diff options
Diffstat (limited to 'cpukit/posix/src/cond.c')
| -rw-r--r-- | cpukit/posix/src/cond.c | 501 |
1 files changed, 501 insertions, 0 deletions
diff --git a/cpukit/posix/src/cond.c b/cpukit/posix/src/cond.c new file mode 100644 index 0000000000..de2e252b95 --- /dev/null +++ b/cpukit/posix/src/cond.c @@ -0,0 +1,501 @@ +/* + * $Id$ + */ + +#include <pthread.h> +#include <errno.h> + +#include <rtems/system.h> +#include <rtems/score/object.h> +#include <rtems/score/states.h> +#include <rtems/score/watchdog.h> +#include <rtems/posix/cond.h> +#include <rtems/posix/time.h> +#include <rtems/posix/mutex.h> + +/* + * TEMPORARY + */ + +void _POSIX_Condition_variables_MP_Send_process_packet ( + POSIX_Condition_variables_MP_Remote_operations operation, + Objects_Id condition_variables_id, + Objects_Name name, + Objects_Id proxy_id +) +{ + (void) POSIX_MP_NOT_IMPLEMENTED(); +} + +void _POSIX_Condition_variables_MP_Send_extract_proxy( + Thread_Control *the_thread +) +{ + (void) POSIX_MP_NOT_IMPLEMENTED(); +} + +/* + * END OF TEMPORARY + */ + +/*PAGE + * + * The default condition variable attributes structure. + */ + +const pthread_condattr_t _POSIX_Condition_variables_Default_attributes = { + TRUE, /* is_initialized */ + PTHREAD_PROCESS_PRIVATE /* process_shared */ +}; + +/*PAGE + * + * _POSIX_Condition_variables_Manager_initialization + * + * This routine initializes all condition variable manager related data + * structures. + * + * Input parameters: + * maximum_condition_variables - maximum configured condition_variables + * + * Output parameters: NONE + */ + +void _POSIX_Condition_variables_Manager_initialization( + unsigned32 maximum_condition_variables +) +{ + _Objects_Initialize_information( + &_POSIX_Condition_variables_Information, + OBJECTS_POSIX_CONDITION_VARIABLES, + TRUE, + maximum_condition_variables, + sizeof( POSIX_Condition_variables_Control ), + FALSE, + 0, + FALSE + ); +} + +/*PAGE + * + * 11.4.1 Condition Variable Initialization Attributes, + * P1003.1c/Draft 10, p. 96 + */ + +int pthread_condattr_init( + pthread_condattr_t *attr +) +{ + if ( !attr ) + return EINVAL; + + *attr = _POSIX_Condition_variables_Default_attributes; + return 0; +} + +/*PAGE + * + * 11.4.1 Condition Variable Initialization Attributes, + * P1003.1c/Draft 10, p. 96 + */ + +int pthread_condattr_destroy( + pthread_condattr_t *attr +) +{ + if ( !attr || attr->is_initialized == FALSE ) + return EINVAL; + + attr->is_initialized = FALSE; + return 0; +} + +/*PAGE + * + * 11.4.1 Condition Variable Initialization Attributes, + * P1003.1c/Draft 10, p. 96 + */ + +int pthread_condattr_getpshared( + const pthread_condattr_t *attr, + int *pshared +) +{ + if ( !attr ) + return EINVAL; + + *pshared = attr->process_shared; + return 0; +} + +/*PAGE + * + * 11.4.1 Condition Variable Initialization Attributes, + * P1003.1c/Draft 10, p. 96 + */ + +int pthread_condattr_setpshared( + pthread_condattr_t *attr, + int pshared +) +{ + if ( !attr ) + return EINVAL; + + switch ( pshared ) { + case PTHREAD_PROCESS_SHARED: + case PTHREAD_PROCESS_PRIVATE: + attr->process_shared = pshared; + return 0; + + default: + return EINVAL; + } +} + +/*PAGE + * + * 11.4.2 Initializing and Destroying a Condition Variable, + * P1003.1c/Draft 10, p. 87 + */ + +int pthread_cond_init( + pthread_cond_t *cond, + const pthread_condattr_t *attr +) +{ + POSIX_Condition_variables_Control *the_cond; + const pthread_condattr_t *the_attr; + + if ( attr ) the_attr = attr; + else the_attr = &_POSIX_Condition_variables_Default_attributes; + + /* + * XXX: Be careful about attributes when global!!! + */ + + if ( the_attr->process_shared == PTHREAD_PROCESS_SHARED ) + return POSIX_MP_NOT_IMPLEMENTED(); + + if ( !the_attr->is_initialized ) + return EINVAL; + + _Thread_Disable_dispatch(); + + the_cond = _POSIX_Condition_variables_Allocate(); + + if ( !the_cond ) { + _Thread_Enable_dispatch(); + return ENOMEM; + } + + if ( the_attr->process_shared == PTHREAD_PROCESS_SHARED && + !