astobj2.c

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/*
 * astobj2 - replacement containers for asterisk data structures.
 *
 * Copyright (C) 2006 Marta Carbone, Luigi Rizzo - Univ. di Pisa, Italy
 *
 * See http://www.asterisk.org for more information about
 * the Asterisk project. Please do not directly contact
 * any of the maintainers of this project for assistance;
 * the project provides a web site, mailing lists and IRC
 * channels for your use.
 *
 * This program is free software, distributed under the terms of
 * the GNU General Public License Version 2. See the LICENSE file
 * at the top of the source tree.
 */
 
/*! \file
 *
 * \brief Functions implementing astobj2 objects.
 *
 * \author Richard Mudgett <rmudgett@digium.com>
 */
 
/*** MODULEINFO
    <support_level>core</support_level>
 ***/
 
/* This reduces the size of lock structures within astobj2 objects when
 * DEBUG_THREADS is not defined. */
#define DEBUG_THREADS_LOOSE_ABI
 
#include "asterisk.h"
 
#include "asterisk/_private.h"
#include "asterisk/astobj2.h"
#include "astobj2_private.h"
#include "astobj2_container_private.h"
#include "asterisk/cli.h"
#include "asterisk/paths.h"
 
/* Use ast_log_safe in place of ast_log. */
#define ast_log ast_log_safe
 
static FILE *ref_log;
 
/*!
 * astobj2 objects are always preceded by this data structure,
 * which contains a reference counter,
 * option flags and a pointer to a destructor.
 * The refcount is used to decide when it is time to
 * invoke the destructor.
 * The magic number is used for consistency check.
 */
struct __priv_data {
    ao2_destructor_fn destructor_fn;
    /*! This field is used for astobj2 and ao2_weakproxy objects to reference each other */
    void *weakptr;
#if defined(AO2_DEBUG)
    /*! User data size for stats */
    size_t data_size;
#endif
    /*! Number of references held for this object */
    int32_t ref_counter;
    /*!
     * \brief The ao2 object option flags.
     *
     * \note This field is constant after object creation.  It shares
     *       a uint32_t with \p lockused and \p magic.
     */
    uint32_t options:3;
    /*!
     * \brief Set to 1 when the lock is used if refdebug is enabled.
     *
     * \note This bit-field may be modified after object creation.  It
     *       shares a uint32_t with \ref options and \ref magic.
     */
    uint32_t lockused:1;
    /*!
     * \brief Magic number.
     *
     * This is used to verify that a pointer is a valid astobj2 or ao2_weak
     * reference.
     *
     * \note This field is constant after object creation.  It shares
     *       a uint32_t with \p options and \p lockused.
     *
     * \warning Stealing bits for any additional writable fields would cause
     *          reentrancy issues if using bitfields.  If any additional
     *          writable bits are required in the future we will need to put
     *          all bitfields into a single 'uint32_t flags' field and use
     *          atomic operations from \file lock.h to perform writes.
     */
    uint32_t magic:28;
};
 
#define AO2_MAGIC   0xa70b123
#define AO2_WEAK    0xa70b122
#define IS_AO2_MAGIC_BAD(p) (AO2_MAGIC != (p->priv_data.magic | 1))
 
/*!
 * What an astobj2 object looks like: fixed-size private data
 * followed by variable-size user data.
 */
struct astobj2 {
    struct __priv_data priv_data;
    void *user_data[0];
};
 
struct ao2_weakproxy_notification {
    ao2_weakproxy_notification_cb cb;
    void *data;
    AST_LIST_ENTRY(ao2_weakproxy_notification) list;
};
 
struct ao2_lock_priv {
    ast_mutex_t lock;
};
 
/* AstObj2 with recursive lock. */
struct astobj2_lock {
    struct ao2_lock_priv mutex;
    struct __priv_data priv_data;
    void *user_data[0];
};
 
struct ao2_rwlock_priv {
    ast_rwlock_t lock;
    /*! Count of the number of threads holding a lock on this object. -1 if it is the write lock. */
    int num_lockers;
};
 
/* AstObj2 with RW lock. */
struct astobj2_rwlock {
    struct ao2_rwlock_priv rwlock;
    struct __priv_data priv_data;
    void *user_data[0];
};
 
struct ao2_lockobj_priv {
    void *lock;
};
 
/* AstObj2 with locking provided by a separate object. */
struct astobj2_lockobj {
    struct ao2_lockobj_priv lockobj;
    struct __priv_data priv_data;
    void *user_data[0];
};
 
#ifdef AO2_DEBUG
struct ao2_stats ao2;
#endif
 
#define INTERNAL_OBJ_MUTEX(user_data) \
    ((struct astobj2_lock *) (((char *) (user_data)) - sizeof(struct astobj2_lock)))
 
#define INTERNAL_OBJ_RWLOCK(user_data) \
    ((struct astobj2_rwlock *) (((char *) (user_data)) - sizeof(struct astobj2_rwlock)))
 
#define INTERNAL_OBJ_LOCKOBJ(user_data) \
    ((struct astobj2_lockobj *) (((char *) (user_data)) - sizeof(struct astobj2_lockobj)))
 
#define INTERNAL_OBJ(user_data) \
    (struct astobj2 *) ((char *) user_data - sizeof(struct astobj2))
 
