go.chromium.org/luci@v0.0.0-20240309015107-7cdc2e660f33/tools/internal/apigen/command.go (about)

     1  // Copyright 2015 The LUCI Authors.
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //      http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package apigen
    16  
    17  import (
    18  	"context"
    19  	"os"
    20  	"os/exec"
    21  	"time"
    22  
    23  	"go.chromium.org/luci/common/clock"
    24  	log "go.chromium.org/luci/common/logging"
    25  )
    26  
    27  const shutdownWait = 20 * time.Second
    28  
    29  // killableCommand is an extension of exec.Cmd that can be easily killed.
    30  type killableCommand struct {
    31  	*exec.Cmd
    32  }
    33  
    34  func (cmd *killableCommand) kill(c context.Context) {
    35  	c = log.SetField(c, "cmd", cmd.Path)
    36  
    37  	// First, try and nicely kill the process.
    38  	log.Debugf(c, "Sending interrupt to process.")
    39  	cmd.Process.Signal(os.Interrupt)
    40  
    41  	processFinishedC := make(chan struct{})
    42  	defer close(processFinishedC)
    43  	go func() {
    44  		total := time.Duration(0)
    45  		t := clock.NewTimer(c)
    46  		for total < shutdownWait {
    47  			t.Reset(time.Second)
    48  			select {
    49  			case <-processFinishedC:
    50  				return
    51  
    52  			case <-t.GetC():
    53  				// Signal the process again.
    54  				total += time.Second
    55  				log.Debugf(c, "Process not terminated; sending interrupt to process.")
    56  				cmd.Process.Signal(os.Interrupt)
    57  			}
    58  		}
    59  
    60  		log.Debugf(c, "Process did not gracefully exit; sending KILL.")
    61  		cmd.Process.Kill()
    62  	}()
    63  
    64  	cmd.Wait()
    65  	log.Debugf(c, "Process terminated.")
    66  }