File content as of revision 39:2719651a5bee:

// Copyright (c) Microsoft. All rights reserved.
// Licensed under the MIT license. See LICENSE file in the project root for full license information.

#include <stdlib.h> 
#ifdef _CRTDBG_MAP_ALLOC
#include <crtdbg.h>
#endif
#include "azure_c_shared_utility/gballoc.h"

#include <stdlib.h>
#include <signal.h>
#include <stddef.h>
#include "azure_c_shared_utility/crt_abstractions.h"
#include "iothub_client.h"
#include "iothub_client_ll.h"
#include "iothubtransport.h"
#include "azure_c_shared_utility/threadapi.h"
#include "azure_c_shared_utility/lock.h"
#include "azure_c_shared_utility/iot_logging.h"

typedef struct IOTHUB_CLIENT_INSTANCE_TAG
{
    IOTHUB_CLIENT_LL_HANDLE IoTHubClientLLHandle;
	TRANSPORT_HANDLE TransportHandle;
    THREAD_HANDLE ThreadHandle;
    LOCK_HANDLE LockHandle;
    sig_atomic_t StopThread;
} IOTHUB_CLIENT_INSTANCE;

/*used by unittests only*/
const size_t IoTHubClient_ThreadTerminationOffset = offsetof(IOTHUB_CLIENT_INSTANCE, StopThread);

static int ScheduleWork_Thread(void* threadArgument)
{
    IOTHUB_CLIENT_INSTANCE* iotHubClientInstance = (IOTHUB_CLIENT_INSTANCE*)threadArgument;
    
    while (1)
    {
        if (Lock(iotHubClientInstance->LockHandle) == LOCK_OK)
        {
            /*Codes_SRS_IOTHUBCLIENT_01_038: [ The thread shall exit when IoTHubClient_Destroy is called. ]*/
            if (iotHubClientInstance->StopThread)
            {
                (void)Unlock(iotHubClientInstance->LockHandle);
                break; /*gets out of the thread*/
            }
            else
            {
                /* Codes_SRS_IOTHUBCLIENT_01_037: [The thread created by IoTHubClient_SendEvent or IoTHubClient_SetMessageCallback shall call IoTHubClient_LL_DoWork every 1 ms.] */
                /* Codes_SRS_IOTHUBCLIENT_01_039: [All calls to IoTHubClient_LL_DoWork shall be protected by the lock created in IotHubClient_Create.] */
                IoTHubClient_LL_DoWork(iotHubClientInstance->IoTHubClientLLHandle);
                (void)Unlock(iotHubClientInstance->LockHandle);
            }
        }
        else
        {
            /*Codes_SRS_IOTHUBCLIENT_01_040: [If acquiring the lock fails, IoTHubClient_LL_DoWork shall not be called.]*/
            /*no code, shall retry*/
        }
        (void)ThreadAPI_Sleep(1);
    }
       
    return 0;
}

static IOTHUB_CLIENT_RESULT StartWorkerThreadIfNeeded(IOTHUB_CLIENT_INSTANCE* iotHubClientInstance)
{
	IOTHUB_CLIENT_RESULT result;
	if (iotHubClientInstance->TransportHandle == NULL)
	{
		if (iotHubClientInstance->ThreadHandle == NULL)
		{
			iotHubClientInstance->StopThread = 0;
			if (ThreadAPI_Create(&iotHubClientInstance->ThreadHandle, ScheduleWork_Thread, iotHubClientInstance) != THREADAPI_OK)
			{
				iotHubClientInstance->ThreadHandle = NULL;
				result = IOTHUB_CLIENT_ERROR;
			}
			else
			{
				result = IOTHUB_CLIENT_OK;
		}
	}
		else
	{
			result = IOTHUB_CLIENT_OK;
		}
	}
	else 
	{
		/*Codes_SRS_IOTHUBCLIENT_17_012: [ If the transport connection is shared, the thread shall be started by calling IoTHubTransport_StartWorkerThread. ]*/
		/*Codes_SRS_IOTHUBCLIENT_17_011: [ If the transport connection is shared, the thread shall be started by calling IoTHubTransport_StartWorkerThread*/

		result = IoTHubTransport_StartWorkerThread(iotHubClientInstance->TransportHandle, iotHubClientInstance);
	}
	return result;
}

