diff options
Diffstat (limited to 'pkg/sentry/vfs/epoll.go')
| -rw-r--r-- | pkg/sentry/vfs/epoll.go | 35 |
1 files changed, 19 insertions, 16 deletions
diff --git a/pkg/sentry/vfs/epoll.go b/pkg/sentry/vfs/epoll.go index 599c3131c..8f36c3e3b 100644 --- a/pkg/sentry/vfs/epoll.go +++ b/pkg/sentry/vfs/epoll.go @@ -27,6 +27,8 @@ import ( var epollCycleMu sync.Mutex // EpollInstance represents an epoll instance, as described by epoll(7). +// +// +stateify savable type EpollInstance struct { vfsfd FileDescription FileDescriptionDefaultImpl @@ -38,11 +40,11 @@ type EpollInstance struct { // interest is the set of file descriptors that are registered with the // EpollInstance for monitoring. interest is protected by interestMu. - interestMu sync.Mutex + interestMu sync.Mutex `state:"nosave"` interest map[epollInterestKey]*epollInterest // mu protects fields in registered epollInterests. - mu sync.Mutex + mu sync.Mutex `state:"nosave"` // ready is the set of file descriptors that may be "ready" for I/O. Note // that this must be an ordered list, not a map: "If more than maxevents @@ -55,6 +57,7 @@ type EpollInstance struct { ready epollInterestList } +// +stateify savable type epollInterestKey struct { // file is the registered FileDescription. No reference is held on file; // instead, when the last reference is dropped, FileDescription.DecRef() @@ -67,6 +70,8 @@ type epollInterestKey struct { } // epollInterest represents an EpollInstance's interest in a file descriptor. +// +// +stateify savable type epollInterest struct { // epoll is the owning EpollInstance. epoll is immutable. epoll *EpollInstance @@ -93,9 +98,9 @@ type epollInterest struct { // NewEpollInstanceFD returns a FileDescription representing a new epoll // instance. A reference is taken on the returned FileDescription. -func (vfs *VirtualFilesystem) NewEpollInstanceFD() (*FileDescription, error) { +func (vfs *VirtualFilesystem) NewEpollInstanceFD(ctx context.Context) (*FileDescription, error) { vd := vfs.NewAnonVirtualDentry("[eventpoll]") - defer vd.DecRef() + defer vd.DecRef(ctx) ep := &EpollInstance{ interest: make(map[epollInterestKey]*epollInterest), } @@ -110,7 +115,7 @@ func (vfs *VirtualFilesystem) NewEpollInstanceFD() (*FileDescription, error) { } // Release implements FileDescriptionImpl.Release. -func (ep *EpollInstance) Release() { +func (ep *EpollInstance) Release(ctx context.Context) { // Unregister all polled fds. ep.interestMu.Lock() defer ep.interestMu.Unlock() @@ -186,7 +191,7 @@ func (ep *EpollInstance) AddInterest(file *FileDescription, num int32, event lin } // Register interest in file. - mask := event.Events | linux.EPOLLERR | linux.EPOLLRDHUP + mask := event.Events | linux.EPOLLERR | linux.EPOLLHUP epi := &epollInterest{ epoll: ep, key: key, @@ -257,7 +262,7 @@ func (ep *EpollInstance) ModifyInterest(file *FileDescription, num int32, event } // Update epi for the next call to ep.ReadEvents(). - mask := event.Events | linux.EPOLLERR | linux.EPOLLRDHUP + mask := event.Events | linux.EPOLLERR | linux.EPOLLHUP ep.mu.Lock() epi.mask = mask epi.userData = event.Data @@ -331,11 +336,9 @@ func (ep *EpollInstance) removeLocked(epi *epollInterest) { ep.mu.Unlock() } -// ReadEvents reads up to len(events) ready events into events and returns the -// number of events read. -// -// Preconditions: len(events) != 0. -func (ep *EpollInstance) ReadEvents(events []linux.EpollEvent) int { +// ReadEvents appends up to maxReady events to events and returns the updated +// slice of events. +func (ep *EpollInstance) ReadEvents(events []linux.EpollEvent, maxEvents int) []linux.EpollEvent { i := 0 // Hot path: avoid defer. ep.mu.Lock() @@ -368,16 +371,16 @@ func (ep *EpollInstance) ReadEvents(events []linux.EpollEvent) int { requeue.PushBack(epi) } // Report ievents. - events[i] = linux.EpollEvent{ + events = append(events, linux.EpollEvent{ Events: ievents.ToLinux(), Data: epi.userData, - } + }) i++ - if i == len(events) { + if i == maxEvents { break } } ep.ready.PushBackList(&requeue) ep.mu.Unlock() - return i + return events } |