/*!
 * \brief convert from a pointer _p to a user-defined object
 *
 * \return the pointer to the astobj2 structure
 */
#define __INTERNAL_OBJ_CHECK(user_data, file, line, func) \
    ({ \
        struct astobj2 *p ## __LINE__; \
        if (!user_data \
            || !(p ## __LINE__ = INTERNAL_OBJ(user_data)) \
            || IS_AO2_MAGIC_BAD(p ## __LINE__)) { \
            log_bad_ao2(user_data, file, line, func); \
            p ## __LINE__ = NULL; \
        } \
        (p ## __LINE__); \
    })
 
#define INTERNAL_OBJ_CHECK(user_data) \
    __INTERNAL_OBJ_CHECK(user_data, __FILE__, __LINE__, __PRETTY_FUNCTION__)
 
/*!
 * \brief convert from a pointer _p to an astobj2 object
 *
 * \return the pointer to the user-defined portion.
 */
#define EXTERNAL_OBJ(_p)    ((_p) == NULL ? NULL : (_p)->user_data)
 
int internal_is_ao2_object(void *user_data)
{
    struct astobj2 *p;
 
    if (!user_data) {
        return 0;
    }
 
    p = INTERNAL_OBJ(user_data);
 
    return !p || IS_AO2_MAGIC_BAD(p) ? 0 : 1;
}
 
void log_bad_ao2(void *user_data, const char *file, int line, const char *func)
{
    struct astobj2 *p;
    char bad_magic[100];
 
    if (!user_data) {
        __ast_assert_failed(0, "user_data is NULL", file, line, func);
        return;
    }
 
    p = INTERNAL_OBJ(user_data);
    snprintf(bad_magic, sizeof(bad_magic), "bad magic number 0x%x for object %p",
        p->priv_data.magic, user_data);
    __ast_assert_failed(0, bad_magic, file, line, func);
}
 
int __ao2_lock(void *user_data, enum ao2_lock_req lock_how, const char *file, const char *func, int line, const char *var)
{
    struct astobj2 *obj = __INTERNAL_OBJ_CHECK(user_data, file, line, func);
    struct astobj2_lock *obj_mutex;
    struct astobj2_rwlock *obj_rwlock;
    struct astobj2_lockobj *obj_lockobj;
    int res = 0;
 
    if (obj == NULL) {
        return -1;
    }
 
    if (ref_log) {
        obj->priv_data.lockused  = 1;
    }
 
    switch (obj->priv_data.options & AO2_ALLOC_OPT_LOCK_MASK) {
    case AO2_ALLOC_OPT_LOCK_MUTEX:
        obj_mutex = INTERNAL_OBJ_MUTEX(user_data);
        res = __ast_pthread_mutex_lock(file, line, func, var, &obj_mutex->mutex.lock);
#ifdef AO2_DEBUG
        if (!res) {
            ast_atomic_fetchadd_int(&ao2.total_locked, 1);
        }
#endif
        break;
    case AO2_ALLOC_OPT_LOCK_RWLOCK:
        obj_rwlock = INTERNAL_OBJ_RWLOCK(user_data);
        switch (lock_how) {
        case AO2_LOCK_REQ_MUTEX:
        case AO2_LOCK_REQ_WRLOCK:
            res = __ast_rwlock_wrlock(file, line, func, &obj_rwlock->rwlock.lock, var);
            if (!res) {
                ast_atomic_fetchadd_int(&obj_rwlock->rwlock.num_lockers, -1);
#ifdef AO2_DEBUG
                ast_atomic_fetchadd_int(&ao2.total_locked, 1);
#endif
            }
            break;
        case AO2_LOCK_REQ_RDLOCK:
            res = __ast_rwlock_rdlock(file, line, func, &obj_rwlock->rwlock.lock, var);
            if (!res) {
                ast_atomic_fetchadd_int(&obj_rwlock->rwlock.num_lockers, +1);
#ifdef AO2_DEBUG
                ast_atomic_fetchadd_int(&ao2.total_locked, 1);
#endif
            }
            break;
        }
        break;
    case AO2_ALLOC_OPT_LOCK_NOLOCK:
        /* The ao2 object has no lock. */
        break;
    case AO2_ALLOC_OPT_LOCK_OBJ:
        obj_lockobj = INTERNAL_OBJ_LOCKOBJ(user_data);
        res = __ao2_lock(obj_lockobj->lockobj.lock, lock_how, file, func, line, var);
        break;
    default:
        ast_log(__LOG_ERROR, file, line, func, "Invalid lock option on ao2 object %p\n",
            user_data);
        return -1;
    }
 
    return res;
}
 
int __ao2_unlock(void *user_data, const char *file, const char *func, int line, const char *var)
{
    struct astobj2 *obj = __INTERNAL_OBJ_CHECK(user_data, file, line, func);
    struct astobj2_lock *obj_mutex;
    struct astobj2_rwlock *obj_rwlock;
    struct astobj2_lockobj *obj_lockobj;
    int res = 0;
    int current_value;
 
    if (obj == NULL) {
        return -1;
    }
 
    switch (obj->priv_data.options & AO2_ALLOC_OPT_LOCK_MASK) {
    case AO2_ALLOC_OPT_LOCK_MUTEX:
        obj_mutex = INTERNAL_OBJ_MUTEX(user_data);
        res = __ast_pthread_mutex_unlock(file, line, func, var, &obj_mutex->mutex.lock);
#ifdef AO2_DEBUG
        if (!res) {
            ast_atomic_fetchadd_int(&ao2.total_locked, -1);
        }
#endif
        break;
    case AO2_ALLOC_OPT_LOCK_RWLOCK:
        obj_rwlock = INTERNAL_OBJ_RWLOCK(user_data);
 
