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-rw-r--r--absl/BUILD.bazel7
-rw-r--r--absl/base/BUILD.bazel1
-rw-r--r--absl/base/CMakeLists.txt2
-rw-r--r--absl/base/internal/raw_logging.cc16
-rw-r--r--absl/base/internal/raw_logging.h43
-rw-r--r--absl/base/raw_logging_test.cc29
-rw-r--r--absl/compiler_config_setting.bzl39
-rw-r--r--absl/container/inlined_vector.h7
-rw-r--r--absl/copts.bzl1
-rw-r--r--absl/debugging/internal/stacktrace_config.h37
-rw-r--r--absl/strings/str_format_test.cc4
-rw-r--r--absl/synchronization/mutex.h4
-rw-r--r--absl/synchronization/mutex_test.cc575
-rw-r--r--absl/time/clock_test.cc94
-rw-r--r--absl/types/variant.h2
15 files changed, 577 insertions, 284 deletions
diff --git a/absl/BUILD.bazel b/absl/BUILD.bazel
index 439addbfc828..edd0274c5d83 100644
--- a/absl/BUILD.bazel
+++ b/absl/BUILD.bazel
@@ -18,11 +18,10 @@ package(default_visibility = ["//visibility:public"])
 
 licenses(["notice"])  # Apache 2.0
 
-config_setting(
+load(":compiler_config_setting.bzl", "create_llvm_config")
+
+create_llvm_config(
     name = "llvm_compiler",
-    values = {
-        "compiler": "llvm",
-    },
     visibility = [":__subpackages__"],
 )
 
diff --git a/absl/base/BUILD.bazel b/absl/base/BUILD.bazel
index 35414a252c62..06d092ebdfa8 100644
--- a/absl/base/BUILD.bazel
+++ b/absl/base/BUILD.bazel
@@ -362,6 +362,7 @@ cc_test(
     copts = ABSL_TEST_COPTS,
     deps = [
         ":base",
+        "//absl/strings",
         "@com_google_googletest//:gtest_main",
     ],
 )
diff --git a/absl/base/CMakeLists.txt b/absl/base/CMakeLists.txt
index 303533e26d1b..01d2af085f58 100644
--- a/absl/base/CMakeLists.txt
+++ b/absl/base/CMakeLists.txt
@@ -310,7 +310,7 @@ absl_test(
 
 # test raw_logging_test
 set(RAW_LOGGING_TEST_SRC "raw_logging_test.cc")
-set(RAW_LOGGING_TEST_PUBLIC_LIBRARIES absl::base)
+set(RAW_LOGGING_TEST_PUBLIC_LIBRARIES absl::base absl::strings)
 
 absl_test(
   TARGET
diff --git a/absl/base/internal/raw_logging.cc b/absl/base/internal/raw_logging.cc
index 1ce138887252..41101bd72eb8 100644
--- a/absl/base/internal/raw_logging.cc
+++ b/absl/base/internal/raw_logging.cc
@@ -206,6 +206,15 @@ void RawLog(absl::LogSeverity severity, const char* file, int line,
   va_end(ap);
 }
 
+// Non-formatting version of RawLog().
+//
+// TODO(gfalcon): When string_view no longer depends on base, change this
+// interface to take its message as a string_view instead.
+static void DefaultInternalLog(absl::LogSeverity severity, const char* file,
+                               int line, const std::string& message) {
+  RawLog(severity, file, line, "%s", message.c_str());
+}
+
 bool RawLoggingFullySupported() {
 #ifdef ABSL_LOW_LEVEL_WRITE_SUPPORTED
   return true;
@@ -214,5 +223,12 @@ bool RawLoggingFullySupported() {
 #endif  // !ABSL_LOW_LEVEL_WRITE_SUPPORTED
 }
 
+ABSL_CONST_INIT absl::base_internal::AtomicHook<InternalLogFunction>
+    internal_log_function(DefaultInternalLog);
+
+void RegisterInternalLogFunction(InternalLogFunction func) {
+  internal_log_function.Store(func);
+}
+
 }  // namespace raw_logging_internal
 }  // namespace absl
diff --git a/absl/base/internal/raw_logging.h b/absl/base/internal/raw_logging.h
index a2b7207a032c..67abfd30798d 100644
--- a/absl/base/internal/raw_logging.h
+++ b/absl/base/internal/raw_logging.h
@@ -19,7 +19,10 @@
 #ifndef ABSL_BASE_INTERNAL_RAW_LOGGING_H_
 #define ABSL_BASE_INTERNAL_RAW_LOGGING_H_
 
+#include <string>
+
 #include "absl/base/attributes.h"
+#include "absl/base/internal/atomic_hook.h"
 #include "absl/base/log_severity.h"
 #include "absl/base/macros.h"
 #include "absl/base/port.h"
@@ -57,6 +60,34 @@
     }                                                                  \
   } while (0)
 
+// ABSL_INTERNAL_LOG and ABSL_INTERNAL_CHECK work like the RAW variants above,
+// except that if the richer log library is linked into the binary, we dispatch
+// to that instead.  This is potentially useful for internal logging and
+// assertions, where we are using RAW_LOG neither for its async-signal-safety
+// nor for its non-allocating nature, but rather because raw logging has very
+// few other dependencies.
+//
+// The API is a subset of the above: each macro only takes two arguments.  Use
+// StrCat if you need to build a richer message.
+#define ABSL_INTERNAL_LOG(severity, message)                          \
+  do {                                                                \
+    constexpr const char* absl_raw_logging_internal_basename =        \
+        ::absl::raw_logging_internal::Basename(__FILE__,              \
+                                               sizeof(__FILE__) - 1); \
+    ::absl::raw_logging_internal::internal_log_function(              \
+        ABSL_RAW_LOGGING_INTERNAL_##severity,                         \
+        absl_raw_logging_internal_basename, __LINE__, message);       \
+  } while (0)
+
+#define ABSL_INTERNAL_CHECK(condition, message)               \
+  do {                                                        \
+    if (ABSL_PREDICT_FALSE(!(condition))) {                   \
+      std::string death_message = "Check " #condition " failed: "; \
+      death_message += std::string(message);                       \
+      ABSL_INTERNAL_LOG(FATAL, death_message);                \
+    }                                                         \
+  } while (0)
+
 #define ABSL_RAW_LOGGING_INTERNAL_INFO ::absl::LogSeverity::kInfo
 #define ABSL_RAW_LOGGING_INTERNAL_WARNING ::absl::LogSeverity::kWarning
 #define ABSL_RAW_LOGGING_INTERNAL_ERROR ::absl::LogSeverity::kError
@@ -131,6 +162,18 @@ using LogPrefixHook = bool (*)(absl::LogSeverity severity, const char* file,
 using AbortHook = void (*)(const char* file, int line, const char* buf_start,
                            const char* prefix_end, const char* buf_end);
 