IOTHUB_CLIENT_HANDLE IoTHubClient_CreateFromConnectionString(const char* connectionString, IOTHUB_CLIENT_TRANSPORT_PROVIDER protocol)
{
    IOTHUB_CLIENT_INSTANCE* result = NULL;

    /* Codes_SRS_IOTHUBCLIENT_12_003: [IoTHubClient_CreateFromConnectionString shall verify the input parameter and if it is NULL then return NULL] */
    if (connectionString == NULL)
    {
        LogError("Input parameter is NULL: connectionString");
    }
    else if (protocol == NULL)
    {
        LogError("Input parameter is NULL: protocol");
    }
    else
    {
        /* Codes_SRS_IOTHUBCLIENT_12_004: [IoTHubClient_CreateFromConnectionString shall allocate a new IoTHubClient instance.] */
        result = malloc(sizeof(IOTHUB_CLIENT_INSTANCE));

        /* Codes_SRS_IOTHUBCLIENT_12_011: [If the allocation failed, IoTHubClient_CreateFromConnectionString returns NULL] */
        if (result == NULL)
        {
            LogError("Malloc failed");
        }
        else
        {
                /* Codes_SRS_IOTHUBCLIENT_12_005: [IoTHubClient_CreateFromConnectionString shall create a lock object to be used later for serializing IoTHubClient calls] */
                result->LockHandle = Lock_Init();
                if (result->LockHandle == NULL)
                {
                    /* Codes_SRS_IOTHUBCLIENT_12_009: [If lock creation failed, IoTHubClient_CreateFromConnectionString shall do clean up and return NULL] */
                    free(result);
                    result = NULL;
                    LogError("Lock_Init failed");
                }
                else
                {
                    /* Codes_SRS_IOTHUBCLIENT_12_006: [IoTHubClient_CreateFromConnectionString shall instantiate a new IoTHubClient_LL instance by calling IoTHubClient_LL_CreateFromConnectionString and passing the connectionString] */
                    result->IoTHubClientLLHandle = IoTHubClient_LL_CreateFromConnectionString(connectionString, protocol);
                    if (result->IoTHubClientLLHandle == NULL)
                    {
                        /* Codes_SRS_IOTHUBCLIENT_12_010: [If IoTHubClient_LL_CreateFromConnectionString fails then IoTHubClient_CreateFromConnectionString shall do clean - up and return NULL] */
                        Lock_Deinit(result->LockHandle);
                        free(result);
                        result = NULL;
                        LogError("IoTHubClient_LL_CreateFromConnectionString failed");
                    }
                    else
                    {
                        result->ThreadHandle = NULL;
						result->TransportHandle = NULL;
                    }
                }
            
        }
    }
    return result;
}


IOTHUB_CLIENT_HANDLE IoTHubClient_Create(const IOTHUB_CLIENT_CONFIG* config)
{
    /* Codes_SRS_IOTHUBCLIENT_01_001: [IoTHubClient_Create shall allocate a new IoTHubClient instance and return a non-NULL handle to it.] */
    IOTHUB_CLIENT_INSTANCE* result = (IOTHUB_CLIENT_INSTANCE*)malloc(sizeof(IOTHUB_CLIENT_INSTANCE));

