[pypy-commit] stmgc queue: Clarify the return value of join()

[arigo]

Author: Armin Rigo <arigo at tunes.org>
Branch: queue
Changeset: r1860:d083e426a17d
Date: 2015-06-18 14:45 +0200
http://bitbucket.org/pypy/stmgc/changeset/d083e426a17d/

Log:	Clarify the return value of join()

diff --git a/c8/stm/queue.c b/c8/stm/queue.c
--- a/c8/stm/queue.c
+++ b/c8/stm/queue.c
@@ -309,7 +309,7 @@
     seg->unfinished_tasks_in_this_transaction--;
 }
 
-int stm_queue_join(object_t *qobj, stm_queue_t *queue, stm_thread_local_t *tl)
+long stm_queue_join(object_t *qobj, stm_queue_t *queue, stm_thread_local_t *tl)
 {
     int64_t result;
 
@@ -317,8 +317,7 @@
     result = queue->unfinished_tasks;   /* can't wait in tests */
     result += (queue->segs[STM_SEGMENT->segment_num - 1]
                .unfinished_tasks_in_this_transaction);
-    if (result > 0)
-        return 42;
+    return result;
 #else
     STM_PUSH_ROOT(*tl, qobj);
     _stm_commit_transaction();
@@ -333,8 +332,9 @@
     STM_POP_ROOT(*tl, qobj);   /* 'queue' should stay alive until here */
 #endif
 
-    /* returns 1 for 'ok', or 0 for error: negative 'unfinished_tasks' */
-    return (result == 0);
+    /* returns 0 for 'ok', or negative if there was more task_done()
+       than put() so far */
+    return result;
 }
 
 static void queue_trace_list(queue_entry_t *entry, void trace(object_t **),
diff --git a/c8/stmgc.h b/c8/stmgc.h
--- a/c8/stmgc.h
+++ b/c8/stmgc.h
@@ -751,7 +751,7 @@
 void stm_queue_task_done(stm_queue_t *queue);
 /* join() commits and waits outside a transaction (so push roots).
    Unsuitable if the current transaction is atomic! */
-int stm_queue_join(object_t *qobj, stm_queue_t *queue, stm_thread_local_t *tl);
+long stm_queue_join(object_t *qobj, stm_queue_t *queue, stm_thread_local_t *tl);
 void stm_queue_tracefn(stm_queue_t *queue, void trace(object_t **));
 
 
diff --git a/c8/test/test_queue.py b/c8/test/test_queue.py
--- a/c8/test/test_queue.py
+++ b/c8/test/test_queue.py
@@ -59,12 +59,12 @@
     def join(self, obj):
         q = get_queue(obj)
         res = lib.stm_queue_join(obj, q, self.tls[self.current_thread]);
-        if res == 1:
+        if res == 0:
             return
-        elif res == 42:
+        elif res > 0:
             raise Conflict("join() cannot wait in tests")
         else:
-            raise AssertionError("stm_queue_join error")
+            raise AssertionError("too much task_done()!")
 
 
 class TestQueue(BaseTestQueue):