        current_value = ast_atomic_fetchadd_int(&obj_rwlock->rwlock.num_lockers, -1) - 1;
        if (current_value < 0) {
            /* It was a WRLOCK that we are unlocking.  Fix the count. */
            ast_atomic_fetchadd_int(&obj_rwlock->rwlock.num_lockers, -current_value);
        }
        res = __ast_rwlock_unlock(file, line, func, &obj_rwlock->rwlock.lock, var);
#ifdef AO2_DEBUG
        if (!res) {
            ast_atomic_fetchadd_int(&ao2.total_locked, -1);
        }
#endif
        break;
    case AO2_ALLOC_OPT_LOCK_NOLOCK:
        /* The ao2 object has no lock. */
        break;
    case AO2_ALLOC_OPT_LOCK_OBJ:
        obj_lockobj = INTERNAL_OBJ_LOCKOBJ(user_data);
        res = __ao2_unlock(obj_lockobj->lockobj.lock, file, func, line, var);
        break;
    default:
        ast_log(__LOG_ERROR, file, line, func, "Invalid lock option on ao2 object %p\n",
            user_data);
        res = -1;
        break;
    }
    return res;
}
 
int __ao2_trylock(void *user_data, enum ao2_lock_req lock_how, const char *file, const char *func, int line, const char *var)
{
    struct astobj2 *obj = __INTERNAL_OBJ_CHECK(user_data, file, line, func);
    struct astobj2_lock *obj_mutex;
    struct astobj2_rwlock *obj_rwlock;
    struct astobj2_lockobj *obj_lockobj;
    int res = 0;
 
    if (obj == NULL) {
        return -1;
    }
 
    if (ref_log) {
        obj->priv_data.lockused  = 1;
    }
 
    switch (obj->priv_data.options & AO2_ALLOC_OPT_LOCK_MASK) {
    case AO2_ALLOC_OPT_LOCK_MUTEX:
        obj_mutex = INTERNAL_OBJ_MUTEX(user_data);
        res = __ast_pthread_mutex_trylock(file, line, func, var, &obj_mutex->mutex.lock);
#ifdef AO2_DEBUG
        if (!res) {
            ast_atomic_fetchadd_int(&ao2.total_locked, 1);
        }
#endif
        break;
    case AO2_ALLOC_OPT_LOCK_RWLOCK:
        obj_rwlock = INTERNAL_OBJ_RWLOCK(user_data);
        switch (lock_how) {
        case AO2_LOCK_REQ_MUTEX:
        case AO2_LOCK_REQ_WRLOCK:
            res = __ast_rwlock_trywrlock(file, line, func, &obj_rwlock->rwlock.lock, var);
            if (!res) {
                ast_atomic_fetchadd_int(&obj_rwlock->rwlock.num_lockers, -1);
#ifdef AO2_DEBUG
                ast_atomic_fetchadd_int(&ao2.total_locked, 1);
#endif
            }
            break;
        case AO2_LOCK_REQ_RDLOCK:
            res = __ast_rwlock_tryrdlock(file, line, func, &obj_rwlock->rwlock.lock, var);
            if (!res) {
                ast_atomic_fetchadd_int(&obj_rwlock->rwlock.num_lockers, +1);
#ifdef AO2_DEBUG
                ast_atomic_fetchadd_int(&ao2.total_locked, 1);
#endif
            }
            break;
        }
        break;
    case AO2_ALLOC_OPT_LOCK_NOLOCK:
        /* The ao2 object has no lock. */
        return 0;
    case AO2_ALLOC_OPT_LOCK_OBJ:
        obj_lockobj = INTERNAL_OBJ_LOCKOBJ(user_data);
        res = __ao2_trylock(obj_lockobj->lockobj.lock, lock_how, file, func, line, var);
        break;
    default:
        ast_log(__LOG_ERROR, file, line, func, "Invalid lock option on ao2 object %p\n",
            user_data);
        return -1;
    }
 
    return res;
}
 
/*!
 * \internal
 * \brief Adjust an object's lock to the requested level.
 *
 * \param user_data An ao2 object to adjust lock level.
 * \param lock_how What level to adjust lock.
 * \param keep_stronger TRUE if keep original lock level if it is stronger.
 *
 * \pre The ao2 object is already locked.
 *
 * \details
 * An ao2 object with a RWLOCK will have its lock level adjusted
 * to the specified level if it is not already there.  An ao2
 * object with a different type of lock is not affected.
 *
 * \return Original lock level.
 */
enum ao2_lock_req __adjust_lock(void *user_data, enum ao2_lock_req lock_how, int keep_stronger)
{
    struct astobj2 *obj = INTERNAL_OBJ(user_data);
    struct astobj2_rwlock *obj_rwlock;
    struct astobj2_lockobj *obj_lockobj;
    enum ao2_lock_req orig_lock;
 
