stellar-stellar/src/session/session_pool.cpp

#include "session_pool.h"
#include "session_private.h"

struct session_pool
{
    uint64_t count;
    struct session *sess;
};

struct session_pool *session_pool_new(uint64_t count)
{
    struct session_pool *pool = (struct session_pool *)calloc(1, sizeof(struct session_pool) + count * sizeof(struct session));
    if (pool == NULL)
    {
        return NULL;
    }

    pool->count = count;
    pool->sess = (struct session *)(pool + 1);

    for (uint64_t i = 0; i < count; i++)
    {
        pool->sess[i].next_free_ptr = &pool->sess[i + 1];
    }
    pool->sess[count - 1].next_free_ptr = NULL;

    return pool;
}

void session_pool_free(struct session_pool *pool)
{
    if (pool)
    {
        free(pool);
        pool = NULL;
    }
}

struct session *session_pool_alloc(struct session_pool *pool)
{
    if (pool == NULL)
    {
        return NULL;
    }

    struct session *sess = pool->sess;
    if (sess == NULL)
    {
        return NULL;
    }

    pool->sess = sess->next_free_ptr;
    sess->next_free_ptr = NULL;
    pool->count--;

    return sess;
}

void session_pool_free(struct session_pool *pool, struct session *sess)
{
    if (pool == NULL || sess == NULL)
    {
        return;
    }

    sess->next_free_ptr = pool->sess;
    pool->sess = sess;
    pool->count++;
}

uint64_t session_pool_get_count(struct session_pool *pool)
{
    if (pool == NULL)
    {
        return 0;
    }

    return pool->count;
}