Move message-queue functions to msgqueue.[ch]

src/msgqueue.h

@@ -0,0 +1,44 @@
+/*
+ * Copyright (C) 2021 kichikuou <KichikuouChrome@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *
+ */
+
+#ifndef __MSGQUEUE_H__
+#define __MSGQUEUE_H__
+
+#include <stdbool.h>
+#include <SDL_mutex.h>
+
+struct msgq_elem;
+
+struct msgq {
+	SDL_mutex *mutex;
+	SDL_cond *cond_nonempty;
+	struct msgq_elem *head;
+	struct msgq_elem *last;
+};
+
+static inline bool msgq_isempty(struct msgq *q) {
+	return !q->head;
+}
+
+struct msgq *msgq_new(void);
+void msgq_free(struct msgq *q);
+void msgq_enqueue(struct msgq *q, void *msg);
+void *msgq_dequeue(struct msgq *q);
+
+#endif // __MSGQUEUE_H__