C

Prevent JavaScript Infinite Loops

See more JavaScript Examples

Demonstrates how prevent infinite loops or prevent the JavaScript from running for a longer amount of time than allowed. C

#include <C_CkStringBuilder.h>
#include <C_CkJs.h>
#include <C_CkJsonObject.h>

void ChilkatSample(void)
    {
    BOOL success;
    HCkStringBuilder sbScript;
    HCkJs js;
    HCkJsonObject result;

    success = FALSE;

    // This is the JavaScript we'll run:

    // console.log('Starting infinite loop...'); while(true) {};

    sbScript = CkStringBuilder_Create();
    CkStringBuilder_Append(sbScript,"console.log('Starting infinite loop...'); while(true) {};");

    js = CkJs_Create();

    // Set a limit on the amount of time (in seconds) the script is allowed to run.
    // If the JavaScript takes longer than this amount of time, then Chilkat kills the script without crashing the host program.
    // The default value of TimeoutSeconds is 0, which indicates no limit.
    // For this example, set a limit of 2 seconds.
    CkJs_putTimeoutSeconds(js,2);

    result = CkJsonObject_Create();
    CkJsonObject_putEmitCompact(result,FALSE);

    // Run the script..
    success = CkJs_Eval(js,sbScript,result);
    if (success == FALSE) {
        // Examine the result for an exception.
        printf("%s\n",CkJsonObject_emit(result));

        // The result contains this:

        // 	{
        // 	  "exception": {
        // 	    "message": "interrupted - JavaScript exceeded the Chilkat.Js.TimeoutSeconds",
        // 	    "stack": [
        // 	      {
        // 	        "func": "<eval>",
        // 	        "file": "<input>",
        // 	        "line": 1,
        // 	        "col": 8
        // 	      }
        // 	    ]
        // 	  }
        // 	}

        // Also examine the LastErrorText.
        printf("%s\n",CkJs_lastErrorText(js));
        CkStringBuilder_Dispose(sbScript);
        CkJs_Dispose(js);
        CkJsonObject_Dispose(result);
        return;
    }

    // We should never get here..
    printf("Succeeded.\n");
    printf("%s\n",CkJsonObject_emit(result));


    CkStringBuilder_Dispose(sbScript);
    CkJs_Dispose(js);
    CkJsonObject_Dispose(result);

    }