xref: /openbmc/qemu/include/glib-compat.h (revision acb0ef58)
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 #if !GLIB_CHECK_VERSION(2, 14, 0)
22 static inline guint g_timeout_add_seconds(guint interval, GSourceFunc function,
23                                           gpointer data)
24 {
25     return g_timeout_add(interval * 1000, function, data);
26 }
27 #endif
28 
29 #ifdef _WIN32
30 /*
31  * g_poll has a problem on Windows when using
32  * timeouts < 10ms, so use wrapper.
33  */
34 #define g_poll(fds, nfds, timeout) g_poll_fixed(fds, nfds, timeout)
35 gint g_poll_fixed(GPollFD *fds, guint nfds, gint timeout);
36 #elif !GLIB_CHECK_VERSION(2, 20, 0)
37 /*
38  * Glib before 2.20.0 doesn't implement g_poll, so wrap it to compile properly
39  * on older systems.
40  */
41 static inline gint g_poll(GPollFD *fds, guint nfds, gint timeout)
42 {
43     GMainContext *ctx = g_main_context_default();
44     return g_main_context_get_poll_func(ctx)(fds, nfds, timeout);
45 }
46 #endif
47 
48 #if !GLIB_CHECK_VERSION(2, 31, 0)
49 /* before glib-2.31, GMutex and GCond was dynamic-only (there was a separate
50  * GStaticMutex, but it didn't work with condition variables).
51  *
52  * Our implementation uses GOnce to fake a static implementation that does
53  * not require separate initialization.
54  * We need to rename the types to avoid passing our CompatGMutex/CompatGCond
55  * by mistake to a function that expects GMutex/GCond.  However, for ease
56  * of use we keep the GLib function names.  GLib uses macros for the
57  * implementation, we use inline functions instead and undefine the macros.
58  */
59 
60 typedef struct CompatGMutex {
61     GOnce once;
62 } CompatGMutex;
63 
64 typedef struct CompatGCond {
65     GOnce once;
66 } CompatGCond;
67 
68 static inline gpointer do_g_mutex_new(gpointer unused)
69 {
70     return (gpointer) g_mutex_new();
71 }
72 
73 static inline void g_mutex_init(CompatGMutex *mutex)
74 {
75     mutex->once = (GOnce) G_ONCE_INIT;
76 }
77 
78 static inline void g_mutex_clear(CompatGMutex *mutex)
79 {
80     assert(mutex->once.status != G_ONCE_STATUS_PROGRESS);
81     if (mutex->once.retval) {
82         g_mutex_free((GMutex *) mutex->once.retval);
83     }
84     mutex->once = (GOnce) G_ONCE_INIT;
85 }
86 
87 static inline void (g_mutex_lock)(CompatGMutex *mutex)
88 {
89     g_once(&mutex->once, do_g_mutex_new, NULL);
90     g_mutex_lock((GMutex *) mutex->once.retval);
91 }
92 #undef g_mutex_lock
93 
94 static inline gboolean (g_mutex_trylock)(CompatGMutex *mutex)
95 {
96     g_once(&mutex->once, do_g_mutex_new, NULL);
97     return g_mutex_trylock((GMutex *) mutex->once.retval);
98 }
99 #undef g_mutex_trylock
100 
101 
102 static inline void (g_mutex_unlock)(CompatGMutex *mutex)
103 {
104     g_mutex_unlock((GMutex *) mutex->once.retval);
105 }
106 #undef g_mutex_unlock
107 
108 static inline gpointer do_g_cond_new(gpointer unused)
109 {
110     return (gpointer) g_cond_new();
111 }
112 
113 static inline void g_cond_init(CompatGCond *cond)
114 {
115     cond->once = (GOnce) G_ONCE_INIT;
116 }
117 
118 static inline void g_cond_clear(CompatGCond *cond)
119 {
120     assert(cond->once.status != G_ONCE_STATUS_PROGRESS);
121     if (cond->once.retval) {
122         g_cond_free((GCond *) cond->once.retval);
123     }
124     cond->once = (GOnce) G_ONCE_INIT;
125 }
126 
127 static inline void (g_cond_wait)(CompatGCond *cond, CompatGMutex *mutex)
128 {
129     assert(mutex->once.status != G_ONCE_STATUS_PROGRESS);
130     g_once(&cond->once, do_g_cond_new, NULL);
131     g_cond_wait((GCond *) cond->once.retval, (GMutex *) mutex->once.retval);
132 }
133 #undef g_cond_wait
134 
135 static inline void (g_cond_broadcast)(CompatGCond *cond)
136 {
137     g_once(&cond->once, do_g_cond_new, NULL);
138     g_cond_broadcast((GCond *) cond->once.retval);
139 }
140 #undef g_cond_broadcast
141 
142 static inline void (g_cond_signal)(CompatGCond *cond)
143 {
144     g_once(&cond->once, do_g_cond_new, NULL);
145     g_cond_signal((GCond *) cond->once.retval);
146 }
147 #undef g_cond_signal
148 
149 
150 /* before 2.31 there was no g_thread_new() */
151 static inline GThread *g_thread_new(const char *name,
152                                     GThreadFunc func, gpointer data)
153 {
154     GThread *thread = g_thread_create(func, data, TRUE, NULL);
155     if (!thread) {
156         g_error("creating thread");
157     }
158     return thread;
159 }
160 #else
161 #define CompatGMutex GMutex
162 #define CompatGCond GCond
163 #endif /* glib 2.31 */
164 
165 #endif
166