X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fthread.h;h=f530913cf22017f21fa49a2ca812dc6861b5439c;hp=ea645b4547fd878742135fdbaa4f7fd79647c14a;hb=3017e8c60401ecd92468a9ede3368002c4ddd440;hpb=d3d26a94b3e501459a610b8d730394125c9afd45

diff --git a/src/thread.h b/src/thread.h
index ea645b45..f530913c 100644
--- a/src/thread.h
+++ b/src/thread.h
@@ -20,11 +20,7 @@
 #ifndef THREAD_H_INCLUDED
 #define THREAD_H_INCLUDED
 
-#include <atomic>
 #include <bitset>
-#include <condition_variable>
-#include <mutex>
-#include <thread>
 #include <vector>
 
 #include "material.h"
@@ -39,20 +35,32 @@ const size_t MAX_THREADS = 128;
 const size_t MAX_SPLITPOINTS_PER_THREAD = 8;
 const size_t MAX_SLAVES_PER_SPLITPOINT = 4;
 
+/// Mutex and ConditionVariable struct are wrappers of the low level locking
+/// machinery and are modeled after the corresponding C++11 classes.
 
-/// Spinlock class wraps low level atomic operations to provide a spin lock
+struct Mutex {
+  Mutex() { lock_init(l); }
+ ~Mutex() { lock_destroy(l); }
 
-class Spinlock {
+  void lock() { lock_grab(l); }
+  void unlock() { lock_release(l); }
 
-  std::atomic_int lock;
+private:
+  friend struct ConditionVariable;
 
-public:
-  Spinlock() { lock = 1; } // Init here to workaround a bug with MSVC 2013
-  void acquire() {
-    while (lock.fetch_sub(1, std::memory_order_acquire) != 1)
-        while (lock.load(std::memory_order_relaxed) <= 0) {}
-  }
-  void release() { lock.store(1, std::memory_order_release); }
+  Lock l;
+};
+
+struct ConditionVariable {
+  ConditionVariable() { cond_init(c); }
+ ~ConditionVariable() { cond_destroy(c); }
+
+  void wait(Mutex& m) { cond_wait(c, m.l); }
+  void wait_for(Mutex& m, int ms) { timed_wait(c, m.l, ms); }
+  void notify_one() { cond_signal(c); }
+
+private:
+  WaitCondition c;
 };
 
 
@@ -75,7 +83,7 @@ struct SplitPoint {
   SplitPoint* parentSplitPoint;
 
   // Shared variable data
-  Spinlock spinlock;
+  Mutex mutex;
   std::bitset<MAX_THREADS> slavesMask;
   volatile bool allSlavesSearching;
   volatile uint64_t nodes;
@@ -92,15 +100,16 @@ struct SplitPoint {
 
 struct ThreadBase {
 
-  virtual ~ThreadBase() = default;
+  ThreadBase() : handle(NativeHandle()), exit(false) {}
+  virtual ~ThreadBase() {}
   virtual void idle_loop() = 0;
   void notify_one();
   void wait_for(volatile const bool& b);
 
-  std::thread nativeThread;
-  std::mutex mutex;
-  std::condition_variable sleepCondition;
-  volatile bool exit = false;
+  Mutex mutex;
+  ConditionVariable sleepCondition;
+  NativeHandle handle;
+  volatile bool exit;
 };
 
 
@@ -136,17 +145,19 @@ struct Thread : public ThreadBase {
 /// special threads: the main one and the recurring timer.
 
 struct MainThread : public Thread {
+  MainThread() : thinking(true) {} // Avoid a race with start_thinking()
   virtual void idle_loop();
-  volatile bool thinking = true; // Avoid a race with start_thinking()
+  volatile bool thinking;
 };
 
 struct TimerThread : public ThreadBase {
 
   static const int Resolution = 5; // Millisec between two check_time() calls
 
+  TimerThread() : run(false) {}
   virtual void idle_loop();
 
-  bool run = false;
+  bool run;
 };
 
 
@@ -166,8 +177,8 @@ struct ThreadPool : public std::vector<Thread*> {
   void start_thinking(const Position&, const Search::LimitsType&, Search::StateStackPtr&);
 
   Depth minimumSplitDepth;
-  Spinlock spinlock;
-  std::condition_variable sleepCondition;
+  Mutex mutex;
+  ConditionVariable sleepCondition;
   TimerThread* timer;
 };