| 1 | package plugin |
| 2 | |
| 3 | import ( |
| 4 | "context" |
| 5 | "fmt" |
| 6 | "io" |
| 7 | "os" |
| 8 | "os/exec" |
| 9 | "path/filepath" |
| 10 | "runtime" |
| 11 | "slices" |
| 12 | "strings" |
| 13 | "sync" |
| 14 | "time" |
| 15 | |
| 16 | "reasonix/internal/proc" |
| 17 | "reasonix/internal/sandbox" |
| 18 | "reasonix/internal/secrets" |
| 19 | ) |
| 20 | |
| 21 | const ( |
| 22 | closeWaitBudget = 5 * time.Second |
| 23 | gracefulCloseWaitBudget = 750 * time.Millisecond |
| 24 | ) |
| 25 | |
| 26 | // stdioTransport owns the Reasonix-specific subprocess lifecycle. MCP framing, |
| 27 | // concurrent request correlation, cancellation, and server requests are owned |
| 28 | // by the official SDK's IOTransport. |
| 29 | type stdioTransport struct { |
| 30 | name string |
| 31 | cmd *exec.Cmd |
| 32 | job uintptr // Windows Job Object handle (0 elsewhere); reaps detached grandchildren on close |
| 33 | stdin io.WriteCloser |
| 34 | stdout io.ReadCloser |
| 35 | stderr *tailBuffer |
| 36 | waitOnce sync.Once |
| 37 | closeOnce sync.Once |
| 38 | releaseSlot func() // returns a bounded instance slot (e.g. CodeGraph) on close; nil when unbounded |
| 39 | } |
| 40 | |
| 41 | func newStdioTransport(ctx context.Context, s Spec) (*stdioTransport, error) { |
| 42 | if strings.TrimSpace(s.Command) == "" { |
| 43 | return nil, fmt.Errorf("stdio plugin %q: command is required", s.Name) |
| 44 | } |
| 45 | var releaseSlot func() |
| 46 | if isCodeGraphSpecName(s.Name) { |
| 47 | release, err := acquireCodeGraphSlot() |
| 48 | if err != nil { |
| 49 | return nil, err |
| 50 | } |
| 51 | releaseSlot = release |
| 52 | } |
| 53 | defer func() { |
| 54 | // Release the reserved slot if construction fails before the transport |
| 55 | // takes ownership of it (set to nil on the success path below). |
| 56 | if releaseSlot != nil { |
| 57 | releaseSlot() |
| 58 | } |
| 59 | }() |
| 60 | env := mergeEnv(secrets.ProcessEnv(), s.Env) |
| 61 | exe, env, err := resolveStdioExecutable(ctx, s, env) |
| 62 | if err != nil { |
| 63 | return nil, err |
| 64 | } |
| 65 | // Private state/cache/temp always apply so MCP processes do not pollute the |
| 66 | // user's home caches. Command-sandbox wrapping is separate and only used for |
| 67 | // confined mode; authorized user installs run as trusted host processes so |
| 68 | // Chrome, Keychain, and local app services keep working. |
| 69 | processSandbox := s.Sandbox |
| 70 | processSandbox, env, err = prepareMCPPrivateState(s, processSandbox, env) |
| 71 | if err != nil { |
| 72 | return nil, err |
| 73 | } |
| 74 | launchArgs := append([]string{exe}, effectiveLaunchArgs(s)...) |
| 75 | var argv []string |
| 76 | if s.ResolvedProcessMode() == MCPProcessConfined { |
| 77 | processSandbox.MinimalWrites = true |
| 78 | var err error |
| 79 | argv, err = wrapConfinedCommand(s.Name, processSandbox, launchArgs, sandbox.CommandArgs) |
| 80 | if err != nil { |
| 81 | return nil, err |
| 82 | } |
| 83 | } else { |
| 84 | argv = launchArgs |
| 85 | } |
| 86 | cmd := proc.CommandContext(ctx, argv[0], argv[1:]...) |
| 87 | proc.HideWindow(cmd) |
| 88 | if s.LowPriority { |
| 89 | proc.LowPriority(cmd) |
