From 511990c83ba7f27ddf62a2067fa9d773aff26aa2 Mon Sep 17 00:00:00 2001
From: afranchuk <alex.franchuk@gmail.com>
Date: Tue, 11 Jan 2022 13:04:24 -0500
Subject: [PATCH] Fix a bug in std.Thread.Condition and add a basic Condition
 test. (#10538)

* Fix FUTEX usage in std.Thread.Condition - It was using an old name.
---
 lib/std/Thread.zig           | 24 ++++++++++++++++++++++++
 lib/std/Thread/Condition.zig |  4 ++--
 2 files changed, 26 insertions(+), 2 deletions(-)

diff --git a/lib/std/Thread.zig b/lib/std/Thread.zig
index f2203e2808..83c2992a45 100644
--- a/lib/std/Thread.zig
+++ b/lib/std/Thread.zig
@@ -1151,3 +1151,27 @@ test "Thread.detach" {
     event.wait();
     try std.testing.expectEqual(value, 1);
 }
+
+fn testWaitForSignal(mutex: *Mutex, cond: *Condition) void {
+    mutex.lock();
+    defer mutex.unlock();
+    cond.signal();
+    cond.wait(mutex);
+}
+
+test "Condition.signal" {
+    if (builtin.single_threaded) return error.SkipZigTest;
+
+    var mutex = Mutex{};
+    var cond = Condition{};
+
+    var thread: Thread = undefined;
+    {
+        mutex.lock();
+        defer mutex.unlock();
+        thread = try Thread.spawn(.{}, testWaitForSignal, .{ &mutex, &cond });
+        cond.wait(&mutex);
+        cond.signal();
+    }
+    thread.join();
+}
diff --git a/lib/std/Thread/Condition.zig b/lib/std/Thread/Condition.zig
index 615f68cd9b..848e17ddce 100644
--- a/lib/std/Thread/Condition.zig
+++ b/lib/std/Thread/Condition.zig
@@ -106,7 +106,7 @@ pub const AtomicCondition = struct {
                     .linux => {
                         switch (linux.getErrno(linux.futex_wait(
                             &cond.futex,
-                            linux.FUTEX_PRIVATE_FLAG | linux.FUTEX_WAIT,
+                            linux.FUTEX.PRIVATE_FLAG | linux.FUTEX.WAIT,
                             0,
                             null,
                         ))) {
@@ -128,7 +128,7 @@ pub const AtomicCondition = struct {
                 .linux => {
                     switch (linux.getErrno(linux.futex_wake(
                         &cond.futex,
-                        linux.FUTEX_PRIVATE_FLAG | linux.FUTEX_WAKE,
+                        linux.FUTEX.PRIVATE_FLAG | linux.FUTEX.WAKE,
                         1,
                     ))) {
                         .SUCCESS => {},