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diff --git a/memory/build/mozmemory_utils.h b/memory/build/mozmemory_utils.h
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+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozjemalloc_utils_h
+#define mozjemalloc_utils_h
+
+#include <optional>
+#include <type_traits>
+
+#if defined(MOZ_MEMORY) && defined(XP_WIN)
+# include "mozmemory_wrap.h"
+#endif
+
+namespace mozilla {
+
+namespace detail {
+// Helper for StallAndRetry error messages.
+template <typename T>
+constexpr bool is_std_optional = false;
+template <typename T>
+constexpr bool is_std_optional<std::optional<T>> = true;
+} // namespace detail
+
+struct StallSpecs {
+ // Maximum number of retry-attempts before giving up.
+ size_t maxAttempts;
+ // Delay time between successive events.
+ size_t delayMs;
+
+ // Retry a fallible operation until it succeeds or until we've run out of
+ // retries.
+ //
+ // Note that this invokes `aDelayFunc` immediately upon being called! It's
+ // intended for use in the unhappy path, after an initial attempt has failed.
+ //
+ // The function type here may be read:
+ // ```
+ // fn StallAndRetry<R>(
+ // delay_func: impl Fn(usize) -> (),
+ // operation: impl Fn() -> Option<R>,
+ // ) -> Option<R>;
+ // ```
+ //
+ template <typename DelayFunc, typename OpFunc>
+ auto StallAndRetry(DelayFunc&& aDelayFunc, OpFunc&& aOperation) const
+ -> decltype(aOperation()) {
+ {
+ // Explicit typecheck for OpFunc, to provide an explicit error message.
+ using detail::is_std_optional;
+ static_assert(is_std_optional<decltype(aOperation())>,
+ "aOperation() must return std::optional");
+
+ // (clang's existing error messages suffice for aDelayFunc.)
+ }
+
+ for (size_t i = 0; i < maxAttempts; ++i) {
+ aDelayFunc(delayMs);
+ if (const auto opt = aOperation()) {
+ return opt;
+ }
+ }
+ return std::nullopt;
+ }
+};
+
+#if defined(MOZ_MEMORY) && defined(XP_WIN)
+MOZ_JEMALLOC_API StallSpecs GetAllocatorStallSpecs();
+#endif
+
+} // namespace mozilla
+
+#endif // mozjemalloc_utils_h