kubo/cmd/ipfs/util/ulimit.go
Jakub Sztandera 42e191c017 gx: unrewrite
License: MIT
Signed-off-by: Jakub Sztandera <kubuxu@protonmail.ch>
2019-03-05 18:33:56 +01:00

88 lines
2.1 KiB
Go

package util
import (
"errors"
"fmt"
"os"
"strconv"
"syscall"
logging "github.com/ipfs/go-log"
)
var log = logging.Logger("ulimit")
var (
supportsFDManagement = false
// getlimit returns the soft and hard limits of file descriptors counts
getLimit func() (uint64, uint64, error)
// set limit sets the soft and hard limits of file descriptors counts
setLimit func(uint64, uint64) error
)
// maxFds is the maximum number of file descriptors that go-ipfs
// can use. The default value is 2048. This can be overwritten by the
// IPFS_FD_MAX env variable
var maxFds = uint64(2048)
// setMaxFds sets the maxFds value from IPFS_FD_MAX
// env variable if it's present on the system
func setMaxFds() {
// check if the IPFS_FD_MAX is set up and if it does
// not have a valid fds number notify the user
if val := os.Getenv("IPFS_FD_MAX"); val != "" {
fds, err := strconv.ParseUint(val, 10, 64)
if err != nil {
log.Errorf("bad value for IPFS_FD_MAX: %s", err)
return
}
maxFds = fds
}
}
// ManageFdLimit raise the current max file descriptor count
// of the process based on the IPFS_FD_MAX value
func ManageFdLimit() (changed bool, newLimit uint64, err error) {
if !supportsFDManagement {
return false, 0, nil
}
setMaxFds()
soft, hard, err := getLimit()
if err != nil {
return false, 0, err
}
if maxFds <= soft {
return false, 0, nil
}
// the soft limit is the value that the kernel enforces for the
// corresponding resource
// the hard limit acts as a ceiling for the soft limit
// an unprivileged process may only set it's soft limit to a
// alue in the range from 0 up to the hard limit
if err = setLimit(maxFds, maxFds); err != nil {
if err != syscall.EPERM {
return false, 0, fmt.Errorf("error setting: ulimit: %s", err)
}
// the process does not have permission so we should only
// set the soft value
if maxFds > hard {
return false, 0, errors.New(
"cannot set rlimit, IPFS_FD_MAX is larger than the hard limit",
)
}
if err = setLimit(maxFds, hard); err != nil {
return false, 0, fmt.Errorf("error setting ulimit wihout hard limit: %s", err)
}
}
return true, maxFds, nil
}