    switch (obj->priv_data.options & AO2_ALLOC_OPT_LOCK_MASK) {
    case AO2_ALLOC_OPT_LOCK_RWLOCK:
        obj_rwlock = INTERNAL_OBJ_RWLOCK(user_data);
        if (obj_rwlock->rwlock.num_lockers < 0) {
            orig_lock = AO2_LOCK_REQ_WRLOCK;
        } else {
            orig_lock = AO2_LOCK_REQ_RDLOCK;
        }
        switch (lock_how) {
        case AO2_LOCK_REQ_MUTEX:
            lock_how = AO2_LOCK_REQ_WRLOCK;
            /* Fall through */
        case AO2_LOCK_REQ_WRLOCK:
            if (lock_how != orig_lock) {
                /* Switch from read lock to write lock. */
                ao2_unlock(user_data);
                ao2_wrlock(user_data);
            }
            break;
        case AO2_LOCK_REQ_RDLOCK:
            if (!keep_stronger && lock_how != orig_lock) {
                /* Switch from write lock to read lock. */
                ao2_unlock(user_data);
                ao2_rdlock(user_data);
            }
            break;
        }
        break;
    case AO2_ALLOC_OPT_LOCK_OBJ:
        obj_lockobj = INTERNAL_OBJ_LOCKOBJ(user_data);
        orig_lock = __adjust_lock(obj_lockobj->lockobj.lock, lock_how, keep_stronger);
        break;
    default:
        ast_log(LOG_ERROR, "Invalid lock option on ao2 object %p\n", user_data);
        /* Fall through */
    case AO2_ALLOC_OPT_LOCK_NOLOCK:
    case AO2_ALLOC_OPT_LOCK_MUTEX:
        orig_lock = AO2_LOCK_REQ_MUTEX;
        break;
    }
 
    return orig_lock;
}
 
void *ao2_object_get_lockaddr(void *user_data)
{
    struct astobj2 *obj;
    struct astobj2_lock *obj_mutex;
 
    obj = INTERNAL_OBJ_CHECK(user_data);
 
    if (obj == NULL) {
        return NULL;
    }
 
    switch (obj->priv_data.options & AO2_ALLOC_OPT_LOCK_MASK) {
    case AO2_ALLOC_OPT_LOCK_MUTEX:
        obj_mutex = INTERNAL_OBJ_MUTEX(user_data);
        return &obj_mutex->mutex.lock;
    default:
        break;
    }
 
    return NULL;
}
 
int __ao2_ref(void *user_data, int delta,
    const char *tag, const char *file, int line, const char *func)
{
    struct astobj2 *obj = __INTERNAL_OBJ_CHECK(user_data, file, line, func);
    struct astobj2_lock *obj_mutex;
    struct astobj2_rwlock *obj_rwlock;
    struct astobj2_lockobj *obj_lockobj;
    int32_t current_value;
    int32_t ret;
    uint32_t privdataoptions;
    struct ao2_weakproxy *weakproxy = NULL;
    const char *lock_state;
 
    if (obj == NULL) {
        if (ref_log && user_data) {
            fprintf(ref_log, "%p,%d,%d,%s,%d,%s,**invalid**,%s\n",
                user_data, delta, ast_get_tid(), file, line, func, tag ?: "");
            fflush(ref_log);
        }
        return -1;
    }
 
    /* if delta is 0, just return the refcount */
    if (delta == 0) {
        return obj->priv_data.ref_counter;
    }
 
    if (delta < 0 && obj->priv_data.magic == AO2_MAGIC && (weakproxy = obj->priv_data.weakptr)) {
        ao2_lock(weakproxy);
    }
 
    /* we modify with an atomic operation the reference counter */
    ret = ast_atomic_fetch_add(&obj->priv_data.ref_counter, delta, __ATOMIC_RELAXED);
    current_value = ret + delta;
 
#ifdef AO2_DEBUG
    ast_atomic_fetchadd_int(&ao2.total_refs, delta);
#endif
 
    if (weakproxy) {
        struct ao2_weakproxy cbs;
 
        if (current_value == 1) {
            /* The only remaining reference is the one owned by the weak object */
            struct astobj2 *internal_weakproxy;
 
            internal_weakproxy = INTERNAL_OBJ_CHECK(weakproxy);
 
            /* Unlink the obj from the weak proxy */
            internal_weakproxy->priv_data.weakptr = NULL;
            obj->priv_data.weakptr = NULL;
 
            /* transfer list to local copy so callbacks are run with weakproxy unlocked. */
            cbs.destroyed_cb = weakproxy->destroyed_cb;
            AST_LIST_HEAD_INIT_NOLOCK(&weakproxy->destroyed_cb);
 
            /* weak is already unlinked from obj so this won't recurse */
            ao2_ref(user_data, -1);
        }
 
        ao2_unlock(weakproxy);
 
        if (current_value == 1) {
            struct ao2_weakproxy_notification *destroyed_cb;
 
            /* Notify the subscribers that weakproxy now points to NULL. */
            while ((destroyed_cb = AST_LIST_REMOVE_HEAD(&cbs.destroyed_cb, list))) {
                destroyed_cb->cb(weakproxy, destroyed_cb->data);
                ast_free(destroyed_cb);
            }
 
            ao2_ref(weakproxy, -1);
        }
    }
 
    if (0 < current_value) {
        /* The object still lives. */
#define EXCESSIVE_REF_COUNT     100000
 
        if (EXCESSIVE_REF_COUNT <= current_value && ret < EXCESSIVE_REF_COUNT) {
            char excessive_ref_buf[100];
 
            /* We just reached or went over the excessive ref count trigger */
            snprintf(excessive_ref_buf, sizeof(excessive_ref_buf),
                "Excessive refcount %d reached on ao2 object %p",
                (int)current_value, user_data);
            ast_log(__LOG_ERROR, file, line, func, "%s\n", excessive_ref_buf);
 
            __ast_assert_failed(0, excessive_ref_buf, file, line, func);
        }
 
        if (ref_log && !(obj->priv_data.options & AO2_ALLOC_OPT_NO_REF_DEBUG)) {
            fprintf(ref_log, "%p,%s%d,%d,%s,%d,%s,%d,%s\n", user_data,
                (delta < 0 ? "" : "+"), delta, ast_get_tid(),
                file, line, func, (int)ret, tag ?: "");
            fflush(ref_log);
        }
        return ret;
    }
 