+// Internal logging function for ABSL_INTERNAL_LOG to dispatch to.
+//
+// TODO(gfalcon): When string_view no longer depends on base, change this
+// interface to take its message as a string_view instead.
+using InternalLogFunction = void (*)(absl::LogSeverity severity,
+                                     const char* file, int line,
+                                     const std::string& message);
+
+extern base_internal::AtomicHook<InternalLogFunction> internal_log_function;
+
+void RegisterInternalLogFunction(InternalLogFunction func);
+
 }  // namespace raw_logging_internal
 }  // namespace absl
 
diff --git a/absl/base/raw_logging_test.cc b/absl/base/raw_logging_test.cc
index dae4b35138c5..ebbc5db90672 100644
--- a/absl/base/raw_logging_test.cc
+++ b/absl/base/raw_logging_test.cc
@@ -18,12 +18,20 @@
 
 #include "absl/base/internal/raw_logging.h"
 
+#include <tuple>
+
 #include "gtest/gtest.h"
+#include "absl/strings/str_cat.h"
 
 namespace {
 
 TEST(RawLoggingCompilationTest, Log) {
   ABSL_RAW_LOG(INFO, "RAW INFO: %d", 1);
+  ABSL_RAW_LOG(INFO, "RAW INFO: %d %d", 1, 2);
+  ABSL_RAW_LOG(INFO, "RAW INFO: %d %d %d", 1, 2, 3);
+  ABSL_RAW_LOG(INFO, "RAW INFO: %d %d %d %d", 1, 2, 3, 4);
+  ABSL_RAW_LOG(INFO, "RAW INFO: %d %d %d %d %d", 1, 2, 3, 4, 5);
+  ABSL_RAW_LOG(WARNING, "RAW WARNING: %d", 1);
   ABSL_RAW_LOG(ERROR, "RAW ERROR: %d", 1);
 }
 
@@ -47,4 +55,25 @@ TEST(RawLoggingDeathTest, LogFatal) {
                             kExpectedDeathOutput);
 }
 
+TEST(InternalLog, CompilationTest) {
+  ABSL_INTERNAL_LOG(INFO, "Internal Log");
+  std::string log_msg = "Internal Log";
+  ABSL_INTERNAL_LOG(INFO, log_msg);
+
+  ABSL_INTERNAL_LOG(INFO, log_msg + " 2");
+
+  float d = 1.1f;
+  ABSL_INTERNAL_LOG(INFO, absl::StrCat("Internal log ", 3, " + ", d));
+}
+
+TEST(InternalLogDeathTest, FailingCheck) {
+  EXPECT_DEATH_IF_SUPPORTED(ABSL_INTERNAL_CHECK(1 == 0, "explanation"),
+                            kExpectedDeathOutput);
+}
+
+TEST(InternalLogDeathTest, LogFatal) {
+  EXPECT_DEATH_IF_SUPPORTED(ABSL_INTERNAL_LOG(FATAL, "my dog has fleas"),
+                            kExpectedDeathOutput);
+}
+
 }  // namespace
diff --git a/absl/compiler_config_setting.bzl b/absl/compiler_config_setting.bzl
new file mode 100644
index 000000000000..b77c4f563b95
--- /dev/null
+++ b/absl/compiler_config_setting.bzl
@@ -0,0 +1,39 @@
+#
+# Copyright 2018 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
+#
+#      http://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.
+#
+
+"""Creates config_setting that allows selecting based on 'compiler' value."""
+
+def create_llvm_config(name, visibility):
+  # The "do_not_use_tools_cpp_compiler_present" attribute exists to
+  # distinguish between older versions of Bazel that do not support
+  # "@bazel_tools//tools/cpp:compiler" flag_value, and newer ones that do.
+  # In the future, the only way to select on the compiler will be through
+  # flag_values{"@bazel_tools//tools/cpp:compiler"} and the else branch can
+  # be removed.
+  if hasattr(cc_common, "do_not_use_tools_cpp_compiler_present"):
+    native.config_setting(
+      name = name,
+      flag_values = {
+          "@bazel_tools//tools/cpp:compiler": "llvm",
+      },
+      visibility = visibility,
+    )
+  else:
+    native.config_setting(
+        name = name,
+        values = {"compiler": "llvm"},
+        visibility = visibility,
+    )
diff --git a/absl/container/inlined_vector.h b/absl/container/inlined_vector.h
index 03660f165353..75d980274a57 100644
--- a/absl/container/inlined_vector.h
+++ b/absl/container/inlined_vector.h
@@ -689,11 +689,14 @@ class InlinedVector {
     new (&rep_.allocation_storage.allocation) Allocation(allocation);
   }
 
+  // TODO(absl-team): investigate whether the reinterpret_cast is appropriate.
   value_type* inlined_space() {
-    return reinterpret_cast<value_type*>(&rep_.inlined_storage.inlined);
+    return reinterpret_cast<value_type*>(
+        std::addressof(rep_.inlined_storage.inlined[0]));
   }
   const value_type* inlined_space() const {
-    return reinterpret_cast<const value_type*>(&rep_.inlined_storage.inlined);
+    return reinterpret_cast<const value_type*>(
+        std::addressof(rep_.inlined_storage.inlined[0]));
   }
 
   value_type* allocated_space() { return allocation().buffer(); }
diff --git a/absl/copts.bzl b/absl/copts.bzl
index 20c9b6190dc9..0168ac5abddc 100644
--- a/absl/copts.bzl
+++ b/absl/copts.bzl
@@ -31,7 +31,6 @@ GCC_TEST_FLAGS = [
     "-Wno-unused-private-field",
 ]
 
-
 # Docs on single flags is preceded by a comment.
 # Docs on groups of flags is preceded by ###.
 
diff --git a/absl/debugging/internal/stacktrace_config.h b/absl/debugging/internal/stacktrace_config.h
index 48adfccc62e5..dd713da8c0c7 100644
--- a/absl/debugging/internal/stacktrace_config.h
+++ b/absl/debugging/internal/stacktrace_config.h
@@ -21,26 +21,16 @@
 #ifndef ABSL_DEBUGGING_INTERNAL_STACKTRACE_CONFIG_H_
 #define ABSL_DEBUGGING_INTERNAL_STACKTRACE_CONFIG_H_
 
