diff options
Diffstat (limited to 'vendor/github.com/Microsoft/hcsshim/internal/jobobject/iocp.go')
-rw-r--r-- | vendor/github.com/Microsoft/hcsshim/internal/jobobject/iocp.go | 111 |
1 files changed, 111 insertions, 0 deletions
diff --git a/vendor/github.com/Microsoft/hcsshim/internal/jobobject/iocp.go b/vendor/github.com/Microsoft/hcsshim/internal/jobobject/iocp.go new file mode 100644 index 000000000..3d640ac7b --- /dev/null +++ b/vendor/github.com/Microsoft/hcsshim/internal/jobobject/iocp.go @@ -0,0 +1,111 @@ +package jobobject + +import ( + "context" + "fmt" + "sync" + "unsafe" + + "github.com/Microsoft/hcsshim/internal/log" + "github.com/Microsoft/hcsshim/internal/queue" + "github.com/Microsoft/hcsshim/internal/winapi" + "github.com/sirupsen/logrus" + "golang.org/x/sys/windows" +) + +var ( + ioInitOnce sync.Once + initIOErr error + // Global iocp handle that will be re-used for every job object + ioCompletionPort windows.Handle + // Mapping of job handle to queue to place notifications in. + jobMap sync.Map +) + +// MsgAllProcessesExited is a type representing a message that every process in a job has exited. +type MsgAllProcessesExited struct{} + +// MsgUnimplemented represents a message that we are aware of, but that isn't implemented currently. +// This should not be treated as an error. +type MsgUnimplemented struct{} + +// pollIOCP polls the io completion port forever. +func pollIOCP(ctx context.Context, iocpHandle windows.Handle) { + var ( + overlapped uintptr + code uint32 + key uintptr + ) + + for { + err := windows.GetQueuedCompletionStatus(iocpHandle, &code, &key, (**windows.Overlapped)(unsafe.Pointer(&overlapped)), windows.INFINITE) + if err != nil { + log.G(ctx).WithError(err).Error("failed to poll for job object message") + continue + } + if val, ok := jobMap.Load(key); ok { + msq, ok := val.(*queue.MessageQueue) + if !ok { + log.G(ctx).WithField("value", msq).Warn("encountered non queue type in job map") + continue + } + notification, err := parseMessage(code, overlapped) + if err != nil { + log.G(ctx).WithFields(logrus.Fields{ + "code": code, + "overlapped": overlapped, + }).Warn("failed to parse job object message") + continue + } + if err := msq.Write(notification); err == queue.ErrQueueClosed { + // Write will only return an error when the queue is closed. + // The only time a queue would ever be closed is when we call `Close` on + // the job it belongs to which also removes it from the jobMap, so something + // went wrong here. We can't return as this is reading messages for all jobs + // so just log it and move on. + log.G(ctx).WithFields(logrus.Fields{ + "code": code, + "overlapped": overlapped, + }).Warn("tried to write to a closed queue") + continue + } + } else { + log.G(ctx).Warn("received a message for a job not present in the mapping") + } + } +} + +func parseMessage(code uint32, overlapped uintptr) (interface{}, error) { + // Check code and parse out relevant information related to that notification + // that we care about. For now all we handle is the message that all processes + // in the job have exited. + switch code { + case winapi.JOB_OBJECT_MSG_ACTIVE_PROCESS_ZERO: + return MsgAllProcessesExited{}, nil + // Other messages for completeness and a check to make sure that if we fall + // into the default case that this is a code we don't know how to handle. + case winapi.JOB_OBJECT_MSG_END_OF_JOB_TIME: + case winapi.JOB_OBJECT_MSG_END_OF_PROCESS_TIME: + case winapi.JOB_OBJECT_MSG_ACTIVE_PROCESS_LIMIT: + case winapi.JOB_OBJECT_MSG_NEW_PROCESS: + case winapi.JOB_OBJECT_MSG_EXIT_PROCESS: + case winapi.JOB_OBJECT_MSG_ABNORMAL_EXIT_PROCESS: + case winapi.JOB_OBJECT_MSG_PROCESS_MEMORY_LIMIT: + case winapi.JOB_OBJECT_MSG_JOB_MEMORY_LIMIT: + case winapi.JOB_OBJECT_MSG_NOTIFICATION_LIMIT: + default: + return nil, fmt.Errorf("unknown job notification type: %d", code) + } + return MsgUnimplemented{}, nil +} + +// Assigns an IO completion port to get notified of events for the registered job +// object. +func attachIOCP(job windows.Handle, iocp windows.Handle) error { + info := winapi.JOBOBJECT_ASSOCIATE_COMPLETION_PORT{ + CompletionKey: job, + CompletionPort: iocp, + } + _, err := windows.SetInformationJobObject(job, windows.JobObjectAssociateCompletionPortInformation, uintptr(unsafe.Pointer(&info)), uint32(unsafe.Sizeof(info))) + return err +} |