPTIONBEGIN####
//
// Author(s): nickg
// Contributors: nickg
// Date: 1997-09-09
// Purpose: Define Mutex class interfaces
// Description: The classes defined here provide the APIs for mutexes
// and condition variables.
// Usage: #include <cyg/kernel/mutex.hxx>
//
//
//####DESCRIPTIONEND####
//
//==========================================================================
#include <cyg/kernel/ktypes.h>
#include <cyg/infra/cyg_ass.h> // assertion macros
#include <cyg/kernel/thread.hxx>
// -------------------------------------------------------------------------
// Mutex.
class Cyg_Mutex
{
friend class Cyg_Condition_Variable;
cyg_atomic locked; // true if locked. This may seem
// redundant due to "owner" below,
// but is intentionally present for
// future SMP support.
Cyg_Thread *owner; // Current locking thread
Cyg_ThreadQueue queue; // Queue of waiting threads
#ifdef CYGSEM_KERNEL_SYNCH_MUTEX_PRIORITY_INVERSION_PROTOCOL_DYNAMIC
public:
enum cyg_protcol
{
NONE = 0, // no inversion protocol
INHERIT, // priority inheritance protocol
CEILING // priority ceiling protocol
};
private:
cyg_protcol protocol; // this mutex's protocol
#endif
#ifdef CYGSEM_KERNEL_SYNCH_MUTEX_PRIORITY_INVERSION_PROTOCOL_CEILING
private:
cyg_priority ceiling; // mutex priority ceiling
#endif
public:
CYGDBG_DEFINE_CHECK_THIS
Cyg_Mutex(); // Create in unlocked state
#ifdef CYGSEM_KERNEL_SYNCH_MUTEX_PRIORITY_INVERSION_PROTOCOL_DYNAMIC
Cyg_Mutex( cyg_protcol protocol ); // Create with defined protocol
#endif
~Cyg_Mutex(); // Destructor
cyg_bool lock(); // lock and/or wait
cyg_bool trylock(); // try to lock and return success
void unlock(); // unlock
void release(); // release all waiting threads
// Get the current owning thread
inline Cyg_Thread *get_owner() { return owner; }
#ifdef CYGSEM_KERNEL_SYNCH_MUTEX_PRIORITY_INVERSION_PROTOCOL_CEILING
// set ceiling priority for priority ceiling protocol
void set_ceiling( cyg_priority priority );
cyg_priority get_ceiling(void) { return ceiling; };
#endif
#ifdef CYGSEM_KERNEL_SYNCH_MUTEX_PRIORITY_INVERSION_PROTOCOL_DYNAMIC
// set inversion protocol
void set_protocol( cyg_protcol new_protocol );
#endif
};
// -------------------------------------------------------------------------
// Condition variable.
class Cyg_Condition_Variable
{
Cyg_Mutex *mutex; // Associated mutex
Cyg_ThreadQueue queue; // Queue of waiting threads
// Private internal implementation function for wait operations
cyg_bool wait_inner( Cyg_Mutex *mutex );
#ifdef CYGMFN_KERNEL_SYNCH_CONDVAR_TIMED_WAIT
// Private internal implementation function for timed wait operations
cyg_bool wait_inner( Cyg_Mutex *mutex, cyg_tick_count timeout );
#endif
public:
CYGDBG_DEFINE_CHECK_THIS
Cyg_Condition_Variable(); // simple constructor
Cyg_Condition_Variable(
Cyg_Mutex &mutex // linked mutex
);
~Cyg_Condition_Variable(); // Destructor
void signal(); // Set cond true, wake one thread
void broadcast(); // Set cond true, wake all threads
// Wait for condition to be true
inline cyg_bool wait() { return wait_inner( mutex ); }
#ifdef CYGMFN_KERNEL_SYNCH_CONDVAR_TIMED_WAIT
// Wait until a signal or timeout expiry
inline cyg_bool wait( cyg_tick_count timeout )
{ return wait_inner( mutex, timeout ); }
#endif
#ifdef CYGMFN_KERNEL_SYNCH_CONDVAR_WAIT_MUTEX
// Wait for condition to be true using the supplied mutex
inline cyg_bool wait( Cyg_Mutex &mx ) { return wait_inner( &mx ); }
#ifdef CYGMFN_KERNEL_SYNCH_CONDVAR_TIMED_WAIT
// Wait until a signal or timeout expiry, using the supplied mutex
inline cyg_bool wait( Cyg_Mutex &mx, cyg_tick_count timeout )
{ return wait_inner( &mx, timeout ); }
#endif
#endif
// Return a pointer to this variables thread queue. Used mainly
// for testing whether a thread is on the queue for a particular
// cv.
inline Cyg_ThreadQueue *get_queue() { return &queue; };
};
// -------------------------------------------------------------------------
#endif // ifndef CYGONCE_KERNEL_MUTEX_HXX
// EOF mutex.hxx
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