/* * (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