-// First, test platforms which only support a stub.
-#if ABSL_STACKTRACE_INL_HEADER
+#if defined(ABSL_STACKTRACE_INL_HEADER)
 #error ABSL_STACKTRACE_INL_HEADER cannot be directly set
-#elif defined(__native_client__) || defined(__APPLE__) || \
-    defined(__FreeBSD__) || defined(__ANDROID__) || defined(__myriad2__) || \
-    defined(__asmjs__) || defined(__wasm__) || defined(__Fuchsia__)
-#define ABSL_STACKTRACE_INL_HEADER \
-    "absl/debugging/internal/stacktrace_unimplemented-inl.inc"
 
-// Next, test for Mips and Windows.
-// TODO(marmstrong): Mips case, remove the check for ABSL_STACKTRACE_INL_HEADER
-#elif defined(__mips__) && !defined(ABSL_STACKTRACE_INL_HEADER)
-#define ABSL_STACKTRACE_INL_HEADER \
-    "absl/debugging/internal/stacktrace_unimplemented-inl.inc"
-#elif defined(_WIN32)  // windows
+#elif defined(_WIN32)
 #define ABSL_STACKTRACE_INL_HEADER \
     "absl/debugging/internal/stacktrace_win32-inl.inc"
 
-// Finally, test NO_FRAME_POINTER.
-#elif !defined(NO_FRAME_POINTER)
+#elif defined(__linux__) && !defined(__ANDROID__)
+
+#if !defined(NO_FRAME_POINTER)
 # if defined(__i386__) || defined(__x86_64__)
 #define ABSL_STACKTRACE_INL_HEADER \
     "absl/debugging/internal/stacktrace_x86-inl.inc"
@@ -53,22 +43,27 @@
 # elif defined(__arm__)
 #define ABSL_STACKTRACE_INL_HEADER \
     "absl/debugging/internal/stacktrace_arm-inl.inc"
+# else
+#define ABSL_STACKTRACE_INL_HEADER \
+   "absl/debugging/internal/stacktrace_unimplemented-inl.inc"
 # endif
 #else  // defined(NO_FRAME_POINTER)
 # if defined(__i386__) || defined(__x86_64__) || defined(__aarch64__)
 #define ABSL_STACKTRACE_INL_HEADER \
-    "absl/debugging/internal/stacktrace_unimplemented-inl.inc"
+    "absl/debugging/internal/stacktrace_generic-inl.inc"
 # elif defined(__ppc__) || defined(__PPC__)
-//  Use glibc's backtrace.
 #define ABSL_STACKTRACE_INL_HEADER \
     "absl/debugging/internal/stacktrace_generic-inl.inc"
-# elif defined(__arm__)
-#   error stacktrace without frame pointer is not supported on ARM
+# else
+#define ABSL_STACKTRACE_INL_HEADER \
+   "absl/debugging/internal/stacktrace_unimplemented-inl.inc"
 # endif
 #endif  // NO_FRAME_POINTER
 
-#if !defined(ABSL_STACKTRACE_INL_HEADER)
-#error Not supported yet
+#else
+#define ABSL_STACKTRACE_INL_HEADER \
+  "absl/debugging/internal/stacktrace_unimplemented-inl.inc"
+
 #endif
 
 #endif  // ABSL_DEBUGGING_INTERNAL_STACKTRACE_CONFIG_H_
diff --git a/absl/strings/str_format_test.cc b/absl/strings/str_format_test.cc
index fe742bf99533..fed75fafb5c6 100644
--- a/absl/strings/str_format_test.cc
+++ b/absl/strings/str_format_test.cc
@@ -384,8 +384,8 @@ TEST(StrFormat, BehavesAsDocumented) {
   EXPECT_EQ(StrFormat("%G", 1e10), "1E+10");
   //     a/A - lower,upper case hex    Eg: -3.0 -> "-0x1.8p+1"/"-0X1.8P+1"
 
-// On NDK r16, there is a regression in hexfloat formatting.
-#if !defined(__NDK_MAJOR__) || __NDK_MAJOR__ != 16
+// On Android platform <=21, there is a regression in hexfloat formatting.
+#if !defined(__ANDROID_API__) || __ANDROID_API__ > 21
   EXPECT_EQ(StrFormat("%.1a", -3.0), "-0x1.8p+1");  // .1 to fix MSVC output
   EXPECT_EQ(StrFormat("%.1A", -3.0), "-0X1.8P+1");  // .1 to fix MSVC output
 #endif
diff --git a/absl/synchronization/mutex.h b/absl/synchronization/mutex.h
index 840b9d6b0e70..4d9e03123e3a 100644
--- a/absl/synchronization/mutex.h
+++ b/absl/synchronization/mutex.h
@@ -24,7 +24,7 @@
 // Unlike a `std::mutex`, the Abseil `Mutex` provides the following additional
 // features:
 //   * Conditional predicates intrinsic to the `Mutex` object
-//   * Reader/writer locks, in addition to standard exclusive/writer locks
+//   * Shared/reader locks, in addition to standard exclusive/writer locks
 //   * Deadlock detection and debug support.
 //
 // The following helper classes are also defined within this file:
@@ -290,7 +290,7 @@ class LOCKABLE Mutex {
   // Mutex::ReaderLockWhen()
   // Mutex::WriterLockWhen()
   //
-  // Blocks until simultaneously both `cond` is `true` and this` Mutex` can
+  // Blocks until simultaneously both `cond` is `true` and this `Mutex` can
   // be acquired, then atomically acquires this `Mutex`. `LockWhen()` is
   // logically equivalent to `*Lock(); Await();` though they may have different
   // performance characteristics.
diff --git a/absl/synchronization/mutex_test.cc b/absl/synchronization/mutex_test.cc
index 53b937843a34..b2820e2068d5 100644
--- a/absl/synchronization/mutex_test.cc
+++ b/absl/synchronization/mutex_test.cc
@@ -29,6 +29,7 @@
 #include <vector>
 
 #include "gtest/gtest.h"
+#include "absl/base/attributes.h"
 #include "absl/base/internal/raw_logging.h"
 #include "absl/base/internal/sysinfo.h"
 #include "absl/memory/memory.h"
@@ -54,8 +55,8 @@ CreateDefaultPool() {
 // Hack to schedule a function to run on a thread pool thread after a
 // duration has elapsed.
 static void ScheduleAfter(absl::synchronization_internal::ThreadPool *tp,
-                          const std::function<void()> &func,
-                          absl::Duration after) {
+                          absl::Duration after,
+                          const std::function<void()> &func) {
   tp->Schedule([func, after] {
     absl::SleepFor(after);
     func();
@@ -1150,249 +1151,369 @@ TEST(Mutex, DeadlockIdBug) NO_THREAD_SAFETY_ANALYSIS {
 // and so never expires/passes, and one that will expire/pass in the near
 // future.
 