    /* Codes_SRS_IOTHUBCLIENT_01_004: [If allocating memory for the new IoTHubClient instance fails, then IoTHubClient_Create shall return NULL.] */
    if (result != NULL)
    {
        /* Codes_SRS_IOTHUBCLIENT_01_029: [IoTHubClient_Create shall create a lock object to be used later for serializing IoTHubClient calls.] */
        result->LockHandle = Lock_Init();
        if (result->LockHandle == NULL)
        {
            /* Codes_SRS_IOTHUBCLIENT_01_030: [If creating the lock fails, then IoTHubClient_Create shall return NULL.] */
            /* Codes_SRS_IOTHUBCLIENT_01_031: [If IoTHubClient_Create fails, all resources allocated by it shall be freed.] */
            free(result);
            result = NULL;
        }
        else
        {
            /* Codes_SRS_IOTHUBCLIENT_01_002: [IoTHubClient_Create shall instantiate a new IoTHubClient_LL instance by calling IoTHubClient_LL_Create and passing the config argument.] */
            result->IoTHubClientLLHandle = IoTHubClient_LL_Create(config);
            if (result->IoTHubClientLLHandle == NULL)
            {
                /* Codes_SRS_IOTHUBCLIENT_01_003: [If IoTHubClient_LL_Create fails, then IoTHubClient_Create shall return NULL.] */
                /* Codes_SRS_IOTHUBCLIENT_01_031: [If IoTHubClient_Create fails, all resources allocated by it shall be freed.] */
                Lock_Deinit(result->LockHandle);
                free(result);
                result = NULL;
            }
			else
			{
				result->TransportHandle = NULL;
				result->ThreadHandle = NULL;
			}
        }
    }

    return result;
}

IOTHUB_CLIENT_HANDLE IoTHubClient_CreateWithTransport(TRANSPORT_HANDLE transportHandle, const IOTHUB_CLIENT_CONFIG* config)
{
	IOTHUB_CLIENT_INSTANCE* result;
	/*Codes_SRS_IOTHUBCLIENT_17_013: [ IoTHubClient_CreateWithTransport shall return NULL if transportHandle is NULL. ]*/
	/*Codes_SRS_IOTHUBCLIENT_17_014: [ IoTHubClient_CreateWithTransport shall return NULL if config is NULL. ]*/
	if (transportHandle == NULL || config == NULL)
	{
		result = NULL;
	}
	else
	{
		/*Codes_SRS_IOTHUBCLIENT_17_001: [ IoTHubClient_CreateWithTransport shall allocate a new IoTHubClient instance and return a non-NULL handle to it. ]*/
		result = (IOTHUB_CLIENT_INSTANCE*)malloc(sizeof(IOTHUB_CLIENT_INSTANCE));
		/*Codes_SRS_IOTHUBCLIENT_17_002: [ If allocating memory for the new IoTHubClient instance fails, then IoTHubClient_CreateWithTransport shall return NULL. ]*/
		if (result != NULL)
		{
			result->ThreadHandle = NULL;
			result->TransportHandle = transportHandle;
			/*Codes_SRS_IOTHUBCLIENT_17_005: [ IoTHubClient_CreateWithTransport shall call IoTHubTransport_GetLock to get the transport lock to be used later for serializing IoTHubClient calls. ]*/
			LOCK_HANDLE transportLock = IoTHubTransport_GetLock(transportHandle);
			result->LockHandle = transportLock;
			if (result->LockHandle == NULL)
			{
				/*Codes_SRS_IOTHUBCLIENT_17_006: [ If IoTHubTransport_GetLock fails, then IoTHubClient_CreateWithTransport shall return NULL. ]*/
				free(result);
				result = NULL;
			}
			else
			{
				IOTHUB_CLIENT_DEVICE_CONFIG deviceConfig;
				deviceConfig.deviceId = config->deviceId;
				deviceConfig.deviceKey = config->deviceKey;
				deviceConfig.protocol = config->protocol;

				/*Codes_SRS_IOTHUBCLIENT_17_003: [ IoTHubClient_CreateWithTransport shall call IoTHubTransport_GetLLTransport on transportHandle to get lower layer transport. ]*/
				deviceConfig.transportHandle = IoTHubTransport_GetLLTransport(transportHandle);

				if (deviceConfig.transportHandle == NULL)
				{
					/*Codes_SRS_IOTHUBCLIENT_17_004: [ If IoTHubTransport_GetLLTransport fails, then IoTHubClient_CreateWithTransport shall return NULL. ]*/
					free(result);
					result = NULL;
				}
				else
				{
					if (Lock(transportLock) != LOCK_OK)
					{
						free(result);
						result = NULL;
					}
					else
					{
						/*Codes_SRS_IOTHUBCLIENT_17_007: [ IoTHubClient_CreateWithTransport shall instantiate a new IoTHubClient_LL instance by calling IoTHubClient_LL_CreateWithTransport and passing the lower layer transport and config argument. ]*/
						result->IoTHubClientLLHandle = IoTHubClient_LL_CreateWithTransport(&deviceConfig);
						if (result->IoTHubClientLLHandle == NULL)
						{
							/*Codes_SRS_IOTHUBCLIENT_17_008: [ If IoTHubClient_LL_CreateWithTransport fails, then IoTHubClient_Create shall return NULL. ]*/
							/*Codes_SRS_IOTHUBCLIENT_17_009: [ If IoTHubClient_LL_CreateWithTransport fails, all resources allocated by it shall be freed. ]*/
							free(result);
							result = NULL;
						}

