include/glib-compat.h

   1 /*
   2  * GLIB Compatibility Functions
   3  *
   4  * Copyright IBM, Corp. 2013
   5  *
   6  * Authors:
   7  *  Anthony Liguori   <aliguori@us.ibm.com>
   8  *  Michael Tokarev   <mjt@tls.msk.ru>
   9  *  Paolo Bonzini     <pbonzini@redhat.com>
  10  *
  11  * This work is licensed under the terms of the GNU GPL, version 2 or later.
  12  * See the COPYING file in the top-level directory.
  13  *
  14  */
  15
  16 #ifndef QEMU_GLIB_COMPAT_H
  17 #define QEMU_GLIB_COMPAT_H
  18
  19 #include <glib.h>
  20
  21 /* GLIB version compatibility flags */
  22 #if !GLIB_CHECK_VERSION(2, 26, 0)
  23 #define G_TIME_SPAN_SECOND              (G_GINT64_CONSTANT(1000000))
  24 #endif
  25
  26 #if !GLIB_CHECK_VERSION(2, 14, 0)
  27 static inline guint g_timeout_add_seconds(guint interval, GSourceFunc function,
  28                                           gpointer data)
  29 {
  30     return g_timeout_add(interval * 1000, function, data);
  31 }
  32 #endif
  33
  34 #if !GLIB_CHECK_VERSION(2, 28, 0)
  35 static inline gint64 g_get_monotonic_time(void)
  36 {
  37     /* g_get_monotonic_time() is best-effort so we can use the wall clock as a
  38      * fallback.
  39      */
  40
  41     GTimeVal time;
  42     g_get_current_time(&time);
  43
  44     return time.tv_sec * G_TIME_SPAN_SECOND + time.tv_usec;
  45 }
  46 #endif
  47
  48 #ifdef _WIN32
  49 /*
  50  * g_poll has a problem on Windows when using
  51  * timeouts < 10ms, so use wrapper.
  52  */
  53 #define g_poll(fds, nfds, timeout) g_poll_fixed(fds, nfds, timeout)
  54 gint g_poll_fixed(GPollFD *fds, guint nfds, gint timeout);
  55 #elif !GLIB_CHECK_VERSION(2, 20, 0)
  56 /*
  57  * Glib before 2.20.0 doesn't implement g_poll, so wrap it to compile properly
  58  * on older systems.
  59  */
  60 static inline gint g_poll(GPollFD *fds, guint nfds, gint timeout)
  61 {
  62     GMainContext *ctx = g_main_context_default();
  63     return g_main_context_get_poll_func(ctx)(fds, nfds, timeout);
  64 }
  65 #endif
  66
  67 #if !GLIB_CHECK_VERSION(2, 31, 0)
  68 /* before glib-2.31, GMutex and GCond was dynamic-only (there was a separate
  69  * GStaticMutex, but it didn't work with condition variables).
  70  *
  71  * Our implementation uses GOnce to fake a static implementation that does
  72  * not require separate initialization.
  73  * We need to rename the types to avoid passing our CompatGMutex/CompatGCond
  74  * by mistake to a function that expects GMutex/GCond.  However, for ease
  75  * of use we keep the GLib function names.  GLib uses macros for the
  76  * implementation, we use inline functions instead and undefine the macros.
  77  */
  78
  79 typedef struct CompatGMutex {
  80     GOnce once;
  81 } CompatGMutex;
  82
  83 typedef struct CompatGCond {
  84     GOnce once;
  85 } CompatGCond;
  86
  87 static inline gpointer do_g_mutex_new(gpointer unused)
  88 {
  89     return (gpointer) g_mutex_new();
  90 }
  91
  92 static inline void g_mutex_init(CompatGMutex *mutex)
  93 {
  94     mutex->once = (GOnce) G_ONCE_INIT;
  95 }
  96
  97 static inline void g_mutex_clear(CompatGMutex *mutex)
  98 {
  99     assert(mutex->once.status != G_ONCE_STATUS_PROGRESS);
 100     if (mutex->once.retval) {
 101         g_mutex_free((GMutex *) mutex->once.retval);
 102     }
 103     mutex->once = (GOnce) G_ONCE_INIT;
 104 }
 105
 106 static inline void (g_mutex_lock)(CompatGMutex *mutex)
 107 {
 108     g_once(&mutex->once, do_g_mutex_new, NULL);
 109     g_mutex_lock((GMutex *) mutex->once.retval);
 110 }
 111 #undef g_mutex_lock
 112
 113 static inline gboolean (g_mutex_trylock)(CompatGMutex *mutex)
 114 {
 115     g_once(&mutex->once, do_g_mutex_new, NULL);
 116     return g_mutex_trylock((GMutex *) mutex->once.retval);
 117 }
 118 #undef g_mutex_trylock
 119
 120
 121 static inline void (g_mutex_unlock)(CompatGMutex *mutex)
 122 {
 123     g_mutex_unlock((GMutex *) mutex->once.retval);
 124 }
 125 #undef g_mutex_unlock
 126
 127 static inline gpointer do_g_cond_new(gpointer unused)
 128 {
 129     return (gpointer) g_cond_new();
 130 }
 131
 132 static inline void g_cond_init(CompatGCond *cond)
 133 {
 134     cond->once = (GOnce) G_ONCE_INIT;
 135 }
 136
 137 static inline void g_cond_clear(CompatGCond *cond)
 138 {
 139     assert(cond->once.status != G_ONCE_STATUS_PROGRESS);
 140     if (cond->once.retval) {
 141         g_cond_free((GCond *) cond->once.retval);
 142     }
 143     cond->once = (GOnce) G_ONCE_INIT;
 144 }
 145
 146 static inline void (g_cond_wait)(CompatGCond *cond, CompatGMutex *mutex)
 147 {
 148     assert(mutex->once.status != G_ONCE_STATUS_PROGRESS);
 149     g_once(&cond->once, do_g_cond_new, NULL);
 150     g_cond_wait((GCond *) cond->once.retval, (GMutex *) mutex->once.retval);
 151 }
 152 #undef g_cond_wait
 153
 154 static inline void (g_cond_broadcast)(CompatGCond *cond)
 155 {
 156     g_once(&cond->once, do_g_cond_new, NULL);
 157     g_cond_broadcast((GCond *) cond->once.retval);
 158 }
 159 #undef g_cond_broadcast
 160
 161 static inline void (g_cond_signal)(CompatGCond *cond)
 162 {
 163     g_once(&cond->once, do_g_cond_new, NULL);
 164     g_cond_signal((GCond *) cond->once.retval);
 165 }
 166 #undef g_cond_signal
 167
 168
 169 /* before 2.31 there was no g_thread_new() */
 170 static inline GThread *g_thread_new(const char *name,
 171                                     GThreadFunc func, gpointer data)
 172 {
 173     GThread *thread = g_thread_create(func, data, TRUE, NULL);
 174     if (!thread) {
 175         g_error("creating thread");
 176     }
 177     return thread;
 178 }
 179 #else
 180 #define CompatGMutex GMutex
 181 #define CompatGCond GCond
 182 #endif /* glib 2.31 */
 183
 184 #endif