-// Encapsulate a Mutex-protected bool with its associated Condition/CondVar.
-class Cond {
- public:
-  explicit Cond(bool use_deadline) : use_deadline_(use_deadline), c_(&b_) {}
-
-  void Set(bool v) {
-    absl::MutexLock lock(&mu_);
-    b_ = v;
+static absl::Duration TimeoutTestAllowedSchedulingDelay() {
+  // Note: we use a function here because Microsoft Visual Studio fails to
+  // properly initialize constexpr static absl::Duration variables.
+  return absl::Milliseconds(150);
+}
+
+// Returns true if `actual_delay` is close enough to `expected_delay` to pass
+// the timeouts/deadlines test.  Otherwise, logs warnings and returns false.
+ABSL_MUST_USE_RESULT
+static bool DelayIsWithinBounds(absl::Duration expected_delay,
+                                absl::Duration actual_delay) {
+  bool pass = true;
+  // Do not allow the observed delay to be less than expected.  This may occur
+  // in practice due to clock skew or when the synchronization primitives use a
+  // different clock than absl::Now(), but these cases should be handled by the
+  // the retry mechanism in each TimeoutTest.
+  if (actual_delay < expected_delay) {
+    ABSL_RAW_LOG(WARNING,
+                 "Actual delay %s was too short, expected %s (difference %s)",
+                 absl::FormatDuration(actual_delay).c_str(),
+                 absl::FormatDuration(expected_delay).c_str(),
+                 absl::FormatDuration(actual_delay - expected_delay).c_str());
+    pass = false;
   }
-
-  bool AwaitWithTimeout(absl::Duration timeout) {
-    absl::MutexLock lock(&mu_);
-    return use_deadline_ ? mu_.AwaitWithDeadline(c_, absl::Now() + timeout)
-                         : mu_.AwaitWithTimeout(c_, timeout);
+  // If the expected delay is <= zero then allow a small error tolerance, since
+  // we do not expect context switches to occur during test execution.
+  // Otherwise, thread scheduling delays may be substantial in rare cases, so
+  // tolerate up to kTimeoutTestAllowedSchedulingDelay of error.
+  absl::Duration tolerance = expected_delay <= absl::ZeroDuration()
+                                 ? absl::Milliseconds(10)
+                                 : TimeoutTestAllowedSchedulingDelay();
+  if (actual_delay > expected_delay + tolerance) {
+    ABSL_RAW_LOG(WARNING,
+                 "Actual delay %s was too long, expected %s (difference %s)",
+                 absl::FormatDuration(actual_delay).c_str(),
+                 absl::FormatDuration(expected_delay).c_str(),
+                 absl::FormatDuration(actual_delay - expected_delay).c_str());
+    pass = false;
   }
+  return pass;
+}
+
+// Parameters for TimeoutTest, below.
+struct TimeoutTestParam {
+  // The file and line number (used for logging purposes only).
+  const char *from_file;
+  int from_line;
+
+  // Should the absolute deadline API based on absl::Time be tested?  If false,
+  // the relative deadline API based on absl::Duration is tested.
+  bool use_absolute_deadline;
+
+  // The deadline/timeout used when calling the API being tested
+  // (e.g. Mutex::LockWhenWithDeadline).
+  absl::Duration wait_timeout;
+
+  // The delay before the condition will be set true by the test code.  If zero
+  // or negative, the condition is set true immediately (before calling the API
+  // being tested).  Otherwise, if infinite, the condition is never set true.
+  // Otherwise a closure is scheduled for the future that sets the condition
+  // true.
+  absl::Duration satisfy_condition_delay;
+
+  // The expected result of the condition after the call to the API being
+  // tested. Generally `true` means the condition was true when the API returns,
+  // `false` indicates an expected timeout.
+  bool expected_result;
+
+  // The expected delay before the API under test returns.  This is inherently
+  // flaky, so some slop is allowed (see `DelayIsWithinBounds` above), and the
+  // test keeps trying indefinitely until this constraint passes.
+  absl::Duration expected_delay;
+};
 
-  bool LockWhenWithTimeout(absl::Duration timeout) {
-    bool b = use_deadline_ ? mu_.LockWhenWithDeadline(c_, absl::Now() + timeout)
-                           : mu_.LockWhenWithTimeout(c_, timeout);
-    mu_.Unlock();
-    return b;
+// Print a `TimeoutTestParam` to a debug log.
+std::ostream &operator<<(std::ostream &os, const TimeoutTestParam &param) {
+  return os << "from: " << param.from_file << ":" << param.from_line
+            << " use_absolute_deadline: "
+            << (param.use_absolute_deadline ? "true" : "false")
+            << " wait_timeout: " << param.wait_timeout
+            << " satisfy_condition_delay: " << param.satisfy_condition_delay
+            << " expected_result: "
+            << (param.expected_result ? "true" : "false")
+            << " expected_delay: " << param.expected_delay;
+}
+
+std::string FormatString(const TimeoutTestParam &param) {
+  std::ostringstream os;
+  os << param;
+  return os.str();
+}
+
+// Like `thread::Executor::ScheduleAt` except:
+// a) Delays zero or negative are executed immediately in the current thread.
+// b) Infinite delays are never scheduled.
+// c) Calls this test's `ScheduleAt` helper instead of using `pool` directly.
+static void RunAfterDelay(absl::Duration delay,
+                          absl::synchronization_internal::ThreadPool *pool,
+                          const std::function<void()> &callback) {
+  if (delay <= absl::ZeroDuration()) {
+    callback();  // immediate
+  } else if (delay != absl::InfiniteDuration()) {
+    ScheduleAfter(pool, delay, callback);
   }
+}
 
