php: repeat function call 2-3 times in catch() - php

Question

so a function crashes sometimes ( uncaught exception ) and i want to re-call it 2 times when that happens with a delay of 1 seconds let's say. Here's is the code but it doesn't seem to work:
$crashesn = 0;
function checkNum($number) {
echo $number . "<br>";
if ($number>1) {
throw new Exception("Value must be 1 or below");
}
return true;
}
try {
checkNum(2);
echo 'If you see this, the number is 1 or below';
}
catch(Exception $e) {
$crashesn++;
echo "crashes number:".$crashesn."<br>";
if ($crashesn <= 2) {
sleep(1);
checkNum(2);
} else {
echo "MESSAGE: " .$e->getMessage();
}
}
checknum is the function which throws the exception ( here it crashes every time by throwing an exception ). The problem is, when I run this piece of code, i still get on my page an error message
Fatal error: Uncaught exception 'Exception' with message 'Value must be 1 or below' in G:\fix\ta_dll\test.php:30 Stack trace: #0 c:\wwwl\test.php(45): checkNum(2) #1 {main} thrown in c:\php\test.php on line 30
instead of a "MESSAGE: ERROR DESCRIPTION". the "crashes number" line only gets printed once, not twice.
anyone knows what I am doing wrong ?

Answer 1

Try with a loop instead
for ($crashes = 0; $crashes < 3; $crashes++) {
try {
checkNum(2);
echo 'If you see this, the number is 1 or below';
break;
}
catch(Exception $e) {
echo "crashes number:" . $crashes . "<br>";
if ($crashes < 2) {
sleep(1);
} else {
echo "MESSAGE: " . $e->getMessage();
}
}
}
When checkNum() returns properly, the for loop is left with the break. Otherwise, when an exception is thrown, break is skipped and the loop repeats.

Answer 2

From your comments : it crashes sometimes (due to memory leaks i guess). So I need to auto-repeat it 2 or 3 more times when the crash happens.
Solution 1 : Try using goto ... its old school and can be evil but it might work for you
$crashesn = 0;
START:
try {
checkNum(2);
echo 'If you see this, the number is 1 or below';
break;
} catch ( Exception $e ) {
$crashesn ++;
echo "crashes number:" . $crashesn . "<br>";
if ($crashesn <= 2) {
sleep(1);
goto START;
} else {
echo "MESSAGE: " . $e->getMessage();
}
}
Solution 2: just use loop you can also read Performance of try-catch in php
$crashesn = 0;
do {
try {
checkNum(2);
echo 'If you see this, the number is 1 or below';
} catch ( Exception $e ) {
$crashesn ++;
echo "crashes number:" . $crashesn . "<br>";
if ($crashesn <= 2) {
sleep(1);
} else {
echo "MESSAGE: " . $e->getMessage();
}
}
} while ( $crashesn <= 2 );
Both would Output
2
crashes number:1
2
crashes number:2
2
crashes number:3
MESSAGE: Value must be 1 or below

Answer 3

In Addition to my comment: Why are you throwing an exception? Your exception is thrown, if the number is greater than 1 - remove the exception and use something like this:
function checkNum($number) {
echo $number . "<br>";
if ($number>1) {
return false;
}
return true;
}
$crashesn = 0;
$number = 2; // number from somewhere.
$failed =false;
while (!$checkNum($number)){
echo $number." is to large!";
$crashesn++;
if ($crashesn > 2){
//stop retrying it.
$failed = true;
break;
}
}
if (!$failed){
echo $number." is valid";
}else{
echo "Failed after 2 retries";
}
However it does NOT make sence to repeat the call if the number is a "fixed" value. It will fail three times or be valid on first run.
Exceptions are for cirital Erros. DON't use them to validate something you can take care of with normal logical expressions.

Answer 4

In your catch , u supposed to have another try catch
try {
// some code here
}
catch(Exception $e) {
try {
$crashesn++;
echo "crashes number:".$crashesn."<br>";
if ($crashesn <= 2) {
sleep(1);
checkNum(2);
}
}
catch(Exception $e) {
echo "MESSAGE: " .$e->getMessage();
}
}

Answer 5

$checked = false;
while ($i < 3 && $checked === false){
try{
$checked = checkNum($number);
}
catch(Exception $e){
$i++;
}
}