github.com/Schaudge/grailbase@v0.0.0-20240223061707-44c758a471c0/shutdown/shutdown.go (about)

     1  // Copyright 2019 GRAIL, Inc. All rights reserved.
     2  // Use of this source code is governed by the Apache 2.0
     3  // license that can be found in the LICENSE file.
     4  
     5  // Package shutdown implements a global process shutdown mechanism.
     6  // It is used by package github.com/Schaudge/grailbase/grail to perform
     7  // graceful shutdown of software components. It is a separate package
     8  // in order to avoid circular dependencies.
     9  package shutdown
    10  
    11  import "sync"
    12  
    13  // Func is the type of function run on shutdowns.
    14  type Func func()
    15  
    16  var (
    17  	mu    sync.Mutex
    18  	funcs []Func
    19  )
    20  
    21  // Register registers a function to be run in the Init shutdown
    22  // callback. The callbacks will run in the reverse order of
    23  // registration.
    24  
    25  func Register(f Func) {
    26  	mu.Lock()
    27  	funcs = append(funcs, f)
    28  	mu.Unlock()
    29  }
    30  
    31  // Run run callbacks added by Register. This function is not for
    32  // general use.
    33  func Run() {
    34  	mu.Lock()
    35  	fns := funcs
    36  	funcs = nil
    37  	mu.Unlock()
    38  	for i := len(fns) - 1; i >= 0; i-- {
    39  		fns[i]()
    40  	}
    41  }