| // Copyright 2017 The LUCI Authors. |
| // |
| // Licensed under the Apache License, Version 2.0 (the "License"); |
| // you may not use this file except in compliance with the License. |
| // You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, software |
| // distributed under the License is distributed on an "AS IS" BASIS, |
| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| // See the License for the specific language governing permissions and |
| // limitations under the License. |
| |
| package main |
| |
| import ( |
| "context" |
| "fmt" |
| "os" |
| |
| "github.com/maruel/subcommands" |
| |
| "go.chromium.org/luci/common/cli" |
| "go.chromium.org/luci/common/clock" |
| "go.chromium.org/luci/common/system/exitcode" |
| "go.chromium.org/luci/mmutex/lib" |
| ) |
| |
| var cmdExclusive = &subcommands.Command{ |
| UsageLine: "exclusive [options] -- <command>", |
| ShortDesc: "acquires an exclusive lock before running the command", |
| CommandRun: func() subcommands.CommandRun { |
| return &cmdExclusiveRun{} |
| }, |
| } |
| |
| type cmdExclusiveRun struct { |
| subcommands.CommandRunBase |
| } |
| |
| func (c *cmdExclusiveRun) Run(a subcommands.Application, args []string, env subcommands.Env) int { |
| ctx := cli.GetContext(a, c, env) |
| if err := RunExclusive(ctx, env, args); err != nil { |
| if exitCode, exitCodePresent := exitcode.Get(err); exitCodePresent { |
| return exitCode |
| } |
| |
| // We encountered an error that's unrelated to the command itself. |
| fmt.Fprintln(os.Stderr, err) |
| return 1 |
| } |
| |
| return 0 |
| } |
| |
| // RunExclusive runs the command with the specified context and environment while |
| // holding an exclusive mmutex lock. |
| func RunExclusive(ctx context.Context, env subcommands.Env, command []string) error { |
| ctx, cancel := clock.WithTimeout(ctx, lib.DefaultCommandTimeout) |
| defer cancel() |
| |
| return lib.RunExclusive(ctx, env, func(ctx context.Context) error { |
| return runCommand(ctx, command) |
| }) |
| } |