1 files changed, 65 insertions, 0 deletions
diff --git a/libcr_ipc/include/libcr_ipc/_TODO_select.h b/libcr_ipc/include/libcr_ipc/_TODO_select.h
new file mode 100644
index 0000000..5510fc4
--- /dev/null
+++ b/libcr_ipc/include/libcr_ipc/_TODO_select.h
@@ -0,0 +1,65 @@
+/*
+ * Copyright (C) 2024  Luke T. Shumaker <lukeshu@lukeshu.com>
+ * SPDX-Licence-Identifier: AGPL-3.0-or-later
+ */
+
+struct _cr_select_arg {
+	enum _cr_select_op {
+		_CR_SELECT_NONE,
+		_CR_SELECT_RECV,
+		_CR_SELECT_SEND,
+		_CR_SELECT_DEFAULT,
+	}                        op;
+	struct _cr_chan		*ch;
+	struct _cr_chan_waiter   self;
+};
+#define CR_SELECT_RECV(ch)      ((struct _cr_select_arg){.op=_CR_SELECT_RECV, sizeof((ch)->vals[0]), ch,
+#define CR_SELECT_SEND(ch)      _CR_SELECT_SEND, sizeof((ch)->vals[0]), ch,
+#define CR_SELECT_DEFAULT       _CR_SELECT_DEFAULT,
+#define CR_SELECT(OPS)          switch(_cr_chan_select(OPS _CR_SELECT_NONE))
+
+size_t _cr_chan_select(enum _cr_select_op a, ...) {
+ restart:
+	size_t blocking, nonblocking;
+	bool have_default = false;
+
+	va_list args;
+	va_start(args, a);
+	bool first = true;
+	for (size_t i = 0; true; i++) {
+		enum _cr_select_op op;
+		if (first) {
+			op = a;
+			first = false;
+		} else
+			op = va_arg(args, enum _cr_select_op);
+		if (op == _CR_SELECT_NONE)
+			break;
+		else if (op == _CR_SELECT_DEFAULT) {
+			have_default = true;
+			continue;
+		}
+		size_t sz;
+		struct _cr_chan *ch;
+		sz = va_arg(args, size_t);
+		ch = va_arg(args, struct _cr_chan *);
+		if (op == _CR_SELECT_RECV) {
+			if (ch->waiters.front && ch->waiter_typ == _CH_CHAN_SENDER)
+				nonblocking++;
+			else
+				blocking++;
+		} else {
+			if (ch->waiters.front && ch->waiter_typ == _CH_CHAN_RECVER)
+				nonblocking++;
+			else
+				blocking++;
+		}
+	}
+	va_end(args);
+
+	random()
+
+	if (nonblocking == 0 && !have_default) {
+		goto restart;
+	}
+}