Perl

Prevent JavaScript Infinite Loops

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

use chilkat();

$success = 0;

# This is the JavaScript we'll run:

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

$sbScript = chilkat::CkStringBuilder->new();
$sbScript->Append("console.log('Starting infinite loop...'); while(true) {};");

$js = chilkat::CkJs->new();

# 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.
$js->put_TimeoutSeconds(2);

$result = chilkat::CkJsonObject->new();
$result->put_EmitCompact(0);

# Run the script..
$success = $js->Eval($sbScript,$result);
if ($success == 0) {
    # Examine the result for an exception.
    print $result->emit() . "\r\n";

    # 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.
    print $js->lastErrorText() . "\r\n";
    exit;
}

# We should never get here..
print "Succeeded." . "\r\n";
print $result->emit() . "\r\n";