9 files changed, 56 insertions, 54 deletions
diff --git a/absl/synchronization/internal/create_thread_identity.cc b/absl/synchronization/internal/create_thread_identity.cc
index fa0070a9..53a71b34 100644
--- a/absl/synchronization/internal/create_thread_identity.cc
+++ b/absl/synchronization/internal/create_thread_identity.cc
@@ -32,9 +32,9 @@ namespace synchronization_internal {
 
 // ThreadIdentity storage is persistent, we maintain a free-list of previously
 // released ThreadIdentity objects.
-static base_internal::SpinLock freelist_lock(
-    base_internal::kLinkerInitialized);
-static base_internal::ThreadIdentity* thread_identity_freelist;
+ABSL_CONST_INIT static base_internal::SpinLock freelist_lock(
+    absl::kConstInit, base_internal::SCHEDULE_KERNEL_ONLY);
+ABSL_CONST_INIT static base_internal::ThreadIdentity* thread_identity_freelist;
 
 // A per-thread destructor for reclaiming associated ThreadIdentity objects.
 // Since we must preserve their storage we cache them for re-use.
diff --git a/absl/synchronization/internal/graphcycles.cc b/absl/synchronization/internal/graphcycles.cc
index 6a2bcdf6..19f9aab5 100644
--- a/absl/synchronization/internal/graphcycles.cc
+++ b/absl/synchronization/internal/graphcycles.cc
@@ -51,9 +51,9 @@ namespace {
 
 // Avoid LowLevelAlloc's default arena since it calls malloc hooks in
 // which people are doing things like acquiring Mutexes.
-static absl::base_internal::SpinLock arena_mu(
-    absl::base_internal::kLinkerInitialized);
-static base_internal::LowLevelAlloc::Arena* arena;
+ABSL_CONST_INIT static absl::base_internal::SpinLock arena_mu(
+    absl::kConstInit, base_internal::SCHEDULE_KERNEL_ONLY);
+ABSL_CONST_INIT static base_internal::LowLevelAlloc::Arena* arena;
 
 static void InitArenaIfNecessary() {
   arena_mu.Lock();
diff --git a/absl/synchronization/internal/kernel_timeout.h b/absl/synchronization/internal/kernel_timeout.h
index d6ac5db0..1084e1e6 100644
--- a/absl/synchronization/internal/kernel_timeout.h
+++ b/absl/synchronization/internal/kernel_timeout.h
@@ -57,6 +57,10 @@ class KernelTimeout {
 
   bool has_timeout() const { return ns_ != 0; }
 
+  // Convert to parameter for sem_timedwait/futex/similar.  Only for approved
+  // users.  Do not call if !has_timeout.
+  struct timespec MakeAbsTimespec();
+
  private:
   // internal rep, not user visible: ns after unix epoch.
   // zero = no timeout.
@@ -82,34 +86,6 @@ class KernelTimeout {
     return x;
   }
 
-  // Convert to parameter for sem_timedwait/futex/similar.  Only for approved
-  // users.  Do not call if !has_timeout.
-  struct timespec MakeAbsTimespec() {
-    int64_t n = ns_;
-    static const int64_t kNanosPerSecond = 1000 * 1000 * 1000;
-    if (n == 0) {
-      ABSL_RAW_LOG(
-          ERROR,
-          "Tried to create a timespec from a non-timeout; never do this.");
-      // But we'll try to continue sanely.  no-timeout ~= saturated timeout.
-      n = (std::numeric_limits<int64_t>::max)();
-    }
-
-    // Kernel APIs validate timespecs as being at or after the epoch,
-    // despite the kernel time type being signed.  However, no one can
-    // tell the difference between a timeout at or before the epoch (since
-    // all such timeouts have expired!)
-    if (n < 0) n = 0;
-
-    struct timespec abstime;
-    int64_t seconds = (std::min)(n / kNanosPerSecond,
-                               int64_t{(std::numeric_limits<time_t>::max)()});
-    abstime.tv_sec = static_cast<time_t>(seconds);
-    abstime.tv_nsec =
-        static_cast<decltype(abstime.tv_nsec)>(n % kNanosPerSecond);
-    return abstime;
-  }
-
 #ifdef _WIN32
   // Converts to milliseconds from now, or INFINITE when
   // !has_timeout(). For use by SleepConditionVariableSRW on
@@ -148,6 +124,30 @@ class KernelTimeout {
   friend class Waiter;
 };
 
