go-judge/pkg/envexec/group.go
criyle 1f86f25995 Refactor & Documentation
- pkg/runner -> pkg/envexec
- add idea about executor server
2020-03-03 02:32:59 -05:00

99 lines
2.1 KiB
Go

package envexec
import (
"fmt"
"sync"
"github.com/criyle/go-sandbox/container"
)
// 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([]container.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)
}
result := make([]Result, len(r.Cmd))
errC := make(chan error, 1)
// wait all cmd to finish
var wg sync.WaitGroup
wg.Add(len(r.Cmd))
for i, c := range r.Cmd {
go func(i int, c *Cmd) {
defer wg.Done()
r, err := runSingle(ms[i], cgs[i], c, fds[i], pipeToCollect[i])
if err != nil {
writeErrorC(errC, err)
result[i].Status = StatusInternalError
result[i].Error = err.Error()
return
}
result[i] = r
}(i, c)
}
wg.Wait()
fileToClose = nil // already closed by runOne
// collect potential error
select {
case err = <-errC:
default:
}
return result, err
}