pd.if.org Git - liblfds/blob - liblfds/liblfds7.1.0/liblfds710/src/lfds710_queue_bounded_manyproducer_manyconsumer/lfds710_queue_bounded_manyproducer_manyconsumer_query.c

   1 /***** includes *****/
   2 #include "lfds710_queue_bounded_manyproducer_manyconsumer_internal.h"
   3
   4 /***** private prototypes *****/
   5 static void lfds710_queue_bmm_internal_validate( struct lfds710_queue_bmm_state *qbmms,
   6                                                  struct lfds710_misc_validation_info *vi,
   7                                                  enum lfds710_misc_validity *lfds710_validity );
   8
   9
  10
  11
  12
  13 /****************************************************************************/
  14 void lfds710_queue_bmm_query( struct lfds710_queue_bmm_state *qbmms,
  15                               enum lfds710_queue_bmm_query query_type,
  16                               void *query_input,
  17                               void *query_output )
  18 {
  19   LFDS710_PAL_ASSERT( qbmms != NULL );
  20   // TRD : query_type can be any value in its range
  21
  22   switch( query_type )
  23   {
  24     case LFDS710_QUEUE_BMM_QUERY_GET_POTENTIALLY_INACCURATE_COUNT:
  25     {
  26       lfds710_pal_uint_t
  27         local_read_index,
  28         local_write_index;
  29
  30       LFDS710_PAL_ASSERT( query_input == NULL );
  31       LFDS710_PAL_ASSERT( query_output != NULL );
  32
  33       LFDS710_MISC_BARRIER_LOAD;
  34
  35       local_read_index = qbmms->read_index;
  36       local_write_index = qbmms->write_index;
  37
  38       *(lfds710_pal_uint_t *) query_output = +( local_write_index - local_read_index );
  39
  40       if( local_read_index > local_write_index )
  41         *(lfds710_pal_uint_t *) query_output = ((lfds710_pal_uint_t) -1) - *(lfds710_pal_uint_t *) query_output;
  42     }
  43     break;
  44
  45     case LFDS710_QUEUE_BMM_QUERY_SINGLETHREADED_VALIDATE:
  46       // TRD : query_input can be NULL
  47       LFDS710_PAL_ASSERT( query_output != NULL );
  48
  49       lfds710_queue_bmm_internal_validate( qbmms, (struct lfds710_misc_validation_info *) query_input, (enum lfds710_misc_validity *) query_output );
  50     break;
  51   }
  52
  53   return;
  54 }
  55
  56
  57
  58
  59
  60 /****************************************************************************/
  61 static void lfds710_queue_bmm_internal_validate( struct lfds710_queue_bmm_state *qbmms,
  62                                                  struct lfds710_misc_validation_info *vi,
  63                                                  enum lfds710_misc_validity *lfds710_validity )
  64 {
  65   lfds710_pal_uint_t
  66     expected_sequence_number,
  67     loop,
  68     number_elements,
  69     sequence_number;
  70
  71   LFDS710_PAL_ASSERT( qbmms != NULL );
  72   // TRD : vi can be NULL
  73   LFDS710_PAL_ASSERT( lfds710_validity != NULL );
  74
  75   *lfds710_validity = LFDS710_MISC_VALIDITY_VALID;
  76
  77   /* TRD : starting from the read_index, we should find number_elements of incrementing sequence numbers
  78            we then perform a second scan from the write_index onwards, which should have (max elements in queue - number_elements) incrementing sequence numbers
  79   */
  80
  81   lfds710_queue_bmm_query( qbmms, LFDS710_QUEUE_BMM_QUERY_GET_POTENTIALLY_INACCURATE_COUNT, NULL, (void *) &number_elements );
  82
  83   expected_sequence_number = qbmms->element_array[ qbmms->read_index & qbmms->mask ].sequence_number;
  84
  85   for( loop = 0 ; loop < number_elements ; loop++ )
  86   {
  87     sequence_number = qbmms->element_array[ (qbmms->read_index + loop) & qbmms->mask ].sequence_number;
  88
  89     if( sequence_number != expected_sequence_number )
  90       *lfds710_validity = LFDS710_MISC_VALIDITY_INVALID_ORDER;
  91
  92     if( sequence_number == expected_sequence_number )
  93       expected_sequence_number = sequence_number + 1;
  94   }
  95
  96   // TRD : now the write_index onwards
  97
  98   expected_sequence_number = qbmms->element_array[ qbmms->write_index & qbmms->mask ].sequence_number;
  99
 100   for( loop = 0 ; loop < qbmms->number_elements - number_elements ; loop++ )
 101   {
 102     sequence_number = qbmms->element_array[ (qbmms->write_index + loop) & qbmms->mask ].sequence_number;
 103
 104     if( sequence_number != expected_sequence_number )
 105       *lfds710_validity = LFDS710_MISC_VALIDITY_INVALID_ORDER;
 106
 107     if( sequence_number == expected_sequence_number )
 108       expected_sequence_number = sequence_number + 1;
 109   }
 110
 111   // TRD : now check against the expected number of elements
 112
 113   if( *lfds710_validity == LFDS710_MISC_VALIDITY_VALID and vi != NULL )
 114   {
 115     lfds710_pal_uint_t
 116       number_elements;
 117
 118     lfds710_queue_bmm_query( qbmms, LFDS710_QUEUE_BMM_QUERY_GET_POTENTIALLY_INACCURATE_COUNT, NULL, (void *) &number_elements );
 119
 120     if( number_elements < vi->min_elements )
 121       *lfds710_validity = LFDS710_MISC_VALIDITY_INVALID_MISSING_ELEMENTS;
 122
 123     if( number_elements > vi->max_elements )
 124       *lfds710_validity = LFDS710_MISC_VALIDITY_INVALID_ADDITIONAL_ELEMENTS;
 125   }
 126
 127   return;
 128 }
 129