+inline struct timespec KernelTimeout::MakeAbsTimespec() {
+  int64_t n = ns_;
+  static const int64_t kNanosPerSecond = 1000 * 1000 * 1000;
+  if (n == 0) {
+    ABSL_RAW_LOG(
+        ERROR, "Tried to create a timespec from a non-timeout; never do this.");
+    // But we'll try to continue sanely.  no-timeout ~= saturated timeout.
+    n = (std::numeric_limits<int64_t>::max)();
+  }
+
+  // Kernel APIs validate timespecs as being at or after the epoch,
+  // despite the kernel time type being signed.  However, no one can
+  // tell the difference between a timeout at or before the epoch (since
+  // all such timeouts have expired!)
+  if (n < 0) n = 0;
+
+  struct timespec abstime;
+  int64_t seconds = (std::min)(n / kNanosPerSecond,
+                             int64_t{(std::numeric_limits<time_t>::max)()});
+  abstime.tv_sec = static_cast<time_t>(seconds);
+  abstime.tv_nsec = static_cast<decltype(abstime.tv_nsec)>(n % kNanosPerSecond);
+  return abstime;
+}
+
 }  // namespace synchronization_internal
 ABSL_NAMESPACE_END
 }  // namespace absl
diff --git a/absl/synchronization/internal/mutex_nonprod.cc b/absl/synchronization/internal/mutex_nonprod.cc
index 4590b98d..334c3bc0 100644
--- a/absl/synchronization/internal/mutex_nonprod.cc
+++ b/absl/synchronization/internal/mutex_nonprod.cc
@@ -27,11 +27,16 @@
 
 #include <algorithm>
 
+#include "absl/base/config.h"
 #include "absl/base/internal/raw_logging.h"
 #include "absl/time/time.h"
 
 namespace absl {
 ABSL_NAMESPACE_BEGIN
+
+void SetMutexDeadlockDetectionMode(OnDeadlockCycle) {}
+void EnableMutexInvariantDebugging(bool) {}
+
 namespace synchronization_internal {
 
 namespace {
@@ -274,7 +279,7 @@ bool CondVar::WaitWithTimeout(Mutex* mu, absl::Duration timeout) {
 
 void CondVar::EnableDebugLog(const char*) {}
 
-#ifdef THREAD_SANITIZER
+#ifdef ABSL_HAVE_THREAD_SANITIZER
 extern "C" void __tsan_read1(void *addr);
 #else
 #define __tsan_read1(addr)  // do nothing if TSan not enabled
diff --git a/absl/synchronization/internal/mutex_nonprod.inc b/absl/synchronization/internal/mutex_nonprod.inc
index a1502e72..d83bc8a9 100644
--- a/absl/synchronization/internal/mutex_nonprod.inc
+++ b/absl/synchronization/internal/mutex_nonprod.inc
@@ -209,31 +209,22 @@ class SynchronizationStorage {
   // Instances allocated on the heap or on the stack should use the default
   // constructor.
   SynchronizationStorage()
-      : is_dynamic_(true), once_() {}
-
-  // Instances allocated in static storage (not on the heap, not on the
-  // stack) should use this constructor.
-  explicit SynchronizationStorage(base_internal::LinkerInitialized) {}
+      : destruct_(true), once_() {}
 
   constexpr explicit SynchronizationStorage(absl::ConstInitType)
-      : is_dynamic_(false), once_(), space_{{0}} {}
+      : destruct_(false), once_(), space_{{0}} {}
 