    /* this case must never happen */
    if (current_value < 0) {
        ast_log(__LOG_ERROR, file, line, func,
            "Invalid refcount %d on ao2 object %p\n", (int)current_value, user_data);
        if (ref_log) {
            /* Log to ref_log even if AO2_ALLOC_OPT_NO_REF_DEBUG */
            fprintf(ref_log, "%p,%d,%d,%s,%d,%s,**invalid**,%s\n",
                user_data, delta, ast_get_tid(), file, line, func, tag ?: "");
            fflush(ref_log);
        }
        ast_assert(0);
        /* stop here even if assert doesn't DO_CRASH */
        return -1;
    }
 
    /* last reference, destroy the object */
    if (obj->priv_data.destructor_fn != NULL) {
        obj->priv_data.destructor_fn(user_data);
    }
 
#ifdef AO2_DEBUG
    ast_atomic_fetchadd_int(&ao2.total_mem, - obj->priv_data.data_size);
    ast_atomic_fetchadd_int(&ao2.total_objects, -1);
#endif
 
    /* In case someone uses an object after it's been freed */
    obj->priv_data.magic = 0;
    /* Save the options locally so the ref_log print at the end doesn't access freed data */
    privdataoptions = obj->priv_data.options;
 
    switch (obj->priv_data.options & AO2_ALLOC_OPT_LOCK_MASK) {
    case AO2_ALLOC_OPT_LOCK_MUTEX:
        obj_mutex = INTERNAL_OBJ_MUTEX(user_data);
        lock_state = obj->priv_data.lockused ? "used" : "unused";
        ast_mutex_destroy(&obj_mutex->mutex.lock);
 
        ast_free(obj_mutex);
        break;
    case AO2_ALLOC_OPT_LOCK_RWLOCK:
        obj_rwlock = INTERNAL_OBJ_RWLOCK(user_data);
        lock_state = obj->priv_data.lockused ? "used" : "unused";
        ast_rwlock_destroy(&obj_rwlock->rwlock.lock);
 
        ast_free(obj_rwlock);
        break;
    case AO2_ALLOC_OPT_LOCK_NOLOCK:
        lock_state = "none";
        ast_free(obj);
        break;
    case AO2_ALLOC_OPT_LOCK_OBJ:
        obj_lockobj = INTERNAL_OBJ_LOCKOBJ(user_data);
        lock_state = obj->priv_data.lockused ? "used" : "unused";
        ao2_t_ref(obj_lockobj->lockobj.lock, -1, "release lockobj");
 
        ast_free(obj_lockobj);
        break;
    default:
        ast_log(__LOG_ERROR, file, line, func,
            "Invalid lock option on ao2 object %p\n", user_data);
        lock_state = "invalid";
        break;
    }
 
    if (ref_log && !(privdataoptions & AO2_ALLOC_OPT_NO_REF_DEBUG)) {
        fprintf(ref_log, "%p,%d,%d,%s,%d,%s,**destructor**lock-state:%s**,%s\n",
            user_data, delta, ast_get_tid(), file, line, func, lock_state, tag ?: "");
        fflush(ref_log);
    }
 
    return ret;
}
 
void __ao2_cleanup_debug(void *obj, const char *tag, const char *file, int line, const char *function)
{
    if (obj) {
        __ao2_ref(obj, -1, tag, file, line, function);
    }
}
 
void __ao2_cleanup(void *obj)
{
    if (obj) {
        ao2_ref(obj, -1);
    }
}
 
static void *internal_ao2_alloc(size_t data_size, ao2_destructor_fn destructor_fn, unsigned int options,
    void *lockobj, const char *tag, const char *file, int line, const char *func)
{
    /* allocation */
    struct astobj2 *obj;
    struct astobj2_lock *obj_mutex;
    struct astobj2_rwlock *obj_rwlock;
    struct astobj2_lockobj *obj_lockobj;
    size_t overhead;
 
    switch (options & AO2_ALLOC_OPT_LOCK_MASK) {
    case AO2_ALLOC_OPT_LOCK_MUTEX:
        overhead = sizeof(*obj_mutex);
        obj_mutex = __ast_calloc(1, overhead + data_size, file, line, func);
        if (obj_mutex == NULL) {
            return NULL;
        }
 
        ast_mutex_init(&obj_mutex->mutex.lock);
        obj = (struct astobj2 *) &obj_mutex->priv_data;
        break;
    case AO2_ALLOC_OPT_LOCK_RWLOCK:
        overhead = sizeof(*obj_rwlock);
        obj_rwlock = __ast_calloc(1, overhead + data_size, file, line, func);
        if (obj_rwlock == NULL) {
            return NULL;
        }
 
        ast_rwlock_init(&obj_rwlock->rwlock.lock);
        obj = (struct astobj2 *) &obj_rwlock->priv_data;
        break;
    case AO2_ALLOC_OPT_LOCK_NOLOCK:
        overhead = sizeof(*obj);
        obj = __ast_calloc(1, overhead + data_size, file, line, func);
        if (obj == NULL) {
            return NULL;
        }
        break;
    case AO2_ALLOC_OPT_LOCK_OBJ:
        lockobj = ao2_t_bump(lockobj, "set lockobj");
        if (!lockobj) {
            ast_log(__LOG_ERROR, file, line, func, "AO2_ALLOC_OPT_LOCK_OBJ requires a non-NULL lockobj.\n");
            return NULL;
        }
 
        overhead = sizeof(*obj_lockobj);
        obj_lockobj = __ast_calloc(1, overhead + data_size, file, line, func);
        if (obj_lockobj == NULL) {
            ao2_t_ref(lockobj, -1, "release lockobj for failed alloc");
            return NULL;
        }
 
        obj_lockobj->lockobj.lock = lockobj;
        obj = (struct astobj2 *) &obj_lockobj->priv_data;
        break;
    default:
        /* Invalid option value. */
        ast_log(__LOG_DEBUG, file, line, func, "Invalid lock option requested\n");
        return NULL;
    }
 