( _Objects_MP_Allocate_and_open( &_POSIX_Condition_variables_Information, + 0, the_cond->Object.id, FALSE ) ) ) { + _POSIX_Condition_variables_Free( the_cond ); + _Thread_Enable_dispatch(); + return EAGAIN; + } + + the_cond->process_shared = the_attr->process_shared; + + the_cond->Mutex = POSIX_CONDITION_VARIABLES_NO_MUTEX; + +/* XXX some more initialization might need to go here */ + _Thread_queue_Initialize( + &the_cond->Wait_queue, + OBJECTS_POSIX_CONDITION_VARIABLES, + THREAD_QUEUE_DISCIPLINE_FIFO, + STATES_WAITING_FOR_CONDITION_VARIABLE, + _POSIX_Condition_variables_MP_Send_extract_proxy, + ETIMEDOUT + ); + + _Objects_Open( + &_POSIX_Condition_variables_Information, + &the_cond->Object, + 0 + ); + + *cond = the_cond->Object.id; + + if ( the_attr->process_shared == PTHREAD_PROCESS_SHARED ) + _POSIX_Condition_variables_MP_Send_process_packet( + POSIX_CONDITION_VARIABLES_MP_ANNOUNCE_CREATE, + the_cond->Object.id, + 0, /* Name not used */ + 0 /* Not used */ + ); + + _Thread_Enable_dispatch(); + + return 0; +} + +/*PAGE + * + * 11.4.2 Initializing and Destroying a Condition Variable, + * P1003.1c/Draft 10, p. 87 + */ + +int pthread_cond_destroy( + pthread_cond_t *cond +) +{ + register POSIX_Condition_variables_Control *the_cond; + Objects_Locations location; + + the_cond = _POSIX_Condition_variables_Get( cond, &location ); + switch ( location ) { + case OBJECTS_ERROR: + return EINVAL; + case OBJECTS_REMOTE: + _Thread_Dispatch(); + return POSIX_MP_NOT_IMPLEMENTED(); + return EINVAL; + case OBJECTS_LOCAL: + + if ( _Thread_queue_First( &the_cond->Wait_queue ) ) { + _Thread_Enable_dispatch(); + return EBUSY; + } + + _Objects_Close( + &_POSIX_Condition_variables_Information, + &the_cond->Object + ); + + _POSIX_Condition_variables_Free( the_cond ); + + if ( the_cond->process_shared == PTHREAD_PROCESS_SHARED ) { + + _Objects_MP_Close( + &_POSIX_Condition_variables_Information, + the_cond->Object.id + ); + + _POSIX_Condition_variables_MP_Send_process_packet( + POSIX_CONDITION_VARIABLES_MP_ANNOUNCE_DELETE, + the_cond->Object.id, + 0, /* Not used */ + 0 /* Not used */ + ); + } + _Thread_Enable_dispatch(); + return 0; + } + return POSIX_BOTTOM_REACHED(); +} + +/*PAGE + * + * _POSIX_Condition_variables_Signal_support + * + * A support routine which implements guts of the broadcast and single task + * wake up version of the "signal" operation. + */ + +int _POSIX_Condition_variables_Signal_support( + pthread_cond_t *cond, + boolean is_broadcast +) +{ + register POSIX_Condition_variables_Control *the_cond; + Objects_Locations location; + Thread_Control *the_thread; + + the_cond = _POSIX_Condition_variables_Get( cond, &location ); + switch ( location ) { + case OBJECTS_ERROR: + return EINVAL; + case OBJECTS_REMOTE: + _Thread_Dispatch(); + return POSIX_MP_NOT_IMPLEMENTED(); + return EINVAL; + case OBJECTS_LOCAL: + + do { + the_thread = _Thread_queue_Dequeue( &the_cond->Wait_queue ); + if ( !the_thread ) + the_cond->Mutex = POSIX_CONDITION_VARIABLES_NO_MUTEX; + } while ( is_broadcast && the_thread ); + + _Thread_Enable_dispatch(); + + return 0; + } + return POSIX_BOTTOM_REACHED(); +} + +/*PAGE + * + * 11.4.3 Broadcasting and Signaling a Condition, P1003.1c/Draft 10, p. 101 + */ + +int pthread_cond_signal( + pthread_cond_t *cond +) +{ + return _POSIX_Condition_variables_Signal_support( cond, FALSE ); +} + +/*PAGE + * + * 11.4.3 Broadcasting and Signaling a Condition, P1003.1c/Draft 10, p. 101 + */ + +int pthread_cond_broadcast( + pthread_cond_t *cond +) +{ + return _POSIX_Condition_variables_Signal_support( cond, TRUE ); +} + +/*PAGE + * + * _POSIX_Condition_variables_Wait_support + * + * A support routine which implements guts of the blocking, non-blocking, and + * timed wait version of condition variable wait routines. + */ + +int _POSIX_Condition_variables_Wait_support( + pthread_cond_t *cond, + pthread_mutex_t *mutex, + Watchdog_Interval timeout, + boolean already_timedout +) +{ + register POSIX_Condition_variables_Control *the_cond; + Objects_Locations location; + int status; + int mutex_status; + + if ( !_POSIX_Mutex_Get( mutex, &location ) ) { + return EINVAL; + } + + _Thread_Unnest_dispatch(); + + the_cond = _POSIX_Condition_variables_Get( cond, &location ); + switch ( location ) { + case OBJECTS_ERROR: + return EINVAL; + case OBJECTS_REMOTE: + _Thread_Dispatch(); + return POSIX_MP_NOT_IMPLEMENTED(); + return EINVAL; + case OBJECTS_LOCAL: + + if ( the_cond->Mutex && ( the_cond->Mutex != *mutex ) ) { + _Thread_Enable_dispatch(); + return EINVAL; + } + + (void) pthread_mutex_unlock( mutex ); +/* XXX ignore this for now since behavior is undefined + if ( mutex_status ) { + _Thread_Enable_dispatch(); + return EINVAL; + } +*/ + + if ( !already_timedout ) { + the_cond->Mutex = *mutex; + + _Thread_queue_Enter_critical_section( &the_cond->Wait_queue ); + _Thread_Executing->Wait.return_code = 0; + _Thread_Executing->Wait.queue = &the_cond->Wait_queue; + _Thread_Executing->Wait.id = *cond; + + _Thread_queue_Enqueue( &the_cond->Wait_queue, timeout ); + + _Thread_Enable_dispatch(); + + /* + * Switch ourself out because we blocked as a result of the + * _Thread_queue_Enqueue. + */ + + status = _Thread_Executing->Wait.return_code; + if ( status && status != ETIMEDOUT ) + return status; + + } + else + status = ETIMEDOUT; + + /* + * When we get here the dispatch disable level is 0. + */ + + mutex_status = pthread_mutex_lock( mutex ); + if ( mutex_status ) + return EINVAL; + + return status; + } + return POSIX_BOTTOM_REACHED(); +} + +/*PAGE + * + * 11.4.4 Waiting on a Condition, P1003.1c/Draft 10, p. 105 + */ + +int pthread_cond_wait( + pthread_cond_t *cond, + pthread_mutex_t *mutex +) +{ + return _POSIX_Condition_variables_Wait_support( + cond, + mutex, + THREAD_QUEUE_WAIT_FOREVER, + FALSE + ); +} + +/*PAGE + * + * 11.4.4 Waiting on a Condition, P1003.1c/Draft 10, p. 105 + */ + +int pthread_cond_timedwait( + pthread_cond_t *cond, + pthread_mutex_t *mutex, + const struct timespec *abstime +) +{ + Watchdog_Interval timeout; + struct timespec current_time; + struct timespec difference; + boolean already_timedout = FALSE; + + if ( !abstime ) + return EINVAL; + + /* + * The abstime is a walltime. We turn it into an interval. + */ + + (void) clock_gettime( CLOCK_REALTIME, ¤t_time ); + + /* XXX probably some error checking should go here */ + + _POSIX_Timespec_subtract( ¤t_time, abstime, &difference ); + + if ( ( difference.tv_sec < 0 ) || ( ( difference.tv_sec == 0 ) && + ( difference.tv_nsec < 0 ) ) ) + already_timedout = TRUE; + + timeout = _POSIX_Timespec_to_interval( &difference ); + + return _POSIX_Condition_variables_Wait_support( + cond, + mutex, + timeout, + already_timedout + ); +} |