#ifndef THREAD_H_INCLUDED
#define THREAD_H_INCLUDED
+#include <atomic>
#include <bitset>
#include <condition_variable>
#include <mutex>
struct Thread;
-const int MAX_THREADS = 128;
-const int MAX_SPLITPOINTS_PER_THREAD = 8;
+const size_t MAX_THREADS = 128;
+const size_t MAX_SPLITPOINTS_PER_THREAD = 8;
+const size_t MAX_SLAVES_PER_SPLITPOINT = 4;
/// SplitPoint struct stores information shared by the threads searching in
/// parallel below the same split point. It is populated at splitting time.
// Const data after split point has been setup
const Position* pos;
Search::Stack* ss;
- Thread* masterThread;
+ Thread* master;
Depth depth;
Value beta;
int nodeType;
};
+/// Spinlock class wraps low level atomic operations to provide spin lock functionality
+
+class Spinlock {
+
+ std::atomic_flag lock;
+
+public:
+ Spinlock() { std::atomic_flag_clear(&lock); }
+ void acquire() { while (lock.test_and_set(std::memory_order_acquire)) {} }
+ void release() { lock.clear(std::memory_order_release); }
+};
+
+
/// ThreadBase struct is the base of the hierarchy from where we derive all the
/// specialized thread classes.
struct ThreadBase {
- ThreadBase() : exit(false) {}
- virtual ~ThreadBase() {}
+ virtual ~ThreadBase() = default;
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;
+ volatile bool exit = false;
};
size_t idx;
int maxPly;
SplitPoint* volatile activeSplitPoint;
- volatile int splitPointsSize;
+ volatile size_t splitPointsSize;
volatile bool searching;
};
/// 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;
+ volatile bool thinking = true; // Avoid a race with start_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;
+ bool run = false;
};