| 90 | } |
| 91 | cmd.Env = env |
| 92 | cmd.Dir = stdioWorkingDir(s) |
| 93 | stderr := &tailBuffer{limit: 16 * 1024} |
| 94 | cmd.Stderr = stderr |
| 95 | if s.Stderr != nil { |
| 96 | cmd.Stderr = io.MultiWriter(stderr, s.Stderr) |
| 97 | } |
| 98 | |
| 99 | stdin, err := cmd.StdinPipe() |
| 100 | if err != nil { |
| 101 | return nil, err |
| 102 | } |
| 103 | stdout, err := cmd.StdoutPipe() |
| 104 | if err != nil { |
| 105 | return nil, err |
| 106 | } |
| 107 | job, err := proc.StartTracked(cmd) |
| 108 | if err != nil { |
| 109 | return nil, err |
| 110 | } |
| 111 | if s.LowPriority { |
| 112 | proc.LowPriorityStarted(cmd) |
| 113 | } |
| 114 | t := &stdioTransport{ |
| 115 | name: s.Name, |
| 116 | cmd: cmd, |
| 117 | job: job, |
| 118 | stdin: stdin, |
| 119 | stdout: stdout, |
| 120 | stderr: stderr, |
| 121 | releaseSlot: releaseSlot, |
| 122 | } |
| 123 | releaseSlot = nil // ownership transferred to t; close() releases it |
| 124 | return t, nil |
| 125 | } |
| 126 | |
| 127 | func prepareMCPPrivateState(s Spec, processSandbox sandbox.Spec, env []string) (sandbox.Spec, []string, error) { |
| 128 | return prepareMCPPrivateStateForOS(s, processSandbox, env, runtime.GOOS) |
| 129 | } |
| 130 | |
| 131 | func prepareMCPPrivateStateForOS(s Spec, processSandbox sandbox.Spec, env []string, goos string) (sandbox.Spec, []string, error) { |
| 132 | root := strings.TrimSpace(s.StateDir) |
| 133 | if root == "" { |
| 134 | return processSandbox, env, nil |
| 135 | } |
| 136 | if err := os.MkdirAll(root, 0o700); err != nil { |
| 137 | return processSandbox, env, err |
| 138 | } |
| 139 | privateRoot := root |
| 140 | cacheDir := filepath.Join(privateRoot, "cache") |
| 141 | stateDir := filepath.Join(privateRoot, "state") |
| 142 | dirs := []string{cacheDir, stateDir} |
| 143 | privateEnv := map[string]string{ |
| 144 | "XDG_CACHE_HOME": cacheDir, "XDG_STATE_HOME": stateDir, |
| 145 | "npm_config_cache": filepath.Join(cacheDir, "npm"), |
| 146 | "UV_CACHE_DIR": filepath.Join(cacheDir, "uv"), |
| 147 | "BUN_INSTALL_CACHE_DIR": filepath.Join(cacheDir, "bun"), |
| 148 | } |
| 149 | if goos != "windows" { |
| 150 | tmpDir := filepath.Join(privateRoot, "tmp") |
| 151 | dirs = append(dirs, tmpDir) |
| 152 | privateEnv["TMP"] = tmpDir |
| 153 | privateEnv["TEMP"] = tmpDir |
| 154 | privateEnv["TMPDIR"] = tmpDir |
| 155 | } |
| 156 | for _, dir := range dirs { |
| 157 | if err := os.MkdirAll(dir, 0o700); err != nil { |
| 158 | return processSandbox, env, err |
| 159 | } |
| 160 | } |
| 161 | // Windows stdio processes are currently unsandboxed and must keep the host's |
| 162 | // short temporary directory. Nesting TEMP below Reasonix's workspace-scoped |
| 163 | // state path can exceed the 108-byte Unix-domain-socket limit used by MCP |
| 164 | // servers such as MATLAB before their initialize response is written. |
| 165 | for key, value := range privateEnv { |
| 166 | env = setEnvValue(env, key, value) |
| 167 | } |
| 168 | processSandbox.WriteRoots = append(processSandbox.WriteRoots, root, privateRoot) |
| 169 | return processSandbox, env, nil |
| 170 | } |
| 171 | |
| 172 | var stdioShellPATH = cachedShellPATH(defaultStdioShellPATH) |