-  bool ReaderLockWhenWithTimeout(absl::Duration timeout) {
-    bool b = use_deadline_
-                 ? mu_.ReaderLockWhenWithDeadline(c_, absl::Now() + timeout)
-                 : mu_.ReaderLockWhenWithTimeout(c_, timeout);
-    mu_.ReaderUnlock();
-    return b;
-  }
+class TimeoutTest : public ::testing::Test,
+                    public ::testing::WithParamInterface<TimeoutTestParam> {};
 
-  void Await() {
-    absl::MutexLock lock(&mu_);
-    mu_.Await(c_);
-  }
+std::vector<TimeoutTestParam> MakeTimeoutTestParamValues() {
+  // The `finite` delay is a finite, relatively short, delay.  We make it larger
+  // than our allowed scheduling delay (slop factor) to avoid confusion when
+  // diagnosing test failures.  The other constants here have clear meanings.
+  const absl::Duration finite = 3 * TimeoutTestAllowedSchedulingDelay();
+  const absl::Duration never = absl::InfiniteDuration();
+  const absl::Duration negative = -absl::InfiniteDuration();
+  const absl::Duration immediate = absl::ZeroDuration();
 
-  void Signal(bool v) {
-    absl::MutexLock lock(&mu_);
-    b_ = v;
-    cv_.Signal();
+  // Every test case is run twice; once using the absolute deadline API and once
+  // using the relative timeout API.
+  std::vector<TimeoutTestParam> values;
+  for (bool use_absolute_deadline : {false, true}) {
+    // Tests with a negative timeout (deadline in the past), which should
+    // immediately return current state of the condition.
+
+    // The condition is already true:
+    values.push_back(TimeoutTestParam{
+        __FILE__, __LINE__, use_absolute_deadline,
+        negative,   // wait_timeout
+        immediate,  // satisfy_condition_delay
+        true,       // expected_result
+        immediate,  // expected_delay
+    });
+
+    // The condition becomes true, but the timeout has already expired:
+    values.push_back(TimeoutTestParam{
+        __FILE__, __LINE__, use_absolute_deadline,
+        negative,  // wait_timeout
+        finite,    // satisfy_condition_delay
+        false,     // expected_result
+        immediate  // expected_delay
+    });
+
+    // The condition never becomes true:
+    values.push_back(TimeoutTestParam{
+        __FILE__, __LINE__, use_absolute_deadline,
+        negative,  // wait_timeout
+        never,     // satisfy_condition_delay
+        false,     // expected_result
+        immediate  // expected_delay
+    });
+
+    // Tests with an infinite timeout (deadline in the infinite future), which
+    // should only return when the condition becomes true.
+
+    // The condition is already true:
+    values.push_back(TimeoutTestParam{
+        __FILE__, __LINE__, use_absolute_deadline,
+        never,      // wait_timeout
+        immediate,  // satisfy_condition_delay
+        true,       // expected_result
+        immediate   // expected_delay
+    });
+
+    // The condition becomes true before the (infinite) expiry:
+    values.push_back(TimeoutTestParam{
+        __FILE__, __LINE__, use_absolute_deadline,
+        never,   // wait_timeout
+        finite,  // satisfy_condition_delay
+        true,    // expected_result
+        finite,  // expected_delay
+    });
+
+    // Tests with a (small) finite timeout (deadline soon), with the condition
+    // becoming true both before and after its expiry.
+
+    // The condition is already true:
+    values.push_back(TimeoutTestParam{
+        __FILE__, __LINE__, use_absolute_deadline,
+        never,      // wait_timeout
+        immediate,  // satisfy_condition_delay
+        true,       // expected_result
+        immediate   // expected_delay
+    });
+
+    // The condition becomes true before the expiry:
+    values.push_back(TimeoutTestParam{
+        __FILE__, __LINE__, use_absolute_deadline,
+        finite * 2,  // wait_timeout
+        finite,      // satisfy_condition_delay
+        true,        // expected_result
+        finite       // expected_delay
+    });
+
+    // The condition becomes true, but the timeout has already expired:
+    values.push_back(TimeoutTestParam{
+        __FILE__, __LINE__, use_absolute_deadline,
+        finite,      // wait_timeout
+        finite * 2,  // satisfy_condition_delay
+        false,       // expected_result
+        finite       // expected_delay
+    });
+
+    // The condition never becomes true:
+    values.push_back(TimeoutTestParam{
+        __FILE__, __LINE__, use_absolute_deadline,
+        finite,  // wait_timeout
+        never,   // satisfy_condition_delay
+        false,   // expected_result
+        finite   // expected_delay
+    });
   }
-
-  bool WaitWithTimeout(absl::Duration timeout) {
-    absl::MutexLock lock(&mu_);
-    absl::Time deadline = absl::Now() + timeout;
-    if (use_deadline_) {
-      while (!b_ && !cv_.WaitWithDeadline(&mu_, deadline)) {
-      }
-    } else {
-      while (!b_ && !cv_.WaitWithTimeout(&mu_, timeout)) {
-        timeout = deadline - absl::Now();  // recompute timeout
-      }
+  return values;
+}
+
+// Instantiate `TimeoutTest` with `MakeTimeoutTestParamValues()`.
+INSTANTIATE_TEST_CASE_P(All, TimeoutTest,
+                        testing::ValuesIn(MakeTimeoutTestParamValues()));
+
+TEST_P(TimeoutTest, Await) {
+  const TimeoutTestParam params = GetParam();
+  ABSL_RAW_LOG(INFO, "Params: %s", FormatString(params).c_str());
+
+  // Because this test asserts bounds on scheduling delays it is flaky.  To
+  // compensate it loops forever until it passes.  Failures express as test
+  // timeouts, in which case the test log can be used to diagnose the issue.
+  for (int attempt = 1;; ++attempt) {
+    ABSL_RAW_LOG(INFO, "Attempt %d", attempt);
+
+    absl::Mutex mu;
+    bool value = false;  // condition value (under mu)
+
+    std::unique_ptr<absl::synchronization_internal::ThreadPool> pool =
+        CreateDefaultPool();
+    RunAfterDelay(params.satisfy_condition_delay, pool.get(), [&] {
+      absl::MutexLock l(&mu);
+      value = true;
+    });
+
+    absl::MutexLock lock(&mu);
+    absl::Time start_time = absl::Now();
+    absl::Condition cond(&value);
+    bool result =
+        params.use_absolute_deadline
+            ? mu.AwaitWithDeadline(cond, start_time + params.wait_timeout)
+            : mu.AwaitWithTimeout(cond, params.wait_timeout);
+    if (DelayIsWithinBounds(params.expected_delay, absl::Now() - start_time)) {
+      EXPECT_EQ(params.expected_result, result);
+      break;
     }
-    return b_;
-  }
-
-  void Wait() {
-    absl::MutexLock lock(&mu_);
-    while (!b_) cv_.Wait(&mu_);
-  }
-
- private:
-  const bool use_deadline_;
-
-  bool b_;
-  absl::Condition c_;
-  absl::CondVar cv_;
-  absl::Mutex mu_;
-};
-
-class OperationTimer {
- public:
-  OperationTimer() : start_(absl::Now()) {}
-  absl::Duration Get() const { return absl::Now() - start_; }
-
- private:
-  const absl::Time start_;
-};
-
-static void CheckResults(bool exp_result, bool act_result,
-                         absl::Duration exp_duration,
-                         absl::Duration act_duration) {
-  ABSL_RAW_CHECK(exp_result == act_result, "CheckResults failed");
-  // Allow for some worse-case scheduling delay and clock skew.
-  if ((exp_duration - absl::Milliseconds(40) > act_duration) ||
-      (exp_duration + absl::Milliseconds(150) < act_duration)) {
-    ABSL_RAW_LOG(FATAL, "CheckResults failed: operation took %s, expected %s",
-                 absl::FormatDuration(act_duration).c_str(),
-                 absl::FormatDuration(exp_duration).c_str());
   }
 }
 
