1 files changed, 104 insertions, 0 deletions
diff --git a/os/kernel/include/chsem.h b/os/kernel/include/chsem.h
new file mode 100644
index 000000000..cced49601
--- /dev/null
+++ b/os/kernel/include/chsem.h
@@ -0,0 +1,104 @@
+/*
+    ChibiOS/RT - Copyright (C) 2006,2007,2008,2009,2010 Giovanni Di Sirio.
+
+    This file is part of ChibiOS/RT.
+
+    ChibiOS/RT 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.
+
+    ChibiOS/RT 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/>.
+*/
+
+/**
+ * @file    semaphores.h
+ * @brief   Semaphores macros and structures.
+ *
+ * @addtogroup semaphores
+ * @{
+ */
+
+#ifndef _SEMAPHORES_H_
+#define _SEMAPHORES_H_
+
+#if CH_USE_SEMAPHORES
+
+/**
+ * @brief   Semaphore structure.
+ */
+typedef struct Semaphore {
+  ThreadsQueue          s_queue;    /**< @brief Queue of the threads sleeping
+                                                on this semaphore.          */
+  cnt_t                 s_cnt;      /**< @brief The semaphore counter.      */
+} Semaphore;
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+  void chSemInit(Semaphore *sp, cnt_t n);
+  void chSemReset(Semaphore *sp, cnt_t n);
+  void chSemResetI(Semaphore *sp, cnt_t n);
+  msg_t chSemWait(Semaphore *sp);
+  msg_t chSemWaitS(Semaphore *sp);
+  msg_t chSemWaitTimeout(Semaphore *sp, systime_t time);
+  msg_t chSemWaitTimeoutS(Semaphore *sp, systime_t time);
+  void chSemSignal(Semaphore *sp);
+  void chSemSignalI(Semaphore *sp);
+#if CH_USE_SEMSW
+  msg_t chSemSignalWait(Semaphore *sps, Semaphore *spw);
+#endif
+#ifdef __cplusplus
+}
+#endif
+
+/**
+ * @brief   Data part of a static semaphore initializer.
+ * @details This macro should be used when statically initializing a semaphore
+ *          that is part of a bigger structure.
+ *
+ * @param[in] name      the name of the semaphore variable
+ * @param[in] n         the counter initial value, this value must be
+ *                      non-negative
+ */
+#define _SEMAPHORE_DATA(name, n) {_THREADSQUEUE_DATA(name.s_queue), n}
+
+/**
+ * @brief   Static semaphore initializer.
+ * @details Statically initialized semaphores require no explicit
+ *          initialization using @p chSemInit().
+ *
+ * @param[in] name      the name of the semaphore variable
+ * @param[in] n         the counter initial value, this value must be
+ *                      non-negative
+ */
+#define SEMAPHORE_DECL(name, n) Semaphore name = _SEMAPHORE_DATA(name, n)
+
+/**
+ * @brief   Decreases the semaphore counter.
+ * @details This macro can be used when the counter is known to be positive.
+ */
+#define chSemFastWaitI(sp)      ((sp)->s_cnt--)
+
+/**
+ * @brief   Increases the semaphore counter.
+ * @details This macro can be used when the counter is known to be not negative.
+ */
+#define chSemFastSignalI(sp)    ((sp)->s_cnt++)
+
+/**
+ * @brief   Returns the semaphore counter current value.
+ */
+#define chSemGetCounterI(sp)    ((sp)->s_cnt)
+
+#endif /* CH_USE_SEMAPHORES */
+
+#endif /* _SEMAPHORES_H_ */
+
+/** @} */