FiberResumeBeforeStart

warning native on by default PHP ≥ 8.1

Group: Probable bugs

A newly created fiber must be started before it can be resumed. Resume only a suspended fiber.

Example

<?php
$f=new Fiber(fn()=>1); $f->resume();

Reported:

• line 2: Start the fiber before resuming it.

Detection

• A local assigned new resolved Fiber is used as resume receiver before start or any unknown escape; require straight-line statements. Highlight resume call.
• Resolve builtin functions, classes, constants and methods; user-defined lookalikes are excluded. Follow only bounded local proof in one lexical scope.
• Emit one finding per violating operation, not per supporting evidence statement. When the proof is inconclusive, nothing is reported.

Exceptions (no report)

• Do not report unresolved or shadowed builtin names, unknown values, or incomplete receiver/type provenance. Unknown calls, aliases escaping, and intervening writes invalidate local proof. Similar code outside the stated detection contract is not a finding.
• Both standard suppression forms suppress this native ID.

Fix

None. Choosing a repair requires intent or additional runtime information.

PHP versions

Requires PHP 8.1 or later.

Configure

In custos.json:

{
  "rules": {
    "FiberResumeBeforeStart": {
      "enabled": false
    }
  }
}

Suppress

Before the statement or declaration (or the first statement of the file):

// @custos-ignore FiberResumeBeforeStart