1 files changed, 0 insertions, 237 deletions
diff --git a/third_party/abseil_cpp/absl/base/internal/spinlock.h b/third_party/abseil_cpp/absl/base/internal/spinlock.h
deleted file mode 100644
index e6ac9e6400b2..000000000000
--- a/third_party/abseil_cpp/absl/base/internal/spinlock.h
+++ /dev/null
@@ -1,237 +0,0 @@
-//
-// Copyright 2017 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.
-//
-
-//  Most users requiring mutual exclusion should use Mutex.
-//  SpinLock is provided for use in three situations:
-//   - for use in code that Mutex itself depends on
-//   - to get a faster fast-path release under low contention (without an
-//     atomic read-modify-write) In return, SpinLock has worse behaviour under
-//     contention, which is why Mutex is preferred in most situations.
-//   - for async signal safety (see below)
-
-// SpinLock is async signal safe.  If a spinlock is used within a signal
-// handler, all code that acquires the lock must ensure that the signal cannot
-// arrive while they are holding the lock.  Typically, this is done by blocking
-// the signal.
-
-#ifndef ABSL_BASE_INTERNAL_SPINLOCK_H_
-#define ABSL_BASE_INTERNAL_SPINLOCK_H_
-
-#include <stdint.h>
-#include <sys/types.h>
-
-#include <atomic>
-
-#include "absl/base/attributes.h"
-#include "absl/base/const_init.h"
-#include "absl/base/dynamic_annotations.h"
-#include "absl/base/internal/low_level_scheduling.h"
-#include "absl/base/internal/raw_logging.h"
-#include "absl/base/internal/scheduling_mode.h"
-#include "absl/base/internal/tsan_mutex_interface.h"
-#include "absl/base/macros.h"
-#include "absl/base/port.h"
-#include "absl/base/thread_annotations.h"
-
-namespace absl {
-ABSL_NAMESPACE_BEGIN
-namespace base_internal {
-
-class ABSL_LOCKABLE SpinLock {
- public:
-  SpinLock() : lockword_(kSpinLockCooperative) {
-    ABSL_TSAN_MUTEX_CREATE(this, __tsan_mutex_not_static);
-  }
-
-  // Constructors that allow non-cooperative spinlocks to be created for use
-  // inside thread schedulers.  Normal clients should not use these.
-  explicit SpinLock(base_internal::SchedulingMode mode);
-
-  // Constructor for global SpinLock instances.  See absl/base/const_init.h.
-  constexpr SpinLock(absl::ConstInitType, base_internal::SchedulingMode mode)
-      : lockword_(IsCooperative(mode) ? kSpinLockCooperative : 0) {}
-
-  // For global SpinLock instances prefer trivial destructor when possible.
-  // Default but non-trivial destructor in some build configurations causes an
-  // extra static initializer.
-#ifdef ABSL_INTERNAL_HAVE_TSAN_INTERFACE
-  ~SpinLock() { ABSL_TSAN_MUTEX_DESTROY(this, __tsan_mutex_not_static); }
-#else
-  ~SpinLock() = default;
-#endif
-
-  // Acquire this SpinLock.
-  inline void Lock() ABSL_EXCLUSIVE_LOCK_FUNCTION() {
-    ABSL_TSAN_MUTEX_PRE_LOCK(this, 0);
-    if (!TryLockImpl()) {
-      SlowLock();
-    }
-    ABSL_TSAN_MUTEX_POST_LOCK(this, 0, 0);
-  }
-
-  // Try to acquire this SpinLock without blocking and return true if the
-  // acquisition was successful.  If the lock was not acquired, false is
-  // returned.  If this SpinLock is free at the time of the call, TryLock
-  // will return true with high probability.
-  inline bool TryLock() ABSL_EXCLUSIVE_TRYLOCK_FUNCTION(true) {
-    ABSL_TSAN_MUTEX_PRE_LOCK(this, __tsan_mutex_try_lock);
-    bool res = TryLockImpl();
-    ABSL_TSAN_MUTEX_POST_LOCK(
-        this, __tsan_mutex_try_lock | (res ? 0 : __tsan_mutex_try_lock_failed),
-        0);
-    return res;
-  }
-
-  // Release this SpinLock, which must be held by the calling thread.
-  inline void Unlock() ABSL_UNLOCK_FUNCTION() {
-    ABSL_TSAN_MUTEX_PRE_UNLOCK(this, 0);
-    uint32_t lock_value = lockword_.load(std::memory_order_relaxed);
-    lock_value = lockword_.exchange(lock_value & kSpinLockCooperative,
-                                    std::memory_order_release);
-
-    if ((lock_value & kSpinLockDisabledScheduling) != 0) {
-      base_internal::SchedulingGuard::EnableRescheduling(true);
-    }
-    if ((lock_value & kWaitTimeMask) != 0) {
-      // Collect contentionz profile info, and speed the wakeup of any waiter.
-      // The wait_cycles value indicates how long this thread spent waiting
-      // for the lock.
-      SlowUnlock(lock_value);
-    }
-    ABSL_TSAN_MUTEX_POST_UNLOCK(this, 0);
-  }
-
-  // Determine if the lock is held.  When the lock is held by the invoking
-  // thread, true will always be returned. Intended to be used as
-  // CHECK(lock.IsHeld()).
