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OsoianMarcel/Basic_Queue_Example.c

Last active December 26, 2021 12:58
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  1. OsoianMarcel revised this gist Dec 26, 2021. 1 changed file with 10 additions and 0 deletions.
    10 changes: 10 additions & 0 deletions Basic_Queue_Example.c
    View file
    Original file line number Diff line number Diff line change
    @@ -61,6 +61,16 @@ QueueItem_t queue_next(Queue_t *q)
    return i;
    }

    void queue_clear(Queue_t *q)
    {
    for (uint8_t i = 0; i < QUEUE_MAX; i++)
    {
    q->items[i].set = 0;
    }
    q->last = 0;
    q->cons = 0;
    }

    int main()
    {
    // Declare queue instance
  2. OsoianMarcel renamed this gist Dec 24, 2021. 1 changed file with 0 additions and 0 deletions.
    0 Basic_Queue_Example2.c → Basic_Queue_Example.c
    View file
    File renamed without changes.
  3. OsoianMarcel created this gist Dec 24, 2021.
    109 changes: 109 additions & 0 deletions Basic_Queue_Example2.c
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    Original file line number Diff line number Diff line change
    @@ -0,0 +1,109 @@
    // A basic example of queue written in C
    // Useful for small microcontrollers
    // Tags: Arduino | Atmega | AVR | STM32

    #include <stdio.h>
    #include <stdint.h>

    // Maximum number of items in queue
    #define QUEUE_MAX 5

    // Add your custom properies (the prop "set" is required)
    typedef struct QueueItem_s
    {
    uint8_t value; // Custom property
    uint8_t set;
    } QueueItem_t;

    typedef struct Queue_s
    {
    uint8_t last;
    uint8_t cons;
    QueueItem_t items[QUEUE_MAX];
    } Queue_t;

    // Returns 1 on success, otherwise if the queue is full returns 0
    uint8_t queue_push(Queue_t *q, QueueItem_t i)
    {
    if (q->last >= QUEUE_MAX)
    {
    q->last = 0;
    }

    if (q->items[q->last].set == 1)
    {
    return 0;
    }

    q->items[q->last++] = i;

    return 1;
    }

    // Returns next queue item, otherwire if the queue is empty then returns an (QueueItem_t){0, 0}
    QueueItem_t queue_next(Queue_t *q)
    {
    if (q->cons >= QUEUE_MAX)
    {
    q->cons = 0;
    }

    if (q->items[q->cons].set == 0)
    {
    return (QueueItem_t){0, 0};
    }

    QueueItem_t i = q->items[q->cons];

    q->items[q->cons].set = 0;
    q->cons++;

    return i;
    }

    int main()
    {
    // Declare queue instance
    Queue_t queue = {
    .last = 0,
    .cons = 0,
    .items = {}
    };

    // Queue testing
    uint8_t i;

    // Push 4 elements
    for (i = 0; i < 4; i++)
    {
    printf("push%d: %d\n", i, queue_push(&queue, (QueueItem_t){i * 10, 1}));
    }

    // Consume 4 elements
    for (i = 0; i < 4; i++)
    {
    printf("next%d: %d\n", i, queue_next(&queue).value);
    }

    // Push 6 elements (last element does not fit in queue)
    for (i = 0; i < 6; i++)
    {
    printf("push%d: %d\n", i, queue_push(&queue, (QueueItem_t){i * 10, 1}));
    }

    // Consume 6 elements (last element does not exists, on last element the queue will return empty element)
    for (i = 0; i < 6; i++)
    {
    printf("next%d: %d\n", i, queue_next(&queue).value);
    }

    // Output queue stats
    printf("\nstats\n");
    for (int si = 0; si < QUEUE_MAX; si++)
    {
    printf("%d: %d / %d\n", si, queue.items[si].value, queue.items[si].set);
    }
    // /Queue testing

    return 0;
    }
    27 changes: 27 additions & 0 deletions Output.txt
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    @@ -0,0 +1,27 @@
    push0: 1
    push1: 1
    push2: 1
    push3: 1
    next0: 0
    next1: 10
    next2: 20
    next3: 30
    push0: 1
    push1: 1
    push2: 1
    push3: 1
    push4: 1
    push5: 0
    next0: 0
    next1: 10
    next2: 20
    next3: 30
    next4: 40
    next5: 0

    stats
    0: 10 / 0
    1: 20 / 0
    2: 30 / 0
    3: 40 / 0
    4: 0 / 0