feat(prefork): delegate to fasthttp/prefork to eliminate code duplication by ReneWerner87 · Pull Request #4210 · gofiber/fiber

ReneWerner87 · 2026-04-11T19:33:00Z

Summary

Replaces previous PR #4037 (accidentally merged via branch tracking misconfiguration).

Replace Fiber's own prefork implementation with fasthttp's prefork package
Eliminate ~100 lines of duplicated process management logic
Add PreforkRecoverThreshold to ListenConfig for configurable child recovery
Add PreforkLogger to ListenConfig for configurable prefork logging
IsChild() delegates to prefork.IsChild()
Callbacks (OnChildSpawn, OnMasterReady, OnChildRecover) integrate Fiber's hooks
New prefork_logger.go with PreforkLoggerInterface

Depends on

https://github.com/ReneWerner87/fasthttp (prefork_optimization branch) — adds OnMasterDeath, OnChildSpawn, OnMasterReady, OnChildRecover, CommandProducer to fasthttp/prefork

Test plan

All prefork tests pass (child, master, TLS, mTLS, hooks)
Full fiber test suite passes (27s)
FastHTTP prefork tests pass (20/20)
gosec security scan: 0 issues

🤖 Generated with Claude Code

…tion Replace Fiber's own prefork implementation with fasthttp's prefork package. This eliminates duplicated process management logic and adds new features: - IsChild() now delegates to prefork.IsChild() - Master process uses fasthttp's recovery loop (RecoverThreshold) - Callbacks (OnChildSpawn, OnMasterReady, OnChildRecover) integrate Fiber's hooks system (OnFork, OnListen, startup message) - CommandProducer enables clean test injection (replaces testPreforkMaster) - OnMasterDeath replaces Fiber's watchMaster (now in fasthttp) - New PreforkRecoverThreshold field in ListenConfig - prefork_logger.go adapts Fiber's logger to fasthttp's Logger interface - go.mod uses replace directive for local fasthttp development Code reduction: ~200 lines of process management removed from Fiber. All existing tests adapted for recovery behavior (ErrOverRecovery). Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Ensures deterministic and fast execution regardless of GOMAXPROCS count. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Use github.com/ReneWerner87/fasthttp@2802b1a (prefork_optimization branch) instead of local ../fasthttp path, so CI and other developers can resolve the dependency. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Includes fix for ListenAndServeTLS parameter order preservation. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

- prefork_logger.go: use grouped import declaration - prefork.go: rename unused 'files' parameter to '_' - prefork.go: wrap external errors from cmd.Start() and ListenAndServe() Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

- Move windowsOS constant to constants.go (global consts file) - Make prefork logger configurable via ListenConfig.PreforkLogger - Define PreforkLoggerInterface for custom logger implementations - Use logger.Printf instead of direct log.Warnf in OnChildRecover - Remove unused log import from prefork.go Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

coderabbitai · 2026-04-11T19:33:08Z

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Code Review

This pull request refactors the preforking mechanism by delegating process management to the fasthttp/prefork package, simplifying the internal implementation and adding support for recovery thresholds and custom loggers. Feedback highlights a security and maintenance risk regarding the use of a personal fork for fasthttp, a bug in the test command producer that starts processes prematurely, and a logic issue where the default recovery threshold could be zero on single-core systems.

gemini-code-assist · 2026-04-11T19:34:34Z

go.mod

 	gopkg.in/yaml.v3 v3.0.1 // indirect
 )
+
+replace github.com/valyala/fasthttp => github.com/ReneWerner87/fasthttp v0.0.0-20260411181936-c1055ce62c37


The replace directive points to a personal fork of fasthttp (ReneWerner87/fasthttp). Depending on a personal fork for core process management logic in a major framework like Fiber is a significant maintenance and security risk. This change should ideally wait until the required features are merged into the official valyala/fasthttp repository to ensure long-term stability and trust.

gemini-code-assist · 2026-04-11T19:34:34Z

prefork.go

+			if err := cmd.Start(); err != nil {
+				return cmd, fmt.Errorf("prefork: failed to start test command: %w", err)
 			}
-			return fmt.Errorf("prefork: %w", err)
+			return cmd, nil


Calling cmd.Start() inside the CommandProducer is likely a bug. An *exec.Cmd can only be started once. Since fasthttp/prefork is responsible for managing the child processes, it will almost certainly call Start() on the command returned by this producer. If it does, the second attempt to start the process will fail with an "exec: already started" error. The producer should only configure and return the command, leaving the execution to the manager.

return cmd, nil

gemini-code-assist · 2026-04-11T19:34:34Z

prefork.go

+	// Determine RecoverThreshold
+	recoverThreshold := cfg.PreforkRecoverThreshold
+	if recoverThreshold == 0 {
+		recoverThreshold = runtime.GOMAXPROCS(0) / 2


The default recoverThreshold calculation (runtime.GOMAXPROCS(0) / 2) results in 0 on systems with a single CPU core. This means that by default, child processes will not be recovered after a crash in single-core environments, which is inconsistent with the behavior on multi-core systems. Consider using a minimum value of at least 1 to ensure consistent recovery behavior across different hardware configurations.

Suggested change

recoverThreshold = runtime.GOMAXPROCS(0) / 2

recoverThreshold = max(1, runtime.GOMAXPROCS(0)/2)

ReneWerner87 and others added 7 commits April 11, 2026 20:09

test(prefork): add PreforkRecoverThreshold to invalid-command test case

dba20e1

Ensures deterministic and fast execution regardless of GOMAXPROCS count. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

refactor(prefork): use windowsOS constant in dummyCmd for consistency

cfc5a9d

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

build: update fasthttp fork reference to c1055ce

3124fc2

Includes fix for ListenAndServeTLS parameter order preservation. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

ReneWerner87 added v3 ✏️ Feature 🤖 Dependencies labels Apr 11, 2026

ReneWerner87 added this to v3 Apr 11, 2026

ReneWerner87 added this to the v3 milestone Apr 11, 2026

ReneWerner87 removed the 🤖 Dependencies label Apr 11, 2026

ReneWerner87 mentioned this pull request Apr 11, 2026

feat(prefork): add support for process monitoring and callbacks in prefork mode #4037

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feat(prefork): delegate to fasthttp/prefork to eliminate code duplication#4210

feat(prefork): delegate to fasthttp/prefork to eliminate code duplication#4210
ReneWerner87 wants to merge 7 commits intomainfrom
prefork_optimization

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	recoverThreshold = runtime.GOMAXPROCS(0) / 2
	recoverThreshold = max(1, runtime.GOMAXPROCS(0)/2)

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ReneWerner87 commented Apr 11, 2026

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