-static void TestAwaitTimeout(Cond *cp, absl::Duration timeout, bool exp_result,
-                             absl::Duration exp_duration) {
-  OperationTimer t;
-  bool act_result = cp->AwaitWithTimeout(timeout);
-  CheckResults(exp_result, act_result, exp_duration, t.Get());
-}
-
-static void TestLockWhenTimeout(Cond *cp, absl::Duration timeout,
-                                bool exp_result, absl::Duration exp_duration) {
-  OperationTimer t;
-  bool act_result = cp->LockWhenWithTimeout(timeout);
-  CheckResults(exp_result, act_result, exp_duration, t.Get());
-}
+TEST_P(TimeoutTest, LockWhen) {
+  const TimeoutTestParam params = GetParam();
+  ABSL_RAW_LOG(INFO, "Params: %s", FormatString(params).c_str());
+
+  // Because this test asserts bounds on scheduling delays it is flaky.  To
+  // compensate it loops forever until it passes.  Failures express as test
+  // timeouts, in which case the test log can be used to diagnose the issue.
+  for (int attempt = 1;; ++attempt) {
+    ABSL_RAW_LOG(INFO, "Attempt %d", attempt);
+
+    absl::Mutex mu;
+    bool value = false;  // condition value (under mu)
+
+    std::unique_ptr<absl::synchronization_internal::ThreadPool> pool =
+        CreateDefaultPool();
+    RunAfterDelay(params.satisfy_condition_delay, pool.get(), [&] {
+      absl::MutexLock l(&mu);
+      value = true;
+    });
+
+    absl::Time start_time = absl::Now();
+    absl::Condition cond(&value);
+    bool result =
+        params.use_absolute_deadline
+            ? mu.LockWhenWithDeadline(cond, start_time + params.wait_timeout)
+            : mu.LockWhenWithTimeout(cond, params.wait_timeout);
+    mu.Unlock();
 
-static void TestReaderLockWhenTimeout(Cond *cp, absl::Duration timeout,
-                                      bool exp_result,
-                                      absl::Duration exp_duration) {
-  OperationTimer t;
-  bool act_result = cp->ReaderLockWhenWithTimeout(timeout);
-  CheckResults(exp_result, act_result, exp_duration, t.Get());
+    if (DelayIsWithinBounds(params.expected_delay, absl::Now() - start_time)) {
+      EXPECT_EQ(params.expected_result, result);
+      break;
+    }
+  }
 }
 
-static void TestWaitTimeout(Cond *cp, absl::Duration timeout, bool exp_result,
-                            absl::Duration exp_duration) {
-  OperationTimer t;
-  bool act_result = cp->WaitWithTimeout(timeout);
-  CheckResults(exp_result, act_result, exp_duration, t.Get());
+TEST_P(TimeoutTest, ReaderLockWhen) {
+  const TimeoutTestParam params = GetParam();
+  ABSL_RAW_LOG(INFO, "Params: %s", FormatString(params).c_str());
+
+  // Because this test asserts bounds on scheduling delays it is flaky.  To
+  // compensate it loops forever until it passes.  Failures express as test
+  // timeouts, in which case the test log can be used to diagnose the issue.
+  for (int attempt = 0;; ++attempt) {
+    ABSL_RAW_LOG(INFO, "Attempt %d", attempt);
+
+    absl::Mutex mu;
+    bool value = false;  // condition value (under mu)
+
+    std::unique_ptr<absl::synchronization_internal::ThreadPool> pool =
+        CreateDefaultPool();
+    RunAfterDelay(params.satisfy_condition_delay, pool.get(), [&] {
+      absl::MutexLock l(&mu);
+      value = true;
+    });
+
+    absl::Time start_time = absl::Now();
+    bool result =
+        params.use_absolute_deadline
+            ? mu.ReaderLockWhenWithDeadline(absl::Condition(&value),
+                                            start_time + params.wait_timeout)
+            : mu.ReaderLockWhenWithTimeout(absl::Condition(&value),
+                                           params.wait_timeout);
+    mu.ReaderUnlock();
+
+    if (DelayIsWithinBounds(params.expected_delay, absl::Now() - start_time)) {
+      EXPECT_EQ(params.expected_result, result);
+      break;
+    }
+  }
 }
 
