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72f1617fac
Moving from Go module v4 to v5 prepares us for public releases. Move done using gomove [1] as with the v3 and v4 moves. [1] https://github.com/KSubedi/gomove Signed-off-by: Matt Heon <mheon@redhat.com>
127 lines
3.1 KiB
Go
127 lines
3.1 KiB
Go
package lock
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import (
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"github.com/containers/podman/v5/libpod/define"
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"github.com/containers/podman/v5/libpod/lock/file"
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)
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// FileLockManager manages shared memory locks.
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type FileLockManager struct {
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locks *file.FileLocks
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}
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// NewFileLockManager makes a new FileLockManager at the specified directory.
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func NewFileLockManager(lockPath string) (Manager, error) {
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locks, err := file.CreateFileLock(lockPath)
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if err != nil {
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return nil, err
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}
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manager := new(FileLockManager)
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manager.locks = locks
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return manager, nil
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}
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// OpenFileLockManager opens an existing FileLockManager at the specified directory.
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func OpenFileLockManager(path string) (Manager, error) {
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locks, err := file.OpenFileLock(path)
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if err != nil {
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return nil, err
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}
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manager := new(FileLockManager)
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manager.locks = locks
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return manager, nil
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}
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// AllocateLock allocates a new lock from the manager.
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func (m *FileLockManager) AllocateLock() (Locker, error) {
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semIndex, err := m.locks.AllocateLock()
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if err != nil {
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return nil, err
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}
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lock := new(FileLock)
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lock.lockID = semIndex
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lock.manager = m
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return lock, nil
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}
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// AllocateAndRetrieveLock allocates the lock with the given ID and returns it.
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// If the lock is already allocated, error.
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func (m *FileLockManager) AllocateAndRetrieveLock(id uint32) (Locker, error) {
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lock := new(FileLock)
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lock.lockID = id
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lock.manager = m
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if err := m.locks.AllocateGivenLock(id); err != nil {
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return nil, err
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}
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return lock, nil
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}
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// RetrieveLock retrieves a lock from the manager given its ID.
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func (m *FileLockManager) RetrieveLock(id uint32) (Locker, error) {
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lock := new(FileLock)
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lock.lockID = id
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lock.manager = m
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return lock, nil
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}
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// FreeAllLocks frees all locks in the manager.
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// This function is DANGEROUS. Please read the full comment in locks.go before
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// trying to use it.
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func (m *FileLockManager) FreeAllLocks() error {
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return m.locks.DeallocateAllLocks()
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}
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// AvailableLocks returns the number of available locks. Since this is not
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// limited in the file lock implementation, nil is returned.
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func (m *FileLockManager) AvailableLocks() (*uint32, error) {
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return nil, nil
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}
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// LocksHeld returns any locks that are presently locked.
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// It is not implemented for the file lock backend.
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// It ought to be possible, but my motivation to dig into c/storage and add
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// trylock semantics to the filelocker implementation for an uncommonly-used
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// lock backend is lacking.
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func (m *FileLockManager) LocksHeld() ([]uint32, error) {
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return nil, define.ErrNotImplemented
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}
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// FileLock is an individual shared memory lock.
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type FileLock struct {
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lockID uint32
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manager *FileLockManager
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}
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// ID returns the ID of the lock.
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func (l *FileLock) ID() uint32 {
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return l.lockID
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}
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// Lock acquires the lock.
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func (l *FileLock) Lock() {
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if err := l.manager.locks.LockFileLock(l.lockID); err != nil {
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panic(err.Error())
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}
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}
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// Unlock releases the lock.
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func (l *FileLock) Unlock() {
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if err := l.manager.locks.UnlockFileLock(l.lockID); err != nil {
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panic(err.Error())
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}
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}
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// Free releases the lock, allowing it to be reused.
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func (l *FileLock) Free() error {
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return l.manager.locks.DeallocateLock(l.lockID)
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}
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