File content as of revision 43:038d8511e817:

// 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 "iothubtransport.h"
#include "iothub_client.h"
#include "iothub_client_private.h"
#include "azure_c_shared_utility/threadapi.h"
#include "azure_c_shared_utility/lock.h"
#include "azure_c_shared_utility/iot_logging.h"
#include "azure_c_shared_utility/vector.h"

typedef struct TRANSPORT_HANDLE_DATA_TAG
{
	TRANSPORT_LL_HANDLE transportLLHandle;
    THREAD_HANDLE workerThreadHandle;
    LOCK_HANDLE lockHandle;
    sig_atomic_t stopThread;
	TRANSPORT_PROVIDER_FIELDS;
	VECTOR_HANDLE clients;
} TRANSPORT_HANDLE_DATA;

/* Used for Unit test */
const size_t IoTHubTransport_ThreadTerminationOffset = offsetof(TRANSPORT_HANDLE_DATA, stopThread);

TRANSPORT_HANDLE  IoTHubTransport_Create(IOTHUB_CLIENT_TRANSPORT_PROVIDER protocol, const char* iotHubName, const char* iotHubSuffix)
{
	TRANSPORT_HANDLE_DATA * result;

	if (protocol == NULL || iotHubName == NULL || iotHubSuffix == NULL)
	{
		/*Codes_SRS_IOTHUBTRANSPORT_17_002: [ If protocol is NULL, this function shall return NULL. ]*/
		/*Codes_SRS_IOTHUBTRANSPORT_17_003: [ If iotHubName is NULL, this function shall return NULL. ]*/
		/*Codes_SRS_IOTHUBTRANSPORT_17_004: [ If iotHubSuffix is NULL, this function shall return NULL. ]*/
		LogError("Invalid NULL argument, protocol [%p], name [%p], suffix [%p].", protocol, iotHubName, iotHubSuffix);
		result = NULL;
	}
	else
	{
		/*Codes_SRS_IOTHUBTRANSPORT_17_032: [ IoTHubTransport_Create shall allocate memory for the transport data. ]*/
		result = (TRANSPORT_HANDLE_DATA*)malloc(sizeof(TRANSPORT_HANDLE_DATA));
		if (result == NULL)
		{
			/*Codes_SRS_IOTHUBTRANSPORT_17_040: [ If memory allocation fails, IoTHubTransport_Create shall return NULL. ]*/
			LogError("Transport handle was not allocated.");
		}
		else
		{
			TRANSPORT_PROVIDER * transportProtocol = (TRANSPORT_PROVIDER*)(protocol());
			IOTHUB_CLIENT_CONFIG upperConfig;
			upperConfig.deviceId = NULL;
			upperConfig.deviceKey = NULL;
			upperConfig.iotHubName = iotHubName;
			upperConfig.iotHubSuffix = iotHubSuffix;
			upperConfig.protocol = protocol;
			upperConfig.protocolGatewayHostName = NULL;

			IOTHUBTRANSPORT_CONFIG transportLLConfig;
			transportLLConfig.upperConfig = &upperConfig;
			transportLLConfig.waitingToSend = NULL;

