Move Predicate.h from Host to Utility

Summary:
This class was initially in Host because its implementation used to be
very OS-specific. However, with C++11, it has become a very simple
std::condition_variable wrapper, with no host-specific code.

It is also a general purpose utility class, so it makes sense for it to
live in a place where it can be used by everyone.

This has no effect on the layering right now, but it enables me to later
move the Listener+Broadcaster+Event combo to a lower layer, which is
important, as these are used in a lot of places (notably for launching a
process in Host code).

Reviewers: jingham, zturner, teemperor

Reviewed By: zturner

Subscribers: xiaobai, mgorny, lldb-commits

Differential Revision: https://reviews.llvm.org/D50384

llvm-svn: 341089

1 files changed, 34 insertions, 0 deletions

diff --git a/lldb/unittests/Utility/PredicateTest.cpp b/lldb/unittests/Utility/PredicateTest.cpp
new file mode 100644
index 00000000000..327dd80b23e
--- /dev/null
+++ b/lldb/unittests/Utility/PredicateTest.cpp
@@ -0,0 +1,34 @@
+//===-- PredicateTest.cpp ---------------------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "lldb/Utility/Predicate.h"
+#include "gtest/gtest.h"
+#include <thread>
+
+using namespace lldb_private;
+
+TEST(Predicate, WaitForValueEqualTo) {
+  Predicate<int> P(0);
+  EXPECT_TRUE(P.WaitForValueEqualTo(0));
+  EXPECT_FALSE(P.WaitForValueEqualTo(1, std::chrono::milliseconds(10)));
+
+  std::thread Setter([&P] {
+    std::this_thread::sleep_for(std::chrono::milliseconds(100));
+    P.SetValue(1, eBroadcastAlways);
+  });
+  EXPECT_TRUE(P.WaitForValueEqualTo(1));
+  Setter.join();
+}
+
+TEST(Predicate, WaitForValueNotEqualTo) {
+  Predicate<int> P(0);
+  EXPECT_EQ(0, P.WaitForValueNotEqualTo(1));
+  EXPECT_EQ(llvm::None,
+            P.WaitForValueNotEqualTo(0, std::chrono::milliseconds(10)));
+}