						if (Unlock(transportLock) != LOCK_OK)
						{
							LogError("unable to Unlock");
						}
					}

				}
			}
		}
	}

	return result;
}

/* Codes_SRS_IOTHUBCLIENT_01_005: [IoTHubClient_Destroy shall free all resources associated with the iotHubClientHandle instance.] */
void IoTHubClient_Destroy(IOTHUB_CLIENT_HANDLE iotHubClientHandle)
{
    /* Codes_SRS_IOTHUBCLIENT_01_008: [IoTHubClient_Destroy shall do nothing if parameter iotHubClientHandle is NULL.] */
    if (iotHubClientHandle != NULL)
    {
		bool okToJoin;

        IOTHUB_CLIENT_INSTANCE* iotHubClientInstance = (IOTHUB_CLIENT_INSTANCE*)iotHubClientHandle;

		/*Codes_SRS_IOTHUBCLIENT_02_043: [ IoTHubClient_Destroy shall lock the serializing lock and signal the worker thread (if any) to end ]*/
		if (Lock(iotHubClientInstance->LockHandle) != LOCK_OK)
		{
			LogError("unable to Lock - - will still proceed to try to end the thread without locking");
		}

        if (iotHubClientInstance->ThreadHandle != NULL)
        {
			iotHubClientInstance->StopThread = 1;
			okToJoin = true;
        }
		else
		{
			okToJoin = false;
		}

		if (iotHubClientInstance->TransportHandle != NULL)
		{
			/*Codes_SRS_IOTHUBCLIENT_01_007: [ The thread created as part of executing IoTHubClient_SendEventAsync or IoTHubClient_SetNotificationMessageCallback shall be joined. ]*/
			okToJoin = IoTHubTransport_SignalEndWorkerThread(iotHubClientInstance->TransportHandle, iotHubClientHandle);
		}

        /* Codes_SRS_IOTHUBCLIENT_01_006: [That includes destroying the IoTHubClient_LL instance by calling IoTHubClient_LL_Destroy.] */
        IoTHubClient_LL_Destroy(iotHubClientInstance->IoTHubClientLLHandle);

		/*Codes_SRS_IOTHUBCLIENT_02_045: [ IoTHubClient_Destroy shall unlock the serializing lock. ]*/
		if (Unlock(iotHubClientInstance->LockHandle) != LOCK_OK)
		{
			LogError("unable to Unlock");
		}
		
		if (okToJoin == true)
		{
			if (iotHubClientInstance->ThreadHandle != NULL)
			{
				int res;
				/*Codes_SRS_IOTHUBCLIENT_01_007: [ The thread created as part of executing IoTHubClient_SendEventAsync or IoTHubClient_SetNotificationMessageCallback shall be joined. ]*/
				if (ThreadAPI_Join(iotHubClientInstance->ThreadHandle, &res) != THREADAPI_OK)
				{
					LogError("ThreadAPI_Join failed");
				}
			}
			if (iotHubClientInstance->TransportHandle != NULL)
			{
				/*Codes_SRS_IOTHUBCLIENT_01_007: [ The thread created as part of executing IoTHubClient_SendEventAsync or IoTHubClient_SetNotificationMessageCallback shall be joined. ]*/
				IoTHubTransport_JoinWorkerThread(iotHubClientInstance->TransportHandle, iotHubClientHandle);
			}
		}

		if (iotHubClientInstance->TransportHandle == NULL)
		{
			/* Codes_SRS_IOTHUBCLIENT_01_032: [If the lock was allocated in IoTHubClient_Create, it shall be also freed..] */
			Lock_Deinit(iotHubClientInstance->LockHandle);
		}