			/*Codes_SRS_IOTHUBTRANSPORT_17_005: [ IoTHubTransport_Create shall create the lower layer transport by calling the protocol's IoTHubTransport_Create function. ]*/
			result->transportLLHandle = transportProtocol->IoTHubTransport_Create(&transportLLConfig);
			if (result->transportLLHandle == NULL)
			{
				/*Codes_SRS_IOTHUBTRANSPORT_17_006: [ If the creation of the transport fails, IoTHubTransport_Create shall return NULL. ]*/
				LogError("Lower Layer transport not created.");
				free(result);
				result = NULL;
			}
			else
			{
				/*Codes_SRS_IOTHUBTRANSPORT_17_007: [ IoTHubTransport_Create shall create the transport lock by Calling Lock_Init. ]*/
				result->lockHandle = Lock_Init();
				if (result->lockHandle == NULL)
				{
					/*Codes_SRS_IOTHUBTRANSPORT_17_008: [ If the lock creation fails, IoTHubTransport_Create shall return NULL. ]*/
					LogError("transport Lock not created.");
					transportProtocol->IoTHubTransport_Destroy(result->transportLLHandle);
					free(result);
					result = NULL;
				}
				else
				{
					/*Codes_SRS_IOTHUBTRANSPORT_17_038: [ IoTHubTransport_Create shall call VECTOR_Create to make a list of IOTHUB_CLIENT_HANDLE using this transport. ]*/
					result->clients = VECTOR_create(sizeof(IOTHUB_CLIENT_HANDLE));
					if (result->clients == NULL)
					{
						/*Codes_SRS_IOTHUBTRANSPORT_17_039: [ If the Vector creation fails, IoTHubTransport_Create shall return NULL. ]*/
						/*Codes_SRS_IOTHUBTRANSPORT_17_009: [ IoTHubTransport_Create shall clean up any resources it creates if the function does not succeed. ]*/
						LogError("clients list not created.");
						Lock_Deinit(result->lockHandle);
						transportProtocol->IoTHubTransport_Destroy(result->transportLLHandle);
						free(result);
						result = NULL;
					}
					else
					{
						/*Codes_SRS_IOTHUBTRANSPORT_17_001: [ IoTHubTransport_Create shall return a non-NULL handle on success.]*/
						result->stopThread = 1;
						result->workerThreadHandle = NULL; /* create thread when work needs to be done */
                        result->IoTHubTransport_GetHostname = transportProtocol->IoTHubTransport_GetHostname;
						result->IoTHubTransport_SetOption = transportProtocol->IoTHubTransport_SetOption;
						result->IoTHubTransport_Create = transportProtocol->IoTHubTransport_Create;
						result->IoTHubTransport_Destroy = transportProtocol->IoTHubTransport_Destroy;
						result->IoTHubTransport_Register = transportProtocol->IoTHubTransport_Register;
						result->IoTHubTransport_Unregister = transportProtocol->IoTHubTransport_Unregister;
						result->IoTHubTransport_Subscribe = transportProtocol->IoTHubTransport_Subscribe;
						result->IoTHubTransport_Unsubscribe = transportProtocol->IoTHubTransport_Unsubscribe;
						result->IoTHubTransport_DoWork = transportProtocol->IoTHubTransport_DoWork;
						result->IoTHubTransport_GetSendStatus = transportProtocol->IoTHubTransport_GetSendStatus;
					}
				}
			}
		}
	}
	
	return result;
}

static int transport_worker_thread(void* threadArgument)
{
	TRANSPORT_HANDLE_DATA* transportData = (TRANSPORT_HANDLE_DATA*)threadArgument;

	while (1)
	{
		/*Codes_SRS_IOTHUBTRANSPORT_17_030: [ All calls to lower layer transport DoWork shall be protected by the lock created in IoTHubTransport_Create. ]*/
		if (Lock(transportData->lockHandle) == LOCK_OK)
		{
			/*Codes_SRS_IOTHUBTRANSPORT_17_031: [ If acquiring the lock fails, lower layer transport DoWork shall not be called. ]*/
			if (transportData->stopThread)
			{
				/*Codes_SRS_IOTHUBTRANSPORT_17_028: [ The thread shall exit when IoTHubTransport_EndWorkerThread has been called for each clientHandle which invoked IoTHubTransport_StartWorkerThread. ]*/
				(void)Unlock(transportData->lockHandle);
				break;
			}
			else
			{
				(transportData->IoTHubTransport_DoWork)(transportData->transportLLHandle, NULL);
				(void)Unlock(transportData->lockHandle);
			}
		}
		/*Codes_SRS_IOTHUBTRANSPORT_17_029: [ The thread shall call lower layer transport DoWork every 1 ms. ]*/
		ThreadAPI_Sleep(1);
	}

	return 0;
}

static bool find_by_handle(const void* element, const void* value)
{
	/* data stored at element is device handle */
	const IOTHUB_CLIENT_HANDLE * guess = (const IOTHUB_CLIENT_HANDLE *)element;
	const IOTHUB_CLIENT_HANDLE match = (const IOTHUB_CLIENT_HANDLE)value;
	return (*guess == match);
}

