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/*
* (c) Copyright 1990-1996 OPEN SOFTWARE FOUNDATION, INC.
* (c) Copyright 1990-1996 HEWLETT-PACKARD COMPANY
* (c) Copyright 1990-1996 DIGITAL EQUIPMENT CORPORATION
* (c) Copyright 1991, 1992 Siemens-Nixdorf Information Systems
* To anyone who acknowledges that this file is provided "AS IS" without
* any express or implied warranty: permission to use, copy, modify, and
* distribute this file for any purpose is hereby granted without fee,
* provided that the above copyright notices and this notice appears in
* all source code copies, and that none of the names listed above be used
* in advertising or publicity pertaining to distribution of the software
* without specific, written prior permission. None of these organizations
* makes any representations about the suitability of this software for
* any purpose.
*/
/*
* Header file for mutex operations
*/
#ifndef CMA_MUTEX
#define CMA_MUTEX
/*
* INCLUDE FILES
*/
#include <cma.h>
#include <cma_attr.h>
#include <cma_defs.h>
#include <cma_semaphore_defs.h>
#include <cma_sequence.h>
#include <cma_tcb_defs.h>
#include <cma_stack.h>
/*
* CONSTANTS AND MACROS
*/
/*
* TYPEDEFS
*/
typedef struct CMA__T_INT_MUTEX {
cma__t_object header; /* Common header (sequence, type) */
cma__t_int_attr *attributes; /* Back link */
cma__t_int_tcb *owner; /* Current owner (if any) */
cma_t_integer nest_count; /* Nesting level for recursive mutex */
cma__t_atomic_bit *unlock; /* Pointer used for unlock operation */
cma__t_atomic_bit lock; /* Set if currently locked */
struct CMA__T_INT_MUTEX *int_lock; /* Internal protection for mutex */
cma__t_atomic_bit event; /* Clear when unlock requires action */
cma__t_atomic_bit waiters; /* Clear when threads are waiting */
cma__t_atomic_bit bitbucket; /* Fake bit to keep friendlies
locked */
cma_t_mutex_kind mutex_kind; /* Kind of mutex */
cma__t_semaphore semaphore; /* Semaphore for low-level wait */
} cma__t_int_mutex;
/*
* FUNCTIONAL DESCRIPTION:
*
* Lock a mutex (internal)
*
* FORMAL PARAMETERS:
*
* mutex Pointer to mutex object to lock
*
* IMPLICIT INPUTS:
*
* none
*
* IMPLICIT OUTPUTS:
*
* none
*
* FUNCTION VALUE:
*
* none
*
* SIDE EFFECTS:
*
* none
*/
#ifdef NDEBUG
# define cma__int_lock(mutex) { \
if (cma__test_and_set (&((cma__t_int_mutex *)mutex)->lock)) { \
cma_t_status res;\
res = cma__int_mutex_block ((cma__t_int_mutex *)mutex); \
if (res != cma_s_normal) cma__error (res); \
} \
}
#else
# define cma__int_lock(mutex) { \
cma__t_int_tcb *__ltcb__; \
__ltcb__ = cma__get_self_tcb (); \
if (cma__test_and_set (&((cma__t_int_mutex *)mutex)->lock)) { \
cma_t_status res;\
res = cma__int_mutex_block ((cma__t_int_mutex *)mutex); \
if (res != cma_s_normal) cma__error (res); \
} \
((cma__t_int_mutex *)mutex)->owner = __ltcb__; \
}
#endif
/*
* FUNCTIONAL DESCRIPTION:
*
* Unlock a mutex (internal)
*
* FORMAL PARAMETERS:
*
* mutex Pointer to mutex object to unlock
*
* IMPLICIT INPUTS:
*
* none
*
* IMPLICIT OUTPUTS:
*
* none
*
* FUNCTION VALUE:
*
* none
*
* SIDE EFFECTS:
*
* none
*/
#ifdef NDEBUG
# define cma__int_unlock(mutex) { \
cma__unset (((cma__t_int_mutex *)mutex)->unlock); \
if (!cma__test_and_set (&((cma__t_int_mutex *)mutex)->event)) { \
cma_t_status res;\
res = cma__int_mutex_unblock ((cma__t_int_mutex *)mutex); \
if (res != cma_s_normal) cma__error (res); \
} \
}
#else
# define cma__int_unlock(mutex) { \
cma__t_int_tcb *__utcb__; \
__utcb__ = cma__get_self_tcb (); \
if (((cma__t_int_mutex *)mutex)->mutex_kind == cma_c_mutex_fast) { \
cma__assert_warn ( \
(__utcb__ == ((cma__t_int_mutex *)mutex)->owner), \
"attempt to release mutx owned by another thread"); \
((cma__t_int_mutex *) mutex)->owner \
= (cma__t_int_tcb *)cma_c_null_ptr; \
} \
cma__unset (((cma__t_int_mutex *)mutex)->unlock); \
if (!cma__test_and_set (&((cma__t_int_mutex *)mutex)->event)) { \
cma_t_status res;\
res = cma__int_mutex_unblock ((cma__t_int_mutex *)mutex); \
if (res != cma_s_normal) cma__error (res); \
} \
}
#endif
/*
* FUNCTIONAL DESCRIPTION:
*
* cma__int_mutex_delete - Performs work for cma_mutex_delete
*
* FORMAL PARAMETERS:
*
* cma__t_mutex _mutex_ - Mutex to be deleted
*
* IMPLICIT INPUTS:
*
* none
*
* IMPLICIT OUTPUTS:
*
* none
*
* FUNCTION VALUE:
*
* none
*
* SIDE EFFECTS:
*
* none
*/
#define cma__int_mutex_delete(_mutex_) { \
cma__t_int_mutex *_int_mutex_; \
_int_mutex_ = cma__validate_null_mutex (_mutex_); \
if (_int_mutex_ == (cma__t_int_mutex *)cma_c_null_ptr) \
return; \
if (cma__int_mutex_locked (_int_mutex_)) \
cma__error (cma_s_in_use); \
cma__free_mutex (_int_mutex_); \
cma__clear_handle (_mutex_); \
}
/*
* GLOBAL DATA
*/
extern cma__t_sequence cma__g_mutex_seq;
extern cma__t_int_mutex *cma__g_global_lock;
/*
* INTERNAL INTERFACES
*/
extern void cma__destroy_mutex (cma__t_int_mutex *);
extern void cma__free_mutex (cma__t_int_mutex *);
extern void cma__free_mutex_nolock (cma__t_int_mutex *);
extern cma__t_int_mutex * cma__get_first_mutex (cma__t_int_attr *);
extern cma__t_int_mutex * cma__get_mutex (cma__t_int_attr *);
extern void cma__init_mutex (void);
extern cma_t_status cma__int_mutex_block (cma__t_int_mutex *);
extern cma_t_boolean cma__int_mutex_locked (cma__t_int_mutex *);
extern cma_t_boolean cma__int_try_lock (cma__t_int_mutex *);
extern cma_t_status cma__int_mutex_unblock (cma__t_int_mutex *);
extern cma_t_boolean cma__mutex_locked (cma_t_mutex);
extern void cma__reinit_mutex (cma_t_integer);
#endif