Tcl

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. Tcl

load ./chilkat.dll

set success 0

# This is the JavaScript we'll run:

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

set sbScript [new_CkStringBuilder]

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

set js [new_CkJs]

# 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_put_TimeoutSeconds $js 2

set result [new_CkJsonObject]

CkJsonObject_put_EmitCompact $result 0

# Run the script..
set success [CkJs_Eval $js $sbScript $result]
if {$success == 0} then {
    # Examine the result for an exception.
    puts [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.
    puts [CkJs_lastErrorText $js]
    delete_CkStringBuilder $sbScript
    delete_CkJs $js
    delete_CkJsonObject $result
    exit
}

# We should never get here..
puts "Succeeded."
puts [CkJsonObject_emit $result]

delete_CkStringBuilder $sbScript
delete_CkJs $js
delete_CkJsonObject $result