static IOTHUB_CLIENT_RESULT start_worker_if_needed(TRANSPORT_HANDLE_DATA * transportData, IOTHUB_CLIENT_HANDLE clientHandle)
{
	IOTHUB_CLIENT_RESULT result;
	if (transportData->workerThreadHandle == NULL)
	{
		/*Codes_SRS_IOTHUBTRANSPORT_17_018: [ If the worker thread does not exist, IoTHubTransport_StartWorkerThread shall start the thread using ThreadAPI_Create. ]*/
		transportData->stopThread = 0;
		if (ThreadAPI_Create(&transportData->workerThreadHandle, transport_worker_thread, transportData) != THREADAPI_OK)
		{
			transportData->workerThreadHandle = NULL;
		}
	}
	if (transportData->workerThreadHandle != NULL)
	{
		/*Codes_SRS_IOTHUBTRANSPORT_17_020: [ IoTHubTransport_StartWorkerThread shall search for IoTHubClient clientHandle in the list of IoTHubClient handles. ]*/
		bool addToList = ((VECTOR_size(transportData->clients) == 0) || (VECTOR_find_if(transportData->clients, find_by_handle, clientHandle) == NULL));
		if (addToList)
		{
			/*Codes_SRS_IOTHUBTRANSPORT_17_021: [ If handle is not found, then clientHandle shall be added to the list. ]*/
			if (VECTOR_push_back(transportData->clients, &clientHandle, 1) != 0)
			{
				/*Codes_SRS_IOTHUBTRANSPORT_17_042: [ If Adding to the client list fails, IoTHubTransport_StartWorkerThread shall return IOTHUB_CLIENT_ERROR. ]*/
				result = IOTHUB_CLIENT_ERROR;
			}
			else
			{
				result = IOTHUB_CLIENT_OK;
			}
		}
		else
		{
			result = IOTHUB_CLIENT_OK;
		}
	}
	else
	{
		result = IOTHUB_CLIENT_ERROR;
	}
	return result;
}

static void stop_worker_thread(TRANSPORT_HANDLE_DATA * transportData)
{
	/*Codes_SRS_IOTHUBTRANSPORT_17_043: [** IoTHubTransport_SignalEndWorkerThread shall signal the worker thread to end.*/
	transportData->stopThread = 1;
}

static void wait_worker_thread(TRANSPORT_HANDLE_DATA * transportData)
{
	if (transportData->workerThreadHandle != NULL)
	{
		int res;
		/*Codes_SRS_IOTHUBTRANSPORT_17_027: [ If handle list is empty, IoTHubTransport_EndWorkerThread shall be joined. ]*/
		if (ThreadAPI_Join(transportData->workerThreadHandle, &res) != THREADAPI_OK)
		{
			LogError("ThreadAPI_Join failed");
		}
		else
		{
			transportData->workerThreadHandle = NULL;
		}
	}
}

static bool signal_end_worker_thread(TRANSPORT_HANDLE_DATA * transportData, IOTHUB_CLIENT_HANDLE clientHandle)
{
	bool okToJoin;
	void* element = VECTOR_find_if(transportData->clients, find_by_handle, clientHandle);
	if (element != NULL)
	{
		/*Codes_SRS_IOTHUBTRANSPORT_17_026: [ IoTHubTransport_EndWorkerThread shall remove clientHandlehandle from handle list. ]*/
		VECTOR_erase(transportData->clients, element, 1);
	}
	/*Codes_SRS_IOTHUBTRANSPORT_17_025: [ If the worker thread does not exist, then IoTHubTransport_EndWorkerThread shall return. ]*/
	if (transportData->workerThreadHandle != NULL)
	{
		if (VECTOR_size(transportData->clients) == 0)
		{
			stop_worker_thread(transportData);
			okToJoin = true;
		}
		else
		{
			okToJoin = false;
		}
	}
	else
	{
		okToJoin = false;
	}
	return okToJoin;
}

void IoTHubTransport_Destroy(TRANSPORT_HANDLE transportHandle)
{
	/*Codes_SRS_IOTHUBTRANSPORT_17_011: [ IoTHubTransport_Destroy shall do nothing if transportHandle is NULL. ]*/
	if (transportHandle != NULL)
	{
		TRANSPORT_HANDLE_DATA * transportData = (TRANSPORT_HANDLE_DATA*)transportHandle;
		/*Codes_SRS_IOTHUBTRANSPORT_17_033: [ IoTHubTransport_Destroy shall lock the transport lock. ]*/
		if (Lock(transportData->lockHandle) != LOCK_OK)
		{
			LogError("Unable to lock - will still attempt to end thread without thread safety");
			stop_worker_thread(transportData);
		}
		else
		{
			stop_worker_thread(transportData);
			(void)Unlock(transportData->lockHandle);
		}
		wait_worker_thread(transportData);
		/*Codes_SRS_IOTHUBTRANSPORT_17_010: [ IoTHubTransport_Destroy shall free all resources. ]*/
		Lock_Deinit(transportData->lockHandle);
		(transportData->IoTHubTransport_Destroy)(transportData->transportLLHandle);
		VECTOR_destroy(transportData->clients);
		free(transportHandle);
	}
}

LOCK_HANDLE IoTHubTransport_GetLock(TRANSPORT_HANDLE transportHandle)
{
	LOCK_HANDLE lock;
	if (transportHandle == NULL)
	{
		/*Codes_SRS_IOTHUBTRANSPORT_17_013: [ If transportHandle is NULL, IoTHubTransport_GetLock shall return NULL. ]*/
		lock = NULL;
	}
	else
	{
		/*Codes_SRS_IOTHUBTRANSPORT_17_012: [ IoTHubTransport_GetLock shall return a handle to the transport lock. ]*/
		TRANSPORT_HANDLE_DATA * transportData = (TRANSPORT_HANDLE_DATA*)transportHandle;
		lock = transportData->lockHandle;
	}
	return lock;
}