        free(iotHubClientInstance);
    }
}

IOTHUB_CLIENT_RESULT IoTHubClient_SendEventAsync(IOTHUB_CLIENT_HANDLE iotHubClientHandle, IOTHUB_MESSAGE_HANDLE eventMessageHandle, IOTHUB_CLIENT_EVENT_CONFIRMATION_CALLBACK eventConfirmationCallback, void* userContextCallback)
{
    IOTHUB_CLIENT_RESULT result;

    if (iotHubClientHandle == NULL)
    {
        /* Codes_SRS_IOTHUBCLIENT_01_011: [If iotHubClientHandle is NULL, IoTHubClient_SendEventAsync shall return IOTHUB_CLIENT_INVALID_ARG.] */
        result = IOTHUB_CLIENT_INVALID_ARG;
        LogError("NULL iothubClientHandle");
    }
    else
    {
        IOTHUB_CLIENT_INSTANCE* iotHubClientInstance = (IOTHUB_CLIENT_INSTANCE*)iotHubClientHandle;

        /* Codes_SRS_IOTHUBCLIENT_01_025: [IoTHubClient_SendEventAsync shall be made thread-safe by using the lock created in IoTHubClient_Create.] */
        if (Lock(iotHubClientInstance->LockHandle) != LOCK_OK)
        {
            /* Codes_SRS_IOTHUBCLIENT_01_026: [If acquiring the lock fails, IoTHubClient_SendEventAsync shall return IOTHUB_CLIENT_ERROR.] */
            result = IOTHUB_CLIENT_ERROR;
            LogError("Could not acquire lock");
        }
        else
        {
            /* Codes_SRS_IOTHUBCLIENT_01_009: [IoTHubClient_SendEventAsync shall start the worker thread if it was not previously started.] */
            if ((result = StartWorkerThreadIfNeeded(iotHubClientInstance)) != IOTHUB_CLIENT_OK)
            {
                /* Codes_SRS_IOTHUBCLIENT_01_010: [If starting the thread fails, IoTHubClient_SendEventAsync shall return IOTHUB_CLIENT_ERROR.] */
                result = IOTHUB_CLIENT_ERROR;
                LogError("Could not start worker thread");
            }
            else
            {
                /* Codes_SRS_IOTHUBCLIENT_01_012: [IoTHubClient_SendEventAsync shall call IoTHubClient_LL_SendEventAsync, while passing the IoTHubClient_LL handle created by IoTHubClient_Create and the parameters eventMessageHandle, eventConfirmationCallback and userContextCallback.] */
                /* Codes_SRS_IOTHUBCLIENT_01_013: [When IoTHubClient_LL_SendEventAsync is called, IoTHubClient_SendEventAsync shall return the result of IoTHubClient_LL_SendEventAsync.] */
                result = IoTHubClient_LL_SendEventAsync(iotHubClientInstance->IoTHubClientLLHandle, eventMessageHandle, eventConfirmationCallback, userContextCallback);
            }

            /* Codes_SRS_IOTHUBCLIENT_01_025: [IoTHubClient_SendEventAsync shall be made thread-safe by using the lock created in IoTHubClient_Create.] */
            (void)Unlock(iotHubClientInstance->LockHandle);
        }
    }

    return result;
}

IOTHUB_CLIENT_RESULT IoTHubClient_GetSendStatus(IOTHUB_CLIENT_HANDLE iotHubClientHandle, IOTHUB_CLIENT_STATUS *iotHubClientStatus)
{
    IOTHUB_CLIENT_RESULT result;

    if (iotHubClientHandle == NULL)
    {
        /* Codes_SRS_IOTHUBCLIENT_01_023: [If iotHubClientHandle is NULL, IoTHubClient_ GetSendStatus shall return IOTHUB_CLIENT_INVALID_ARG.] */
        result = IOTHUB_CLIENT_INVALID_ARG;
        LogError("NULL iothubClientHandle");
    }
    else
    {
        IOTHUB_CLIENT_INSTANCE* iotHubClientInstance = (IOTHUB_CLIENT_INSTANCE*)iotHubClientHandle;

