Diff: api/BusOut.h

Revision:

144:ef7eb2e8f9f7

Parent:

0:9b334a45a8ff

--- a/api/BusOut.h	Tue Aug 02 14:07:36 2016 +0000
+++ b/api/BusOut.h	Fri Sep 02 15:07:44 2016 +0100
@@ -1,101 +1,107 @@
-/* mbed Microcontroller Library
- * Copyright (c) 2006-2013 ARM Limited
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-#ifndef MBED_BUSOUT_H
-#define MBED_BUSOUT_H
-
-#include "DigitalOut.h"
-
-namespace mbed {
-
-/** A digital output bus, used for setting the state of a collection of pins
- */
-class BusOut {
-
-public:
-
-    /** Create an BusOut, connected to the specified pins
-     *
-     *  @param p<n> DigitalOut pin to connect to bus bit <n> (p5-p30, NC)
-     *
-     *  @note
-     *  It is only required to specify as many pin variables as is required
-     *  for the bus; the rest will default to NC (not connected)
-     */
-    BusOut(PinName p0, PinName p1 = NC, PinName p2 = NC, PinName p3 = NC,
-           PinName p4 = NC, PinName p5 = NC, PinName p6 = NC, PinName p7 = NC,
-           PinName p8 = NC, PinName p9 = NC, PinName p10 = NC, PinName p11 = NC,
-           PinName p12 = NC, PinName p13 = NC, PinName p14 = NC, PinName p15 = NC);
-
-    BusOut(PinName pins[16]);
-
-    virtual ~BusOut();
-
-    /** Write the value to the output bus
-     *
-     *  @param value An integer specifying a bit to write for every corresponding DigitalOut pin
-     */
-    void write(int value);
-
-    /** Read the value currently output on the bus
-     *
-     *  @returns
-     *    An integer with each bit corresponding to associated DigitalOut pin setting
-     */
-    int read();
-
-    /** Binary mask of bus pins connected to actual pins (not NC pins)
-     *  If bus pin is in NC state make corresponding bit will be cleared (set to 0), else bit will be set to 1
-     *
-     *  @returns
-     *    Binary mask of connected pins
-     */
-    int mask() {
-        return _nc_mask;
-    }
-
-#ifdef MBED_OPERATORS
-    /** A shorthand for write()
-     */
-    BusOut& operator= (int v);
-    BusOut& operator= (BusOut& rhs);
-
-    /** Access to particular bit in random-iterator fashion
-     */
-    DigitalOut& operator[] (int index);
-
-    /** A shorthand for read()
-     */
-    operator int();
-#endif
-
-protected:
-    DigitalOut* _pin[16];
-
-    /** Mask of bus's NC pins
-     * If bit[n] is set to 1 - pin is connected
-     * if bit[n] is cleared - pin is not connected (NC)
-     */
-    int _nc_mask;
-
-   /* disallow copy constructor and assignment operators */
-private:
-    BusOut(const BusOut&);
-    BusOut & operator = (const BusOut&);
-};
-
-} // namespace mbed
-
-#endif
+/* mbed Microcontroller Library
+ * Copyright (c) 2006-2013 ARM Limited
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+#ifndef MBED_BUSOUT_H
+#define MBED_BUSOUT_H
+
+#include "DigitalOut.h"
+#include "PlatformMutex.h"
+
+namespace mbed {
+
+/** A digital output bus, used for setting the state of a collection of pins
+ */
+class BusOut {
+
+public:
+
+    /** Create an BusOut, connected to the specified pins
+     *
+     *  @param p<n> DigitalOut pin to connect to bus bit <n> (p5-p30, NC)
+     *
+     *  @Note Synchronization level: Thread safe
+     *
+     *  @note
+     *  It is only required to specify as many pin variables as is required
+     *  for the bus; the rest will default to NC (not connected)
+     */
+    BusOut(PinName p0, PinName p1 = NC, PinName p2 = NC, PinName p3 = NC,
+           PinName p4 = NC, PinName p5 = NC, PinName p6 = NC, PinName p7 = NC,
+           PinName p8 = NC, PinName p9 = NC, PinName p10 = NC, PinName p11 = NC,
+           PinName p12 = NC, PinName p13 = NC, PinName p14 = NC, PinName p15 = NC);
+
+    BusOut(PinName pins[16]);
+
+    virtual ~BusOut();
+
+    /** Write the value to the output bus
+     *
+     *  @param value An integer specifying a bit to write for every corresponding DigitalOut pin
+     */
+    void write(int value);
+
+    /** Read the value currently output on the bus
+     *
+     *  @returns
+     *    An integer with each bit corresponding to associated DigitalOut pin setting
+     */
+    int read();
+
+    /** Binary mask of bus pins connected to actual pins (not NC pins)
+     *  If bus pin is in NC state make corresponding bit will be cleared (set to 0), else bit will be set to 1
+     *
+     *  @returns
+     *    Binary mask of connected pins
+     */
+    int mask() {
+        // No lock needed since _nc_mask is not modified outside the constructor
+        return _nc_mask;
+    }
+
+    /** A shorthand for write()
+     */
+    BusOut& operator= (int v);
+    BusOut& operator= (BusOut& rhs);
+
+    /** Access to particular bit in random-iterator fashion
+     */
+    DigitalOut& operator[] (int index);
+
+    /** A shorthand for read()
+     */
+    operator int();
+
+protected:
+    virtual void lock();
+    virtual void unlock();
+    DigitalOut* _pin[16];
+
+    /** Mask of bus's NC pins
+     * If bit[n] is set to 1 - pin is connected
+     * if bit[n] is cleared - pin is not connected (NC)
+     */
+    int _nc_mask;
+
+    PlatformMutex _mutex;
+
+   /* disallow copy constructor and assignment operators */
+private:
+    BusOut(const BusOut&);
+    BusOut & operator = (const BusOut&);
+};
+
+} // namespace mbed
+
+#endif