1 files changed, 94 insertions, 0 deletions
diff --git a/libpod/lock/shm_lock_manager_linux.go b/libpod/lock/shm_lock_manager_linux.go
new file mode 100644
index 000000000..3e8f4f3d2
--- /dev/null
+++ b/libpod/lock/shm_lock_manager_linux.go
@@ -0,0 +1,94 @@
+// +build linux
+
+package lock
+
+import (
+	"github.com/containers/libpod/libpod/lock/shm"
+)
+
+// SHMLockManager manages shared memory locks.
+type SHMLockManager struct {
+	locks *shm.SHMLocks
+}
+
+// NewSHMLockManager makes a new SHMLockManager with the given number of locks.
+// Due to the underlying implementation, the exact number of locks created may
+// be greater than the number given here.
+func NewSHMLockManager(path string, numLocks uint32) (Manager, error) {
+	locks, err := shm.CreateSHMLock(path, numLocks)
+	if err != nil {
+		return nil, err
+	}
+
+	manager := new(SHMLockManager)
+	manager.locks = locks
+
+	return manager, nil
+}
+
+// OpenSHMLockManager opens an existing SHMLockManager with the given number of
+// locks.
+func OpenSHMLockManager(path string, numLocks uint32) (Manager, error) {
+	locks, err := shm.OpenSHMLock(path, numLocks)
+	if err != nil {
+		return nil, err
+	}
+
+	manager := new(SHMLockManager)
+	manager.locks = locks
+
+	return manager, nil
+}
+
+// AllocateLock allocates a new lock from the manager.
+func (m *SHMLockManager) AllocateLock() (Locker, error) {
+	semIndex, err := m.locks.AllocateSemaphore()
+	if err != nil {
+		return nil, err
+	}
+
+	lock := new(SHMLock)
+	lock.lockID = semIndex
+	lock.manager = m
+
+	return lock, nil
+}
+
+// RetrieveLock retrieves a lock from the manager given its ID.
+func (m *SHMLockManager) RetrieveLock(id uint32) (Locker, error) {
+	lock := new(SHMLock)
+	lock.lockID = id
+	lock.manager = m
+
+	return lock, nil
+}
+
+// SHMLock is an individual shared memory lock.
+type SHMLock struct {
+	lockID  uint32
+	manager *SHMLockManager
+}
+
+// ID returns the ID of the lock.
+func (l *SHMLock) ID() uint32 {
+	return l.lockID
+}
+
+// Lock acquires the lock.
+func (l *SHMLock) Lock() {
+	if err := l.manager.locks.LockSemaphore(l.lockID); err != nil {
+		panic(err.Error())
+	}
+}
+
+// Unlock releases the lock.
+func (l *SHMLock) Unlock() {
+	if err := l.manager.locks.UnlockSemaphore(l.lockID); err != nil {
+		panic(err.Error())
+	}
+}
+
+// Free releases the lock, allowing it to be reused.
+func (l *SHMLock) Free() error {
+	return l.manager.locks.DeallocateSemaphore(l.lockID)
+}