go-judge/pkg/pool/envpool.go
2020-04-16 20:15:59 -04:00

94 lines
1.7 KiB
Go

package pool
import (
"fmt"
"sync"
"syscall"
"github.com/criyle/go-judge/pkg/envexec"
"github.com/criyle/go-sandbox/container"
)
// EnvPool implements container environment pool
type EnvPool struct {
builder EnvironmentBuilder
cgPool CgroupPool
env []*Environment
mu sync.Mutex
}
// NewEnvPool creats new EnvPool with a builder
func NewEnvPool(builder EnvironmentBuilder, cgPool CgroupPool) *EnvPool {
return &EnvPool{
builder: builder,
cgPool: cgPool,
}
}
// Get gets environment from pool, if pool is empty, creates new environment
func (p *EnvPool) Get() (envexec.Environment, error) {
p.mu.Lock()
defer p.mu.Unlock()
if len(p.env) > 0 {
rt := p.env[len(p.env)-1]
p.env = p.env[:len(p.env)-1]
return rt, nil
}
m, err := p.builder.Build()
if err != nil {
return nil, err
}
wd, err := m.Open([]container.OpenCmd{{
Path: "/w",
Flag: syscall.O_CLOEXEC | syscall.O_DIRECTORY,
Perm: 0777,
}})
if err != nil {
return nil, fmt.Errorf("container: failed to prepare work directory")
}
return &Environment{
Environment: m,
cgPool: p.cgPool,
wd: wd[0],
}, nil
}
// Put puts environment to the pool with reset the environment
func (p *EnvPool) Put(e envexec.Environment) {
env, _ := e.(*Environment)
env.Reset()
p.mu.Lock()
defer p.mu.Unlock()
p.env = append(p.env, env)
}
// Destroy destory an environment
func (p *EnvPool) Destroy(e envexec.Environment) {
env, _ := e.(*Environment)
env.Destroy()
}
// Release clears the pool
func (p *EnvPool) Release() {
p.mu.Lock()
defer p.mu.Unlock()
for _, e := range p.env {
p.Destroy(e)
}
}
// Shutdown indicates a shutdown event, not implemented yes
func (p *EnvPool) Shutdown() {
p.mu.Lock()
defer p.mu.Unlock()
for _, e := range p.env {
p.Destroy(e)
}
}