From 2609c2ca2fa85ab027af772cae74af5d4ecb25cf Mon Sep 17 00:00:00 2001
From: Drew DeVault <sir@cmpwn.com>
Date: Wed, 30 Nov 2022 13:23:29 +0100
Subject: [PATCH] Flesh out dispatch

---
 ev/+linux/file.ha |  2 +-
 ev/+linux/io.ha   | 22 ++++++++++++++++++++--
 ev/+linux/loop.ha | 31 +++++++++++++++++++++++--------

diff --git a/ev/+linux/file.ha b/ev/+linux/file.ha
index a4ef4e35ff5dae63e340ba4ceb9678b8c790ec9f..01db94908217af2725d8921b9c1b1a6362015d86 100644
--- a/ev/+linux/file.ha
+++ b/ev/+linux/file.ha
@@ -13,7 +13,7 @@ 	fd: io::file,
 	ev: *loop,
 	// Pending operation on this file object
 	op: op,
-	callback: nullable *void,
+	cb: nullable *void,
 
 	// Operation-specific data
 	vbuf: rt::iovec,
diff --git a/ev/+linux/io.ha b/ev/+linux/io.ha
index 3c72ee857910c88ac9259a4884899e761131e924..0e20b4d468d2049f221c6076856914f779be0153 100644
--- a/ev/+linux/io.ha
+++ b/ev/+linux/io.ha
@@ -24,10 +24,19 @@ 	vec: io::vector...
 ) req = {
 	assert(file.op == op::NONE);
 	file.op = op::READV;
-	file.callback = cb;
+	file.cb = cb;
 	file.vec = vec;
 	filemod(file, rt::EPOLLOUT);
 	return req { ... };
+};
+
+fn readv_finish(file: *file, ev: *rt::epoll_event) void = {
+	assert(file.op == op::READV && ev.events & rt::EPOLLIN != 0);
+	assert(file.cb != null);
+	const r = io::readv(file.fd, file.vec...);
+	const cb = file.cb: *readcb;
+	cb(file, r);
+	file.op = op::NONE;
 };
 
 // A callback for a [[write]] or [[writev]] operation.
@@ -55,8 +64,17 @@ 	// XXX: Should we support both pending reads and writes at the same
 	// time? (yes)
 	assert(file.op == op::NONE);
 	file.op = op::WRITEV;
-	file.callback = cb;
+	file.cb = cb;
 	file.vec = vec;
 	filemod(file, rt::EPOLLOUT);
 	return req { ... };
 };
+
+fn writev_finish(file: *file, ev: *rt::epoll_event) void = {
+	assert(file.op == op::WRITEV && ev.events & rt::EPOLLOUT != 0);
+	assert(file.cb != null);
+	const r = io::writev(file.fd, file.vec...);
+	const cb = file.cb: *writecb;
+	cb(file, r);
+	file.op = op::NONE;
+};
diff --git a/ev/+linux/loop.ha b/ev/+linux/loop.ha
index f3492ffaa4d2a8d5c341d4fb3f4c8782bc6acbf2..17f658f30a787306a38c8c59004bbffc7c2562f9 100644
--- a/ev/+linux/loop.ha
+++ b/ev/+linux/loop.ha
@@ -39,8 +39,9 @@ export fn loop_file(loop: *loop) io::file = {
 	return loop.fd;
 };
 
-// Dispatches the event loop. A duration of -1 specifies an indefinite timeout,
-// and will cause dispatch to block until the next event is available.
+// Dispatches the event loop. A timeout of 0 specifies an indefinite timeout,
+// and will cause dispatch to block until the next event is available. A timeout
+// of -1 will return immediately if no events are available.
 //
 // Portable use of the timeout argument supports only millisecond granularity of
 // up to 24 days (INT_MAX milliseconds). Negative values other than -1 will
@@ -65,10 +66,24 @@ 	// TODO: Deal with signals
 	const maxev = len(loop.events);
 	assert(maxev <= types::INT_MAX: size, "ev::dispatch: too many events");
 	const events = rt::epoll_pwait(
-		loop.fd,
-		&loop.events[0],
-		maxev: int,
-		millis,
-		null)!;
-	return true;
+		loop.fd, &loop.events[0],
+		maxev: int, millis, null)!;
+
+	for (let i = 0z; i < maxev; i += 1) {
+		const ev = &loop.events[i];
+		const file = ev.data.ptr: *file;
+		if (ev.events == 0) {
+			continue;
+		};
+		switch (file.op) {
+		case op::NONE =>
+			abort("Invalid pending operation");
+		case op::READV =>
+			readv_finish(file, ev);
+		case op::WRITEV =>
+			writev_finish(file, ev);
+		};
+	};
+
+	return events != 0;
 };

-- 
2.48.1