Retire Thread::INITIALIZING

Was used to prevent issues when creating multiple threads
on Windows, but now it seems we can remove it safely.

No functional change.

Signed-off-by: Marco Costalba <mcostalba@gmail.com>

src/search.cpp

@@ -2159,23 +2159,20 @@ void Thread::idle_loop(SplitPoint* sp) {
              || do_terminate
              || (Threads.use_sleeping_threads() && state == Thread::AVAILABLE))
       {
-          assert(!sp || Threads.use_sleeping_threads());
+          assert((!sp && threadID) || Threads.use_sleeping_threads());
-          assert(threadID != 0 || Threads.use_sleeping_threads());
+
+          // Grab the lock to avoid races with Thread::wake_up()
+          lock_grab(&sleepLock);
 
           // Slave thread should exit as soon as do_terminate flag raises
           if (do_terminate)
           {
               assert(!sp);
               state = Thread::TERMINATED;
+              lock_release(&sleepLock);
               return;
           }
 
-          if (state == Thread::INITIALIZING)
-              state = Thread::AVAILABLE;
-
-          // Grab the lock to avoid races with Thread::wake_up()
-          lock_grab(&sleepLock);
-
           // If we are master and all slaves have finished don't go to sleep
           if (sp && all_slaves_finished(sp))
           {

src/thread.cpp

@@ -135,7 +135,7 @@ void ThreadsManager::set_size(int cnt) {
 
 void ThreadsManager::init() {
 
-  // Threads will sent to sleep as soon as created, only main thread is kept alive
+  // Threads will go to sleep as soon as created, only main thread is kept alive
   set_size(1);
   threads[0].state = Thread::SEARCHING;
   threads[0].threadID = 0;
@@ -159,7 +159,7 @@ void ThreadsManager::init() {
   // Create and startup all the threads but the main that is already running
   for (int i = 1; i < MAX_THREADS; i++)
   {
-      threads[i].state = Thread::INITIALIZING;
+      threads[i].state = Thread::AVAILABLE;
       threads[i].threadID = i;
 
 #if defined(_MSC_VER)
@@ -174,9 +174,6 @@ void ThreadsManager::init() {
           std::cout << "Failed to create thread number " << i << std::endl;
           ::exit(EXIT_FAILURE);
       }
-
-      // Wait until the thread has finished launching and is gone to sleep
-      while (threads[i].state == Thread::INITIALIZING) {}
   }
 }
 

src/thread.h

@@ -67,7 +67,6 @@ struct Thread {
 
   enum ThreadState
   {
-    INITIALIZING,  // Thread is initializing itself
     SEARCHING,     // Thread is performing work
     AVAILABLE,     // Thread is waiting for work
     WORKISWAITING, // Master has ordered us to start searching