-  inline bool IsHeld() const {
-    return (lockword_.load(std::memory_order_relaxed) & kSpinLockHeld) != 0;
-  }
-
- protected:
-  // These should not be exported except for testing.
-
-  // Store number of cycles between wait_start_time and wait_end_time in a
-  // lock value.
-  static uint32_t EncodeWaitCycles(int64_t wait_start_time,
-                                   int64_t wait_end_time);
-
-  // Extract number of wait cycles in a lock value.
-  static uint64_t DecodeWaitCycles(uint32_t lock_value);
-
-  // Provide access to protected method above.  Use for testing only.
-  friend struct SpinLockTest;
-
- private:
-  // lockword_ is used to store the following:
-  //
-  // bit[0] encodes whether a lock is being held.
-  // bit[1] encodes whether a lock uses cooperative scheduling.
-  // bit[2] encodes whether a lock disables scheduling.
-  // bit[3:31] encodes time a lock spent on waiting as a 29-bit unsigned int.
-  static constexpr uint32_t kSpinLockHeld = 1;
-  static constexpr uint32_t kSpinLockCooperative = 2;
-  static constexpr uint32_t kSpinLockDisabledScheduling = 4;
-  static constexpr uint32_t kSpinLockSleeper = 8;
-  // Includes kSpinLockSleeper.
-  static constexpr uint32_t kWaitTimeMask =
-      ~(kSpinLockHeld | kSpinLockCooperative | kSpinLockDisabledScheduling);
-
-  // Returns true if the provided scheduling mode is cooperative.
-  static constexpr bool IsCooperative(
-      base_internal::SchedulingMode scheduling_mode) {
-    return scheduling_mode == base_internal::SCHEDULE_COOPERATIVE_AND_KERNEL;
-  }
-
-  uint32_t TryLockInternal(uint32_t lock_value, uint32_t wait_cycles);
-  void SlowLock() ABSL_ATTRIBUTE_COLD;
-  void SlowUnlock(uint32_t lock_value) ABSL_ATTRIBUTE_COLD;
-  uint32_t SpinLoop();
-
-  inline bool TryLockImpl() {
-    uint32_t lock_value = lockword_.load(std::memory_order_relaxed);
-    return (TryLockInternal(lock_value, 0) & kSpinLockHeld) == 0;
-  }
-
-  std::atomic<uint32_t> lockword_;
-
-  SpinLock(const SpinLock&) = delete;
-  SpinLock& operator=(const SpinLock&) = delete;
-};
-
-// Corresponding locker object that arranges to acquire a spinlock for
-// the duration of a C++ scope.
-class ABSL_SCOPED_LOCKABLE SpinLockHolder {
- public:
-  inline explicit SpinLockHolder(SpinLock* l) ABSL_EXCLUSIVE_LOCK_FUNCTION(l)
-      : lock_(l) {
-    l->Lock();
-  }
-  inline ~SpinLockHolder() ABSL_UNLOCK_FUNCTION() { lock_->Unlock(); }
-
-  SpinLockHolder(const SpinLockHolder&) = delete;
-  SpinLockHolder& operator=(const SpinLockHolder&) = delete;
-
- private:
-  SpinLock* lock_;
-};
-
-// Register a hook for profiling support.
-//
-// The function pointer registered here will be called whenever a spinlock is
-// contended.  The callback is given an opaque handle to the contended spinlock
-// and the number of wait cycles.  This is thread-safe, but only a single
-// profiler can be registered.  It is an error to call this function multiple
-// times with different arguments.
-void RegisterSpinLockProfiler(void (*fn)(const void* lock,
-                                         int64_t wait_cycles));
-
-//------------------------------------------------------------------------------
-// Public interface ends here.
-//------------------------------------------------------------------------------
-
-// If (result & kSpinLockHeld) == 0, then *this was successfully locked.
-// Otherwise, returns last observed value for lockword_.
-inline uint32_t SpinLock::TryLockInternal(uint32_t lock_value,
-                                          uint32_t wait_cycles) {
-  if ((lock_value & kSpinLockHeld) != 0) {
-    return lock_value;
-  }
-
-  uint32_t sched_disabled_bit = 0;
-  if ((lock_value & kSpinLockCooperative) == 0) {
-    // For non-cooperative locks we must make sure we mark ourselves as
-    // non-reschedulable before we attempt to CompareAndSwap.
-    if (base_internal::SchedulingGuard::DisableRescheduling()) {
-      sched_disabled_bit = kSpinLockDisabledScheduling;
-    }
-  }
-
-  if (!lockword_.compare_exchange_strong(
-          lock_value,
-          kSpinLockHeld | lock_value | wait_cycles | sched_disabled_bit,
-          std::memory_order_acquire, std::memory_order_relaxed)) {
-    base_internal::SchedulingGuard::EnableRescheduling(sched_disabled_bit != 0);
-  }
-
-  return lock_value;
-}
-
-}  // namespace base_internal
-ABSL_NAMESPACE_END
-}  // namespace absl
-
-#endif  // ABSL_BASE_INTERNAL_SPINLOCK_H_