Restructure platform directory (#382)

This updates the platform and logging directory and moves it to the following places:
FreeRTOS\FreeRTOS-Plus\Source\Utilities
FreeRTOS\FreeRTOS-Plus\Source\Application-Protocols\network_transport\freertos_plus_tcp

Project files are updated to follow suite. All updated demos are tested to work as expected.

FreeRTOS-Plus/Source/Utilities/exponential_backoff/exponential_backoff.c

@@ -0,0 +1,101 @@
+/*
+ * Copyright (C) 2020 Amazon.com, Inc. or its affiliates.  All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of
+ * this software and associated documentation files (the "Software"), to deal in
+ * the Software without restriction, including without limitation the rights to
+ * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
+ * the Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+ * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+ * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
+ * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+/**
+ * @file exponential_backoff.c
+ * @brief Utility implementation of backoff logic, used for attempting retries of failed processes.
+ */
+
+/* Standard includes. */
+#include <stdint.h>
+
+/* Kernel includes. */
+#include "FreeRTOS.h"
+#include "task.h"
+
+#include "exponential_backoff.h"
+
+#define MILLISECONDS_PER_SECOND    ( 1000U )                                                         /**< @brief Milliseconds per second. */
+
+extern UBaseType_t uxRand( void );
+
+/*-----------------------------------------------------------*/
+
+RetryUtilsStatus_t RetryUtils_BackoffAndSleep( RetryUtilsParams_t * pRetryParams )
+{
+    RetryUtilsStatus_t status = RetryUtilsRetriesExhausted;
+    uint32_t backOffDelayMs = 0;
+
+    /* If pRetryParams->maxRetryAttempts is set to 0, try forever. */
+    if( ( pRetryParams->attemptsDone < pRetryParams->maxRetryAttempts ) ||
+        ( 0U == pRetryParams->maxRetryAttempts ) )
+    {
+        /* Choose a random value for back-off time between 0 and the max jitter value. */
+        backOffDelayMs = uxRand() % pRetryParams->nextJitterMax;
+
+        /*  Wait for backoff time to expire for the next retry. */
+        vTaskDelay( pdMS_TO_TICKS( backOffDelayMs * MILLISECONDS_PER_SECOND ) );
+
+        /* Increment backoff counts. */
+        pRetryParams->attemptsDone++;
+
+        /* Double the max jitter value for the next retry attempt, only
+         * if the new value will be less than the max backoff time value. */
+        if( pRetryParams->nextJitterMax < ( MAX_RETRY_BACKOFF_SECONDS / 2U ) )
+        {
+            pRetryParams->nextJitterMax += pRetryParams->nextJitterMax;
+        }
+        else
+        {
+            pRetryParams->nextJitterMax = MAX_RETRY_BACKOFF_SECONDS;
+        }
+
+        status = RetryUtilsSuccess;
+    }
+    else
+    {
+        /* When max retry attempts are exhausted, let application know by
+         * returning RetryUtilsRetriesExhausted. Application may choose to
+         * restart the retry process after calling RetryUtils_ParamsReset(). */
+        status = RetryUtilsRetriesExhausted;
+        RetryUtils_ParamsReset( pRetryParams );
+    }
+
+    return status;
+}
+
+/*-----------------------------------------------------------*/
+
+void RetryUtils_ParamsReset( RetryUtilsParams_t * pRetryParams )
+{
+    uint32_t jitter = 0;
+
+    /* Reset attempts done to zero so that the next retry cycle can start. */
+    pRetryParams->attemptsDone = 0;
+
+    /* Calculate jitter value using picking a random number. */
+    jitter = ( uxRand() % MAX_JITTER_VALUE_SECONDS );
+
+    /* Reset the backoff value to the initial time out value plus jitter. */
+    pRetryParams->nextJitterMax = INITIAL_RETRY_BACKOFF_SECONDS + jitter;
+}
+
+/*-----------------------------------------------------------*/