| 173 | |
| 174 | // cachedShellPATH memoizes the first completed shell-PATH probe: the user's |
| 175 | // interactive PATH is stable for the process, and resolveStdioExecutable now |
| 176 | // probes for every stdio plugin, so caching avoids a login shell per server. |
| 177 | // The probe runs up to three login shells with a 2s timeout each, so it must |
| 178 | // not run under the lock; concurrent spawns share the in-flight probe instead |
| 179 | // of each running (or queueing behind) their own. Empty results are cached too |
| 180 | // — a host without a usable login shell must not re-probe on every spawn — |
| 181 | // except when the probe's context was cancelled, since that empty reflects the |
| 182 | // aborted caller rather than the host, and caching it would pin "" for the |
| 183 | // rest of the process. |
| 184 | func cachedShellPATH(probe func(context.Context) string) func(context.Context) string { |
| 185 | var ( |
| 186 | mu sync.Mutex |
| 187 | cached string |
| 188 | done bool |
| 189 | inflight chan struct{} // non-nil while a probe runs; closed when it settles |
| 190 | ) |
| 191 | return func(ctx context.Context) string { |
| 192 | for { |
| 193 | mu.Lock() |
| 194 | if done { |
| 195 | p := cached |
| 196 | mu.Unlock() |
| 197 | return p |
| 198 | } |
| 199 | if inflight != nil { |
| 200 | wait := inflight |
| 201 | mu.Unlock() |
| 202 | select { |
| 203 | case <-wait: |
| 204 | continue // re-check: the probe may not have cached (cancelled) |
| 205 | case <-ctx.Done(): |
| 206 | return "" |
| 207 | } |
| 208 | } |
| 209 | ch := make(chan struct{}) |
| 210 | inflight = ch |
| 211 | mu.Unlock() |
| 212 | |
| 213 | p := probe(ctx) |
| 214 | |
| 215 | mu.Lock() |
| 216 | inflight = nil |
| 217 | if p != "" || ctx.Err() == nil { |
| 218 | cached, done = p, true |
| 219 | } |
| 220 | mu.Unlock() |
| 221 | close(ch) |
| 222 | return p |
| 223 | } |
| 224 | } |
| 225 | } |
| 226 | |
| 227 | func resolveStdioExecutable(ctx context.Context, s Spec, env []string) (string, []string, error) { |
| 228 | // Unconditionally enrich PATH with the user's shell PATH so every |
| 229 | // subprocess—including wrapper scripts that invoke npx, uvx, etc.— |
| 230 | // inherits the expected tool locations even under a GUI launch. |
| 231 | env = enrichStdioShellPATH(ctx, env) |
| 232 | |
| 233 | if hasPathSeparator(s.Command) { |
| 234 | exe := s.Command |
| 235 | if !filepath.IsAbs(exe) { |
| 236 | if dir := stdioWorkingDir(s); dir != "" { |
| 237 | exe = filepath.Join(dir, exe) |
| 238 | } |
| 239 | abs, err := filepath.Abs(exe) |
| 240 | if err != nil { |
| 241 | return "", env, fmt.Errorf("stdio plugin %q: resolve command %q: %w", s.Name, s.Command, err) |
| 242 | } |
| 243 | exe = abs |
| 244 | } |
| 245 | return exe, env, nil |
| 246 | } |
| 247 | if exe, ok := lookPathInEnv(s.Command, env); ok { |
| 248 | return exe, env, nil |
| 249 | } |
| 250 | |
| 251 | currentPath, _ := envValue(env, "PATH") |
| 252 | if runtime.GOOS == "windows" { |
| 253 | fallbackPath := mergePathLists(windowsStdioFallbackPATH(env), currentPath) |
| 254 | if fallbackPath != currentPath { |