        /* Codes_SRS_IOTHUBCLIENT_01_033: [IoTHubClient_GetSendStatus shall be made thread-safe by using the lock created in IoTHubClient_Create.] */
        if (Lock(iotHubClientInstance->LockHandle) != LOCK_OK)
        {
            /* Codes_SRS_IOTHUBCLIENT_01_034: [If acquiring the lock fails, IoTHubClient_GetSendStatus shall return IOTHUB_CLIENT_ERROR.] */
            result = IOTHUB_CLIENT_ERROR;
            LogError("Could not acquire lock");
        }
        else
        {
            /* Codes_SRS_IOTHUBCLIENT_01_022: [IoTHubClient_GetSendStatus shall call IoTHubClient_LL_GetSendStatus, while passing the IoTHubClient_LL handle created by IoTHubClient_Create and the parameter iotHubClientStatus.] */
            /* Codes_SRS_IOTHUBCLIENT_01_024: [Otherwise, IoTHubClient_GetSendStatus shall return the result of IoTHubClient_LL_GetSendStatus.] */
            result = IoTHubClient_LL_GetSendStatus(iotHubClientInstance->IoTHubClientLLHandle, iotHubClientStatus);

            /* Codes_SRS_IOTHUBCLIENT_01_033: [IoTHubClient_GetSendStatus shall be made thread-safe by using the lock created in IoTHubClient_Create.] */
            (void)Unlock(iotHubClientInstance->LockHandle);
        }
    }

    return result;
}

IOTHUB_CLIENT_RESULT IoTHubClient_SetMessageCallback(IOTHUB_CLIENT_HANDLE iotHubClientHandle, IOTHUB_CLIENT_MESSAGE_CALLBACK_ASYNC messageCallback, void* userContextCallback)
{
    IOTHUB_CLIENT_RESULT result;

    if (iotHubClientHandle == NULL)
    {
        /* Codes_SRS_IOTHUBCLIENT_01_016: [If iotHubClientHandle is NULL, IoTHubClient_SetMessageCallback shall return IOTHUB_CLIENT_INVALID_ARG.] */
        result = IOTHUB_CLIENT_INVALID_ARG;
        LogError("NULL iothubClientHandle");
    }
    else
    {
        IOTHUB_CLIENT_INSTANCE* iotHubClientInstance = (IOTHUB_CLIENT_INSTANCE*)iotHubClientHandle;

        /* Codes_SRS_IOTHUBCLIENT_01_027: [IoTHubClient_SetMessageCallback shall be made thread-safe by using the lock created in IoTHubClient_Create.] */
        if (Lock(iotHubClientInstance->LockHandle) != LOCK_OK)
        {
            /* Codes_SRS_IOTHUBCLIENT_01_028: [If acquiring the lock fails, IoTHubClient_SetMessageCallback shall return IOTHUB_CLIENT_ERROR.] */
            result = IOTHUB_CLIENT_ERROR;
            LogError("Could not acquire lock");
        }
        else
        {
            /* Codes_SRS_IOTHUBCLIENT_01_014: [IoTHubClient_SetMessageCallback shall start the worker thread if it was not previously started.] */
            if ((result = StartWorkerThreadIfNeeded(iotHubClientInstance)) != IOTHUB_CLIENT_OK)
            {
                /* Codes_SRS_IOTHUBCLIENT_01_015: [If starting the thread fails, IoTHubClient_SetMessageCallback shall return IOTHUB_CLIENT_ERROR.] */
                result = IOTHUB_CLIENT_ERROR;
                LogError("Could not start worker thread");
            }
            else
            {
                /* Codes_SRS_IOTHUBCLIENT_01_017: [IoTHubClient_SetMessageCallback shall call IoTHubClient_LL_SetMessageCallback, while passing the IoTHubClient_LL handle created by IoTHubClient_Create and the parameters messageCallback and userContextCallback.] */
                result = IoTHubClient_LL_SetMessageCallback(iotHubClientInstance->IoTHubClientLLHandle, messageCallback, userContextCallback);
            }

