From 6484c1a27697f1b3a8326dbae0d3fa5eb4be7b4f Mon Sep 17 00:00:00 2001
From: "Robin.Mueller" <robin.mueller.m@gmail.com>
Date: Sat, 8 Aug 2020 23:45:18 +0200
Subject: [PATCH] shared ring buffer simplified

---
 container/SharedRingBuffer.cpp | 46 +++++++---------------------------
 container/SharedRingBuffer.h   | 43 +++++++++++++++----------------
 2 files changed, 29 insertions(+), 60 deletions(-)

diff --git a/container/SharedRingBuffer.cpp b/container/SharedRingBuffer.cpp
index a8b06b01..afcd89c7 100644
--- a/container/SharedRingBuffer.cpp
+++ b/container/SharedRingBuffer.cpp
@@ -5,7 +5,7 @@
 SharedRingBuffer::SharedRingBuffer(object_id_t objectId, const size_t size,
 		bool overwriteOld, size_t maxExcessBytes, dur_millis_t mutexTimeout):
 		SystemObject(objectId), SimpleRingBuffer(size, overwriteOld,
-		maxExcessBytes), mutexTimeout(mutexTimeout) {
+		maxExcessBytes) {
 	mutex = MutexFactory::instance()->createMutex();
 }
 
@@ -13,47 +13,19 @@ SharedRingBuffer::SharedRingBuffer(object_id_t objectId, uint8_t *buffer,
 		const size_t size, bool overwriteOld, size_t maxExcessBytes,
 		dur_millis_t mutexTimeout):
 		SystemObject(objectId), SimpleRingBuffer(buffer, size, overwriteOld,
-		maxExcessBytes), mutexTimeout(mutexTimeout) {
+		maxExcessBytes) {
 	mutex = MutexFactory::instance()->createMutex();
 }
 
-ReturnValue_t SharedRingBuffer::getFreeElementProtected(uint8_t** writePtr,
-		size_t amount) {
-	MutexHelper(mutex, MutexIF::TimeoutType::WAITING, mutexTimeout);
-	return SimpleRingBuffer::getFreeElement(writePtr,amount);
+ReturnValue_t SharedRingBuffer::lockRingBufferMutex(
+        MutexIF::TimeoutType timeoutType, dur_millis_t timeout) {
+    return mutex->lockMutex(timeoutType, timeout);
 }
 
-ReturnValue_t SharedRingBuffer::writeDataProtected(const uint8_t *data,
-		size_t amount) {
-	MutexHelper(mutex, MutexIF::TimeoutType::WAITING, mutexTimeout);
-	return SimpleRingBuffer::writeData(data,amount);
+ReturnValue_t SharedRingBuffer::unlockRingBufferMutex() {
+    return mutex->unlockMutex();
 }
 
-ReturnValue_t SharedRingBuffer::readDataProtected(uint8_t *data, size_t amount,
-		bool incrementReadPtr, bool readRemaining,
-		size_t *trueAmount) {
-	MutexHelper(mutex, MutexIF::TimeoutType::WAITING, mutexTimeout);
-	return SimpleRingBuffer::readData(data,amount, incrementReadPtr,
-			readRemaining, trueAmount);
-}
-
-ReturnValue_t SharedRingBuffer::deleteDataProtected(size_t amount,
-		bool deleteRemaining, size_t *trueAmount) {
-	MutexHelper(mutex, MutexIF::TimeoutType::WAITING, mutexTimeout);
-	return SimpleRingBuffer::deleteData(amount, deleteRemaining, trueAmount);
-}
-
-size_t SharedRingBuffer::getExcessBytes() const {
-	MutexHelper(mutex, MutexIF::TimeoutType::WAITING, mutexTimeout);
-	return SimpleRingBuffer::getExcessBytes();
-}
-
-void SharedRingBuffer::moveExcessBytesToStart() {
-	MutexHelper(mutex, MutexIF::TimeoutType::WAITING, mutexTimeout);
-	return SimpleRingBuffer::moveExcessBytesToStart();
-}
-
-size_t SharedRingBuffer::getAvailableReadDataProtected(uint8_t n) const {
-	MutexHelper(mutex, MutexIF::TimeoutType::WAITING, mutexTimeout);
-	return ((write + size) - read[n]) % size;
+MutexIF* SharedRingBuffer::getMutexHandle() const {
+    return mutex;
 }
diff --git a/container/SharedRingBuffer.h b/container/SharedRingBuffer.h
index 8d68b967..69a3d724 100644
--- a/container/SharedRingBuffer.h
+++ b/container/SharedRingBuffer.h
@@ -6,6 +6,13 @@
 #include <framework/objectmanager/SystemObject.h>
 #include <framework/timemanager/Clock.h>
 
+/**
+ * @brief   Ring buffer which can be shared among multiple objects
+ * @details
+ * This class offers a mutex to perform thread-safe operation on the ring
+ * buffer. It is still up to the developer to actually perform the lock
+ * and unlock operations.
+ */
 class SharedRingBuffer: public SystemObject,
 		public SimpleRingBuffer {
 public:
@@ -32,34 +39,24 @@ public:
 			bool overwriteOld, size_t maxExcessBytes,
 			dur_millis_t mutexTimeout = 10);
 
-	void setMutexTimeout(dur_millis_t newTimeout);
-
-	virtual size_t getExcessBytes() const override;
 	/**
-	 * Helper functions which moves any excess bytes to the start
-	 * of the ring buffer.
+	 * Unless a read-only constant value is read, all operations on the
+	 * shared ring buffer should be protected by calling this function.
+	 * @param timeoutType
+	 * @param timeout
 	 * @return
 	 */
-	virtual void moveExcessBytesToStart() override;
+	virtual ReturnValue_t lockRingBufferMutex(MutexIF::TimeoutType timeoutType,
+	        dur_millis_t timeout);
+	/**
+	 * Any locked mutex also has to be unlocked, otherwise, access to the
+	 * shared ring buffer will be blocked.
+	 * @return
+	 */
+	virtual ReturnValue_t unlockRingBufferMutex();
 
-	/** Performs mutex protected SimpleRingBuffer::getFreeElement call */
-	ReturnValue_t getFreeElementProtected(uint8_t** writePtr, size_t amount);
-
-	/** Performs mutex protected SimpleRingBuffer::writeData call */
-	ReturnValue_t writeDataProtected(const uint8_t* data, size_t amount);
-
-	/** Performs mutex protected SimpleRingBuffer::readData call */
-	ReturnValue_t readDataProtected(uint8_t *data, size_t amount,
-			bool incrementReadPtr = false,
-			bool readRemaining = false, size_t *trueAmount = nullptr);
-
-	/** Performs mutex protected SimpleRingBuffer::deleteData call */
-	ReturnValue_t deleteDataProtected(size_t amount,
-			bool deleteRemaining = false, size_t* trueAmount = nullptr);
-
-	size_t getAvailableReadDataProtected (uint8_t n = 0) const;
+	MutexIF* getMutexHandle() const;
 private:
-	dur_millis_t mutexTimeout;
 	MutexIF* mutex = nullptr;
 };