io: fix file:close() and file:__gc() blocking

2 files changed, 117 insertions, 11 deletions

diff --git a/lem/io/file.c b/lem/io/file.c
index c9f675a..b7ad297 100644
--- a/lem/io/file.c
+++ b/lem/io/file.c
@@ -45,6 +45,11 @@ struct file {
 	struct lem_inputbuf buf;
 };
 
+struct file_gc {
+	struct lem_async a;
+	int fd;
+};
+
 static struct file *
 file_new(lua_State *T, int fd, int mt)
 {
@@ -63,14 +68,38 @@ file_new(lua_State *T, int fd, int mt)
 	return f;
 }
 
+/*
+ * file:__gc() metamethod
+ */
+static void
+file_gc_work(struct lem_async *a)
+{
+	struct file_gc *gc = (struct file_gc *)a;
+
+	close(gc->fd);
+}
+
+static void
+file_gc_reap(struct lem_async *a)
+{
+	struct file_gc *gc = (struct file_gc *)a;
+
+	free(gc);
+}
+
 static int
 file_gc(lua_State *T)
 {
 	struct file *f = lua_touserdata(T, 1);
 
 	lem_debug("collecting %p, fd = %d", f, f->fd);
-	if (f->fd >= 0)
-		(void)close(f->fd);
+	if (f->fd >= 0) {
+		struct file_gc *gc = lem_xmalloc(sizeof(struct file_gc));
+
+		gc->fd = f->fd;
+		f->fd = -1;
+		lem_async_do(&gc->a, NULL, file_gc_work, file_gc_reap);
+	}
 
 	return 0;
 }
@@ -86,11 +115,41 @@ file_closed(lua_State *T)
 	return 1;
 }
 
+/*
+ * file:close() method
+ */
+static void
+file_close_work(struct lem_async *a)
+{
+	struct file *f = (struct file *)a;
+
+	if (close(f->fd))
+		f->ret = errno;
+	else
+		f->ret = 0;
+}
+
+static void
+file_close_reap(struct lem_async *a)
+{
+	struct file *f = (struct file *)a;
+	lua_State *T = f->a.T;
+
+	f->a.T = NULL;
+	f->fd = -1;
+	if (f->ret) {
+		lem_queue(T, io_strerror(T, f->ret));
+		return;
+	}
+
+	lua_pushboolean(T, 1);
+	lem_queue(T, 1);
+}
+
 static int
 file_close(lua_State *T)
 {
 	struct file *f;
-	int ret;
 
 	luaL_checktype(T, 1, LUA_TUSERDATA);
 	f = lua_touserdata(T, 1);
@@ -99,14 +158,9 @@ file_close(lua_State *T)
 	if (f->a.T != NULL)
 		return io_busy(T);
 
-	lem_debug("collecting %d", f->fd);
-	ret = close(f->fd);
-	f->fd = -1;
-	if (ret)
-		return io_strerror(T, errno);
-
-	lua_pushboolean(T, 1);
-	return 1;
+	lem_async_do(&f->a, T, file_close_work, file_close_reap);
+	lua_settop(T, 1);
+	return lua_yield(T, 1);
 }
 
 /*
diff --git a/test/fclose.lua b/test/fclose.lua
new file mode 100755
index 0000000..417decd
--- /dev/null
+++ b/test/fclose.lua
@@ -0,0 +1,52 @@
+#!bin/lem
+--
+-- This file is part of LEM, a Lua Event Machine.
+-- Copyright 2013 Ico Doornekamp
+-- Copyright 2013 Emil Renner Berthing
+--
+-- LEM 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 3 of
+-- the License, or (at your option) any later version.
+--
+-- LEM 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 LEM.  If not, see <http://www.gnu.org/licenses/>.
+--
+
+package.path = '?.lua'
+package.cpath = '?.so'
+
+local utils = require 'lem.utils'
+local io    = require 'lem.io'
+
+local done = false
+
+utils.spawn(function()
+	local s, now, format = utils.newsleeper(), utils.now, string.format
+	local t1, t2 = now(), 0
+	repeat
+		s:sleep(0.1)
+		t2 = now()
+		print(format("Tick after %uus", (t2 - t1)*1000000))
+		t1 = t2
+	until done
+end)
+
+local file = assert(io.open('file.txt', 'w'))
+local b = string.rep("a", 1024*1024)
+for i = 1, 150 do
+	file:write(b)
+end
+print("Closing file")
+file:close()
+print("Write done")
+
+utils.newsleeper():sleep(1)
+done = true
+
+-- vim: set ts=2 sw=2 noet: