apr_pools.c

来自「Apache 2.0.63 is the current stable vers」· C语言 代码 · 共 2,297 行 · 第 1/5 页

{
    debug_node_t *node;
    apr_uint32_t index;

    /* Destroy the subpools.  The subpools will detach themselves from
     * this pool thus this loop is safe and easy.
     */
    while (pool->child)
        apr_pool_destroy_debug(pool->child, file_line);

    /* Run cleanups */
    run_cleanups(&pool->cleanups);
    pool->cleanups = NULL;

    /* Free subprocesses */
    free_proc_chain(pool->subprocesses);
    pool->subprocesses = NULL;

    /* Clear the user data. */
    pool->user_data = NULL;

    /* Free the blocks, scribbling over them first to help highlight
     * use-after-free issues. */
    while ((node = pool->nodes) != NULL) {
        pool->nodes = node->next;

        for (index = 0; index < node->index; index++) {
            memset(node->beginp[index], POOL_POISON_BYTE,
                   node->endp[index] - node->beginp[index]);
            free(node->beginp[index]);
        }

        memset(node, POOL_POISON_BYTE, SIZEOF_DEBUG_NODE_T);
        free(node);
    }

    pool->stat_alloc = 0;
    pool->stat_clear++;
}

APR_DECLARE(void) apr_pool_clear_debug(apr_pool_t *pool,
                                       const char *file_line)
{
#if APR_HAS_THREADS
    apr_thread_mutex_t *mutex = NULL;
#endif

    apr_pool_check_integrity(pool);

#if (APR_POOL_DEBUG & APR_POOL_DEBUG_VERBOSE)
    apr_pool_log_event(pool, "CLEAR", file_line, 1);
#endif /* (APR_POOL_DEBUG & APR_POOL_DEBUG_VERBOSE) */

#if APR_HAS_THREADS
    if (pool->parent != NULL)
        mutex = pool->parent->mutex;

    /* Lock the parent mutex before clearing so that if we have our
     * own mutex it won't be accessed by apr_pool_walk_tree after
     * it has been destroyed.
     */
    if (mutex != NULL && mutex != pool->mutex) {
        apr_thread_mutex_lock(mutex);
    }
#endif

    pool_clear_debug(pool, file_line);

#if APR_HAS_THREADS
    /* If we had our own mutex, it will have been destroyed by
     * the registered cleanups.  Recreate the mutex.  Unlock
     * the mutex we obtained above.
     */
    if (mutex != pool->mutex) {
        (void)apr_thread_mutex_create(&pool->mutex,
                                      APR_THREAD_MUTEX_NESTED, pool);

        if (mutex != NULL)
            (void)apr_thread_mutex_unlock(mutex);
    }
#endif /* APR_HAS_THREADS */
}

APR_DECLARE(void) apr_pool_destroy_debug(apr_pool_t *pool,
                                         const char *file_line)
{
    apr_pool_check_integrity(pool);

#if (APR_POOL_DEBUG & APR_POOL_DEBUG_VERBOSE)
    apr_pool_log_event(pool, "DESTROY", file_line, 1);
#endif /* (APR_POOL_DEBUG & APR_POOL_DEBUG_VERBOSE) */

    pool_clear_debug(pool, file_line);

    /* Remove the pool from the parents child list */
    if (pool->parent) {
#if APR_HAS_THREADS
        apr_thread_mutex_t *mutex;

        if ((mutex = pool->parent->mutex) != NULL)
            apr_thread_mutex_lock(mutex);
#endif /* APR_HAS_THREADS */

        if ((*pool->ref = pool->sibling) != NULL)
            pool->sibling->ref = pool->ref;

#if APR_HAS_THREADS
        if (mutex)
            apr_thread_mutex_unlock(mutex);
#endif /* APR_HAS_THREADS */
    }

    if (pool->allocator != NULL
        && apr_allocator_owner_get(pool->allocator) == pool) {
        apr_allocator_destroy(pool->allocator);
    }

    /* Free the pool itself */
    free(pool);
}

APR_DECLARE(apr_status_t) apr_pool_create_ex_debug(apr_pool_t **newpool,
                                                   apr_pool_t *parent,
                                                   apr_abortfunc_t abort_fn,
                                                   apr_allocator_t *allocator,
                                                   const char *file_line)
{
    apr_pool_t *pool;