-// Tests with a negative timeout (deadline in the past), which should
-// immediately return the current state of the condition.
-static void TestNegativeTimeouts(absl::synchronization_internal::ThreadPool *tp,
-                                 Cond *cp) {
-  const absl::Duration negative = -absl::InfiniteDuration();
-  const absl::Duration immediate = absl::ZeroDuration();
-
-  // The condition is already true:
-  cp->Set(true);
-  TestAwaitTimeout(cp, negative, true, immediate);
-  TestLockWhenTimeout(cp, negative, true, immediate);
-  TestReaderLockWhenTimeout(cp, negative, true, immediate);
-  TestWaitTimeout(cp, negative, true, immediate);
-
-  // The condition becomes true, but the timeout has already expired:
-  const absl::Duration delay = absl::Milliseconds(200);
-  cp->Set(false);
-  ScheduleAfter(tp, std::bind(&Cond::Set, cp, true), 3 * delay);
-  TestAwaitTimeout(cp, negative, false, immediate);
-  TestLockWhenTimeout(cp, negative, false, immediate);
-  TestReaderLockWhenTimeout(cp, negative, false, immediate);
-  cp->Await();  // wait for the scheduled Set() to complete
-  cp->Set(false);
-  ScheduleAfter(tp, std::bind(&Cond::Signal, cp, true), delay);
-  TestWaitTimeout(cp, negative, false, immediate);
-  cp->Wait();  // wait for the scheduled Signal() to complete
-
-  // The condition never becomes true:
-  cp->Set(false);
-  TestAwaitTimeout(cp, negative, false, immediate);
-  TestLockWhenTimeout(cp, negative, false, immediate);
-  TestReaderLockWhenTimeout(cp, negative, false, immediate);
-  TestWaitTimeout(cp, negative, false, immediate);
-}
-
-// Tests with an infinite timeout (deadline in the infinite future), which
-// should only return when the condition becomes true.
-static void TestInfiniteTimeouts(absl::synchronization_internal::ThreadPool *tp,
-                                 Cond *cp) {
-  const absl::Duration infinite = absl::InfiniteDuration();
-  const absl::Duration immediate = absl::ZeroDuration();
-
-  // The condition is already true:
-  cp->Set(true);
-  TestAwaitTimeout(cp, infinite, true, immediate);
-  TestLockWhenTimeout(cp, infinite, true, immediate);
-  TestReaderLockWhenTimeout(cp, infinite, true, immediate);
-  TestWaitTimeout(cp, infinite, true, immediate);
-
-  // The condition becomes true before the (infinite) expiry:
-  const absl::Duration delay = absl::Milliseconds(200);
-  cp->Set(false);
-  ScheduleAfter(tp, std::bind(&Cond::Set, cp, true), delay);
-  TestAwaitTimeout(cp, infinite, true, delay);
-  cp->Set(false);
-  ScheduleAfter(tp, std::bind(&Cond::Set, cp, true), delay);
-  TestLockWhenTimeout(cp, infinite, true, delay);
-  cp->Set(false);
-  ScheduleAfter(tp, std::bind(&Cond::Set, cp, true), delay);
-  TestReaderLockWhenTimeout(cp, infinite, true, delay);
-  cp->Set(false);
-  ScheduleAfter(tp, std::bind(&Cond::Signal, cp, true), delay);
-  TestWaitTimeout(cp, infinite, true, delay);
-}
-
-// Tests with a (small) finite timeout (deadline soon), with the condition
-// becoming true both before and after its expiry.
-static void TestFiniteTimeouts(absl::synchronization_internal::ThreadPool *tp,
-                               Cond *cp) {
-  const absl::Duration finite = absl::Milliseconds(400);
-  const absl::Duration immediate = absl::ZeroDuration();
+TEST_P(TimeoutTest, Wait) {
+  const TimeoutTestParam params = GetParam();
+  ABSL_RAW_LOG(INFO, "Params: %s", FormatString(params).c_str());
+
+  // Because this test asserts bounds on scheduling delays it is flaky.  To
+  // compensate it loops forever until it passes.  Failures express as test
+  // timeouts, in which case the test log can be used to diagnose the issue.
+  for (int attempt = 0;; ++attempt) {
+    ABSL_RAW_LOG(INFO, "Attempt %d", attempt);
+
+    absl::Mutex mu;
+    bool value = false;  // condition value (under mu)
+    absl::CondVar cv;    // signals a change of `value`
+
+    std::unique_ptr<absl::synchronization_internal::ThreadPool> pool =
+        CreateDefaultPool();
+    RunAfterDelay(params.satisfy_condition_delay, pool.get(), [&] {
+      absl::MutexLock l(&mu);
+      value = true;
+      cv.Signal();
+    });
+
+    absl::MutexLock lock(&mu);
+    absl::Time start_time = absl::Now();
+    absl::Duration timeout = params.wait_timeout;
+    absl::Time deadline = start_time + timeout;
+    while (!value) {
+      if (params.use_absolute_deadline ? cv.WaitWithDeadline(&mu, deadline)
+                                       : cv.WaitWithTimeout(&mu, timeout)) {
+        break;  // deadline/timeout exceeded
+      }
+      timeout = deadline - absl::Now();  // recompute
+    }
+    bool result = value;  // note: `mu` is still held
 
-  // The condition is already true:
-  cp->Set(true);
-  TestAwaitTimeout(cp, finite, true, immediate);
-  TestLockWhenTimeout(cp, finite, true, immediate);
-  TestReaderLockWhenTimeout(cp, finite, true, immediate);
-  TestWaitTimeout(cp, finite, true, immediate);
-
-  // The condition becomes true before the expiry:
-  const absl::Duration delay1 = finite / 2;
-  cp->Set(false);
-  ScheduleAfter(tp, std::bind(&Cond::Set, cp, true), delay1);
-  TestAwaitTimeout(cp, finite, true, delay1);
-  cp->Set(false);
-  ScheduleAfter(tp, std::bind(&Cond::Set, cp, true), delay1);
-  TestLockWhenTimeout(cp, finite, true, delay1);
-  cp->Set(false);
-  ScheduleAfter(tp, std::bind(&Cond::Set, cp, true), delay1);
-  TestReaderLockWhenTimeout(cp, finite, true, delay1);
-  cp->Set(false);
-  ScheduleAfter(tp, std::bind(&Cond::Signal, cp, true), delay1);
-  TestWaitTimeout(cp, finite, true, delay1);
-
-  // The condition becomes true, but the timeout has already expired:
-  const absl::Duration delay2 = finite * 2;
-  cp->Set(false);
-  ScheduleAfter(tp, std::bind(&Cond::Set, cp, true), 3 * delay2);
-  TestAwaitTimeout(cp, finite, false, finite);
-  TestLockWhenTimeout(cp, finite, false, finite);
-  TestReaderLockWhenTimeout(cp, finite, false, finite);
-  cp->Await();  // wait for the scheduled Set() to complete
-  cp->Set(false);
-  ScheduleAfter(tp, std::bind(&Cond::Signal, cp, true), delay2);
-  TestWaitTimeout(cp, finite, false, finite);
-  cp->Wait();  // wait for the scheduled Signal() to complete
-
-  // The condition never becomes true:
-  cp->Set(false);
-  TestAwaitTimeout(cp, finite, false, finite);
-  TestLockWhenTimeout(cp, finite, false, finite);
-  TestReaderLockWhenTimeout(cp, finite, false, finite);
-  TestWaitTimeout(cp, finite, false, finite);
-}
-
-TEST(Mutex, Timeouts) {
-  auto tp = CreateDefaultPool();
-  for (bool use_deadline : {false, true}) {
-    Cond cond(use_deadline);
-    TestNegativeTimeouts(tp.get(), &cond);
-    TestInfiniteTimeouts(tp.get(), &cond);
-    TestFiniteTimeouts(tp.get(), &cond);
+    if (DelayIsWithinBounds(params.expected_delay, absl::Now() - start_time)) {
+      EXPECT_EQ(params.expected_result, result);
+      break;
+    }
   }
 }
 
