How to read the information and after, write it to a text file?

How to read the information and after, write it to a text file?

I try to do it as described in the following text, but apparently, a race condition is formed . Suppose if there are only two iterations in the loop, then this code will work well.

See:

File cahe.json is in the system and contains the original entry

{"count":"1", "count_1":"0"} 

We use variant A with two iterations for ($i=0; $i < 2; $i++) {

at the output we get a record in the file

 {"count":"1", "count_1":"2"} 

We use variant B with a thousand iterations for ($i=0; $i < 1000; $i++) {

at the output we get a record in the file

 {"count":"1", "count_1":"01"} 

instead

 {"count":"1", "count_1":"1000"} 

We use the C variant with a thousand iterations for ($i=0; $i < 1000; $i++) { , but we change the initial value in the cahe.json file

with

 {"count":"1", "count_1":"0"} 

on

 {"count":"1", "count_1":"1000"} 

at the output we get a record in the file

 {"count":"1", "count_1":"2000"} 

Use option D with a thousand iterations for ($i=0; $i < 1000; $i++) { and plus , remove a piece of code filesize(__DIR__.'/cahe.json') , replacing it with this one - '20000', let's say

at the output we get a record in the file

 {"count":"1", "count_1":"1000"} 

//CODE

 for ($i=0; $i < 1000; $i++) { //------------------------------------------------ $json_data; $contents = ''; $fp = fopen(__DIR__.'/cahe.json', "c+" ); if($fp == false){ //была ошибка var_dump("Была ошибка при открытии файла"); }else{ if (flock($fp, LOCK_EX)) { // выполняем эксклюзивную блокировку //------------------------------------------------ $contents = fread($fp, filesize(__DIR__.'/cahe.json')); $json_data = json_decode($contents, true); //------------------------------------------------ ftruncate($fp, 0); // очищаем файл //перемещаем файловый указаттель в начало файла fseek($fp, 0); //------------------------------------------------ $count_1 = $json_data['count_1'] + 1; $data = '{"count":"1", "count_1":"'.$count_1.'"}'; fwrite($fp, $data); //------------------------------------------------ fflush($fp); // очищаем вывод перед отменой блокировки flock($fp, LOCK_UN); // отпираем файл } else { var_dump("Не удалось получить блокировку!"); } fclose($fp); } //------------------------------------------------ }