mirror of
https://github.com/xemu-project/xemu.git
synced 2024-12-05 02:06:40 +00:00
737e150e89
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
215 lines
5.8 KiB
C
215 lines
5.8 KiB
C
/*
|
|
* GThread coroutine initialization code
|
|
*
|
|
* Copyright (C) 2006 Anthony Liguori <anthony@codemonkey.ws>
|
|
* Copyright (C) 2011 Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
|
|
*
|
|
* This library is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU Lesser General Public
|
|
* License as published by the Free Software Foundation; either
|
|
* version 2.0 of the License, or (at your option) any later version.
|
|
*
|
|
* This library is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
* Lesser General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU Lesser General Public
|
|
* License along with this library; if not, see <http://www.gnu.org/licenses/>.
|
|
*/
|
|
|
|
#include <glib.h>
|
|
#include "qemu-common.h"
|
|
#include "block/coroutine_int.h"
|
|
|
|
typedef struct {
|
|
Coroutine base;
|
|
GThread *thread;
|
|
bool runnable;
|
|
bool free_on_thread_exit;
|
|
CoroutineAction action;
|
|
} CoroutineGThread;
|
|
|
|
static GStaticMutex coroutine_lock = G_STATIC_MUTEX_INIT;
|
|
|
|
/* GLib 2.31 and beyond deprecated various parts of the thread API,
|
|
* but the new interfaces are not available in older GLib versions
|
|
* so we have to cope with both.
|
|
*/
|
|
#if GLIB_CHECK_VERSION(2, 31, 0)
|
|
/* Default zero-initialisation is sufficient for 2.31+ GCond */
|
|
static GCond the_coroutine_cond;
|
|
static GCond *coroutine_cond = &the_coroutine_cond;
|
|
static inline void init_coroutine_cond(void)
|
|
{
|
|
}
|
|
|
|
/* Awkwardly, the GPrivate API doesn't provide a way to update the
|
|
* GDestroyNotify handler for the coroutine key dynamically. So instead
|
|
* we track whether or not the CoroutineGThread should be freed on
|
|
* thread exit / coroutine key update using the free_on_thread_exit
|
|
* field.
|
|
*/
|
|
static void coroutine_destroy_notify(gpointer data)
|
|
{
|
|
CoroutineGThread *co = data;
|
|
if (co && co->free_on_thread_exit) {
|
|
g_free(co);
|
|
}
|
|
}
|
|
|
|
static GPrivate coroutine_key = G_PRIVATE_INIT(coroutine_destroy_notify);
|
|
|
|
static inline CoroutineGThread *get_coroutine_key(void)
|
|
{
|
|
return g_private_get(&coroutine_key);
|
|
}
|
|
|
|
static inline void set_coroutine_key(CoroutineGThread *co,
|
|
bool free_on_thread_exit)
|
|
{
|
|
/* Unlike g_static_private_set() this does not call the GDestroyNotify
|
|
* if the previous value of the key was NULL. Fortunately we only need
|
|
* the GDestroyNotify in the non-NULL key case.
