Clarified the spec for the thread_pool.

--HG--
extra : convert_revision : svn%3Afdd8eb12-d10e-0410-9acb-85c331704f74/trunk%402682

dlib/threads/thread_pool_extension.cpp

@@ -267,6 +267,16 @@ namespace dlib
         return tasks[idx].task_id;
     }
 
+// ----------------------------------------------------------------------------------------
+
+    bool thread_pool::
+    is_task_thread (
+    ) const
+    {
+        auto_mutex M(m);
+        return is_worker_thread(get_thread_id());
+    }
+
 // ----------------------------------------------------------------------------------------
 
 }

dlib/threads/thread_pool_extension.h

@@ -130,6 +130,8 @@ namespace dlib
                 - else
                     - we_are_destructing == false
 
+                - is_task_thread() == is_worker_thread(get_thread_id())
+
                 - m == the mutex used to protect everything in this object
                 - worker_thread_ids == an array that contains the thread ids for
                   all the threads in the thread pool
@@ -154,6 +156,9 @@ namespace dlib
         void wait_for_all_tasks (
         ) const;
 
+        bool is_task_thread (
+        ) const;
+
         template <typename T>
         uint64 add_task (
             T& obj,

dlib/threads/thread_pool_extension_abstract.h

@@ -236,6 +236,17 @@ namespace dlib
                 - all resources allocated by *this have been freed.  
         !*/
 
+        bool is_task_thread (
+        ) const;
+        /*!
+            ensures
+                - if (the thread calling this function is one of the threads in this
+                  thread pool or num_threads_in_pool() == 0) then
+                    - returns true
+                - else
+                    - returns false
+        !*/
+
         unsigned long num_threads_in_pool (
         ) const;
         /*!
@@ -253,8 +264,7 @@ namespace dlib
             requires
                 - funct == a valid member function pointer for class T
             ensures
-                - if (the thread calling this function is actually one of the threads in the
-                  thread pool and there aren't any free threads available) then
+                - if (is_task_thread() == true and there aren't any free threads available) then
                     - calls (obj.*funct)() within the calling thread and returns
                       when it finishes
                 - else
@@ -275,8 +285,7 @@ namespace dlib
             requires
                 - funct == a valid member function pointer for class T
             ensures
-                - if (the thread calling this function is actually one of the threads in the
-                  thread pool and there aren't any free threads available) then
+                - if (is_task_thread() == true and there aren't any free threads available) then
                     - calls (obj.*funct)(arg1) within the calling thread and returns
                       when it finishes
                 - else
@@ -298,8 +307,7 @@ namespace dlib
             requires
                 - funct == a valid member function pointer for class T
             ensures
-                - if (the thread calling this function is actually one of the threads in the
-                  thread pool and there aren't any free threads available) then
+                - if (is_task_thread() == true and there aren't any free threads available) then
                     - calls (obj.*funct)(arg1,arg2) within the calling thread and returns
                       when it finishes
                 - else
@@ -342,8 +350,7 @@ namespace dlib
                 - function_object(arg1.get()) is a valid expression 
                   (i.e. The A1 type stored in the future must be a type that can be passed into the given function object)
             ensures
-                - if (the thread calling this function is actually one of the threads in the
-                  thread pool and there aren't any free threads available) then
+                - if (is_task_thread() == true and there aren't any free threads available) then
                     - calls function_object(arg1.get()) within the calling thread and returns
                       when it finishes
                 - else
@@ -367,8 +374,7 @@ namespace dlib
                 - (obj.*funct)(arg1.get()) must be a valid expression.
                   (i.e. The A1 type stored in the future must be a type that can be passed into the given function)
             ensures
-                - if (the thread calling this function is actually one of the threads in the
-                  thread pool and there aren't any free threads available) then
+                - if (is_task_thread() == true and there aren't any free threads available) then
                     - calls (obj.*funct)(arg1.get()) within the calling thread and returns
                       when it finishes
                 - else
@@ -392,8 +398,7 @@ namespace dlib
                 - (obj.*funct)(arg1.get()) must be a valid expression.
                   (i.e. The A1 type stored in the future must be a type that can be passed into the given function)
             ensures
-                - if (the thread calling this function is actually one of the threads in the
-                  thread pool and there aren't any free threads available) then
+                - if (is_task_thread() == true and there aren't any free threads available) then
                     - calls (obj.*funct)(arg1.get()) within the calling thread and returns
                       when it finishes
                 - else
@@ -416,8 +421,7 @@ namespace dlib
                 - (funct)(arg1.get()) must be a valid expression.
                   (i.e. The A1 type stored in the future must be a type that can be passed into the given function)
             ensures
-                - if (the thread calling this function is actually one of the threads in the
-                  thread pool and there aren't any free threads available) then
+                - if (is_task_thread() == true and there aren't any free threads available) then
                     - calls funct(arg1.get()) within the calling thread and returns
                       when it finishes
                 - else