| 255 | fallbackEnv := setEnvValue(env, "PATH", fallbackPath) |
| 256 | if exe, ok := lookPathInEnv(s.Command, fallbackEnv); ok { |
| 257 | return exe, fallbackEnv, nil |
| 258 | } |
| 259 | env = fallbackEnv |
| 260 | currentPath = fallbackPath |
| 261 | } |
| 262 | } |
| 263 | |
| 264 | return "", env, fmt.Errorf("stdio plugin %q: command %q not found on PATH; GUI launches and non-interactive sessions may not inherit your shell PATH. Use an absolute command path or set PATH in the MCP server env. PATH=%q", |
| 265 | s.Name, s.Command, currentPath) |
| 266 | } |
| 267 | |
| 268 | // stdioWorkingDir keeps WorkspaceRoot's roots/list role separate from process |
| 269 | // execution for user-installed servers. Only repository-declared servers need |
| 270 | // relative arguments to resolve against the project that supplied the config. |
| 271 | func stdioWorkingDir(s Spec) string { |
| 272 | if s.Dir != "" { |
| 273 | return s.Dir |
| 274 | } |
| 275 | if s.RequireLaunchApproval { |
| 276 | return s.WorkspaceRoot |
| 277 | } |
| 278 | return "" |
| 279 | } |
| 280 | |
| 281 | // enrichStdioShellPATH probes the user's interactive login shell for its PATH |
| 282 | // and prepends those directories to the current environment. The result is the |
| 283 | // subprocess environment with a PATH that matches what the user sees in their |
| 284 | // terminal, even when Reasonix was launched from the Finder / Dock / open(1). |
| 285 | func enrichStdioShellPATH(ctx context.Context, env []string) []string { |
| 286 | currentPath, _ := envValue(env, "PATH") |
| 287 | if shellPath := strings.TrimSpace(stdioShellPATH(ctx)); shellPath != "" { |
| 288 | if fallbackPath := mergePathLists(shellPath, currentPath); fallbackPath != currentPath { |
| 289 | env = setEnvValue(env, "PATH", fallbackPath) |
| 290 | } |
| 291 | } |
| 292 | return env |
| 293 | } |
| 294 | |
| 295 | func hasPathSeparator(s string) bool { |
| 296 | return strings.ContainsAny(s, `/\`) |
| 297 | } |
| 298 | |
| 299 | func lookPathInEnv(command string, env []string) (string, bool) { |
| 300 | path, _ := envValue(env, "PATH") |
| 301 | pathext, _ := envValue(env, "PATHEXT") |
| 302 | for _, dir := range filepath.SplitList(path) { |
| 303 | if dir == "" || !filepath.IsAbs(dir) { |
| 304 | continue |
| 305 | } |
| 306 | for _, name := range executableNames(command, pathext) { |
| 307 | candidate := filepath.Join(dir, name) |
| 308 | if isExecutableFile(candidate) { |
| 309 | return candidate, true |
| 310 | } |
| 311 | } |
| 312 | } |
| 313 | return "", false |
| 314 | } |
| 315 | |
| 316 | func executableNames(command, pathext string) []string { |
| 317 | if runtime.GOOS != "windows" || filepath.Ext(command) != "" { |
| 318 | return []string{command} |
| 319 | } |
| 320 | if strings.TrimSpace(pathext) == "" { |
| 321 | pathext = ".COM;.EXE;.BAT;.CMD" |
| 322 | } |
| 323 | names := []string{command} |
| 324 | seen := map[string]bool{strings.ToLower(command): true} |
| 325 | for ext := range strings.SplitSeq(pathext, ";") { |
| 326 | ext = strings.TrimSpace(ext) |
| 327 | if ext == "" { |
| 328 | continue |
| 329 | } |
| 330 | if !strings.HasPrefix(ext, ".") { |
| 331 | ext = "." + ext |
