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-rw-r--r--coroutine-gthread.c96
1 files changed, 87 insertions, 9 deletions
diff --git a/coroutine-gthread.c b/coroutine-gthread.c
index 662801b2fa..30c24c94b8 100644
--- a/coroutine-gthread.c
+++ b/coroutine-gthread.c
@@ -26,13 +26,93 @@ typedef struct {
Coroutine base;
GThread *thread;
bool runnable;
+ bool free_on_thread_exit;
CoroutineAction action;
} CoroutineGThread;
-static GCond *coroutine_cond;
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()) {
@@ -44,7 +124,7 @@ static void __attribute__((constructor)) coroutine_init(void)
#endif
}
- coroutine_cond = g_cond_new();
+ init_coroutine_cond();
}
static void coroutine_wait_runnable_locked(CoroutineGThread *co)
@@ -65,7 +145,7 @@ static gpointer coroutine_thread(gpointer opaque)
{
CoroutineGThread *co = opaque;
- g_static_private_set(&coroutine_key, co, NULL);
+ 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);
@@ -77,8 +157,7 @@ Coroutine *qemu_coroutine_new(void)
CoroutineGThread *co;
co = g_malloc0(sizeof(*co));
- co->thread = g_thread_create_full(coroutine_thread, co, 0, TRUE, TRUE,
- G_THREAD_PRIORITY_NORMAL, NULL);
+ co->thread = create_thread(coroutine_thread, co);
if (!co->thread) {
g_free(co);
return NULL;
@@ -117,12 +196,11 @@ CoroutineAction qemu_coroutine_switch(Coroutine *from_,
Coroutine *qemu_coroutine_self(void)
{
- CoroutineGThread *co = g_static_private_get(&coroutine_key);
-
+ CoroutineGThread *co = get_coroutine_key();
if (!co) {
co = g_malloc0(sizeof(*co));
co->runnable = true;
- g_static_private_set(&coroutine_key, co, (GDestroyNotify)g_free);
+ set_coroutine_key(co, true);
}
return &co->base;
@@ -130,7 +208,7 @@ Coroutine *qemu_coroutine_self(void)
bool qemu_in_coroutine(void)
{
- CoroutineGThread *co = g_static_private_get(&coroutine_key);
+ CoroutineGThread *co = get_coroutine_key();
return co && co->base.caller;
}