MINOR: task: replace task_set_affinity() with task_set_thread()

The latter passes a thread ID instead of a mask, making the code simpler.

doc/internals/api/scheduler.txt

@@ -91,10 +91,12 @@ void task_queue(t)
         function for local tasks or for shared tasks who have the calling
         thread in their thread mask.
 
-void task_set_affinity(t, m)
+void task_set_thread(t, id)
-        Change task <t>'s thread_mask to new value <m>. This may only be
+        Change task <t>'s thread ID to new value <id>. This may only be
         performed by the task itself while running. This is only used to let a
-        task voluntarily migrate to another thread.
+        task voluntarily migrate to another thread. Thread id -1 is used to
+        indicate "any thread". It's ignored and replaced by zero when threads
+        are disabled.
 
 void tasklet_wakeup(tl)
         Make sure that tasklet <tl> will wake up, that is, will execute at

include/haproxy/applet.h

@@ -66,7 +66,7 @@ static inline int appctx_init(struct appctx *appctx)
 	 * eventually be created. The affinity must be set now !
 	 */
 	BUG_ON(appctx->t->tid != tid);
-	task_set_affinity(appctx->t, tid_bit);
+	task_set_thread(appctx->t, tid);
 
 	if (appctx->applet->init)
 		return appctx->applet->init(appctx);

include/haproxy/task.h

@@ -324,22 +324,22 @@ static inline void task_queue(struct task *task)
 	}
 }
 
-/* change the thread affinity of a task to <thread_mask>.
+/* Change the thread affinity of a task to <thr>, which may either be a valid
+ * thread number from 0 to nbthread-1, or a negative value to allow the task
+ * to run on any thread.
+ *
  * This may only be done from within the running task itself or during its
  * initialization. It will unqueue and requeue the task from the wait queue
  * if it was in it. This is safe against a concurrent task_queue() call because
  * task_queue() itself will unlink again if needed after taking into account
  * the new thread_mask.
  */
-static inline void task_set_affinity(struct task *t, unsigned long thread_mask)
+static inline void task_set_thread(struct task *t, int thr)
 {
-	int thr;
+#ifndef USE_THREAD
-
+	/* no shared queue without threads */
-	if (atleast2(thread_mask))
+	thr = 0;
-		thr = -1;
+#endif
-	else
-		thr = my_ffsl(thread_mask) - 1;
-
 	if (unlikely(task_in_wq(t))) {
 		task_unlink_wq(t);
 		t->tid = thr;

src/check.c

@@ -1118,7 +1118,7 @@ struct task *process_chk_conn(struct task *t, void *context, unsigned int state)
 		check->state |= CHK_ST_INPROGRESS;
 		TRACE_STATE("init new health-check", CHK_EV_TASK_WAKE|CHK_EV_HCHK_START, check);
 
-		task_set_affinity(t, tid_bit);
+		task_set_thread(t, tid);
 
 		check->current_step = NULL;
 
@@ -1217,7 +1217,7 @@ struct task *process_chk_conn(struct task *t, void *context, unsigned int state)
         if (LIST_INLIST(&check->buf_wait.list))
                 LIST_DEL_INIT(&check->buf_wait.list);
 
-	task_set_affinity(t, all_threads_mask);
+	task_set_thread(t, -1);
 	check_release_buf(check, &check->bi);
 	check_release_buf(check, &check->bo);
 	check->state &= ~(CHK_ST_INPROGRESS|CHK_ST_IN_ALLOC|CHK_ST_OUT_ALLOC);

src/extcheck.c

@@ -525,7 +525,7 @@ struct task *process_chk_proc(struct task *t, void *context, unsigned int state)
 				int t_con = tick_add(now_ms, s->proxy->timeout.connect);
 				t->expire = tick_first(t->expire, t_con);
 			}
-			task_set_affinity(t, tid_bit);
+			task_set_thread(t, tid);
 			goto reschedule;
 		}
 
@@ -588,7 +588,7 @@ struct task *process_chk_proc(struct task *t, void *context, unsigned int state)
 			/* a success was detected */
 			check_notify_success(check);
 		}
-		task_set_affinity(t, 1);
+		task_set_thread(t, 0);
 		check->state &= ~CHK_ST_INPROGRESS;
 
 		pid_list_del(check->curpid);