Error in PHP 7.4: mkdir(): file exists solution (error control operator: @ )

1. Report an error in PHP 7.4: mkdir(): file exists. as shown in Figure 1

if (!file_exists($prefix.DIRECTORY_SEPARATOR.$currentFolder)) {
	mkdir($currentFolder, 0755);
	chmod($currentFolder, 0755);
}

2. However, in the code implementation, it is first judged that the directory does not exist before executing mkdir(). But at the time of execution, the directory already exists. It should be a problem caused by request concurrency.

3. Reproduce this error in the local environment

$currentFolder = 'E:/wwwroot/currentFolder';
mkdir($currentFolder, 0755);
chmod($currentFolder, 0755);

4. During the first run, no errors were reported, and the directory: e:/wwwroot/currentfolder was successfully created. as shown in Figure 2

5. During the second run, an error is reported: warning: mkdir(): file exists in e:\wwwroot\phpinfo.php on line 6. as shown in Figure 3

6. Adjust the code implementation, use the error control operator: @ Solve. Test code runs in the local environment.

$currentFolder = 'E:/wwwroot/currentFolder';
@mkdir($currentFolder, 0755);
chmod($currentFolder, 0755);

7. During the third run, there is no error.

8. Delete the directory: e:/wwwroot/currentfolder, run again. No error is reported, directory: e:/wwwroot/currentFolder was successfully created. as shown in Figure 4

9. The final code is implemented as follows

if (!file_exists($prefix.DIRECTORY_SEPARATOR.$currentFolder)) {
	@mkdir($currentFolder, 0755);
	chmod($currentFolder, 0755);
}