1 files changed, 22 insertions, 8 deletions
diff --git a/absl/synchronization/internal/kernel_timeout.h b/absl/synchronization/internal/kernel_timeout.h
index bbd4d2d7..f5c2c0ef 100644
--- a/absl/synchronization/internal/kernel_timeout.h
+++ b/absl/synchronization/internal/kernel_timeout.h
@@ -19,8 +19,8 @@
 // Constructible from a absl::Time (for a timeout to be respected) or {}
 // (for "no timeout".)
 // This is a private low-level API for use by a handful of low-level
-// components that are friends of this class. Higher-level components
-// should build APIs based on absl::Time and absl::Duration.
+// components. Higher-level components should build APIs based on
+// absl::Time and absl::Duration.
 
 #ifndef ABSL_SYNCHRONIZATION_INTERNAL_KERNEL_TIMEOUT_H_
 #define ABSL_SYNCHRONIZATION_INTERNAL_KERNEL_TIMEOUT_H_
@@ -28,6 +28,7 @@
 #include <time.h>
 
 #include <algorithm>
+#include <cstdint>
 #include <limits>
 
 #include "absl/base/internal/raw_logging.h"
@@ -38,7 +39,6 @@ namespace absl {
 ABSL_NAMESPACE_BEGIN
 namespace synchronization_internal {
 
-class Futex;
 class Waiter;
 
 class KernelTimeout {
@@ -60,7 +60,10 @@ class KernelTimeout {
 
   // Convert to parameter for sem_timedwait/futex/similar.  Only for approved
   // users.  Do not call if !has_timeout.
-  struct timespec MakeAbsTimespec();
+  struct timespec MakeAbsTimespec() const;
+
+  // Convert to unix epoch nanos.  Do not call if !has_timeout.
+  int64_t MakeAbsNanos() const;
 
  private:
   // internal rep, not user visible: ns after unix epoch.
@@ -111,7 +114,8 @@ class KernelTimeout {
       constexpr uint64_t max_nanos =
           (std::numeric_limits<int64_t>::max)() - 999999u;
       uint64_t ms_from_now =
-          (std::min<uint64_t>(max_nanos, ns_ - now) + 999999u) / 1000000u;
+          ((std::min)(max_nanos, static_cast<uint64_t>(ns_ - now)) + 999999u) /
+          1000000u;
       if (ms_from_now > kInfinite) {
         return kInfinite;
       }
@@ -119,13 +123,12 @@ class KernelTimeout {
     }
     return 0;
   }
-#endif
 
-  friend class Futex;
   friend class Waiter;
+#endif
 };
 
-inline struct timespec KernelTimeout::MakeAbsTimespec() {
+inline struct timespec KernelTimeout::MakeAbsTimespec() const {
   int64_t n = ns_;
   static const int64_t kNanosPerSecond = 1000 * 1000 * 1000;
   if (n == 0) {
@@ -149,6 +152,17 @@ inline struct timespec KernelTimeout::MakeAbsTimespec() {
   return abstime;
 }
 
+inline int64_t KernelTimeout::MakeAbsNanos() const {
+  if (ns_ == 0) {
+    ABSL_RAW_LOG(
+        ERROR, "Tried to create a timeout from a non-timeout; never do this.");
+    // But we'll try to continue sanely.  no-timeout ~= saturated timeout.
+    return (std::numeric_limits<int64_t>::max)();
+  }
+
+  return ns_;
+}
+
 }  // namespace synchronization_internal
 ABSL_NAMESPACE_END
 }  // namespace absl