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<?php |
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namespace phasync; |
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/** |
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* A safety mechanism that triggers a callback when garbage collected. |
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* |
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* This is useful for detecting when a coroutine terminates unexpectedly, |
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* allowing cleanup actions like marking a buffer as failed or closing a connection. |
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* |
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* Usage: |
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* ```php |
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* phasync::go(function() use ($sb) { |
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* $deadman = $sb->getDeadmanSwitch(); |
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* |
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* while ($data = fread($socket, 8192)) { |
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* $sb->write($data); |
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* } |
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* $sb->end(); // Always end properly |
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* // If coroutine exits without calling end(), $deadman triggers on GC |
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* }); |
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* ``` |
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*/ |
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final class DeadmanSwitch |
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{ |
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private ?\Closure $callback; |
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private bool $triggered = false; |
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/** |
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* Create a new DeadmanSwitch. |
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* |
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* @param callable $callback The callback to execute when the switch is triggered |
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*/ |
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public function __construct(callable $callback) |
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{ |
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$this->callback = $callback(...); |
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} |
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/** |
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* Destructor triggers the callback if not already triggered or disarmed. |
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*/ |
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public function __destruct() |
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{ |
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if (!$this->triggered && null !== $this->callback) { |
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$this->trigger(); |
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} |
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} |
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/** |
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* Manually trigger the switch, executing the callback. |
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* Can only be triggered once. |
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*/ |
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public function trigger(): void |
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{ |
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if ($this->triggered) { |
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return; |
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} |
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$this->triggered = true; |
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if (null !== $this->callback) { |
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($this->callback)(); |
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$this->callback = null; |
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} |
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} |
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/** |
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* Disarm the switch, preventing the callback from being executed. |
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* Use this when the resource was closed normally. |
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*/ |
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public function disarm(): void |
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{ |
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$this->triggered = true; |
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$this->callback = null; |
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} |
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/** |
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* Check if the switch has been triggered. |
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*/ |
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public function isTriggered(): bool |
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{ |
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return $this->triggered; |
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} |
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} |
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