go-judge/pkg/envexec/group.go
criyle a79543f0af Cache container work directory for performance
- 140 op/s -> 170 op/s for A+B problem
2020-03-16 20:16:18 -04:00

88 lines
1.9 KiB
Go

package envexec
import (
"fmt"
"golang.org/x/sync/errgroup"
)
// Group defines the running instruction to run multiple
// exec in parallel restricted within cgroup
type Group struct {
// CgroupPool defines pool of cgroup used for Cmd
CgroupPool CgroupPool
// EnvironmentPool defines pool used for runner environment
EnvironmentPool EnvironmentPool
// Cmd defines Cmd running in parallel in multiple environments
Cmd []*Cmd
// Pipes defines the potential mapping between Cmd.
// ensure nil is used as placeholder in correspond cmd
Pipes []*Pipe
}
// PipeIndex defines the index of cmd and the fd of the that cmd
type PipeIndex struct {
Index int
Fd int
}
// Pipe defines the pipe between parallel Cmd
type Pipe struct {
In, Out PipeIndex
}
// Run starts the cmd and returns exec results
func (r *Group) Run() ([]Result, error) {
// prepare files
fds, pipeToCollect, fileToClose, err := prepareFds(r)
defer func() { closeFiles(fileToClose) }()
if err != nil {
return nil, err
}
// prepare environments
ms := make([]Environment, 0, len(r.Cmd))
for range r.Cmd {
m, err := r.EnvironmentPool.Get()
if err != nil {
return nil, fmt.Errorf("failed to get environment %v", err)
}
defer r.EnvironmentPool.Put(m)
ms = append(ms, m)
}
// prepare cgroup
cgs := make([]Cgroup, 0, len(r.Cmd))
for range r.Cmd {
cg, err := r.CgroupPool.Get()
if err != nil {
return nil, fmt.Errorf("failed to get cgroup %v", err)
}
defer r.CgroupPool.Put(cg)
cgs = append(cgs, cg)
}
// wait all cmd to finish
var g errgroup.Group
result := make([]Result, len(r.Cmd))
for i, c := range r.Cmd {
i, c := i, c
g.Go(func() error {
r, err := runSingle(ms[i], cgs[i], c, fds[i], pipeToCollect[i])
result[i] = r
if err != nil {
result[i].Status = StatusInternalError
result[i].Error = err.Error()
return err
}
return nil
})
}
err = g.Wait()
return result, err
}