| 332 | } |
| 333 | name := command + ext |
| 334 | key := strings.ToLower(name) |
| 335 | if !seen[key] { |
| 336 | seen[key] = true |
| 337 | names = append(names, name) |
| 338 | } |
| 339 | } |
| 340 | return names |
| 341 | } |
| 342 | |
| 343 | func isExecutableFile(path string) bool { |
| 344 | info, err := os.Stat(path) |
| 345 | if err != nil || info.IsDir() { |
| 346 | return false |
| 347 | } |
| 348 | if runtime.GOOS == "windows" { |
| 349 | return true |
| 350 | } |
| 351 | return info.Mode().Perm()&0o111 != 0 |
| 352 | } |
| 353 | |
| 354 | func windowsStdioFallbackPATH(env []string) string { |
| 355 | if runtime.GOOS != "windows" { |
| 356 | return "" |
| 357 | } |
| 358 | programFiles, _ := envValue(env, "ProgramFiles") |
| 359 | programFilesX86, _ := envValue(env, "ProgramFiles(x86)") |
| 360 | localAppData, _ := envValue(env, "LOCALAPPDATA") |
| 361 | appData, _ := envValue(env, "APPDATA") |
| 362 | userProfile, _ := envValue(env, "USERPROFILE") |
| 363 | chocolatey, _ := envValue(env, "ChocolateyInstall") |
| 364 | if localAppData == "" && userProfile != "" { |
| 365 | localAppData = filepath.Join(userProfile, "AppData", "Local") |
| 366 | } |
| 367 | if appData == "" && userProfile != "" { |
| 368 | appData = filepath.Join(userProfile, "AppData", "Roaming") |
| 369 | } |
| 370 | candidates := []string{ |
| 371 | filepath.Join(programFiles, "nodejs"), |
| 372 | filepath.Join(programFilesX86, "nodejs"), |
| 373 | filepath.Join(localAppData, "Programs", "nodejs"), |
| 374 | filepath.Join(appData, "npm"), |
| 375 | filepath.Join(localAppData, "Microsoft", "WindowsApps"), |
| 376 | filepath.Join(userProfile, "scoop", "shims"), |
| 377 | filepath.Join(userProfile, ".bun", "bin"), |
| 378 | filepath.Join(userProfile, ".cargo", "bin"), |
| 379 | filepath.Join(chocolatey, "bin"), |
| 380 | } |
| 381 | var existing []string |
| 382 | for _, dir := range candidates { |
| 383 | if isDir(dir) { |
| 384 | existing = append(existing, dir) |
| 385 | } |
| 386 | } |
| 387 | return strings.Join(existing, string(os.PathListSeparator)) |
| 388 | } |
| 389 | |
| 390 | func isDir(path string) bool { |
| 391 | if path == "" { |
| 392 | return false |
| 393 | } |
| 394 | if !filepath.IsAbs(path) { |
| 395 | return false |
| 396 | } |
| 397 | info, err := os.Stat(path) |
| 398 | return err == nil && info.IsDir() |
| 399 | } |
| 400 | |
| 401 | func defaultStdioShellPATH(ctx context.Context) string { |
| 402 | if runtime.GOOS == "windows" { |
| 403 | return "" |
| 404 | } |
| 405 | shell := stdioShell() |
| 406 | if shell == "" { |
| 407 | return "" |
| 408 | } |
| 409 | const marker = "__REASONIX_PATH__=" |
| 410 | script := "printf '\\n" + marker + "%s\\n' \"$PATH\"" |
| 411 | for _, args := range [][]string{ |
| 412 | {"-l", "-i", "-c", script}, |
| 413 | {"-l", "-c", script}, |
| 414 | {"-c", script}, |
| 415 | } { |
| 416 | out := runShellPATHCommand(ctx, shell, args) |
| 417 | if path := parseShellPATH(out, marker); path != "" { |
| 418 | return path |
| 419 | } |
| 420 | } |
| 421 | return "" |
| 422 | } |
| 423 | |
| 424 | func stdioShell() string { |
| 425 | if shell := strings.TrimSpace(os.Getenv("SHELL")); shell != "" { |
