glib-compat.h

/*
 * GLIB Compatibility Functions
 *
 * Copyright IBM, Corp. 2013
 *
 * Authors:
 *  Anthony Liguori   <aliguori@us.ibm.com>
 *  Michael Tokarev   <mjt@tls.msk.ru>
 *  Paolo Bonzini     <pbonzini@redhat.com>
 *
 * This work is licensed under the terms of the GNU GPL, version 2 or later.
 * See the COPYING file in the top-level directory.
 *
 */

#ifndef QEMU_GLIB_COMPAT_H
#define QEMU_GLIB_COMPAT_H

#include <glib.h>

/* GLIB version compatibility flags */
#if !GLIB_CHECK_VERSION(2, 26, 0)
#define G_TIME_SPAN_SECOND              (G_GINT64_CONSTANT(1000000))
#endif

#if !GLIB_CHECK_VERSION(2, 28, 0)
static inline gint64 qemu_g_get_monotonic_time(void)
{
    /* g_get_monotonic_time() is best-effort so we can use the wall clock as a
     * fallback.
     */

    GTimeVal time;
    g_get_current_time(&time);

    return time.tv_sec * G_TIME_SPAN_SECOND + time.tv_usec;
}
/* work around distro backports of this interface */
#define g_get_monotonic_time() qemu_g_get_monotonic_time()
#endif

#ifdef _WIN32
/*
 * g_poll has a problem on Windows when using
 * timeouts < 10ms, so use wrapper.
 */
#define g_poll(fds, nfds, timeout) g_poll_fixed(fds, nfds, timeout)
gint g_poll_fixed(GPollFD *fds, guint nfds, gint timeout);
#endif

#if !GLIB_CHECK_VERSION(2, 30, 0)
/* Not a 100% compatible implementation, but good enough for most
 * cases. Placeholders are only supported at the end of the
 * template. */
static inline gchar *qemu_g_dir_make_tmp(gchar const *tmpl, GError **error)
{
    gchar *path = g_build_filename(g_get_tmp_dir(), tmpl ?: ".XXXXXX", NULL);

    if (mkdtemp(path) != NULL) {
        return path;
    }
    /* Error occurred, clean up. */
    g_set_error(error, G_FILE_ERROR, g_file_error_from_errno(errno),
                "mkdtemp() failed");
    g_free(path);
    return NULL;
}
#define g_dir_make_tmp(tmpl, error) qemu_g_dir_make_tmp(tmpl, error)
#endif /* glib 2.30 */

#if !GLIB_CHECK_VERSION(2, 31, 0)
/* before glib-2.31, GMutex and GCond was dynamic-only (there was a separate
 * GStaticMutex, but it didn't work with condition variables).
 *
 * Our implementation uses GOnce to fake a static implementation that does
 * not require separate initialization.
 * We need to rename the types to avoid passing our CompatGMutex/CompatGCond
 * by mistake to a function that expects GMutex/GCond.  However, for ease
 * of use we keep the GLib function names.  GLib uses macros for the
 * implementation, we use inline functions instead and undefine the macros.
 */

typedef struct CompatGMutex {
    GOnce once;
} CompatGMutex;

typedef struct CompatGCond {
    GOnce once;
} CompatGCond;

static inline gpointer do_g_mutex_new(gpointer unused)
{
    return (gpointer) g_mutex_new();
}

static inline void g_mutex_init(CompatGMutex *mutex)
{
    mutex->once = (GOnce) G_ONCE_INIT;
}

static inline void g_mutex_clear(CompatGMutex *mutex)
{
    g_assert(mutex->once.status != G_ONCE_STATUS_PROGRESS);
    if (mutex->once.retval) {
        g_mutex_free((GMutex *) mutex->once.retval);
    }
    mutex->once = (GOnce) G_ONCE_INIT;
}

static inline void (g_mutex_lock)(CompatGMutex *mutex)
{
    g_once(&mutex->once, do_g_mutex_new, NULL);
    g_mutex_lock((GMutex *) mutex->once.retval);
}
#undef g_mutex_lock

static inline gboolean (g_mutex_trylock)(CompatGMutex *mutex)
{
    g_once(&mutex->once, do_g_mutex_new, NULL);
    return g_mutex_trylock((GMutex *) mutex->once.retval);
}
#undef g_mutex_trylock


static inline void (g_mutex_unlock)(CompatGMutex *mutex)
{
    g_mutex_unlock((GMutex *) mutex->once.retval);
}
#undef g_mutex_unlock

static inline gpointer do_g_cond_new(gpointer unused)
{
    return (gpointer) g_cond_new();
}

static inline void g_cond_init(CompatGCond *cond)
{
    cond->once = (GOnce) G_ONCE_INIT;
}

static inline void g_cond_clear(CompatGCond *cond)
{
    g_assert(cond->once.status != G_ONCE_STATUS_PROGRESS);
    if (cond->once.retval) {
        g_cond_free((GCond *) cond->once.retval);
    }
    cond->once = (GOnce) G_ONCE_INIT;
}

static inline void (g_cond_wait)(CompatGCond *cond, CompatGMutex *mutex)
{
    g_assert(mutex->once.status != G_ONCE_STATUS_PROGRESS);
    g_once(&cond->once, do_g_cond_new, NULL);
    g_cond_wait((GCond *) cond->once.retval, (GMutex *) mutex->once.retval);
}
#undef g_cond_wait

