From 05ec2f808a73f1042dc1a228fa7dc1822c46b07f Mon Sep 17 00:00:00 2001
From: Marcus Winter <marcus.winter.ext@siemens.com>
Date: Thu, 12 Mar 2015 11:23:55 +0100
Subject: [PATCH] mtapi_c: only notify workers if they are actually sleeping

---
 mtapi_c/src/embb_mtapi_scheduler_t.c      | 8 ++++++--
 mtapi_c/src/embb_mtapi_thread_context_t.c | 1 +
 mtapi_c/src/embb_mtapi_thread_context_t.h | 1 +
 3 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/mtapi_c/src/embb_mtapi_scheduler_t.c b/mtapi_c/src/embb_mtapi_scheduler_t.c
index 5e9bf4c..28cc5ce 100644
--- a/mtapi_c/src/embb_mtapi_scheduler_t.c
+++ b/mtapi_c/src/embb_mtapi_scheduler_t.c
@@ -356,12 +356,14 @@ int embb_mtapi_scheduler_worker(void * arg) {
       counter++;
     } else {
       /* no work, go to sleep */
+      embb_atomic_store_int(&thread_context->is_sleeping, 1);
       embb_mutex_lock(&thread_context->work_available_mutex);
       embb_condition_wait_for(
         &thread_context->work_available,
         &thread_context->work_available_mutex,
         &sleep_duration);
       embb_mutex_unlock(&thread_context->work_available_mutex);
+      embb_atomic_store_int(&thread_context->is_sleeping, 0);
     }
   }
 
@@ -593,8 +595,10 @@ mtapi_boolean_t embb_mtapi_scheduler_schedule_task(
 
     if (pushed) {
       /* signal the worker thread a task was pushed to */
-      embb_condition_notify_one(
-        &scheduler->worker_contexts[ii].work_available);
+      if (embb_atomic_load_int(&scheduler->worker_contexts[ii].is_sleeping)) {
+        embb_condition_notify_one(
+          &scheduler->worker_contexts[ii].work_available);
+      }
     } else {
       /* task could not be launched */
       embb_atomic_fetch_and_add_int(&local_action->num_tasks, -1);
diff --git a/mtapi_c/src/embb_mtapi_thread_context_t.c b/mtapi_c/src/embb_mtapi_thread_context_t.c
index ea5d4d1..2a7bdc4 100644
--- a/mtapi_c/src/embb_mtapi_thread_context_t.c
+++ b/mtapi_c/src/embb_mtapi_thread_context_t.c
@@ -70,6 +70,7 @@ void embb_mtapi_thread_context_initialize_with_node_worker_and_core(
 
   embb_mutex_init(&that->work_available_mutex, EMBB_MUTEX_PLAIN);
   embb_condition_init(&that->work_available);
+  embb_atomic_store_int(&that->is_sleeping, 0);
 }
 
 mtapi_boolean_t embb_mtapi_thread_context_start(
diff --git a/mtapi_c/src/embb_mtapi_thread_context_t.h b/mtapi_c/src/embb_mtapi_thread_context_t.h
index 0ed2dd3..a207886 100644
--- a/mtapi_c/src/embb_mtapi_thread_context_t.h
+++ b/mtapi_c/src/embb_mtapi_thread_context_t.h
@@ -56,6 +56,7 @@ struct embb_mtapi_thread_context_struct {
   embb_condition_t work_available;
   embb_thread_t thread;
   embb_tss_t tss_id;
+  embb_atomic_int is_sleeping;
 
   embb_mtapi_node_t* node;
   embb_mtapi_task_queue_t** queue;
--
libgit2 0.26.0