| 426 | if hasPathSeparator(shell) { |
| 427 | if isExecutableFile(shell) { |
| 428 | return shell |
| 429 | } |
| 430 | } else if exe, ok := lookPathInEnv(shell, secrets.ProcessEnv()); ok { |
| 431 | return exe |
| 432 | } |
| 433 | } |
| 434 | for _, shell := range []string{"/bin/zsh", "/bin/bash", "/bin/sh"} { |
| 435 | if isExecutableFile(shell) { |
| 436 | return shell |
| 437 | } |
| 438 | } |
| 439 | return "" |
| 440 | } |
| 441 | |
| 442 | func runShellPATHCommand(parent context.Context, shell string, args []string) []byte { |
| 443 | ctx, cancel := context.WithTimeout(parent, 2*time.Second) |
| 444 | defer cancel() |
| 445 | cmd := proc.CommandContext(ctx, shell, args...) |
| 446 | // Explicit env so the login-shell probe honors [secrets] |
| 447 | // filter_subprocess_env instead of inheriting the full environment. |
| 448 | cmd.Env = secrets.ProcessEnv() |
| 449 | prepareStdioShellPATHProbe(cmd) |
| 450 | cmd.Stdin = strings.NewReader("") |
| 451 | out, _ := cmd.CombinedOutput() |
| 452 | return out |
| 453 | } |
| 454 | |
| 455 | func prepareStdioShellPATHProbe(cmd *exec.Cmd) { |
| 456 | proc.PrepareShellPATHProbe(cmd) |
| 457 | } |
| 458 | |
| 459 | func parseShellPATH(out []byte, marker string) string { |
| 460 | lines := strings.Split(strings.ReplaceAll(string(out), "\r\n", "\n"), "\n") |
| 461 | for _, line := range slices.Backward(lines) { |
| 462 | if rest, ok := strings.CutPrefix(line, marker); ok { |
| 463 | return strings.TrimSpace(rest) |
| 464 | } |
| 465 | } |
| 466 | return "" |
| 467 | } |
| 468 | |
| 469 | func mergeEnv(base []string, overrides map[string]string) []string { |
| 470 | out := append([]string(nil), base...) |
| 471 | for k, v := range overrides { |
| 472 | out = setEnvValue(out, k, v) |
| 473 | } |
| 474 | return out |
| 475 | } |
| 476 | |
| 477 | func setEnvValue(env []string, key, value string) []string { |
| 478 | out := make([]string, 0, len(env)) |
| 479 | replaced := false |
| 480 | for _, kv := range env { |
| 481 | k, _, ok := strings.Cut(kv, "=") |
| 482 | if ok && envKeyEqual(k, key) { |
| 483 | if !replaced { |
| 484 | out = append(out, key+"="+value) |
| 485 | replaced = true |
| 486 | } |
| 487 | continue |
| 488 | } |
| 489 | out = append(out, kv) |
| 490 | } |
| 491 | if !replaced { |
| 492 | out = append(out, key+"="+value) |
| 493 | } |
| 494 | return out |
| 495 | } |
| 496 | |
| 497 | func envValue(env []string, key string) (string, bool) { |
| 498 | for _, entry := range slices.Backward(env) { |
| 499 | k, v, ok := strings.Cut(entry, "=") |
| 500 | if ok && envKeyEqual(k, key) { |
| 501 | return v, true |
| 502 | } |
| 503 | } |
| 504 | return "", false |
| 505 | } |
| 506 | |
| 507 | func envKeyEqual(a, b string) bool { |
| 508 | if runtime.GOOS == "windows" { |
| 509 | return strings.EqualFold(a, b) |
| 510 | } |
| 511 | return a == b |
| 512 | } |
| 513 | |
| 514 | func mergePathLists(primary, secondary string) string { |
| 515 | var out []string |
| 516 | seen := map[string]bool{} |
| 517 | for _, path := range []string{primary, secondary} { |
| 518 | for _, dir := range filepath.SplitList(path) { |
| 519 | if dir == "" || seen[dir] { |
