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diff --git a/compiler-rt/lib/scudo/standalone/condition_variable.h b/compiler-rt/lib/scudo/standalone/condition_variable.h
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+//===-- condition_variable.h ------------------------------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef SCUDO_CONDITION_VARIABLE_H_
+#define SCUDO_CONDITION_VARIABLE_H_
+
+#include "condition_variable_base.h"
+
+#include "common.h"
+#include "platform.h"
+
+#include "condition_variable_linux.h"
+
+namespace scudo {
+
+// A default implementation of default condition variable. It doesn't do a real
+// `wait`, instead it spins a short amount of time only.
+class ConditionVariableDummy
+ : public ConditionVariableBase<ConditionVariableDummy> {
+public:
+ void notifyAllImpl(UNUSED HybridMutex &M) REQUIRES(M) {}
+
+ void waitImpl(UNUSED HybridMutex &M) REQUIRES(M) {
+ M.unlock();
+
+ constexpr u32 SpinTimes = 64;
+ volatile u32 V = 0;
+ for (u32 I = 0; I < SpinTimes; ++I) {
+ u32 Tmp = V + 1;
+ V = Tmp;
+ }
+
+ M.lock();
+ }
+};
+
+template <typename Config, typename = const bool>
+struct ConditionVariableState {
+ static constexpr bool enabled() { return false; }
+ // This is only used for compilation purpose so that we won't end up having
+ // many conditional compilations. If you want to use `ConditionVariableDummy`,
+ // define `ConditionVariableT` in your allocator configuration. See
+ // allocator_config.h for more details.
+ using ConditionVariableT = ConditionVariableDummy;
+};
+
+template <typename Config>
+struct ConditionVariableState<Config, decltype(Config::UseConditionVariable)> {
+ static constexpr bool enabled() { return true; }
+ using ConditionVariableT = typename Config::ConditionVariableT;
+};
+
+} // namespace scudo
+
+#endif // SCUDO_CONDITION_VARIABLE_H_