qemu/include/glib-compat.h
Michael Tokarev 86946a2d83 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 <mjt@tls.msk.ru>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
[Use GOnce to support lazy initialization; introduce CompatGMutex
 and CompatGCond.  - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-06-10 07:44:01 +02:00

166 lines
4.3 KiB
C

/*
* 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>
#if !GLIB_CHECK_VERSION(2, 14, 0)
static inline guint g_timeout_add_seconds(guint interval, GSourceFunc function,
gpointer data)
{
return g_timeout_add(interval * 1000, function, data);
}
#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);
#elif !GLIB_CHECK_VERSION(2, 20, 0)
/*
* Glib before 2.20.0 doesn't implement g_poll, so wrap it to compile properly
* on older systems.
*/
static inline gint g_poll(GPollFD *fds, guint nfds, gint timeout)
{
GMainContext *ctx = g_main_context_default();
return g_main_context_get_poll_func(ctx)(fds, nfds, 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