Application Termination

Application Termination

Enums

The following exit code enums are defined in the dx_exit_codes.h file.

/// <summary>
/// Exit codes for the DevX library. These are used for the
/// library exit codes.  They must all be between 150 and 255,
/// where zero is reserved for successful termination.  Exit
/// codes 1 - 149 are reserved for application level exit codes.
/// </summary>
typedef enum {
    DX_ExitCode_Success = 0,
    DX_ExitCode_TermHandler_SigTerm = 254,
    DX_ExitCode_Main_EventLoopFail = 253,
    DX_ExitCode_Missing_ID_Scope = 252,

    DX_ExitCode_Open_Peripheral = 251,
    DX_ExitCode_OpenDeviceTwin = 250,
    DX_ExitCode_AzureCloudToDeviceHandler = 249,
    DX_ExitCode_InterCoreHandler = 248,
    DX_ExitCode_ConsumeEventLoopTimeEvent = 247,
    DX_ExitCode_Gpio_Read = 246,
    DX_ExitCode_InterCoreReceiveFailed = 245,
    DX_ExitCode_PnPModelJsonMemoryAllocationFailed = 244,
    DX_ExitCode_PnPModelJsonFailed = 243,
    DX_ExitCode_IsButtonPressed = 242,
    DX_ExitCode_ButtonPressCheckHandler = 241,
    DX_ExitCode_Led2OffHandler = 240,

    DX_ExitCode_MissingRealTimeComponentId = 239,

    DX_ExitCode_Validate_Hostname_Not_Defined = 238,
    DX_ExitCode_Validate_ScopeId_Not_Defined = 237,
    DX_ExitCode_Validate_Connection_Type_Not_Defined = 236,

    DX_ExitCode_Gpio_Not_Initialized = 235,
    DX_ExitCode_Gpio_Wrong_Direction = 234,
    DX_ExitCode_Gpio_Open_Output_Failed = 233,
    DX_ExitCode_Gpio_Open_Input_Failed = 232,
    DX_ExitCode_Gpio_Open_Direction_Unknown = 231,

    DX_ExitCode_UpdateCallback_UnexpectedEvent = 230,
    DX_ExitCode_UpdateCallback_GetUpdateEvent = 229,
    DX_ExitCode_UpdateCallback_DeferEvent = 228,
    DX_ExitCode_UpdateCallback_FinalUpdate = 227,
    DX_ExitCode_UpdateCallback_UnexpectedStatus = 226,
    DX_ExitCode_SetUpSysEvent_RegisterEvent = 225,

    DX_ExitCode_Init_IoTCTimer = 220,
    DX_ExitCode_IoTCTimer_Consume = 219,

    DX_ExitCode_Uart_Open_Failed = 215,
    DX_ExitCode_Uart_Read_Failed = 214,
    DX_ExitCode_Uart_Write_Failed = 213,
    DX_ExitCode_UartHandler = 212
} ExitCode;

Functions

void dx_registerTerminationHandler(void);
void dx_terminationHandler(int signalNumber);
void dx_terminate(int exitCode);
bool dx_isTerminationRequired(void);
int dx_getTerminationExitCode(void);

Example

static void LedOffToggleHandler(EventLoopTimer* eventLoopTimer) {
    if (ConsumeEventLoopTimerEvent(eventLoopTimer) != 0) {
        dx_terminate(DX_ExitCode_ConsumeEventLoopTimeEvent);
        return;
    }
    dx_gpioOff(&led);
}

int main(void)
{
    dx_registerTerminationHandler();
    InitPeripheralsAndHandlers();

    // Main loop
    while (!dx_isTerminationRequired())
    {
        int result = EventLoop_Run(dx_timerGetEventLoop(), -1, true);
        // Continue if interrupted by signal, e.g. due to breakpoint being set.
        if (result == -1 && errno != EINTR)
        {
            dx_terminate(DX_ExitCode_Main_EventLoopFail);
        }
    }

    ClosePeripheralsAndHandlers();
    Log_Debug("Application exiting.\n");
    return dx_getTerminationExitCode();
}

Application Exit Codes

By convention, create application specific exit codes in a file named app_exit_codes.h in your project.

See avnet_send_message example.

/* Copyright (c) Microsoft Corporation. All rights reserved.
   Licensed under the MIT License. */

#pragma once

// Include the DevX exit codes
#include "dx_exit_codes.h"

/// <summary>
/// Exit codes for this application.  Application exit codes 
/// must be between 1 and 149, where 0 is reserved for successful 
//  termination.  Exit codes 150 - 254 are reserved for the
//  Exit_Code enumeration located in dx_exit_codes.h.
/// </summary>
typedef enum {
    APP_ExitCode_Telemetry_Buffer_Too_Small = 1
} App_Exit_Code;