Files
mgmt/resources/pgraph.go

76 lines
2.1 KiB
Go

// Mgmt
// Copyright (C) 2013-2017+ James Shubin and the project contributors
// Written by James Shubin <james@shubin.ca> and the project contributors
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
package resources
import (
"fmt"
"log"
"github.com/purpleidea/mgmt/pgraph"
)
//go:generate stringer -type=graphState -output=graphstate_stringer.go
type graphState uint
const (
graphStateNil graphState = iota
graphStateStarting
graphStateStarted
graphStatePausing
graphStatePaused
)
// getState returns the state of the graph. This state is used for optimizing
// certain algorithms by knowing what part of processing the graph is currently
// undergoing.
func getState(g *pgraph.Graph) graphState {
//mutex := StateLockFromGraph(g)
//mutex.Lock()
//defer mutex.Unlock()
if u, ok := g.Value("state"); ok {
return util.Uint(u)
}
return graphStateNil
}
// setState sets the graph state and returns the previous state.
func setState(g *pgraph.Graph, state graphState) graphState {
mutex := StateLockFromGraph(g)
mutex.Lock()
defer mutex.Unlock()
prev := getState(g)
g.SetValue("state", state)
return prev
}
// StateLockFromGraph returns a pointer to the state lock stored with the graph,
// otherwise it panics. If one does not exist, it will create it.
func StateLockFromGraph(g *pgraph.Graph) *sync.Mutex {
x, exists := g.Value("mutex")
if !exists {
g.SetValue("mutex", &sync.Mutex{})
x, _ = g.Value("mutex")
}
m, ok := x.(*sync.Mutex)
if !ok {
panic("not a *sync.Mutex")
}
return m
}