    *newpool = NULL;

    if (!parent) {
        parent = global_pool;
    }
    else {
       apr_pool_check_integrity(parent);

       if (!allocator)
           allocator = parent->allocator;
    }

    if (!abort_fn && parent)
        abort_fn = parent->abort_fn;

    if ((pool = malloc(SIZEOF_POOL_T)) == NULL) {
        if (abort_fn)
            abort_fn(APR_ENOMEM);

         return APR_ENOMEM;
    }

    memset(pool, 0, SIZEOF_POOL_T);

    pool->allocator = allocator;
    pool->abort_fn = abort_fn;
    pool->tag = file_line;
    pool->file_line = file_line;

    if ((pool->parent = parent) != NULL) {
#if APR_HAS_THREADS
        if (parent->mutex)
            apr_thread_mutex_lock(parent->mutex);
#endif /* APR_HAS_THREADS */
        if ((pool->sibling = parent->child) != NULL)
            pool->sibling->ref = &pool->sibling;

        parent->child = pool;
        pool->ref = &parent->child;

#if APR_HAS_THREADS
        if (parent->mutex)
            apr_thread_mutex_unlock(parent->mutex);
#endif /* APR_HAS_THREADS */
    }
    else {
        pool->sibling = NULL;
        pool->ref = NULL;
    }

#if APR_HAS_THREADS
    pool->owner = apr_os_thread_current();
#endif /* APR_HAS_THREADS */

    if (parent == NULL || parent->allocator != allocator) {
#if APR_HAS_THREADS
        apr_status_t rv;

        /* No matter what the creation flags say, always create
         * a lock.  Without it integrity_check and apr_pool_num_bytes
         * blow up (because they traverse pools child lists that
         * possibly belong to another thread, in combination with
         * the pool having no lock).  However, this might actually
         * hide problems like creating a child pool of a pool
         * belonging to another thread.
         */
        if ((rv = apr_thread_mutex_create(&pool->mutex,
                APR_THREAD_MUTEX_NESTED, pool)) != APR_SUCCESS) {
            free(pool);
            return rv;
        }
#endif /* APR_HAS_THREADS */
    }
    else {
#if APR_HAS_THREADS
        if (parent)
            pool->mutex = parent->mutex;
#endif /* APR_HAS_THREADS */
    }

    *newpool = pool;

#if (APR_POOL_DEBUG & APR_POOL_DEBUG_VERBOSE)
    apr_pool_log_event(pool, "CREATE", file_line, 1);
#endif /* (APR_POOL_DEBUG & APR_POOL_DEBUG_VERBOSE) */

    return APR_SUCCESS;
}


/*
 * "Print" functions (debug)
 */

struct psprintf_data {
    apr_vformatter_buff_t vbuff;
    char      *mem;
    apr_size_t size;
};

static int psprintf_flush(apr_vformatter_buff_t *vbuff)
{
    struct psprintf_data *ps = (struct psprintf_data *)vbuff;
    apr_size_t size;

    size = ps->vbuff.curpos - ps->mem;

    ps->size <<= 1;
    if ((ps->mem = realloc(ps->mem, ps->size)) == NULL)
        return -1;

    ps->vbuff.curpos = ps->mem + size;
    ps->vbuff.endpos = ps->mem + ps->size - 1;

    return 0;
}

APR_DECLARE(char *) apr_pvsprintf(apr_pool_t *pool, const char *fmt, va_list ap)
{
    struct psprintf_data ps;
    debug_node_t *node;

    apr_pool_check_integrity(pool);

    ps.size = 64;
    ps.mem = malloc(ps.size);
    ps.vbuff.curpos  = ps.mem;

    /* Save a byte for the NUL terminator */
    ps.vbuff.endpos = ps.mem + ps.size - 1;

    if (apr_vformatter(psprintf_flush, &ps.vbuff, fmt, ap) == -1) {
        if (pool->abort_fn)
            pool->abort_fn(APR_ENOMEM);

        return NULL;
    }

    *ps.vbuff.curpos++ = '\0';