    /* Initialize common ao2 values. */
    obj->priv_data.destructor_fn = destructor_fn;   /* can be NULL */
    obj->priv_data.ref_counter = 1;
    obj->priv_data.options = options;
    obj->priv_data.magic = AO2_MAGIC;
 
#ifdef AO2_DEBUG
    obj->priv_data.data_size = data_size;
    ast_atomic_fetchadd_int(&ao2.total_objects, 1);
    ast_atomic_fetchadd_int(&ao2.total_mem, data_size);
    ast_atomic_fetchadd_int(&ao2.total_refs, 1);
#endif
 
    if (ref_log && !(obj->priv_data.options & AO2_ALLOC_OPT_NO_REF_DEBUG)) {
        fprintf(ref_log, "%p,+1,%d,%s,%d,%s,**constructor**%zu**%zu**,%s\n",
            EXTERNAL_OBJ(obj), ast_get_tid(), file, line, func, overhead, data_size, tag ?: "");
        fflush(ref_log);
    }
 
    /* return a pointer to the user data */
    return EXTERNAL_OBJ(obj);
}
 
void *__ao2_alloc(size_t data_size, ao2_destructor_fn destructor_fn, unsigned int options,
    const char *tag, const char *file, int line, const char *func)
{
    return internal_ao2_alloc(data_size, destructor_fn, options, NULL, tag, file, line, func);
}
 
void *__ao2_alloc_with_lockobj(size_t data_size, ao2_destructor_fn destructor_fn, void *lockobj,
    const char *tag, const char *file, int line, const char *func)
{
    return internal_ao2_alloc(data_size, destructor_fn, AO2_ALLOC_OPT_LOCK_OBJ, lockobj,
        tag, file, line, func);
}
 
unsigned int ao2_options_get(void *obj)
{
    struct astobj2 *orig_obj;
 
    orig_obj = INTERNAL_OBJ_CHECK(obj);
    if (!orig_obj) {
        return 0;
    }
    return orig_obj->priv_data.options;
}
 
 
void *__ao2_weakproxy_alloc(size_t data_size, ao2_destructor_fn destructor_fn,
    const char *tag, const char *file, int line, const char *func)
{
    struct ao2_weakproxy *weakproxy;
 
    if (data_size < sizeof(*weakproxy)) {
        ast_assert(0);
        ast_log(LOG_ERROR, "Requested data_size smaller than minimum.\n");
        return NULL;
    }
 
    weakproxy = __ao2_alloc(data_size, destructor_fn, AO2_ALLOC_OPT_LOCK_MUTEX,
        tag, file, line, func);
 
    if (weakproxy) {
        struct astobj2 *weakproxy_internal;
 
        /* Just created weakproxy, no need to check if it's valid. */
        weakproxy_internal = INTERNAL_OBJ(weakproxy);
        weakproxy_internal->priv_data.magic = AO2_WEAK;
    }
 
    return weakproxy;
}
 
int __ao2_weakproxy_set_object(void *weakproxy, void *obj, int flags,
    const char *tag, const char *file, int line, const char *func)
{
    struct astobj2 *weakproxy_internal = __INTERNAL_OBJ_CHECK(weakproxy, file, line, func);
    struct astobj2 *obj_internal = __INTERNAL_OBJ_CHECK(obj, file, line, func);
    int ret = -1;
 
    if (!weakproxy_internal
        || weakproxy_internal->priv_data.magic != AO2_WEAK) {
        return -1;
    }
 
    if (!obj_internal
        || obj_internal->priv_data.weakptr
        || obj_internal->priv_data.magic != AO2_MAGIC) {
        return -1;
    }
 
    if (!(flags & OBJ_NOLOCK)) {
        ao2_lock(weakproxy);
    }
 
    if (!weakproxy_internal->priv_data.weakptr) {
        __ao2_ref(obj, +1, tag, file, line, func);
        __ao2_ref(weakproxy, +1, tag, file, line, func);
 
        weakproxy_internal->priv_data.weakptr = obj;
        obj_internal->priv_data.weakptr = weakproxy;
 
        ret = 0;
    }
 
    if (!(flags & OBJ_NOLOCK)) {
        ao2_unlock(weakproxy);
        /* It is possible for obj to be accessed now.  It's allowed
         * for weakproxy to already be in a container.  Another thread
         * could have been waiting for a lock on weakproxy to retrieve
         * the object.
         */
    }
 
    return ret;
}
 
int __ao2_weakproxy_ref_object(void *weakproxy, int delta, int flags,
    const char *tag, const char *file, int line, const char *func)
{
    struct astobj2 *internal = __INTERNAL_OBJ_CHECK(weakproxy, file, line, func);
    int ret = -1;
 
    if (!internal || internal->priv_data.magic != AO2_WEAK) {
        /* This method is meant to be run on weakproxy objects! */
        return -2;
    }
 
