mirror of https://go.googlesource.com/go
69 lines
2.3 KiB
Go
69 lines
2.3 KiB
Go
// Copyright 2022 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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package runtime
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// addExitHook registers the specified function 'f' to be run at
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// program termination (e.g. when someone invokes os.Exit(), or when
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// main.main returns). Hooks are run in reverse order of registration:
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// first hook added is the last one run.
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//
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// CAREFUL: the expectation is that addExitHook should only be called
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// from a safe context (e.g. not an error/panic path or signal
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// handler, preemption enabled, allocation allowed, write barriers
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// allowed, etc), and that the exit function 'f' will be invoked under
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// similar circumstances. That is the say, we are expecting that 'f'
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// uses normal / high-level Go code as opposed to one of the more
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// restricted dialects used for the trickier parts of the runtime.
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func addExitHook(f func(), runOnNonZeroExit bool) {
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exitHooks.hooks = append(exitHooks.hooks, exitHook{f: f, runOnNonZeroExit: runOnNonZeroExit})
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}
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// exitHook stores a function to be run on program exit, registered
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// by the utility runtime.addExitHook.
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type exitHook struct {
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f func() // func to run
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runOnNonZeroExit bool // whether to run on non-zero exit code
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}
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// exitHooks stores state related to hook functions registered to
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// run when program execution terminates.
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var exitHooks struct {
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hooks []exitHook
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runningExitHooks bool
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}
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// runExitHooks runs any registered exit hook functions (funcs
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// previously registered using runtime.addExitHook). Here 'exitCode'
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// is the status code being passed to os.Exit, or zero if the program
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// is terminating normally without calling os.Exit.
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func runExitHooks(exitCode int) {
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if exitHooks.runningExitHooks {
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throw("internal error: exit hook invoked exit")
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}
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exitHooks.runningExitHooks = true
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runExitHook := func(f func()) (caughtPanic bool) {
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defer func() {
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if x := recover(); x != nil {
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caughtPanic = true
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}
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}()
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f()
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return
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}
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for i := range exitHooks.hooks {
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h := exitHooks.hooks[len(exitHooks.hooks)-i-1]
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if exitCode != 0 && !h.runOnNonZeroExit {
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continue
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}
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if caughtPanic := runExitHook(h.f); caughtPanic {
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throw("internal error: exit hook invoked panic")
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}
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}
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exitHooks.hooks = nil
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exitHooks.runningExitHooks = false
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}
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