    /*
     * Link the node in
     */
    node = pool->nodes;
    if (node == NULL || node->index == 64) {
        if ((node = malloc(SIZEOF_DEBUG_NODE_T)) == NULL) {
            if (pool->abort_fn)
                pool->abort_fn(APR_ENOMEM);

            return NULL;
        }

        node->next = pool->nodes;
        pool->nodes = node;
        node->index = 0;
    }

    node->beginp[node->index] = ps.mem;
    node->endp[node->index] = ps.mem + ps.size;
    node->index++;

    return ps.mem;
}


/*
 * Debug functions
 */

APR_DECLARE(void) apr_pool_join(apr_pool_t *p, apr_pool_t *sub)
{
}

static int pool_find(apr_pool_t *pool, void *data)
{
    void **pmem = (void **)data;
    debug_node_t *node;
    apr_uint32_t index;

    node = pool->nodes;

    while (node) {
        for (index = 0; index < node->index; index++) {
             if (node->beginp[index] <= *pmem
                 && node->endp[index] > *pmem) {
                 *pmem = pool;
                 return 1;
             }
        }

        node = node->next;
    }

    return 0;
}

APR_DECLARE(apr_pool_t *) apr_pool_find(const void *mem)
{
    void *pool = (void *)mem;

    if (apr_pool_walk_tree(global_pool, pool_find, &pool))
        return pool;

    return NULL;
}

static int pool_num_bytes(apr_pool_t *pool, void *data)
{
    apr_size_t *psize = (apr_size_t *)data;
    debug_node_t *node;
    apr_uint32_t index;

    node = pool->nodes;

    while (node) {
        for (index = 0; index < node->index; index++) {
            *psize += (char *)node->endp[index] - (char *)node->beginp[index];
        }

        node = node->next;
    }

    return 0;
}

APR_DECLARE(apr_size_t) apr_pool_num_bytes(apr_pool_t *pool, int recurse)
{
    apr_size_t size = 0;

    if (!recurse) {
        pool_num_bytes(pool, &size);

        return size;
    }

    apr_pool_walk_tree(pool, pool_num_bytes, &size);

    return size;
}

APR_DECLARE(void) apr_pool_lock(apr_pool_t *pool, int flag)
{
}

#endif /* !APR_POOL_DEBUG */


/*
 * "Print" functions (common)
 */

APR_DECLARE_NONSTD(char *) apr_psprintf(apr_pool_t *p, const char *fmt, ...)
{
    va_list ap;
    char *res;

    va_start(ap, fmt);
    res = apr_pvsprintf(p, fmt, ap);
    va_end(ap);
    return res;
}

/*
 * Pool Properties
 */

APR_DECLARE(void) apr_pool_abort_set(apr_abortfunc_t abort_fn,
                                     apr_pool_t *pool)
{
    pool->abort_fn = abort_fn;
}

APR_DECLARE(apr_abortfunc_t) apr_pool_abort_get(apr_pool_t *pool)
{
    return pool->abort_fn;
}

APR_DECLARE(apr_pool_t *) apr_pool_parent_get(apr_pool_t *pool)
{
#ifdef NETWARE
    /* On NetWare, don't return the global_pool, return the application pool 
       as the top most pool */
    if (pool->parent == global_pool)
        return NULL;
    else
#endif
    return pool->parent;
}

APR_DECLARE(apr_allocator_t *) apr_pool_allocator_get(apr_pool_t *pool)
{
    return pool->allocator;
}

/* return TRUE if a is an ancestor of b
 * NULL is considered an ancestor of all pools
 */
APR_DECLARE(int) apr_pool_is_ancestor(apr_pool_t *a, apr_pool_t *b)
{
    if (a == NULL)
        return 1;

    while (b) {
        if (a == b)
            return 1;

        b = b->parent;
    }

    return 0;
}

APR_DECLARE(void) apr_pool_tag(apr_pool_t *pool, const char *tag)
{
    pool->tag = tag;
}


/*
 * User data management
 */

APR_DECLARE(apr_status_t) apr_pool_userdata_set(const void *data, const char *key,
                                                apr_status_t (*cleanup) (void *),
                                                apr_pool_t *pool)
{
#if APR_POOL_DEBUG
    apr_pool_check_integrity(pool);
#endif /* APR_POOL_DEBUG */

    if (pool->user_data == NULL)