    /* We have a weak object, grab lock. */
    if (!(flags & OBJ_NOLOCK)) {
        ao2_lock(weakproxy);
    }
 
    if (internal->priv_data.weakptr) {
        ret = __ao2_ref(internal->priv_data.weakptr, delta, tag, file, line, func);
    }
 
    if (!(flags & OBJ_NOLOCK)) {
        ao2_unlock(weakproxy);
    }
 
    return ret;
}
 
void *__ao2_weakproxy_get_object(void *weakproxy, int flags,
    const char *tag, const char *file, int line, const char *func)
{
    struct astobj2 *internal = __INTERNAL_OBJ_CHECK(weakproxy, file, line, func);
    void *obj;
 
    if (!internal || internal->priv_data.magic != AO2_WEAK) {
        /* This method is meant to be run on weakproxy objects! */
        return NULL;
    }
 
    /* We have a weak object, grab reference to object within lock */
    if (!(flags & OBJ_NOLOCK)) {
        ao2_lock(weakproxy);
    }
 
    obj = internal->priv_data.weakptr;
    if (obj) {
        __ao2_ref(obj, +1, tag, file, line, func);
    }
 
    if (!(flags & OBJ_NOLOCK)) {
        ao2_unlock(weakproxy);
    }
 
    return obj;
}
 
void *__ao2_get_weakproxy(void *obj, const char *tag, const char *file, int line, const char *func)
{
    struct astobj2 *obj_internal = __INTERNAL_OBJ_CHECK(obj, file, line, func);
 
    if (!obj_internal || obj_internal->priv_data.magic != AO2_MAGIC) {
        /* This method is meant to be run on normal ao2 objects! */
        return NULL;
    }
 
    if (!obj_internal->priv_data.weakptr) {
        return NULL;
    }
 
    __ao2_ref(obj_internal->priv_data.weakptr, +1, tag, file, line, func);
    return obj_internal->priv_data.weakptr;
}
 
int ao2_weakproxy_subscribe(void *weakproxy, ao2_weakproxy_notification_cb cb, void *data, int flags)
{
    struct astobj2 *weakproxy_internal = INTERNAL_OBJ_CHECK(weakproxy);
    int ret = -1;
    int hasobj;
 
    if (!weakproxy_internal || weakproxy_internal->priv_data.magic != AO2_WEAK) {
        return -1;
    }
 
    if (!(flags & OBJ_NOLOCK)) {
        ao2_lock(weakproxy);
    }
 
    hasobj = weakproxy_internal->priv_data.weakptr != NULL;
    if (hasobj) {
        struct ao2_weakproxy *weak = weakproxy;
        struct ao2_weakproxy_notification *sub = ast_calloc(1, sizeof(*sub));
 
        if (sub) {
            sub->cb = cb;
            sub->data = data;
            AST_LIST_INSERT_HEAD(&weak->destroyed_cb, sub, list);
            ret = 0;
        }
    }
 
    if (!(flags & OBJ_NOLOCK)) {
        ao2_unlock(weakproxy);
    }
 
    if (!hasobj) {
        cb(weakproxy, data);
        ret = 0;
    }
 
    return ret;
}
 
int ao2_weakproxy_unsubscribe(void *weakproxy, ao2_weakproxy_notification_cb destroyed_cb, void *data, int flags)
{
    struct astobj2 *internal_weakproxy = INTERNAL_OBJ_CHECK(weakproxy);
    struct ao2_weakproxy *weak;
    struct ao2_weakproxy_notification *sub;
    int ret = 0;
 
    if (!internal_weakproxy || internal_weakproxy->priv_data.magic != AO2_WEAK || !destroyed_cb) {
        return -1;
    }
 
    if (!(flags & OBJ_NOLOCK)) {
        ao2_lock(weakproxy);
    }
 
    weak = weakproxy;
    AST_LIST_TRAVERSE_SAFE_BEGIN(&weak->destroyed_cb, sub, list) {
        if (sub->cb == destroyed_cb && sub->data == data) {
            AST_LIST_REMOVE_CURRENT(list);
            ast_free(sub);
            ret++;
            if (!(flags & OBJ_MULTIPLE)) {
                break;
            }
        }
    }
    AST_LIST_TRAVERSE_SAFE_END;
 
    if (!(flags & OBJ_NOLOCK)) {
        ao2_unlock(weakproxy);
    }
 
    return ret;
}
 
 
#ifdef AO2_DEBUG
static int print_cb(void *obj, void *arg, int flag)
{
    struct ast_cli_args *a = (struct ast_cli_args *) arg;
    char *s = (char *)obj;
 
    ast_cli(a->fd, "string <%s>\n", s);
    return 0;
}
 
/*
 * Print stats
 */
static char *handle_astobj2_stats(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
{
    switch (cmd) {
    case CLI_INIT:
        e->command = "astobj2 show stats";
        e->usage = "Usage: astobj2 show stats\n"
               "       Show astobj2 show stats\n";
        return NULL;
    case CLI_GENERATE:
        return NULL;
    }
    ast_cli(a->fd, "Objects    : %d\n", ao2.total_objects);
    ast_cli(a->fd, "Containers : %d\n", ao2.total_containers);
    ast_cli(a->fd, "Memory     : %d\n", ao2.total_mem);
    ast_cli(a->fd, "Locked     : %d\n", ao2.total_locked);
    ast_cli(a->fd, "Refs       : %d\n", ao2.total_refs);
    return CLI_SUCCESS;
}
 
