FiberStartedTwice

error native on by default PHP ≥ 8.1

Group: Probable bugs

Identify a second start on the same locally allocated Fiber after a successful first start on an unconditional straight-line path; no reset or reassignment may intervene.

Detection

• Report a second start on the same locally allocated Fiber after a successful first start on an unconditional straight-line path; no reset or reassignment may intervene. Only a real invocation counts as a start, for the earlier call and for the reported one: the first-class callable form $fiber->start(...) merely builds a closure.
• Resolve builtin functions, classes, constants and methods, including imports and supported named arguments. Follow only bounded local facts within one lexical scope. Receiver and argument provenance must establish the specific API contract; variable names and comments never prove intent.
• Report one finding per violating operation. A reachable path, unchanged value identity and applicable API behavior are required. Intervening mutation, unknown calls involving tracked values, escaped aliases or exhausted analysis budgets invalidate proof.

Exceptions (no report)

• Exclude unresolved required symbols, user-defined lookalikes, incomplete syntax, unknown required values and unsupported versions.
• No report when the receiver variable is bound again between the two starts: any assignment whose target mentions it (plain, [$f] = ... or list($f) = ... destructuring), a foreach that uses it as key or value, or a catch clause that names it. The second call then acts on another value.
• No report when either call is a first-class callable creation ($f->start(...)).
• Both @custos-ignore FiberStartedTwice and @noinspection FiberStartedTwice suppress this native rule.

Fix

None. A repair requires a semantic decision or application error-handling policy.

PHP versions

Requires PHP 8.1 or later. Do not apply extension contracts when the resolved API is unavailable. Gate syntax and version-specific behavior to the configured target.

Configure

In custos.json:

{
  "rules": {
    "FiberStartedTwice": {
      "enabled": false
    }
  }
}

Suppress

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

// @custos-ignore FiberStartedTwice