| 520 | continue |
| 521 | } |
| 522 | seen[dir] = true |
| 523 | out = append(out, dir) |
| 524 | } |
| 525 | } |
| 526 | return strings.Join(out, string(os.PathListSeparator)) |
| 527 | } |
| 528 | |
| 529 | func (t *stdioTransport) startupStderr() string { |
| 530 | if t == nil || t.stderr == nil { |
| 531 | return "" |
| 532 | } |
| 533 | return secrets.RedactCredentials(t.stderr.String()) |
| 534 | } |
| 535 | |
| 536 | func (t *stdioTransport) withStderr(err error) error { |
| 537 | if t == nil || t.stderr == nil { |
| 538 | return err |
| 539 | } |
| 540 | waitWithBudget(t.wait, closeWaitBudget) |
| 541 | message := secrets.RedactCredentials(t.stderr.String()) |
| 542 | if message == "" { |
| 543 | return err |
| 544 | } |
| 545 | return fmt.Errorf("%w: stderr: %s", err, message) |
| 546 | } |
| 547 | |
| 548 | // wait reaps the child exactly once; cmd.Wait blocks until the stderr-copy |
| 549 | // goroutine completes, so the tail buffer is settled before anyone reads it. |
| 550 | func (t *stdioTransport) wait() { |
| 551 | t.waitOnce.Do(func() { |
| 552 | if t.cmd != nil && t.cmd.Process != nil { |
| 553 | _ = t.cmd.Wait() |
| 554 | } |
| 555 | }) |
| 556 | } |
| 557 | |
| 558 | // waitWithBudget runs wait in a goroutine and returns once it finishes or the |
| 559 | // budget elapses, whichever comes first. On timeout the goroutine is left to |
| 560 | // complete the reap in the background, so wait must be safe to abandon |
| 561 | // (stdioTransport.wait is single-shot via waitOnce). |
| 562 | func waitWithBudget(wait func(), budget time.Duration) { |
| 563 | _ = waitFinishedWithinBudget(wait, budget) |
| 564 | } |
| 565 | |
| 566 | func waitFinishedWithinBudget(wait func(), budget time.Duration) bool { |
| 567 | done := make(chan struct{}) |
| 568 | go func() { wait(); close(done) }() |
| 569 | select { |
| 570 | case <-done: |
| 571 | return true |
| 572 | case <-time.After(budget): |
| 573 | return false |
| 574 | } |
| 575 | } |
| 576 | |
| 577 | // close first offers a short stdin-EOF grace period, then kills the whole |
| 578 | // process tree if needed (a launcher's surviving grandchild can otherwise keep |
| 579 | // inherited pipes open). Both paths are budgeted so one wedged server can never |
| 580 | // stall a boot or turn teardown. |
| 581 | func (t *stdioTransport) close() { |
| 582 | t.closeOnce.Do(func() { |
| 583 | if t.releaseSlot != nil { |
| 584 | defer t.releaseSlot() |
| 585 | } |
| 586 | if t.stdin != nil { |
| 587 | _ = t.stdin.Close() |
| 588 | } |
| 589 | if t.stdout != nil { |
| 590 | _ = t.stdout.Close() |
| 591 | } |
| 592 | if t.cmd == nil || t.cmd.Process == nil { |
| 593 | return |
| 594 | } |
| 595 | // Give protocol-aware servers a short chance to observe stdin EOF and |
| 596 | // clean up resources they launched outside the process group. Hard-kill |
| 597 | // after the bounded grace period so teardown cannot wedge. |
| 598 | if waitFinishedWithinBudget(t.wait, gracefulCloseWaitBudget) { |
| 599 | proc.FinishTracked(t.job) |
| 600 | return |
| 601 | } |
| 602 | proc.KillTracked(t.cmd, t.job) |
| 603 | waitWithBudget(t.wait, closeWaitBudget) |
| 604 | }) |
| 605 | } |
| 606 |