/*
 * This is testing code for astobj
 */
static char *handle_astobj2_test(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
{
    struct ao2_container *c1;
    struct ao2_container *c2;
    int i, lim;
    char *obj;
    static int prof_id = -1;
    struct ast_cli_args fake_args = { a->fd, 0, NULL };
 
    switch (cmd) {
    case CLI_INIT:
        e->command = "astobj2 test";
        e->usage = "Usage: astobj2 test <num>\n"
               "       Runs astobj2 test. Creates 'num' objects,\n"
               "       and test iterators, callbacks and maybe other stuff\n";
        return NULL;
    case CLI_GENERATE:
        return NULL;
    }
 
    if (a->argc != 3) {
        return CLI_SHOWUSAGE;
    }
 
    if (prof_id == -1) {
        prof_id = ast_add_profile("ao2_alloc", 0);
    }
 
    ast_cli(a->fd, "argc %d argv %s %s %s\n", a->argc, a->argv[0], a->argv[1], a->argv[2]);
    lim = atoi(a->argv[2]);
    ast_cli(a->fd, "called astobj_test\n");
 
    handle_astobj2_stats(e, CLI_HANDLER, &fake_args);
    /*
     * Allocate a list container.
     */
    c1 = ao2_t_container_alloc_list(AO2_ALLOC_OPT_LOCK_MUTEX, 0, NULL /* no sort */,
        NULL /* no callback */, "test");
    ast_cli(a->fd, "container allocated as %p\n", c1);
 
    /*
     * fill the container with objects.
     * ao2_alloc() gives us a reference which we pass to the
     * container when we do the insert.
     */
    for (i = 0; i < lim; i++) {
        ast_mark(prof_id, 1 /* start */);
        obj = ao2_t_alloc(80, NULL,"test");
        ast_mark(prof_id, 0 /* stop */);
        ast_cli(a->fd, "object %d allocated as %p\n", i, obj);
        sprintf(obj, "-- this is obj %d --", i);
        ao2_link(c1, obj);
        /* At this point, the refcount on obj is 2 due to the allocation
         * and linking. We can go ahead and reduce the refcount by 1
         * right here so that when the container is unreffed later, the
         * objects will be freed
         */
        ao2_t_ref(obj, -1, "test");
    }
 
    ast_cli(a->fd, "testing callbacks\n");
    ao2_t_callback(c1, 0, print_cb, a, "test callback");
 
    ast_cli(a->fd, "testing container cloning\n");
    c2 = ao2_container_clone(c1, 0);
    if (ao2_container_count(c1) != ao2_container_count(c2)) {
        ast_cli(a->fd, "Cloned container does not have the same number of objects!\n");
    }
    ao2_t_callback(c2, 0, print_cb, a, "test callback");
 
    ast_cli(a->fd, "testing iterators, remove every second object\n");
    {
        struct ao2_iterator ai;
        int x = 0;
 
        ai = ao2_iterator_init(c1, 0);
        while ( (obj = ao2_t_iterator_next(&ai,"test")) ) {
            ast_cli(a->fd, "iterator on <%s>\n", obj);
            if (x++ & 1)
                ao2_t_unlink(c1, obj,"test");
            ao2_t_ref(obj, -1,"test");
        }
        ao2_iterator_destroy(&ai);
        ast_cli(a->fd, "testing iterators again\n");
        ai = ao2_iterator_init(c1, 0);
        while ( (obj = ao2_t_iterator_next(&ai,"test")) ) {
            ast_cli(a->fd, "iterator on <%s>\n", obj);
            ao2_t_ref(obj, -1,"test");
        }
        ao2_iterator_destroy(&ai);
    }
 
    ast_cli(a->fd, "testing callbacks again\n");
    ao2_t_callback(c1, 0, print_cb, a, "test callback");
 
    ast_verbose("now you should see an error and possible assertion failure messages:\n");
    ao2_t_ref(&i, -1, "");  /* i is not a valid object so we print an error here */
 
    ast_cli(a->fd, "destroy container\n");
    ao2_t_ref(c1, -1, "");  /* destroy container */
    ao2_t_ref(c2, -1, "");  /* destroy container */
    handle_astobj2_stats(e, CLI_HANDLER, &fake_args);
    return CLI_SUCCESS;
}
#endif /* AO2_DEBUG */
 
#if defined(AO2_DEBUG)
static struct ast_cli_entry cli_astobj2[] = {
    AST_CLI_DEFINE(handle_astobj2_stats, "Print astobj2 statistics"),
    AST_CLI_DEFINE(handle_astobj2_test, "Test astobj2"),
};
#endif /* AO2_DEBUG */
 
static void astobj2_cleanup(void)
{
#if defined(AO2_DEBUG)
    ast_cli_unregister_multiple(cli_astobj2, ARRAY_LEN(cli_astobj2));
#endif
 
    if (ast_opt_ref_debug) {
        fclose(ref_log);
        ref_log = NULL;
    }
}
 
int astobj2_init(void)
{
    char ref_filename[1024];
 
    if (ast_opt_ref_debug) {
        snprintf(ref_filename, sizeof(ref_filename), "%s/refs", ast_config_AST_LOG_DIR);
        ref_log = fopen(ref_filename, "w");
        if (!ref_log) {
            ast_log(LOG_ERROR, "Could not open ref debug log file: %s\n", ref_filename);
        }
    }
 
    ast_register_cleanup(astobj2_cleanup);
 
    if (container_init() != 0) {
        fclose(ref_log);
        ref_log = NULL;
        return -1;
    }
 
#if defined(AO2_DEBUG)
    ast_cli_register_multiple(cli_astobj2, ARRAY_LEN(cli_astobj2));
#endif  /* defined(AO2_DEBUG) */
 
    return 0;
}