本文介紹ERROR模塊，通過設置無效的內存分配，來導致程序的中止。
/*
* ======== error.c ========
* This example shows the use of xdc.runtime.Error module to catch errors.
* An Error_Block passed to Task_create() checked to see if the create
* failed. In no Error_Block is passed, then the application will terminate
* when an error occurs. This is shown in the Memory_alloc() call when the
* Error_Block passed in is NULL. The error.cfg file also shows how to plug
* and error hook function that will get called as soon as an error occurs.
*/
#include <xdc/std.h>
#include <xdc/runtime/System.h>
#include <xdc/runtime/Memory.h>
#include <xdc/runtime/Error.h>
#include <ti/sysbios/BIOS.h>
#include <ti/sysbios/knl/Task.h>
#include <xdc/cfg/global.h>
Void task1(UArg arg0, UArg arg1);
Void task2(UArg arg0, UArg arg1);
Void timerFxn(UArg arg);
/* pre-configured hook function called when errors are raised */
Void errHook(Error_Block *eb);
Int canFail1(Error_Block *eb, UInt val);
Void canFail2(Error_Block *eb, UInt val);
Task_Handle tsk1, tsk2;
Int numTasksCreated = 0;
/*
* ======== main ========
*/
Int main()
{
Task_Params taskParams; //創建taskParams結構體對象
Error_Block eb; //創建eb結構體對象
Memory_Stats stats; //創建stats結構體對象
Error_init(&eb); //初始化eb錯誤塊參數
/* Picking a stackSize such that the second Task_create() will fail */
Memory_getStats(Memory_defaultHeapInstance, &stats);//從堆中獲取數據
Task_Params_init(&taskParams);//初始化任務線程參數
taskParams.priority = 1; //設置優先級爲1
taskParams.stackSize = (stats.totalFreeSize/2) + 64;//設置Task線程的棧大小
/*
* Create two tasks, The first one succeeds and the second one fails
* We catch the second failure in the Error_Block
*/
tsk1 = Task_create(task1, &taskParams, &eb);//創建第一個任務線程函數task1
if (Error_check(&eb)) {//錯誤塊的檢測
/* Should not get here */
System_printf("First Task_create() failed\n");
BIOS_exit(0);
}
Error_init(&eb);//初始化錯誤塊參數
tsk2 = Task_create(task2, &taskParams, &eb);//創建第二個任務線程函數task2
if (Error_check(&eb)) {//這裏會出現錯誤
/* Should get here */
System_printf("Second Task_create() failed\n");
}
BIOS_start(); /* does not return */
return(0);
}
/*
* ======== task1 ========
*/
Void task1(UArg arg0, UArg arg1)
{
Error_Block eb;
Int value;
Error_init(&eb);//初始化錯誤塊參數
System_printf("Running task1 function\n");
/*
* Showing a case where we call a function that takes an Error_Block.
* This function calls another function which can fail.
* The Error_Block to passed up to the caller in case an error occurs.
*/
value = canFail1(&eb, 11);
System_printf("Value returned from canFail1 = %d\n", value);
if (Error_check(&eb)) {
/* Should get here */
System_printf("Incorrect value used. Must be a multiple of 2\n");
}
/*
* Showing a case where a Memory_alloc() is called but no Error_Block
* is passed. This Memory_alloc() will fail because the size is larger
* than the available memory in the default heap.
*
* This call will cause the program to abort. The error message can
* be found in the LoggerBuf ROV view.
*/
Memory_alloc(NULL, 0xffff, 0, NULL);
}
/*
* ======== timerFxn ========
*/
Void timerFxn(UArg arg)
{
System_printf("Running timerFxn\n");
}
/*
* ======== task2 ========
*/
Void task2(UArg arg0, UArg arg1)
{
System_printf("Running task2 function\n");
}
/*
* ======== errorHook ========
*/
Void errorHook(Error_Block *eb)
{
System_printf(Error_getMsg(eb), Error_getData(eb)->arg[0],
Error_getData(eb)->arg[1]);
System_printf("\n");
}
/*
* ======== canFail1 ========
*/
Int canFail1(Error_Block *eb, UInt val)
{
canFail2(eb, val);//傳入的val爲11
if (Error_check(eb)) {
return (-1);
}
else {
return (val * 10);
}
}
/*
* ======== canFail2 ========
* fails if val is not a mulitple of 2.