   SynchronizationStorage(SynchronizationStorage&) = delete;
   SynchronizationStorage& operator=(SynchronizationStorage&) = delete;
 
   ~SynchronizationStorage() {
-    if (is_dynamic_) {
+    if (destruct_) {
       get()->~T();
     }
   }
 
   // Retrieve the object in storage. This is fast and thread safe, but does
   // incur the cost of absl::call_once().
-  //
-  // For instances in static storage constructed with the
-  // LinkerInitialized constructor, may be called at any time without
-  // regard for order of dynamic initialization or destruction of objects
-  // in static storage. See the class comment for caveats.
   T* get() {
     absl::call_once(once_, SynchronizationStorage::Construct, this);
     return reinterpret_cast<T*>(&space_);
@@ -245,10 +236,7 @@ class SynchronizationStorage {
   }
 
   // When true, T's destructor is run when this is destructed.
-  //
-  // The LinkerInitialized constructor assumes this value will be set
-  // false by static initialization.
-  bool is_dynamic_;
+  const bool destruct_;
 
   absl::once_flag once_;
 
diff --git a/absl/synchronization/internal/per_thread_sem.h b/absl/synchronization/internal/per_thread_sem.h
index 8ab43915..2228b6e8 100644
--- a/absl/synchronization/internal/per_thread_sem.h
+++ b/absl/synchronization/internal/per_thread_sem.h
@@ -78,7 +78,7 @@ class PerThreadSem {
   // !t.has_timeout() => Wait(t) will return true.
   static inline bool Wait(KernelTimeout t);
 
-  // White-listed callers.
+  // Permitted callers.
   friend class PerThreadSemTest;
   friend class absl::Mutex;
   friend absl::base_internal::ThreadIdentity* CreateThreadIdentity();
diff --git a/absl/synchronization/internal/per_thread_sem_test.cc b/absl/synchronization/internal/per_thread_sem_test.cc
index b5a2f6d4..8cf59e64 100644
--- a/absl/synchronization/internal/per_thread_sem_test.cc
+++ b/absl/synchronization/internal/per_thread_sem_test.cc
@@ -23,6 +23,7 @@
 #include <thread>              // NOLINT(build/c++11)
 
 #include "gtest/gtest.h"
+#include "absl/base/config.h"
 #include "absl/base/internal/cycleclock.h"
 #include "absl/base/internal/thread_identity.h"
 #include "absl/strings/str_cat.h"
diff --git a/absl/synchronization/internal/waiter.cc b/absl/synchronization/internal/waiter.cc
index 2949f5a8..b6150b9b 100644
--- a/absl/synchronization/internal/waiter.cc
+++ b/absl/synchronization/internal/waiter.cc
@@ -86,6 +86,14 @@ static void MaybeBecomeIdle() {
 #endif
 #endif
 
+#if defined(__NR_futex_time64) && !defined(SYS_futex_time64)
+#define SYS_futex_time64 __NR_futex_time64
+#endif
+
+#if defined(SYS_futex_time64) && !defined(SYS_futex)
+#define SYS_futex SYS_futex_time64
+#endif
+
 class Futex {
  public:
   static int WaitUntil(std::atomic<int32_t> *v, int32_t val,
diff --git a/absl/synchronization/internal/waiter.h b/absl/synchronization/internal/waiter.h
index a6e6d4c7..887f9b1b 100644
--- a/absl/synchronization/internal/waiter.h
+++ b/absl/synchronization/internal/waiter.h
@@ -100,8 +100,8 @@ class Waiter {
   }
 
   // How many periods to remain idle before releasing resources
-#ifndef THREAD_SANITIZER
-  static const int kIdlePeriods = 60;
+#ifndef ABSL_HAVE_THREAD_SANITIZER
+  static constexpr int kIdlePeriods = 60;
 #else
   // Memory consumption under ThreadSanitizer is a serious concern,
   // so we release resources sooner. The value of 1 leads to 1 to 2 second