2 #include "lfds700_stack_internal.h"
4 /***** private prototypes *****/
5 static void lfds700_stack_internal_stack_validate( struct lfds700_stack_state *ss, struct lfds700_misc_validation_info *vi, enum lfds700_misc_validity *lfds700_stack_validity );
11 /****************************************************************************/
12 void lfds700_stack_query( struct lfds700_stack_state *ss, enum lfds700_stack_query query_type, void *query_input, void *query_output )
14 struct lfds700_stack_element
17 LFDS700_MISC_BARRIER_LOAD;
19 LFDS700_PAL_ASSERT( ss != NULL );
20 // TRD : query_type can be any value in its range
24 case LFDS700_STACK_QUERY_SINGLETHREADED_GET_COUNT:
25 LFDS700_PAL_ASSERT( query_input == NULL );
26 LFDS700_PAL_ASSERT( query_output != NULL );
28 *(lfds700_pal_uint_t *) query_output = 0;
30 se = (struct lfds700_stack_element *) ss->top[POINTER];
34 ( *(lfds700_pal_uint_t *) query_output )++;
35 se = (struct lfds700_stack_element *) se->next;
39 case LFDS700_STACK_QUERY_SINGLETHREADED_VALIDATE:
40 // TRD : query_input can be NULL
41 LFDS700_PAL_ASSERT( query_output != NULL );
43 lfds700_stack_internal_stack_validate( ss, (struct lfds700_misc_validation_info *) query_input, (enum lfds700_misc_validity *) query_output );
54 /****************************************************************************/
55 static void lfds700_stack_internal_stack_validate( struct lfds700_stack_state *ss, struct lfds700_misc_validation_info *vi, enum lfds700_misc_validity *lfds700_stack_validity )
60 struct lfds700_stack_element
64 LFDS700_PAL_ASSERT( ss != NULL );
65 // TRD : vi can be NULL
66 LFDS700_PAL_ASSERT( lfds700_stack_validity != NULL );
68 *lfds700_stack_validity = LFDS700_MISC_VALIDITY_VALID;
70 se_slow = se_fast = (struct lfds700_stack_element *) ss->top[POINTER];
72 /* TRD : first, check for a loop
74 both of which start at the top of the stack
77 we advance one pointer by one element
80 we exit the loop when both pointers are NULL
81 (have reached the end of the stack)
85 if we fast pointer 'sees' the slow pointer
86 which means we have a loop
92 se_slow = se_slow->next;
95 se_fast = se_fast->next;
98 se_fast = se_fast->next;
100 while( se_slow != NULL and se_fast != se_slow );
102 if( se_fast != NULL and se_slow != NULL and se_fast == se_slow )
103 *lfds700_stack_validity = LFDS700_MISC_VALIDITY_INVALID_LOOP;
105 /* TRD : now check for expected number of elements
106 vi can be NULL, in which case we do not check
107 we know we don't have a loop from our earlier check
110 if( *lfds700_stack_validity == LFDS700_MISC_VALIDITY_VALID and vi != NULL )
112 lfds700_stack_query( ss, LFDS700_STACK_QUERY_SINGLETHREADED_GET_COUNT, NULL, (void *) &number_elements );
114 if( number_elements < vi->min_elements )
115 *lfds700_stack_validity = LFDS700_MISC_VALIDITY_INVALID_MISSING_ELEMENTS;
117 if( number_elements > vi->max_elements )
118 *lfds700_stack_validity = LFDS700_MISC_VALIDITY_INVALID_ADDITIONAL_ELEMENTS;