*/
Void canFail2(Error_Block *eb, UInt val)
{
if (val % 2) {//傳入的爲11
Error_raise(eb, Error_E_generic, "Value is not a multiple of 2", 0);//拋出一個錯誤並傳遞給eb
}
}
CFG配置文件：
var Defaults = xdc.useModule('xdc.runtime.Defaults');
var Diags = xdc.useModule('xdc.runtime.Diags');
var Error = xdc.useModule("xdc.runtime.Error");
var LoggerBuf = xdc.useModule('xdc.runtime.LoggerBuf');
var Log = xdc.useModule('xdc.runtime.Log');
var Main = xdc.useModule('xdc.runtime.Main');
var SysMin = xdc.useModule('xdc.runtime.SysMin');
var System = xdc.useModule('xdc.runtime.System');
var Text = xdc.useModule('xdc.runtime.Text');
var BIOS = xdc.useModule("ti.sysbios.BIOS");
var Hwi = xdc.useModule("ti.sysbios.hal.Hwi");
var Task = xdc.useModule("ti.sysbios.knl.Task");
var Timer = xdc.useModule("ti.sysbios.hal.Timer");
/*
* Uncomment this line to globally disable Asserts.
* All modules inherit the default from the 'Defaults' module. You
* can override these defaults on a per-module basis using Module.common$.
* Disabling Asserts will save code space and improve runtime performance.
Defaults.common$.diags_ASSERT = Diags.ALWAYS_OFF;
*/
/*
* Uncomment this line to keep module names from being loaded on the target.
* The module name strings are placed in the .const section. Setting this
* parameter to false will save space in the .const section. Error and
* Assert messages will contain an "unknown module" prefix instead
* of the actual module name.
Defaults.common$.namedModule = false;
*/
/*
* Minimize exit handler array in System. The System module includes
* an array of functions that are registered with System_atexit() to be
* called by System_exit().
*/
System.maxAtexitHandlers = 4;
/*
* Uncomment this line to disable the Error print function.
* We lose error information when this is disabled since the errors are
* not printed. Disabling the raiseHook will save some code space if
* your app is not using System_printf() since the Error_print() function
* calls System_printf().
Error.raiseHook = null;
*/
/*
* Uncomment this line to keep Error, Assert, and Log strings from being
* loaded on the target. These strings are placed in the .const section.
* Setting this parameter to false will save space in the .const section.
* Error, Assert and Log message will print raw ids and args instead of
* a formatted message.
Text.isLoaded = false;
*/
/*
* Uncomment this line to disable the output of characters by SysMin
* when the program exits. SysMin writes characters to a circular buffer.
* This buffer can be viewed using the SysMin Output view in ROV.
SysMin.flushAtExit = false;
*/
/*
* The BIOS module will create the default heap for the system.
* Specify the size of this default heap.
*/
BIOS.heapSize = 0x2000;
/*
* Build a custom SYS/BIOS library from sources.
*/
BIOS.libType = BIOS.LibType_Custom;
/* System stack size (used by ISRs and Swis) */
Program.stack = 0x1000;
/* Circular buffer size for System_printf() */
SysMin.bufSize = 0x400;
/*
* Create and install logger for the whole system
*/
var loggerBufParams = new LoggerBuf.Params();
loggerBufParams.numEntries = 32;
var logger0 = LoggerBuf.create(loggerBufParams);
Defaults.common$.logger = logger0;
Main.common$.diags_INFO = Diags.ALWAYS_ON;
System.SupportProxy = SysMin;
/* Plug in app specific error hook */
Error.raiseHook = '&errorHook';
運行結果：
代碼分析：
- 通過創建兩個任務線程task1,task2。對於task1，先初始化錯誤塊參數，之後調用canFail1(&eb, 11)函數，在canFail2中，因爲val值爲11，因此通過Error_raise函數拋出一個錯誤，並且傳遞個eb。
- 在返回到canFail1中，因爲eb爲錯誤，因此執行if中的語句，返回-1，返回到task1中，因爲拋出了錯誤，因此在task1中Error_check爲真。之後執行Memory_alloc，因爲分配的尺寸大於內存中可使用的默認堆大小，因此分配會失敗。
- 執行Error.raiseHook = '&errorHook'創建的errorHook函數。