|
|
*/
|
|
co->free_on_thread_exit = free_on_thread_exit;
|
|
g_private_replace(&coroutine_key, co);
|
|
}
|
|
|
|
static inline GThread *create_thread(GThreadFunc func, gpointer data)
|
|
{
|
|
return g_thread_new("coroutine", func, data);
|
|
}
|
|
|
|
#else
|
|
|
|
/* Handle older GLib versions */
|
|
static GCond *coroutine_cond;
|
|
static inline void init_coroutine_cond(void)
|
|
{
|
|
coroutine_cond = g_cond_new();
|
|
}
|
|
|
|
static GStaticPrivate coroutine_key = G_STATIC_PRIVATE_INIT;
|
|
|
|
static inline CoroutineGThread *get_coroutine_key(void)
|
|
{
|
|
return g_static_private_get(&coroutine_key);
|
|
}
|
|
|
|
static inline void set_coroutine_key(CoroutineGThread *co,
|
|
bool free_on_thread_exit)
|
|
{
|
|
g_static_private_set(&coroutine_key, co,
|
|
free_on_thread_exit ? (GDestroyNotify)g_free : NULL);
|
|
}
|
|
|
|
static inline GThread *create_thread(GThreadFunc func, gpointer data)
|
|
{
|
|
return g_thread_create_full(func, data, 0, TRUE, TRUE,
|
|
G_THREAD_PRIORITY_NORMAL, NULL);
|
|
}
|
|
|
|
#endif
|
|
|
|
|
|
static void __attribute__((constructor)) coroutine_init(void)
|
|
{
|
|
if (!g_thread_supported()) {
|
|
#if !GLIB_CHECK_VERSION(2, 31, 0)
|
|
g_thread_init(NULL);
|
|
#else
|
|
fprintf(stderr, "glib threading failed to initialize.\n");
|
|
exit(1);
|
|
#endif
|
|
}
|
|
|
|
init_coroutine_cond();
|
|
}
|
|
|
|
static void coroutine_wait_runnable_locked(CoroutineGThread *co)
|
|
{
|
|
while (!co->runnable) {
|
|
g_cond_wait(coroutine_cond, g_static_mutex_get_mutex(&coroutine_lock));
|
|
}
|
|
}
|
|
|
|
static void coroutine_wait_runnable(CoroutineGThread *co)
|
|
{
|
|
g_static_mutex_lock(&coroutine_lock);
|
|
coroutine_wait_runnable_locked(co);
|
|
g_static_mutex_unlock(&coroutine_lock);
|
|
}
|
|
|
|
static gpointer coroutine_thread(gpointer opaque)
|
|
{
|
|
CoroutineGThread *co = opaque;
|
|
|
|
set_coroutine_key(co, false);
|
|
coroutine_wait_runnable(co);
|
|
co->base.entry(co->base.entry_arg);
|
|
qemu_coroutine_switch(&co->base, co->base.caller, COROUTINE_TERMINATE);
|
|
return NULL;
|
|
}
|
|
|
|
Coroutine *qemu_coroutine_new(void)
|
|
{
|
|
CoroutineGThread *co;
|
|
|
|
co = g_malloc0(sizeof(*co));
|
|
co->thread = create_thread(coroutine_thread, co);
|
|
if (!co->thread) {
|
|
g_free(co);
|
|
return NULL;
|
|
}
|
|
return &co->base;
|
|
}
|
|
|
|
void qemu_coroutine_delete(Coroutine *co_)
|
|
{
|
|
CoroutineGThread *co = DO_UPCAST(CoroutineGThread, base, co_);
|
|
|
|
g_thread_join(co->thread);
|
|
g_free(co);
|
|
}
|
|
|
|
CoroutineAction qemu_coroutine_switch(Coroutine *from_,
|
|
Coroutine *to_,
|
|
CoroutineAction action)
|
|
{
|
|
CoroutineGThread *from = DO_UPCAST(CoroutineGThread, base, from_);
|
|
CoroutineGThread *to = DO_UPCAST(CoroutineGThread, base, to_);
|
|
|
|
g_static_mutex_lock(&coroutine_lock);
|
|
from->runnable = false;
|
|
from->action = action;
|
|
to->runnable = true;
|
|
to->action = action;
|
|
g_cond_broadcast(coroutine_cond);
|
|
|
|
if (action != COROUTINE_TERMINATE) {
|
|
coroutine_wait_runnable_locked(from);
|
|
}
|
|
g_static_mutex_unlock(&coroutine_lock);
|
|
return from->action;
|
|
}
|
|
|
|
Coroutine *qemu_coroutine_self(void)
|
|
{
|
|
CoroutineGThread *co = get_coroutine_key();
|
|
if (!co) {
|
|
co = g_malloc0(sizeof(*co));
|
|
co->runnable = true;
|
|
set_coroutine_key(co, true);
|
|
}
|
|
|
|
return &co->base;
|
|
}
|
|
|
|
bool qemu_in_coroutine(void)
|
|
{
|
|
CoroutineGThread *co = get_coroutine_key();
|
|
|
|
return co && co->base.caller;
|
|
}
|