forked from
karlseguin.tngl.sh/websocket.zig
A websocket implementation for zig
Use mutex to protect handleconn of doublefree
This can happen if the client is disconneted just before the server is shutdown.
https://github.com/karlseguin/websocket.zig/issues/80
Karl Seguin
(Sep 14, 2025, 10:55 AM +0800)
4deaaef2
f7e2c02b
+15
-6
+15
-6
src/server/server.zig
+15
-6
src/server/server.zig
···
775
775
}
776
776
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777
fn cleanupConn(self: *Self, hc: *HandlerConn(H)) void {
778
-
if (hc.reader) |*reader| {
779
-
if (self.small_buffer_pool) |*sbp| {
780
-
sbp.release(reader.static);
781
-
} else {
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-
self.allocator.free(reader.static);
778
+
{
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+
hc.cleanup.lock();
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+
defer hc.cleanup.unlock();
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+
if (hc.reader) |*reader| {
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+
if (self.small_buffer_pool) |*sbp| {
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+
sbp.release(reader.static);
784
+
} else {
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+
self.allocator.free(reader.static);
786
+
}
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+
hc.reader = null;
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788
}
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}
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790
self.conn_manager.cleanup(hc);
···
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797
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798
// called for each hc when shutting down
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799
fn shutdownCleanup(self: *Self, hc: *HandlerConn(H)) void {
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+
hc.cleanup.lock();
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+
defer hc.cleanup.unlock();
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802
if (hc.reader) |*reader| {
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803
if (self.small_buffer_pool == null) {
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804
self.allocator.free(reader.static);
798
805
}
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+
hc.reader = null;
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807
}
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808
}
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809
};
···
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1094
reader: ?Reader,
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1095
socket: posix.socket_t, // denormalization from conn.stream.handle
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1096
handshake: ?*Handshake.State,
1097
+
cleanup: Thread.Mutex = .{},
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1098
compression: ?Compression = null,
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1099
next: ?*HandlerConn(H) = null,
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1100
prev: ?*HandlerConn(H) = null,
···
1272
1281
// This is sloppy and leaves things in an unrecoverable state. To keep
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1282
// things clean, we should call self.cleanup(hc) on each entry in the list
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// but that does a bunch of things we don't need if we know that we're
1275
-
// shutting down - like returning data to the pools, nd popping items
1284
+
// shutting down - like returning data to the pools, and popping items
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// out of the list.
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1286
fn shutdownList(head: ?*HandlerConn(H), worker: anytype) void {
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var next_node = head;