From f890b35a039134145dddb224a49bf4c71bc51d3e Mon Sep 17 00:00:00 2001
From: Michael Ploujnikov <ploujj@gmail.com>
Date: Mon, 11 Jan 2010 15:04:52 -0500
Subject: [PATCH] continuation of working_list introduction

---
 src/backend/threadpool.c | 31 ++++++++++++++++++++++++-------
 src/backend/threadpool.h |  2 +-
 src/backend/threads.c    |  3 +++
 3 files changed, 28 insertions(+), 8 deletions(-)

diff --git a/src/backend/threadpool.c b/src/backend/threadpool.c
index 346a847d2..f08bfd0e0 100644
--- a/src/backend/threadpool.c
+++ b/src/backend/threadpool.c
@@ -105,26 +105,37 @@ lumiera_threadpool_acquire_thread(enum lumiera_thread_class kind,
 
   LUMIERA_CONDITION_SECTION (threadpool, &threadpool.pool[kind].sync)
     {
-      if (llist_is_empty (&threadpool.pool[kind].list))
+      if (llist_is_empty (&threadpool.pool[kind].idle_list))
         {
           ret = lumiera_thread_new (kind, purpose, flag,
                                     &threadpool.pool[kind].pthread_attrs);
           ENSURE (ret, "did not create a valid thread");
           TODO ("no error handing, let the resourcecollector do it, no need when returning the thread");
-          LUMIERA_CONDITION_WAIT (!llist_is_empty (&threadpool.pool[kind].list));
+          LUMIERA_CONDITION_WAIT (!llist_is_empty (&threadpool.pool[kind].idel_list));
         }
       // use an existing thread, pick the first one
       // remove it from the pool's list
-      ret = (LumieraThread)(llist_unlink (llist_head (&threadpool.pool[kind].list)));
+      ret = (LumieraThread)(llist_unlink (llist_head (&threadpool.pool[kind].idle_list)));
+
+      ENSURE (ret, "did not find a valid thread");
+
       REQUIRE (ret->state == LUMIERA_THREADSTATE_IDLE, "trying to return a non-idle thread (state=%s)", lumiera_threadstate_names[ret->state]);
+
+      llist_insert_head (&threadpool.pool[kind].working_list, ret);
+
       threadpool.pool[kind].working_thread_count++;
       threadpool.pool[kind].idle_thread_count--; // cheaper than using llist_count
+      ENSURE (threadpool.pool[kind].working_thread_count ==
+              llist_count (&threadpool.pool[kind].working_list),
+              "working thread count %d is wrong, should be %d",
+              threadpool.pool[kind].working_thread_count,
+              llist_count (&threadpool.pool[kind].working_list));
+
       ENSURE (threadpool.pool[kind].idle_thread_count ==
-              llist_count (&threadpool.pool[kind].list),
+              llist_count (&threadpool.pool[kind].idle_list),
               "idle thread count %d is wrong, should be %d",
               threadpool.pool[kind].idle_thread_count,
-              llist_count (&threadpool.pool[kind].list));
-      ENSURE (ret, "did not find a valid thread");
+              llist_count (&threadpool.pool[kind].idle_list));
     }
   return ret;
 }
@@ -142,7 +153,8 @@ lumiera_threadpool_release_thread(LumieraThread thread)
     {
       thread->state = LUMIERA_THREADSTATE_IDLE;
       REQUIRE (llist_is_empty (&thread->node), "thread already belongs to some list");
-      llist_insert_head (&threadpool.pool[thread->kind].list, &thread->node);
+      llist_unlink (&thread); // remove thread from the working_list
+      llist_insert_head (&threadpool.pool[thread->kind].idle_list, &thread->node);
 
       threadpool.pool[thread->kind].working_thread_count--;
       threadpool.pool[thread->kind].idle_thread_count++; // cheaper than using llist_count
@@ -152,6 +164,11 @@ lumiera_threadpool_release_thread(LumieraThread thread)
               "idle thread count %d is wrong, should be %d",
               threadpool.pool[thread->kind].idle_thread_count,
               llist_count (&threadpool.pool[thread->kind].list));
+      ENSURE (threadpool.pool[thread->kind].working_thread_count ==
+              llist_count (&threadpool.pool[thread->kind].working_list),
+              "working thread count %d is wrong, should be %d",
+              threadpool.pool[thread->kind].working_thread_count,
+              llist_count (&threadpool.pool[thread->kind].workinglist));
       REQUIRE (!llist_is_empty (&threadpool.pool[thread->kind].list), "thread pool is still empty after insertion");
       LUMIERA_CONDITION_BROADCAST;
     }
diff --git a/src/backend/threadpool.h b/src/backend/threadpool.h
index b3fb5a18e..ac3a52ad2 100644
--- a/src/backend/threadpool.h
+++ b/src/backend/threadpool.h
@@ -69,7 +69,7 @@ struct lumiera_threadpool_struct
   struct
   {
     llist working_list;
-    llist working_idle;
+    llist idle_list;
     unsigned working_thread_count;
     unsigned idle_thread_count;
     pthread_attr_t pthread_attrs;
diff --git a/src/backend/threads.c b/src/backend/threads.c
index 1781832e3..5c8d69eba 100644
--- a/src/backend/threads.c
+++ b/src/backend/threads.c
@@ -76,6 +76,9 @@ static void* thread_loop (void* thread)
         INFO(threads, "function %p", t->function);
         if (t->function)
           t->function (t->arguments);
+        // TODO: problem:
+        // calling release on a not-yet properly setup thread
+        // threadpool.pool[thread->kind].working_thread_count == 0
         lumiera_threadpool_release_thread(t);
         LUMIERA_CONDITION_WAIT(t->state != LUMIERA_THREADSTATE_IDLE);
         INFO(threads, "Thread awaken with state %d", t->state);