From 86946a2d835614050b90bc8e5c82982fe45deff2 Mon Sep 17 00:00:00 2001 From: Michael Tokarev Date: Thu, 8 May 2014 12:30:46 +0400 Subject: glib-compat.h: add new thread API emulation on top of pre-2.31 API Thread API changed in glib-2.31 significantly. Before that version, conditionals and mutexes were only allocated dynamically, using _new()/_free() interface. in 2.31 and up, they're allocated statically as regular variables, and old interface is deprecated. (Note: glib docs says the new interface is available since version 2.32, but it was actually introduced in version 2.31). Create the new interface using old primitives, by providing non-opaque definitions of the base types (GCond and GMutex) using GOnces. Replace #ifdeffery around GCond and GMutex in trace/simple.c and coroutine-gthread.c too because it does not work anymore with the new glib-compat.h. Signed-off-by: Michael Tokarev Reviewed-by: Stefan Hajnoczi [Use GOnce to support lazy initialization; introduce CompatGMutex and CompatGCond. - Paolo] Signed-off-by: Paolo Bonzini --- include/glib-compat.h | 119 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 119 insertions(+) (limited to 'include/glib-compat.h') diff --git a/include/glib-compat.h b/include/glib-compat.h index 1280fb2c1f..4ae0671a8e 100644 --- a/include/glib-compat.h +++ b/include/glib-compat.h @@ -5,6 +5,8 @@ * * Authors: * Anthony Liguori + * Michael Tokarev + * Paolo Bonzini * * This work is licensed under the terms of the GNU GPL, version 2 or later. * See the COPYING file in the top-level directory. @@ -43,4 +45,121 @@ static inline gint g_poll(GPollFD *fds, guint nfds, gint timeout) } #endif +#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) +{ + 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) +{ + 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) +{ + 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 + + +/* 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 */ + #endif -- cgit v1.2.1