diff --git a/absl/time/clock_test.cc b/absl/time/clock_test.cc
index f143c0360b0d..707166d0c289 100644
--- a/absl/time/clock_test.cc
+++ b/absl/time/clock_test.cc
@@ -35,36 +35,84 @@ TEST(Time, Now) {
   EXPECT_GE(after, now);
 }
 
-TEST(SleepForTest, BasicSanity) {
-  absl::Duration sleep_time = absl::Milliseconds(2500);
-  absl::Time start = absl::Now();
-  absl::SleepFor(sleep_time);
-  absl::Time end = absl::Now();
-  EXPECT_LE(sleep_time - absl::Milliseconds(100), end - start);
-  EXPECT_GE(sleep_time + absl::Milliseconds(200), end - start);
-}
+enum class AlarmPolicy { kWithoutAlarm, kWithAlarm };
 
-#ifdef ABSL_HAVE_ALARM
-// Helper for test SleepFor.
+#if defined(ABSL_HAVE_ALARM)
 bool alarm_handler_invoked = false;
+
 void AlarmHandler(int signo) {
   ASSERT_EQ(signo, SIGALRM);
   alarm_handler_invoked = true;
 }
+#endif
+
+// Does SleepFor(d) take between lower_bound and upper_bound at least
+// once between now and (now + timeout)?  If requested (and supported),
+// add an alarm for the middle of the sleep period and expect it to fire.
+bool SleepForBounded(absl::Duration d, absl::Duration lower_bound,
+                     absl::Duration upper_bound, absl::Duration timeout,
+                     AlarmPolicy alarm_policy, int* attempts) {
+  const absl::Time deadline = absl::Now() + timeout;
+  while (absl::Now() < deadline) {
+#if defined(ABSL_HAVE_ALARM)
+    sig_t old_alarm = SIG_DFL;
+    if (alarm_policy == AlarmPolicy::kWithAlarm) {
+      alarm_handler_invoked = false;
+      old_alarm = signal(SIGALRM, AlarmHandler);
+      alarm(absl::ToInt64Seconds(d / 2));
+    }
+#else
+    EXPECT_EQ(alarm_policy, AlarmPolicy::kWithoutAlarm);
+#endif
+    ++*attempts;
+    absl::Time start = absl::Now();
+    absl::SleepFor(d);
+    absl::Duration actual = absl::Now() - start;
+#if defined(ABSL_HAVE_ALARM)
+    if (alarm_policy == AlarmPolicy::kWithAlarm) {
+      signal(SIGALRM, old_alarm);
+      if (!alarm_handler_invoked) continue;
+    }
+#endif
+    if (lower_bound <= actual && actual <= upper_bound) {
+      return true;  // yes, the SleepFor() was correctly bounded
+    }
+  }
+  return false;
+}
 
-TEST(SleepForTest, AlarmSupport) {
-  alarm_handler_invoked = false;
-  sig_t old_alarm = signal(SIGALRM, AlarmHandler);
-  alarm(2);
-  absl::Duration sleep_time = absl::Milliseconds(3500);
-  absl::Time start = absl::Now();
-  absl::SleepFor(sleep_time);
-  absl::Time end = absl::Now();
-  EXPECT_TRUE(alarm_handler_invoked);
-  EXPECT_LE(sleep_time - absl::Milliseconds(100), end - start);
-  EXPECT_GE(sleep_time + absl::Milliseconds(200), end - start);
-  signal(SIGALRM, old_alarm);
+testing::AssertionResult AssertSleepForBounded(absl::Duration d,
+                                               absl::Duration early,
+                                               absl::Duration late,
+                                               absl::Duration timeout,
+                                               AlarmPolicy alarm_policy) {
+  const absl::Duration lower_bound = d - early;
+  const absl::Duration upper_bound = d + late;
+  int attempts = 0;
+  if (SleepForBounded(d, lower_bound, upper_bound, timeout, alarm_policy,
+                      &attempts)) {
+    return testing::AssertionSuccess();
+  }
+  return testing::AssertionFailure()
+         << "SleepFor(" << d << ") did not return within [" << lower_bound
+         << ":" << upper_bound << "] in " << attempts << " attempt"
+         << (attempts == 1 ? "" : "s") << " over " << timeout
+         << (alarm_policy == AlarmPolicy::kWithAlarm ? " with" : " without")
+         << " an alarm";
+}
+
+// Tests that SleepFor() returns neither too early nor too late.
+TEST(SleepFor, Bounded) {
+  const absl::Duration d = absl::Milliseconds(2500);
+  const absl::Duration early = absl::Milliseconds(100);
+  const absl::Duration late = absl::Milliseconds(300);
+  const absl::Duration timeout = 48 * d;
+  EXPECT_TRUE(AssertSleepForBounded(d, early, late, timeout,
+                                    AlarmPolicy::kWithoutAlarm));
+#if defined(ABSL_HAVE_ALARM)
+  EXPECT_TRUE(AssertSleepForBounded(d, early, late, timeout,
+                                    AlarmPolicy::kWithAlarm));
+#endif
 }
-#endif  // ABSL_HAVE_ALARM
 
 }  // namespace
diff --git a/absl/types/variant.h b/absl/types/variant.h
index fd1d49ac890a..9d98a9ed0edb 100644
--- a/absl/types/variant.h
+++ b/absl/types/variant.h
@@ -248,7 +248,7 @@ using variant_alternative_t = typename variant_alternative<I, T>::type;
 //
 // Example:
 //
-//   absl::variant<int, std::string> bar = 42;
+//   absl::variant<int, std::string> foo = 42;
 //   if (absl::holds_alternative<int>(foo)) {
 //       std::cout << "The variant holds an integer";
 //   }