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 #if !GLIB_CHECK_VERSION(2, 16, 0)
  49 static inline int g_strcmp0(const char *str1, const char *str2)
  50 {
  51     int result;
  52
  53     if (!str1) {
  54         result = -(str1 != str2);
  55     } else if (!str2) {
  56         result = (str1 != str2);
  57     } else {
  58         result = strcmp(str1, str2);
  59     }
  60
  61     return result;
  62 }
  63 #endif
  64
  65 #ifdef _WIN32
  66 /*
  67  * g_poll has a problem on Windows when using
  68  * timeouts < 10ms, so use wrapper.
  69  */
  70 #define g_poll(fds, nfds, timeout) g_poll_fixed(fds, nfds, timeout)
  71 gint g_poll_fixed(GPollFD *fds, guint nfds, gint timeout);
  72 #elif !GLIB_CHECK_VERSION(2, 20, 0)
  73 /*
  74  * Glib before 2.20.0 doesn't implement g_poll, so wrap it to compile properly
  75  * on older systems.
  76  */
  77 static inline gint g_poll(GPollFD *fds, guint nfds, gint timeout)
  78 {
  79     GMainContext *ctx = g_main_context_default();
  80     return g_main_context_get_poll_func(ctx)(fds, nfds, timeout);
  81 }
  82 #endif
  83
  84 #if !GLIB_CHECK_VERSION(2, 31, 0)
  85 /* before glib-2.31, GMutex and GCond was dynamic-only (there was a separate
  86  * GStaticMutex, but it didn't work with condition variables).
  87  *
  88  * Our implementation uses GOnce to fake a static implementation that does
  89  * not require separate initialization.
  90  * We need to rename the types to avoid passing our CompatGMutex/CompatGCond
  91  * by mistake to a function that expects GMutex/GCond.  However, for ease
  92  * of use we keep the GLib function names.  GLib uses macros for the
  93  * implementation, we use inline functions instead and undefine the macros.
  94  */
  95
  96 typedef struct CompatGMutex {
  97     GOnce once;
  98 } CompatGMutex;
  99
 100 typedef struct CompatGCond {
 101     GOnce once;
 102 } CompatGCond;
 103
 104 static inline gpointer do_g_mutex_new(gpointer unused)
 105 {
 106     return (gpointer) g_mutex_new();
 107 }
 108
 109 static inline void g_mutex_init(CompatGMutex *mutex)
 110 {
 111     mutex->once = (GOnce) G_ONCE_INIT;
 112 }
 113
 114 static inline void g_mutex_clear(CompatGMutex *mutex)
 115 {
 116     assert(mutex->once.status != G_ONCE_STATUS_PROGRESS);
 117     if (mutex->once.retval) {
 118         g_mutex_free((GMutex *) mutex->once.retval);
 119     }
 120     mutex->once = (GOnce) G_ONCE_INIT;
 121 }
 122
 123 static inline void (g_mutex_lock)(CompatGMutex *mutex)
 124 {
 125     g_once(&mutex->once, do_g_mutex_new, NULL);
 126     g_mutex_lock((GMutex *) mutex->once.retval);
 127 }
 128 #undef g_mutex_lock
 129
 130 static inline gboolean (g_mutex_trylock)(CompatGMutex *mutex)
 131 {
 132     g_once(&mutex->once, do_g_mutex_new, NULL);
 133     return g_mutex_trylock((GMutex *) mutex->once.retval);
 134 }
 135 #undef g_mutex_trylock
 136
 137
 138 static inline void (g_mutex_unlock)(CompatGMutex *mutex)
 139 {
 140     g_mutex_unlock((GMutex *) mutex->once.retval);
 141 }
 142 #undef g_mutex_unlock
 143
 144 static inline gpointer do_g_cond_new(gpointer unused)
 145 {
 146     return (gpointer) g_cond_new();
 147 }
 148
 149 static inline void g_cond_init(CompatGCond *cond)
 150 {
 151     cond->once = (GOnce) G_ONCE_INIT;
 152 }
 153
 154 static inline void g_cond_clear(CompatGCond *cond)
 155 {
 156     assert(cond->once.status != G_ONCE_STATUS_PROGRESS);
 157     if (cond->once.retval) {
 158         g_cond_free((GCond *) cond->once.retval);
 159     }
 160     cond->once = (GOnce) G_ONCE_INIT;
 161 }
 162
 163 static inline void (g_cond_wait)(CompatGCond *cond, CompatGMutex *mutex)
 164 {
 165     assert(mutex->once.status != G_ONCE_STATUS_PROGRESS);
 166     g_once(&cond->once, do_g_cond_new, NULL);
 167     g_cond_wait((GCond *) cond->once.retval, (GMutex *) mutex->once.retval);
 168 }
 169 #undef g_cond_wait
 170
 171 static inline void (g_cond_broadcast)(CompatGCond *cond)
 172 {
 173     g_once(&cond->once, do_g_cond_new, NULL);
 174     g_cond_broadcast((GCond *) cond->once.retval);
 175 }
 176 #undef g_cond_broadcast
 177
 178 static inline void (g_cond_signal)(CompatGCond *cond)
 179 {
 180     g_once(&cond->once, do_g_cond_new, NULL);
 181     g_cond_signal((GCond *) cond->once.retval);
 182 }
 183 #undef g_cond_signal
 184
 185
 186 /* before 2.31 there was no g_thread_new() */
 187 static inline GThread *g_thread_new(const char *name,
 188                                     GThreadFunc func, gpointer data)
 189 {
 190     GThread *thread = g_thread_create(func, data, TRUE, NULL);
 191     if (!thread) {
 192         g_error("creating thread");
 193     }
 194     return thread;
 195 }
 196 #else
 197 #define CompatGMutex GMutex
 198 #define CompatGCond GCond
 199 #endif /* glib 2.31 */
 200
 201 #endif