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diff --git a/absl/strings/internal/cordz_functions.h b/absl/strings/internal/cordz_functions.h
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+// Copyright 2019 The Abseil Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef ABSL_STRINGS_CORDZ_FUNCTIONS_H_
+#define ABSL_STRINGS_CORDZ_FUNCTIONS_H_
+
+#include <stdint.h>
+
+#include "absl/base/attributes.h"
+#include "absl/base/config.h"
+#include "absl/base/optimization.h"
+
+namespace absl {
+ABSL_NAMESPACE_BEGIN
+namespace cord_internal {
+
+// Returns the current sample rate. This represents the average interval
+// between samples.
+int32_t get_cordz_mean_interval();
+
+// Sets the sample rate with the average interval between samples.
+void set_cordz_mean_interval(int32_t mean_interval);
+
+// Enable cordz unless any of the following applies:
+// - no thread local support
+// - MSVC build
+// - Android build
+// - Apple build
+// - DLL build
+// Hashtablez is turned off completely in opensource builds.
+// MSVC's static atomics are dynamically initialized in debug mode, which breaks
+// sampling.
+#if defined(ABSL_HAVE_THREAD_LOCAL) && !defined(_MSC_VER)  && \
+    !defined(ABSL_BUILD_DLL) && !defined(ABSL_CONSUME_DLL) && \
+    !defined(__ANDROID__) && !defined(__APPLE__)
+#define ABSL_INTERNAL_CORDZ_ENABLED 1
+#endif
+
+#ifdef ABSL_INTERNAL_CORDZ_ENABLED
+
+// cordz_next_sample is the number of events until the next sample event. If
+// the value is 1 or less, the code will check on the next event if cordz is
+// enabled, and if so, will sample the Cord. cordz is only enabled when we can
+// use thread locals.
+ABSL_CONST_INIT extern thread_local int64_t cordz_next_sample;
+
+// Determines if the next sample should be profiled. If it is, the value pointed
+// at by next_sample will be set with the interval until the next sample.
+bool cordz_should_profile_slow();
+
+// Returns true if the next cord should be sampled.
+inline bool cordz_should_profile() {
+  if (ABSL_PREDICT_TRUE(cordz_next_sample > 1)) {
+    cordz_next_sample--;
+    return false;
+  }
+  return cordz_should_profile_slow();
+}
+
+// Sets the interval until the next sample (for testing only)
+void cordz_set_next_sample_for_testing(int64_t next_sample);
+
+#else  // ABSL_INTERNAL_CORDZ_ENABLED
+
+inline bool cordz_should_profile() { return false; }
+inline void cordz_set_next_sample_for_testing(int64_t) {}
+
+#endif  // ABSL_INTERNAL_CORDZ_ENABLED
+
+}  // namespace cord_internal
+ABSL_NAMESPACE_END
+}  // namespace absl
+
+#endif  // ABSL_STRINGS_CORDZ_FUNCTIONS_H_