static inline void (g_cond_broadcast)(CompatGCond *cond)
{
    g_once(&cond->once, do_g_cond_new, NULL);
    g_cond_broadcast((GCond *) cond->once.retval);
}
#undef g_cond_broadcast

static inline void (g_cond_signal)(CompatGCond *cond)
{
    g_once(&cond->once, do_g_cond_new, NULL);
    g_cond_signal((GCond *) cond->once.retval);
}
#undef g_cond_signal

static inline gboolean (g_cond_timed_wait)(CompatGCond *cond,
                                           CompatGMutex *mutex,
                                           GTimeVal *time)
{
    g_assert(mutex->once.status != G_ONCE_STATUS_PROGRESS);
    g_once(&cond->once, do_g_cond_new, NULL);
    return g_cond_timed_wait((GCond *) cond->once.retval,
                             (GMutex *) mutex->once.retval, time);
}
#undef g_cond_timed_wait

/* This is not a macro, because it didn't exist until 2.32.  */
static inline gboolean g_cond_wait_until(CompatGCond *cond, CompatGMutex *mutex,
                                         gint64 end_time)
{
    GTimeVal time;

    /* Convert from monotonic to CLOCK_REALTIME.  */
    end_time -= g_get_monotonic_time();
    g_get_current_time(&time);
    end_time += time.tv_sec * G_TIME_SPAN_SECOND + time.tv_usec;

    time.tv_sec = end_time / G_TIME_SPAN_SECOND;
    time.tv_usec = end_time % G_TIME_SPAN_SECOND;
    return g_cond_timed_wait(cond, mutex, &time);
}

/* before 2.31 there was no g_thread_new() */
static inline GThread *g_thread_new(const char *name,
                                    GThreadFunc func, gpointer data)
{
    GThread *thread = g_thread_create(func, data, TRUE, NULL);
    if (!thread) {
        g_error("creating thread");
    }
    return thread;
}
#else
#define CompatGMutex GMutex
#define CompatGCond GCond
#endif /* glib 2.31 */

#if !GLIB_CHECK_VERSION(2, 32, 0)
/* Beware, function returns gboolean since 2.39.2, see GLib commit 9101915 */
static inline void g_hash_table_add(GHashTable *hash_table, gpointer key)
{
    g_hash_table_replace(hash_table, key, key);
}
#endif

#ifndef g_assert_true
#define g_assert_true(expr)                                                    \
    do {                                                                       \
        if (G_LIKELY(expr)) {                                                  \
        } else {                                                               \
            g_assertion_message(G_LOG_DOMAIN, __FILE__, __LINE__, G_STRFUNC,   \
                                "'" #expr "' should be TRUE");                 \
        }                                                                      \
    } while (0)
#endif

#ifndef g_assert_false
#define g_assert_false(expr)                                                   \
    do {                                                                       \
        if (G_LIKELY(!(expr))) {                                               \
        } else {                                                               \
            g_assertion_message(G_LOG_DOMAIN, __FILE__, __LINE__, G_STRFUNC,   \
                                "'" #expr "' should be FALSE");                \
        }                                                                      \
    } while (0)
#endif

#ifndef g_assert_null
#define g_assert_null(expr)                                                    \
    do {                                                                       \
        if (G_LIKELY((expr) == NULL)) {                                        \
        } else {                                                               \
            g_assertion_message(G_LOG_DOMAIN, __FILE__, __LINE__, G_STRFUNC,   \
                                "'" #expr "' should be NULL");                 \
        }                                                                      \
    } while (0)
#endif

#ifndef g_assert_nonnull
#define g_assert_nonnull(expr)                                                 \
    do {                                                                       \
        if (G_LIKELY((expr) != NULL)) {                                        \
        } else {                                                               \
            g_assertion_message(G_LOG_DOMAIN, __FILE__, __LINE__, G_STRFUNC,   \
                                "'" #expr "' should not be NULL");             \
        }                                                                      \
    } while (0)
#endif

#ifndef g_assert_cmpmem
#define g_assert_cmpmem(m1, l1, m2, l2)                                        \
    do {                                                                       \
        gconstpointer __m1 = m1, __m2 = m2;                                    \
        int __l1 = l1, __l2 = l2;                                              \
        if (__l1 != __l2) {                                                    \
            g_assertion_message_cmpnum(                                        \
                G_LOG_DOMAIN, __FILE__, __LINE__, G_STRFUNC,                   \
                #l1 " (len(" #m1 ")) == " #l2 " (len(" #m2 "))", __l1, "==",   \
                __l2, 'i');                                                    \
        } else if (memcmp(__m1, __m2, __l1) != 0) {                            \
            g_assertion_message(G_LOG_DOMAIN, __FILE__, __LINE__, G_STRFUNC,   \
                                "assertion failed (" #m1 " == " #m2 ")");      \
        }                                                                      \
    } while (0)
#endif

#if !GLIB_CHECK_VERSION(2, 28, 0)
static inline void g_list_free_full(GList *list, GDestroyNotify free_func)
{
    GList *l;

    for (l = list; l; l = l->next) {
        free_func(l->data);
    }

    g_list_free(list);
}

static inline void g_slist_free_full(GSList *list, GDestroyNotify free_func)
{
    GSList *l;

    for (l = list; l; l = l->next) {
        free_func(l->data);
    }

    g_slist_free(list);
}
#endif

#if !GLIB_CHECK_VERSION(2, 26, 0)
static inline void g_source_set_name(GSource *source, const char *name)
{
    /* This is just a debugging aid, so leaving it a no-op */
}
#endif

#endif