Remove MicroLock::init()

Summary: Have constructor do init() instead. I can't think of any valid reason to have this API other than confusing everyone who decides to use it.

Reviewed By: praihan

Differential Revision: D32302228

fbshipit-source-id: 136e0d2919291acd60be953337309cd006bd674b

folly/MicroLock.h

@@ -94,7 +94,7 @@ namespace folly {
 
 class MicroLockCore {
  protected:
-  uint8_t lock_;
+  uint8_t lock_{};
   /**
    * Arithmetic shift required to get to the byte from the word.
    */
@@ -183,11 +183,6 @@ class MicroLockCore {
    */
   void unlockAndStore(uint8_t value) noexcept;
   void unlock() noexcept;
-
-  /**
-   * Initializes the lock state and sets the data bits to 0.
-   */
-  void init() noexcept { lock_ = 0; }
 };
 
 inline detail::Futex<>* MicroLockCore::word() const noexcept {

folly/synchronization/CallOnce.h

@@ -168,7 +168,7 @@ class basic_once_flag {
 
 class compact_once_flag {
  public:
-  compact_once_flag() noexcept { mutex_.init(); }
+  compact_once_flag() = default;
   compact_once_flag(const compact_once_flag&) = delete;
   compact_once_flag& operator=(const compact_once_flag&) = delete;
 

folly/synchronization/test/SmallLocksBenchmark.cpp

@@ -401,7 +401,7 @@ BENCHMARK(PicoSpinLockUncontendedBenchmark, iters) {
 }
 
 BENCHMARK(MicroLockUncontendedBenchmark, iters) {
-  runUncontended<InitLock<folly::MicroLock>>(iters);
+  runUncontended<folly::MicroLock>(iters);
 }
 
 BENCHMARK(SharedMutexUncontendedBenchmark, iters) {
@@ -718,7 +718,7 @@ int main(int argc, char** argv) {
           "folly::MicroSpinLock", numThreads);
       fairnessTest<InitLock<folly::PicoSpinLock<std::uint16_t>>>(
           "folly::PicoSpinLock<std::uint16_t>", numThreads);
-      fairnessTest<InitLock<folly::MicroLock>>("folly::MicroLock", numThreads);
+      fairnessTest<folly::MicroLock>("folly::MicroLock", numThreads);
       fairnessTest<folly::SharedMutex>("folly::SharedMutex", numThreads);
       fairnessTest<folly::DistributedMutex>(
           "folly::DistributedMutex", numThreads);

folly/synchronization/test/SmallLocksTest.cpp

@@ -267,7 +267,6 @@ TEST(SmallLocks, MicroLock) {
 
   x.a = 'a';
   x.b = origB;
-  x.alock.init();
   x.d = origD;
 
   // This thread touches other parts of the host word to show that
@@ -317,7 +316,6 @@ TEST(SmallLocks, MicroLock) {
 
 TEST(SmallLocks, MicroLockTryLock) {
   MicroLock lock;
-  lock.init();
   EXPECT_TRUE(lock.try_lock());
   EXPECT_FALSE(lock.try_lock());
   lock.unlock();
@@ -325,7 +323,6 @@ TEST(SmallLocks, MicroLockTryLock) {
 
 TEST(SmallLocks, MicroLockWithData) {
   MicroLock lock;
-  lock.init();
   EXPECT_EQ(lock.load(std::memory_order_relaxed), 0);
 
   EXPECT_EQ(lock.lockAndLoad(), 0);
@@ -363,7 +360,6 @@ TEST(SmallLocks, MicroLockDataAlignment) {
     uint8_t padding2;
   } thing;
   auto& lock = thing.lock;
-  lock.init();
 
   EXPECT_EQ(lock.lockAndLoad(), 0);
   lock.unlockAndStore(60);