From fc16de332f06e84b4b2bd71df9ec77fa1c7e2854 Mon Sep 17 00:00:00 2001
From: Michael Ploujnikov <ploujj@gmail.com>
Date: Sun, 29 Nov 2009 17:55:20 -0500
Subject: [PATCH] convert lumiera_thread_class to using the enum string trick
 and use it in a test

---
 src/backend/threads.c            |  7 +++++++
 src/backend/threads.h            | 31 +++++++++++++++++++++----------
 tests/30backend-threadpool.tests |  2 ++
 tests/backend/test-threadpool.c  |  6 +++---
 4 files changed, 33 insertions(+), 13 deletions(-)

diff --git a/src/backend/threads.c b/src/backend/threads.c
index 5d849943f..4fe0c8ac5 100644
--- a/src/backend/threads.c
+++ b/src/backend/threads.c
@@ -46,6 +46,13 @@ NOBUG_DEFINE_FLAG_PARENT (threads, threads_dbg); /*TODO insert a suitable/better
 
 //code goes here//
 
+#define LUMIERA_THREAD_CLASS(name) #name,
+// enum string trick: expands as an array of thread class name strings
+const char* lumiera_threadclass_names[] = {
+  LUMIERA_THREAD_CLASSES
+};
+
+#undef LUMIERA_THREAD_CLASS
 
 struct lumiera_thread_mockup
 {
diff --git a/src/backend/threads.h b/src/backend/threads.h
index 4c15a8ad8..ce9a7605b 100644
--- a/src/backend/threads.h
+++ b/src/backend/threads.h
@@ -46,6 +46,21 @@
 typedef struct lumiera_thread_struct lumiera_thread;
 typedef lumiera_thread* LumieraThread;
 
+// this is used for an enum string trick
+#define LUMIERA_THREAD_CLASSES                  \
+  /** mostly idle, low latency **/              \
+  LUMIERA_THREAD_CLASS(INTERACTIVE)             \
+  /** busy at average priority **/              \
+  LUMIERA_THREAD_CLASS(WORKER)                  \
+  /** busy, soft realtime, high priority **/    \
+  LUMIERA_THREAD_CLASS(URGENT)                  \
+  /** high latency, background jobs **/         \
+  LUMIERA_THREAD_CLASS(BATCH)                   \
+  /** Something to do when there is really nothing else to do **/       \
+  LUMIERA_THREAD_CLASS(IDLE)
+
+// enum string trick: expands as an enum of thread classes
+#define LUMIERA_THREAD_CLASS(name) LUMIERA_THREADCLASS_##name,
 
 /**
  * Thread classes.
@@ -54,16 +69,7 @@ typedef lumiera_thread* LumieraThread;
  */
 enum lumiera_thread_class
   {
-    /** mostly idle, low latency **/
-    LUMIERA_THREADCLASS_INTERACTIVE,
-    /** busy at average priority **/
-    LUMIERA_THREADCLASS_WORKER,
-    /** busy, soft realtime, high priority **/
-    LUMIERA_THREADCLASS_URGENT,
-    /** high latency, background jobs **/
-    LUMIERA_THREADCLASS_BATCH,
-    /** Something to do when there is really nothing else to do **/
-    LUMIERA_THREADCLASS_IDLE,
+    LUMIERA_THREAD_CLASSES
     /** this just denotes the number of classes listed above,
         it is used to create arrays **/
     LUMIERA_THREADCLASS_COUNT,
@@ -79,6 +85,11 @@ enum lumiera_thread_class
     LUMIERA_THREAD_OR_NOT = 1<<16
   };
 
+#undef LUMIERA_THREAD_CLASS
+
+// defined in threads.c
+extern const char* lumiera_threadclass_names[];
+
 /**
  * Thread state.
  * These are the only states our threads can be in.
diff --git a/tests/30backend-threadpool.tests b/tests/30backend-threadpool.tests
index ca2464bfe..e4f4e4005 100644
--- a/tests/30backend-threadpool.tests
+++ b/tests/30backend-threadpool.tests
@@ -9,6 +9,8 @@ TEST "Acquire/Release test" basic-acquire-release <<END
 err: start by initializing the threadpool
 err: acquiring thread 1
 err: acquiring thread 2
+err: thread 1 kind=INTERACTIVE
+err: thread 2 kind=IDLE
 err: releasing thread 1
 err: thread 1 has been released
 err: releasing thread 2
diff --git a/tests/backend/test-threadpool.c b/tests/backend/test-threadpool.c
index 41f5ae4ee..0a4319bfb 100644
--- a/tests/backend/test-threadpool.c
+++ b/tests/backend/test-threadpool.c
@@ -44,12 +44,12 @@ TEST ("basic-acquire-release")
 				      "test purpose",
 				      NULL);
 
-  //ECHO("thread 1 kind=%d", t1->kind);
+  ECHO("thread 1 kind=%s", lumiera_threadclass_names[t1->kind]);
   CHECK(LUMIERA_THREADCLASS_INTERACTIVE == t1->kind);
   //ECHO("thread 1 state=%d", t1->state);
   CHECK(LUMIERA_THREADSTATE_IDLE == t1->state);
-  //ECHO("thread 2 kind=%d", t2->kind);
-   CHECK(LUMIERA_THREADCLASS_IDLE == t2->kind);
+  ECHO("thread 2 kind=%s", lumiera_threadclass_names[t2->kind]);
+  CHECK(LUMIERA_THREADCLASS_IDLE == t2->kind);
   //ECHO("thread 2 state=%d", t2->state);
   CHECK(LUMIERA_THREADSTATE_IDLE == t2->state);