Export of internal Abseil changes

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53550735f5a943dfb99225e7c53f211c2d6e7951 by Gennadiy Rozental <rogeeff@google.com>:

Import of CCTZ from GitHub.

PiperOrigin-RevId: 309333648

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847bbf8a1d9cd322ec058c6f932d1f687fd3d331 by Gennadiy Rozental <rogeeff@google.com>:

Make Validation interfaces private in CommandLineFlag.

Calls are rewired via private interface access struct.

PiperOrigin-RevId: 309323013

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a600fc5051e0a0af50a7850450fd3ed1aef3f316 by Matthew Brown <matthewbr@google.com>:

Internal Change.

PiperOrigin-RevId: 309292207

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937d00ce3cf62c5f23f59b5377471fd01d6bfbc7 by Gennadiy Rozental <rogeeff@google.com>:

Make TypeId interface private in CommandLineFlag.

We also rewire the SaveState via the new PrivateHandleInterface trampoline class. This class will be the only way to access private methods of class CommandLineFlag.

PiperOrigin-RevId: 309282547

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796c4bd35073b6a8337762bdb13603dae12a4df1 by Derek Mauro <dmauro@google.com>:

Cleanup uses of kLinkerInitialized

PiperOrigin-RevId: 309274734

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c831446c52d9ef4bdcb1ea369840904620abc4b9 by Gennadiy Rozental <rogeeff@google.com>:

Eliminate the interface IsModified of CommndLineFlag.

PiperOrigin-RevId: 309256248

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a1db59d7f7aa39cb0a37dbf80f8c04e371da8465 by Gennadiy Rozental <rogeeff@google.com>:

Avoid default value generator if default value expression is constexpr.

If possible, we detect constexpr-ness of default value expression and avoid storing default value generator in side of flag and instead set the flag's value to the value of that expression at const initialization time of flag objects.

At the moment we only do this for flags of (all) integral, float and double value types

PiperOrigin-RevId: 309110630

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ae3b4a139aacd8fc165c9acd2a3cbae1f9e26af4 by Gennadiy Rozental <rogeeff@google.com>:

Make SaveState a private method of the CommandLineFlag and make it only accessible from FlagSaverImpl. There is no other call sites for this call.

PiperOrigin-RevId: 309073989

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cbc24b4dcc166dd6b0208e9d7620484eaaaa7ee0 by Abseil Team <absl-team@google.com>:

Eliminate the interface IsModified of CommndLineFlag.

PiperOrigin-RevId: 309064639

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08e79645a89d71785c5381cea9c413357db9824a by Gennadiy Rozental <rogeeff@google.com>:

Eliminate the interface IsModified of CommndLineFlag.

PiperOrigin-RevId: 309054430

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4a6c70233c60dc8c39b7fa9beb5fa687c215261f by Gennadiy Rozental <rogeeff@google.com>:

Internal change

PiperOrigin-RevId: 308900784

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13160efdf7710f142778d5a1e4c85aa309f019b6 by Abseil Team <absl-team@google.com>:

Provide definitions of static member variables -- improved C++11 support.

PiperOrigin-RevId: 308900290

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0343b8228657b9b313afdfe88c4a7b2137d56db4 by Gennadiy Rozental <rogeeff@google.com>:

Rename method Get<T> to TryGet<T> per approved spec before making interface public.

PiperOrigin-RevId: 308889113

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7b84e27fb857fc1296a05504970f506d47d2f2c1 by Derek Mauro <dmauro@google.com>:

Remove node_hash_* methods that were deprecated on release

PiperOrigin-RevId: 308837933

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599d44ee72c02b6bb6e1c1a1db72873841441416 by Gennadiy Rozental <rogeeff@google.com>:

Eliminate CommandLineFlag::Typename interface per approved spec before making CommandLineFlag public.

PiperOrigin-RevId: 308814376
GitOrigin-RevId: 53550735f5a943dfb99225e7c53f211c2d6e7951
Change-Id: Iae52c65b7322152c7e58f222d60eb5a21699a2cb

3 files changed, 14 insertions, 15 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/mutex.cc b/absl/synchronization/mutex.cc
index 8cda5a1c..1f8a696e 100644
--- a/absl/synchronization/mutex.cc
+++ b/absl/synchronization/mutex.cc
@@ -207,12 +207,12 @@ static void AtomicClearBits(std::atomic<intptr_t>* pv, intptr_t bits,
 //------------------------------------------------------------------
 
 // Data for doing deadlock detection.
-static absl::base_internal::SpinLock deadlock_graph_mu(
-    absl::base_internal::kLinkerInitialized);
+ABSL_CONST_INIT static absl::base_internal::SpinLock deadlock_graph_mu(
+    absl::kConstInit, base_internal::SCHEDULE_KERNEL_ONLY);
 
-// graph used to detect deadlocks.
-static GraphCycles *deadlock_graph ABSL_GUARDED_BY(deadlock_graph_mu)
-    ABSL_PT_GUARDED_BY(deadlock_graph_mu);
+// Graph used to detect deadlocks.
+ABSL_CONST_INIT static GraphCycles *deadlock_graph
+    ABSL_GUARDED_BY(deadlock_graph_mu) ABSL_PT_GUARDED_BY(deadlock_graph_mu);
 
 //------------------------------------------------------------------
 // An event mechanism for debugging mutex use.
@@ -273,13 +273,12 @@ static const struct {
     {0, "SignalAll on "},
 };
 
-static absl::base_internal::SpinLock synch_event_mu(
-    absl::base_internal::kLinkerInitialized);
-// protects synch_event
+ABSL_CONST_INIT static absl::base_internal::SpinLock synch_event_mu(
+    absl::kConstInit, base_internal::SCHEDULE_KERNEL_ONLY);
 
 // Hash table size; should be prime > 2.
 // Can't be too small, as it's used for deadlock detection information.
-static const uint32_t kNSynchEvent = 1031;
+static constexpr uint32_t kNSynchEvent = 1031;
 
 static struct SynchEvent {     // this is a trivial hash table for the events
   // struct is freed when refcount reaches 0