add timed-eventflag

ChangeLog

@@ -1,5 +1,8 @@
 2013-06-19  Niibe Yutaka  <gniibe@fsij.org>
 
+	* rules.mk (CSRC): Add eventflag.c.
+	* eventflag.h, eventflag.c: New.
+
 	* chopstx.c (chopstx_main): New.
 	(chx_init): Initialize chopstx_main.
 

eventflag.c

@@ -0,0 +1,84 @@
+/*
+ * eventflag.c - Eventflag with timeout
+ *
+ * Copyright (C) 2013 Flying Stone Technology
+ * Author: NIIBE Yutaka <gniibe@fsij.org>
+ *
+ * This file is a part of Chopstx, a thread library for embedded.
+ *
+ * Chopstx is free software: you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Chopstx is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * As additional permission under GNU GPL version 3 section 7, you may
+ * distribute non-source form of the Program without the copy of the
+ * GNU GPL normally required by section 4, provided you inform the
+ * receipents of GNU GPL by a written offer.
+ *
+ */
+
+#include <stdint.h>
+#include <stdlib.h>
+#include <chopstx.h>
+#include <eventflag.h>
+
+void
+eventflag_init (struct event_flag *ev, chopstx_t owner)
+{
+  ev->owner = owner;
+  ev->wait_usec = 0;
+  ev->flag = 0;
+  chopstx_mutex_init (&ev->mutex);
+}
+
+
+eventmask_t
+eventflag_wait_timeout (struct event_flag *ev, uint32_t usec)
+{
+  eventmask_t em = 0;
+  int n;
+
+  chopstx_mutex_lock (&ev->mutex);
+
+  if (!ev->flag)
+    {
+      ev->wait_usec = usec;
+      chopstx_mutex_unlock (&ev->mutex);
+      chopstx_usec_wait_var (&ev->wait_usec);
+      chopstx_mutex_lock (&ev->mutex);
+      ev->wait_usec = 0;
+    }
+
+  n = __builtin_ffs (ev->flag);
+  if (n)
+    {
+      em = (1 << (n - 1));
+      ev->flag &= ~em;
+    }
+
+  chopstx_mutex_unlock (&ev->mutex);
+  return em;
+}
+
+
+void
+eventflag_signal (struct event_flag *ev, eventmask_t m)
+{
+  chopstx_mutex_lock (&ev->mutex);
+  ev->flag |= m;
+  if (ev->wait_usec)
+    {
+      ev->wait_usec = 0;
+      chopstx_wakeup_usec_wait (ev->owner);
+    }
+  chopstx_mutex_unlock (&ev->mutex);
+}

eventflag.h

@@ -0,0 +1,12 @@
+typedef uint32_t eventmask_t;
+
+struct eventflag {
+  chopstx_t owner;
+  uint32_t wait_usec;
+  eventmask_t flag;
+  chopstx_mutex_t mutex;
+};
+
+void eventflag_init (struct eventflag *ev, chopstx_t owner);
+eventmask_t eventflag_wait_timeout (struct eventflag *ev, uint32_t usec);
+void eventflag_signal (struct eventflag *ev, eventmask_t m);

rules.mk

@@ -1,6 +1,11 @@
 # Chopstx make rules.
 
 CSRC += $(CHOPSTX)/entry.c $(CHOPSTX)/chopstx.c
+
+ifneq ($(USE_EVENTFLAG),)
+CSRC += $(CHOPSTX)/eventflag.c
+endif
+
 INCDIR = $(CHOPSTX)
 
 BUILDDIR = build