From d194e49d8f03e17ca2e664bae865fcb6bb0f62be Mon Sep 17 00:00:00 2001
From: YiraSan <yirasan.bk@gmail.com>
Date: Tue, 28 Jan 2025 17:51:24 +0100
Subject: [PATCH] test locks on cancellation

---
 src/coro/sync.zig | 140 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 140 insertions(+)

diff --git a/src/coro/sync.zig b/src/coro/sync.zig
index 8c28c64..1b73bf9 100644
--- a/src/coro/sync.zig
+++ b/src/coro/sync.zig
@@ -333,3 +333,143 @@ test "RwLock" {
     std.debug.assert(lock.counter == 0);
     std.debug.assert(lock.locked == false);
 }
+
+test "Mutex.Cancel" {
+    const Test = struct {
+        fn incrementer(lock: *Mutex, value: *usize, check_value: *usize) !void {
+            while (true) {
+                try lock.lock();
+                defer lock.unlock();
+
+                value.* += 1000;
+
+                const stored = check_value.*;
+
+                // simulates a "workload" + makes coroutines to try lock
+                try coro.io.single(.timeout, .{ .ns = std.time.ns_per_ms });
+
+                check_value.* = stored + 1000;
+            }
+        }
+
+        fn cancel(canceled: *bool) !void {
+            try coro.io.single(.timeout, .{ .ns = 16 * std.time.ns_per_ms });
+            canceled.* = true;
+        }
+
+        fn test_thread(lock: *Mutex, value: *usize, check_value: *usize) !void {
+            var scheduler = try coro.Scheduler.init(std.testing.allocator, .{});
+            defer scheduler.deinit();
+
+            for (0..128) |_| {
+                _ = try scheduler.spawn(incrementer, .{ lock, value, check_value }, .{ .detached = true });
+            }
+
+            var canceled = false;
+            _ = try scheduler.spawn(cancel, .{&canceled}, .{ .detached = true });
+
+            while (!canceled) {
+                _ = try scheduler.tick(.blocking);
+            }
+
+            try scheduler.run(.cancel);
+        }
+    };
+
+    var lock = try Mutex.init();
+    defer lock.deinit();
+
+    var value: usize = 0;
+    var check_value: usize = 0;
+
+    var threads: [8]std.Thread = undefined;
+
+    for (0..8) |i| {
+        threads[i] = try std.Thread.spawn(.{}, Test.test_thread, .{ &lock, &value, &check_value });
+    }
+
+    for (threads) |thread| {
+        thread.join();
+    }
+
+    std.debug.assert(value == check_value);
+}
+
+test "RwLock.Cancel" {
+    const Test = struct {
+        fn incrementer(lock: *RwLock, value: *usize, check_value: *usize) !void {
+            while (true) {
+                try lock.lock();
+                defer lock.unlock();
+
+                value.* += 1000;
+
+                const stored = check_value.*;
+
+                // simulates a "workload" + makes coroutines to try lock
+                try coro.io.single(.timeout, .{ .ns = std.time.ns_per_ms });
+
+                check_value.* = stored + 1000;
+            }
+        }
+
+        fn locksharer(lock: *RwLock) !void {
+            while (true) {
+                // simulates a "workload"
+                try coro.io.single(.timeout, .{ .ns = std.time.ns_per_ms });
+
+                try lock.lockShared();
+                defer lock.unlock();
+            }
+        }
+
+        fn cancel(canceled: *bool) !void {
+            try coro.io.single(.timeout, .{ .ns = 16 * std.time.ns_per_ms });
+            canceled.* = true;
+        }
+
+        fn test_thread(lock: *RwLock, value: *usize, check_value: *usize) !void {
+            var scheduler = try coro.Scheduler.init(std.testing.allocator, .{});
+            defer scheduler.deinit();
+
+            for (0..128) |_| {
+                _ = try scheduler.spawn(incrementer, .{ lock, value, check_value }, .{ .detached = true });
+            }
+
+            for (0..16) |_| {
+                _ = try scheduler.spawn(locksharer, .{lock}, .{ .detached = true });
+            }
+
+            var canceled = false;
+            _ = try scheduler.spawn(cancel, .{&canceled}, .{ .detached = true });
+
+            while (!canceled) {
+                _ = try scheduler.tick(.blocking);
+            }
+
+            try scheduler.run(.cancel);
+        }
+    };
+
+    var lock = try RwLock.init();
+    defer lock.deinit();
+
+    var value: usize = 0;
+    var check_value: usize = 0;
+
+    var threads: [8]std.Thread = undefined;
+
+    for (0..8) |i| {
+        threads[i] = try std.Thread.spawn(.{}, Test.test_thread, .{ &lock, &value, &check_value });
+    }
+
+    for (threads) |thread| {
+        thread.join();
+    }
+
+    std.debug.assert(value == check_value);
+
+    // check if it has successfully returned in its initial state.
+    std.debug.assert(lock.counter == 0);
+    std.debug.assert(lock.locked == false);
+}