Diff: api/BusIn.h

Revision:

144:ef7eb2e8f9f7

Parent:

0:9b334a45a8ff

--- a/api/BusIn.h	Tue Aug 02 14:07:36 2016 +0000
+++ b/api/BusIn.h	Fri Sep 02 15:07:44 2016 +0100
@@ -1,98 +1,104 @@
-/* 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_BUSIN_H
-#define MBED_BUSIN_H
-
-#include "platform.h"
-#include "DigitalIn.h"
-
-namespace mbed {
-
-/** A digital input bus, used for reading the state of a collection of pins
- */
-class BusIn {
-
-public:
-    /* Group: Configuration Methods */
-
-    /** Create an BusIn, connected to the specified pins
-     *
-     * @param <n> DigitalIn 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)
-     */
-    BusIn(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);
-
-    BusIn(PinName pins[16]);
-
-    virtual ~BusIn();
-
-    /** Read the value of the input bus
-     *
-     *  @returns
-     *   An integer with each bit corresponding to the value read from the associated DigitalIn pin
-     */
-    int read();
-
-    /** Set the input pin mode
-     *
-     *  @param mode PullUp, PullDown, PullNone
-     */
-    void mode(PinMode pull);
-
-    /** 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 read()
-     */
-    operator int();
-
-    /** Access to particular bit in random-iterator fashion
-     */
-    DigitalIn & operator[] (int index);
-#endif
-
-protected:
-    DigitalIn* _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:
-    BusIn(const BusIn&);
-    BusIn & operator = (const BusIn&);
-};
-
-} // 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_BUSIN_H
+#define MBED_BUSIN_H
+
+#include "platform.h"
+#include "DigitalIn.h"
+#include "PlatformMutex.h"
+
+namespace mbed {
+
+/** A digital input bus, used for reading the state of a collection of pins
+ *
+ * @Note Synchronization level: Thread safe
+ */
+class BusIn {
+
+public:
+    /* Group: Configuration Methods */
+
+    /** Create an BusIn, connected to the specified pins
+     *
+     * @param <n> DigitalIn 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)
+     */
+    BusIn(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);
+
+    BusIn(PinName pins[16]);
+
+    virtual ~BusIn();
+
+    /** Read the value of the input bus
+     *
+     *  @returns
+     *   An integer with each bit corresponding to the value read from the associated DigitalIn pin
+     */
+    int read();
+
+    /** Set the input pin mode
+     *
+     *  @param mode PullUp, PullDown, PullNone
+     */
+    void mode(PinMode pull);
+
+    /** 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 read()
+     */
+    operator int();
+
+    /** Access to particular bit in random-iterator fashion
+     */
+    DigitalIn & operator[] (int index);
+
+protected:
+    DigitalIn* _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:
+    virtual void lock();
+    virtual void unlock();
+    BusIn(const BusIn&);
+    BusIn & operator = (const BusIn&);
+};
+
+} // namespace mbed
+
+#endif