How to properly detach and remove shared memory between 2 processes in PHP?

I developed a way to make async tasks with PHP and it's working very well, until now.

The logic based in 3 extensions PCNTL, POSIX e Semaphore.

To have a full control of the master process and child process I must share the status of the task and the PID between them. These 2 variables are shared using shm_attach, the fork uses pcntl_fork.

The problem described in the title of this questions is related to the status of the task and the PID between them. These 2 variables are shared using shm_attach method because there is no more space available to share create a shared memory.

I use it for 2 moments: At constructor to create the shared memory

<?php 
//...
 final public function __construct() {
self::$shmId = shm_attach((int) (ftok(self::$file, 'A') . self::$line), self::SHARED_MEMORY_SIZE);

            $this->var_key_pid = $this->alocatesharedMemory(getmypid(), 112112105100); //112112105100;
            $this->var_key_status = $this->alocatesharedMemory('PENDING', 11511697116117115);  //11511697116117115;
}

And on the run method after forking the process

<?php 
final public function run($parameters) {
//...
} else { //Frok process
                ignore_user_abort(); //I dont know why but must be set again.
                $sid = posix_setsid();
                self::$shmId = shm_attach((int) (ftok(self::$file, 'A') . self::$line), self::SHARED_MEMORY_SIZE);

NOTE: The code is a little extensive and I put it into a gist https://gist.github.com/LeonanCarvalho/62c6fe0b62db8a478f502f84c5734c83

I think I'm doing something wrong because even though I'm using shm_detach and shm_remove the process sometimes returns the error PHP Warning: "shm_attach" failed for key No space left on the device in when I try to attach a new shared memory.

It is happening because some shared memory is detached and not removed from Shared memory segments, its the result of command ipcs -m :

The tasks are running for months before start doing this, so the one way to work around this problem I removed all shared memory identifiers with the command

ipcrm --all=shm

But I think it's silently growing and for sure it going to happen again.

How to prevent it?