            /* Codes_SRS_IOTHUBCLIENT_01_027: [IoTHubClient_SetMessageCallback shall be made thread-safe by using the lock created in IoTHubClient_Create.] */
            Unlock(iotHubClientInstance->LockHandle);
        }
    }

    return result;
}

IOTHUB_CLIENT_RESULT IoTHubClient_GetLastMessageReceiveTime(IOTHUB_CLIENT_HANDLE iotHubClientHandle, time_t* lastMessageReceiveTime)
{
    IOTHUB_CLIENT_RESULT result;

    if (iotHubClientHandle == NULL)
    {
        /* Codes_SRS_IOTHUBCLIENT_01_020: [If iotHubClientHandle is NULL, IoTHubClient_GetLastMessageReceiveTime shall return IOTHUB_CLIENT_INVALID_ARG.] */
        result = IOTHUB_CLIENT_INVALID_ARG;
        LogError("NULL iothubClientHandle");
    }
    else
    {
        IOTHUB_CLIENT_INSTANCE* iotHubClientInstance = (IOTHUB_CLIENT_INSTANCE*)iotHubClientHandle;

        /* Codes_SRS_IOTHUBCLIENT_01_035: [IoTHubClient_GetLastMessageReceiveTime shall be made thread-safe by using the lock created in IoTHubClient_Create.] */
        if (Lock(iotHubClientInstance->LockHandle) != LOCK_OK)
        {
            /* Codes_SRS_IOTHUBCLIENT_01_036: [If acquiring the lock fails, IoTHubClient_GetLastMessageReceiveTime shall return IOTHUB_CLIENT_ERROR.] */
            result = IOTHUB_CLIENT_ERROR;
            LogError("Could not acquire lock");
        }
        else
        {
            /* Codes_SRS_IOTHUBCLIENT_01_019: [IoTHubClient_GetLastMessageReceiveTime shall call IoTHubClient_LL_GetLastMessageReceiveTime, while passing the IoTHubClient_LL handle created by IoTHubClient_Create and the parameter lastMessageReceiveTime.] */
            /* Codes_SRS_IOTHUBCLIENT_01_021: [Otherwise, IoTHubClient_GetLastMessageReceiveTime shall return the result of IoTHubClient_LL_GetLastMessageReceiveTime.] */
            result = IoTHubClient_LL_GetLastMessageReceiveTime(iotHubClientInstance->IoTHubClientLLHandle, lastMessageReceiveTime);

            /* Codes_SRS_IOTHUBCLIENT_01_035: [IoTHubClient_GetLastMessageReceiveTime shall be made thread-safe by using the lock created in IoTHubClient_Create.] */
            Unlock(iotHubClientInstance->LockHandle);
        }
    }

    return result;
}

IOTHUB_CLIENT_RESULT IoTHubClient_SetOption(IOTHUB_CLIENT_HANDLE iotHubClientHandle, const char* optionName, const void* value)
{
    IOTHUB_CLIENT_RESULT result;
    /*Codes_SRS_IOTHUBCLIENT_02_034: [If parameter iotHubClientHandle is NULL then IoTHubClient_SetOption shall return IOTHUB_CLIENT_INVALID_ARG.] */
    if (
        (iotHubClientHandle == NULL) ||
        (optionName == NULL) ||
        (value == NULL)
        )
    {
        result = IOTHUB_CLIENT_INVALID_ARG;
        LogError("invalid arg (NULL)r\n");
    }
    else
    {
        IOTHUB_CLIENT_INSTANCE* iotHubClientInstance = (IOTHUB_CLIENT_INSTANCE*)iotHubClientHandle;
        /*Codes_SRS_IOTHUBCLIENT_02_038: [If optionName doesn't match one of the options handled by this module then IoTHubClient_SetOption shall call IoTHubClient_LL_SetOption passing the same parameters and return what IoTHubClient_LL_SetOption returns.] */
        result = IoTHubClient_LL_SetOption(iotHubClientInstance->IoTHubClientLLHandle, optionName, value);

        if (result != IOTHUB_CLIENT_OK)
        {
            LogError("IoTHubClient_LL_SetOption failed");
        }
    }
    return result;
}