TRANSPORT_LL_HANDLE IoTHubTransport_GetLLTransport(TRANSPORT_HANDLE transportHandle)
{
	TRANSPORT_LL_HANDLE llTransport;
	if (transportHandle == NULL)
	{
		/*Codes_SRS_IOTHUBTRANSPORT_17_015: [ If transportHandle is NULL, IoTHubTransport_GetLLTransport shall return NULL. ]*/
		llTransport = NULL;
	}
	else
	{
		/*Codes_SRS_IOTHUBTRANSPORT_17_014: [ IoTHubTransport_GetLLTransport shall return a handle to the lower layer transport. ]*/
		TRANSPORT_HANDLE_DATA * transportData = (TRANSPORT_HANDLE_DATA*)transportHandle;
		llTransport = transportData->transportLLHandle;
	}
	return llTransport;
}

IOTHUB_CLIENT_RESULT IoTHubTransport_StartWorkerThread(TRANSPORT_HANDLE transportHandle, IOTHUB_CLIENT_HANDLE clientHandle)
{
	IOTHUB_CLIENT_RESULT result;
	if (transportHandle == NULL || clientHandle == NULL)
	{
		/*Codes_SRS_IOTHUBTRANSPORT_17_016: [ If transportHandle is NULL, IoTHubTransport_StartWorkerThread shall return IOTHUB_CLIENT_INVALID_ARG. ]*/
		/*Codes_SRS_IOTHUBTRANSPORT_17_017: [ If clientHandle is NULL, IoTHubTransport_StartWorkerThread shall return IOTHUB_CLIENT_INVALID_ARG. ]*/
		result = IOTHUB_CLIENT_INVALID_ARG;
	}
	else
	{
		TRANSPORT_HANDLE_DATA * transportData = (TRANSPORT_HANDLE_DATA*)transportHandle;

		if ((result = start_worker_if_needed(transportData, clientHandle)) != IOTHUB_CLIENT_OK)
		{
			/*Codes_SRS_IOTHUBTRANSPORT_17_019: [ If thread creation fails, IoTHubTransport_StartWorkerThread shall return IOTHUB_CLIENT_ERROR. */
			LogError("Unable to start thread safely");
		}
		else
		{
			/*Codes_SRS_IOTHUBTRANSPORT_17_022: [ Upon success, IoTHubTransport_StartWorkerThread shall return IOTHUB_CLIENT_OK. ]*/
			result = IOTHUB_CLIENT_OK;
		}
	}
	return result;
}

bool IoTHubTransport_SignalEndWorkerThread(TRANSPORT_HANDLE transportHandle, IOTHUB_CLIENT_HANDLE clientHandle)
{
	bool okToJoin;
	/*Codes_SRS_IOTHUBTRANSPORT_17_023: [ If transportHandle is NULL, IoTHubTransport_EndWorkerThread shall return. ]*/
	/*Codes_SRS_IOTHUBTRANSPORT_17_024: [ If clientHandle is NULL, IoTHubTransport_EndWorkerThread shall return. ]*/
	if (!(transportHandle == NULL || clientHandle == NULL))
	{
		TRANSPORT_HANDLE_DATA * transportData = (TRANSPORT_HANDLE_DATA*)transportHandle;
		okToJoin = signal_end_worker_thread(transportData, clientHandle);
	}
	else
	{
		okToJoin = false;
	}
	return okToJoin;
}

void IoTHubTransport_JoinWorkerThread(TRANSPORT_HANDLE transportHandle, IOTHUB_CLIENT_HANDLE clientHandle)
{
	/*Codes_SRS_IOTHUBTRANSPORT_17_044: [ If transportHandle is NULL, IoTHubTransport_JoinWorkerThread shall do nothing. ]*/
	/*Codes_SRS_IOTHUBTRANSPORT_17_045: [ If clientHandle is NULL, IoTHubTransport_JoinWorkerThread shall do nothing. ]*/
	if (!(transportHandle == NULL || clientHandle == NULL))
	{
		TRANSPORT_HANDLE_DATA * transportData = (TRANSPORT_HANDLE_DATA*)transportHandle;
		/*Codes_SRS_IOTHUBTRANSPORT_17_027: [ The worker thread shall be joined. ]*/
		wait_worker_thread(transportData);
	}
}