[threadpool] Pass callback at initialization (#4546)

This remove the possibility to execute different callbacks on the threadpool, but this allows us to remove the work_items_lock, which is called on the hot path of the ThreadPool.

diff --git a/mono/metadata/threadpool-worker-default.c b/mono/metadata/threadpool-worker-default.c
index f410534223dacd272fa9c95d6320d0426eab7438..cfcecf95a85e73d07860d22ffdcc2419e3b2142c 100644 (file)
--- a/mono/metadata/threadpool-worker-default.c
+++ b/mono/metadata/threadpool-worker-default.c
@@ -110,11 +110,6 @@ typedef struct {
        gdouble accumulated_sample_duration;
 } ThreadPoolHillClimbing;
 
-typedef struct {
-       MonoThreadPoolWorkerCallback callback;
-       gpointer data;
-} ThreadPoolWorkItem;
-
 typedef union {
        struct {
                gint16 max_working; /* determined by heuristic */
@@ -128,16 +123,15 @@ typedef union {
 typedef struct {
        MonoRefCount ref;
 
+       MonoThreadPoolWorkerCallback callback;
+
        ThreadPoolWorkerCounter counters;
 
        MonoCoopMutex parked_threads_lock;
        gint32 parked_threads_count;
        MonoCoopCond parked_threads_cond;
 
-       ThreadPoolWorkItem *work_items; // ThreadPoolWorkItem []
-       gint32 work_items_count;
-       gint32 work_items_size;
-       MonoCoopMutex work_items_lock;
+       volatile gint32 work_items_count;
 
        guint32 worker_creation_current_second;
        guint32 worker_creation_current_count;
@@ -221,8 +215,6 @@ destroy (gpointer data)
        mono_coop_mutex_destroy (&worker.parked_threads_lock);
        mono_coop_cond_destroy (&worker.parked_threads_cond);
 
-       mono_coop_mutex_destroy (&worker.work_items_lock);
-
        mono_coop_mutex_destroy (&worker.worker_creation_lock);
 
        mono_coop_mutex_destroy (&worker.heuristic_lock);
@@ -231,7 +223,7 @@ destroy (gpointer data)
 }
 
 void
-mono_threadpool_worker_init (void)
+mono_threadpool_worker_init (MonoThreadPoolWorkerCallback callback)
 {
        ThreadPoolHillClimbing *hc;
        const char *threads_per_cpu_env;
@@ -240,13 +232,12 @@ mono_threadpool_worker_init (void)
 
        mono_refcount_init (&worker, destroy);
 
+       worker.callback = callback;
+
        mono_coop_mutex_init (&worker.parked_threads_lock);
        worker.parked_threads_count = 0;
        mono_coop_cond_init (&worker.parked_threads_cond);
 
-       /* worker.work_items_size is inited to 0 */
-       mono_coop_mutex_init (&worker.work_items_lock);
-
        worker.worker_creation_current_second = -1;
        mono_coop_mutex_init (&worker.worker_creation_lock);
 
@@ -313,69 +304,32 @@ mono_threadpool_worker_cleanup (void)
 }
 
 static void
-work_item_lock (void)
-{
-       mono_coop_mutex_lock (&worker.work_items_lock);
-}
-
-static void
-work_item_unlock (void)
+work_item_push (void)
 {
-       mono_coop_mutex_unlock (&worker.work_items_lock);
-}
-
-static void
-work_item_push (MonoThreadPoolWorkerCallback callback, gpointer data)
-{
-       ThreadPoolWorkItem work_item;
-
-       g_assert (callback);
-
-       work_item.callback = callback;
-       work_item.data = data;
+       gint32 old, new;
 
-       work_item_lock ();
-
-       g_assert (worker.work_items_count <= worker.work_items_size);
-
-       if (G_UNLIKELY (worker.work_items_count == worker.work_items_size)) {
-               worker.work_items_size += 64;
-               worker.work_items = g_renew (ThreadPoolWorkItem, worker.work_items, worker.work_items_size);
-       }
-
-       g_assert (worker.work_items);
-
-       worker.work_items [worker.work_items_count ++] = work_item;
-
-       // printf ("[push] worker.work_items = %p, worker.work_items_count = %d, worker.work_items_size = %d\n",
-       //      worker.work_items, worker.work_items_count, worker.work_items_size);
+       do {
+               old = InterlockedRead (&worker.work_items_count);
+               g_assert (old >= 0);
 
-       work_item_unlock ();
+               new = old + 1;
+       } while (InterlockedCompareExchange (&worker.work_items_count, new, old) != old);
 }
 
 static gboolean
-work_item_try_pop (ThreadPoolWorkItem *work_item)
+work_item_try_pop (void)
 {
-       g_assert (work_item);
-
-       work_item_lock ();
-
-       // printf ("[pop]  worker.work_items = %p, worker.work_items_count = %d, worker.work_items_size = %d\n",
-       //      worker.work_items, worker.work_items_count, worker.work_items_size);
+       gint32 old, new;
 
-       if (worker.work_items_count == 0) {
-               work_item_unlock ();
-               return FALSE;
-       }
-
-       *work_item = worker.work_items [-- worker.work_items_count];
+       do {
+               old = InterlockedRead (&worker.work_items_count);
+               g_assert (old >= 0);
 
-       if (G_UNLIKELY (worker.work_items_count >= 64 * 3 && worker.work_items_count < worker.work_items_size / 2)) {
-               worker.work_items_size -= 64;
-               worker.work_items = g_renew (ThreadPoolWorkItem, worker.work_items, worker.work_items_size);
-       }
+               if (old == 0)
+                       return FALSE;
 
-       work_item_unlock ();
+               new = old - 1;
+       } while (InterlockedCompareExchange (&worker.work_items_count, new, old) != old);
 
        return TRUE;
 }
@@ -383,24 +337,18 @@ work_item_try_pop (ThreadPoolWorkItem *work_item)
 static gint32
 work_item_count (void)
 {
-       gint32 count;
-
-       work_item_lock ();
-       count = worker.work_items_count;
-       work_item_unlock ();
-
-       return count;
+       return InterlockedRead (&worker.work_items_count);
 }
 
 static void worker_request (void);
 
 void
-mono_threadpool_worker_enqueue (MonoThreadPoolWorkerCallback callback, gpointer data)
+mono_threadpool_worker_request (void)
 {
        if (!mono_refcount_tryinc (&worker))
                return;
 
-       work_item_push (callback, data);
+       work_item_push ();
 
        worker_request ();
 
@@ -523,12 +471,10 @@ worker_thread (gpointer unused)
        g_assert (thread);
 
        while (!mono_runtime_is_shutting_down ()) {
-               ThreadPoolWorkItem work_item;
-
                if (mono_thread_interruption_checkpoint ())
                        continue;
 
-               if (!work_item_try_pop (&work_item)) {
+               if (!work_item_try_pop ()) {
                        gboolean timeout;
 
                        timeout = worker_park ();
@@ -538,10 +484,10 @@ worker_thread (gpointer unused)
                        continue;
                }
 
-               mono_trace (G_LOG_LEVEL_DEBUG, MONO_TRACE_THREADPOOL, "[%p] worker executing %p (%p)",
-                       mono_native_thread_id_get (), work_item.callback, work_item.data);
+               mono_trace (G_LOG_LEVEL_DEBUG, MONO_TRACE_THREADPOOL, "[%p] worker executing",
+                       mono_native_thread_id_get ());
 
-               work_item.callback (work_item.data);
+               worker.callback ();
        }
 
        COUNTER_ATOMIC (counter, {

diff --git a/mono/metadata/threadpool-worker.h b/mono/metadata/threadpool-worker.h
index e6f6e10eb42f4068b3bcb97478065b476c155c45..9b2c51d7f65eaffadea062299bd6d96e26cefe8c 100644 (file)
--- a/mono/metadata/threadpool-worker.h
+++ b/mono/metadata/threadpool-worker.h
@@ -7,16 +7,16 @@
 
 #include <glib.h>
 
-typedef void (*MonoThreadPoolWorkerCallback)(gpointer);
+typedef void (*MonoThreadPoolWorkerCallback)(void);
 
 void
-mono_threadpool_worker_init (void);
+mono_threadpool_worker_init (MonoThreadPoolWorkerCallback callback);
 
 void
 mono_threadpool_worker_cleanup (void);
 
 void
-mono_threadpool_worker_enqueue (MonoThreadPoolWorkerCallback callback, gpointer data);
+mono_threadpool_worker_request (void);
 
 gboolean
 mono_threadpool_worker_notify_completed (void);

diff --git a/mono/metadata/threadpool.c b/mono/metadata/threadpool.c
index cf9a8e69deb9d4be8c5262e2ea07bd343b2e48ce..3c0fa3d7f6db0ebda4cd140ae42d6f7a7b60e716 100644 (file)
--- a/mono/metadata/threadpool.c
+++ b/mono/metadata/threadpool.c
@@ -122,6 +122,9 @@ destroy (gpointer unused)
        mono_coop_mutex_destroy (&threadpool.domains_lock);
 }
 
+static void
+worker_callback (void);
+
 static void
 initialize (void)
 {
@@ -135,7 +138,7 @@ initialize (void)
        threadpool.limit_io_min = mono_cpu_count ();
        threadpool.limit_io_max = CLAMP (threadpool.limit_io_min * 100, MIN (threadpool.limit_io_min, 200), MAX (threadpool.limit_io_min, 200));
 
-       mono_threadpool_worker_init ();
+       mono_threadpool_worker_init (worker_callback);
 }
 
 static void
@@ -277,7 +280,7 @@ try_invoke_perform_wait_callback (MonoObject** exc, MonoError *error)
 }
 
 static void
-worker_callback (gpointer unused)
+worker_callback (void)
 {
        MonoError error;
        ThreadPoolDomain *tpdomain, *previous_tpdomain;
@@ -779,7 +782,7 @@ ves_icall_System_Threading_ThreadPool_RequestWorkerThread (void)
                counter._.starting ++;
        });
 
-       mono_threadpool_worker_enqueue (worker_callback, NULL);
+       mono_threadpool_worker_request ();
 
        mono_refcount_dec (&threadpool);
        return TRUE;