pthreads: allow to set `ThreadPool::nb_thread` before first execute

Signed-off-by: Alexis Laferrière <alexis.laf@xymus.net>

diff --git a/lib/pthreads/threadpool.nit b/lib/pthreads/threadpool.nit
index cd14ab1..cbb6594 100644 (file)
--- a/lib/pthreads/threadpool.nit
+++ b/lib/pthreads/threadpool.nit
@@ -23,21 +23,22 @@ class ThreadPool
        private var queue = new ConcurrentList[Task]
        private var mutex = new Mutex
        private var cond = new NativePthreadCond
+       private var threads = new Array[PoolThread]
 
-       # Number of threads used
-       var nb_threads: Int is noinit
+       # Number of threads used, can only grow after the first call to `execute`
+       var nb_threads = 5 is optional, writable
 
-       init do
-               for i in [0..nb_threads[ do
+       private fun create_threads do
+               while threads.length < nb_threads do
                        var t = new PoolThread(queue, mutex, cond)
                        t.start
+                       threads.add t
                end
        end
 
-       private fun set_nb_threads(nb: nullable Int) is autoinit do nb_threads = nb or else 5
-
        # Adds a Task into the queue
-       fun execute(task: JoinTask) do
+       fun execute(task: Task) do
+               create_threads
                queue.push(task)
                cond.signal
        end