diff options
Diffstat (limited to 'pkg/sentry/context/context.go')
-rw-r--r-- | pkg/sentry/context/context.go | 63 |
1 files changed, 39 insertions, 24 deletions
diff --git a/pkg/sentry/context/context.go b/pkg/sentry/context/context.go index dfd62cbdb..23e009ef3 100644 --- a/pkg/sentry/context/context.go +++ b/pkg/sentry/context/context.go @@ -12,10 +12,20 @@ // See the License for the specific language governing permissions and // limitations under the License. -// Package context defines the sentry's Context type. +// Package context defines an internal context type. +// +// The given Context conforms to the standard Go context, but mandates +// additional methods that are specific to the kernel internals. Note however, +// that the Context described by this package carries additional constraints +// regarding concurrent access and retaining beyond the scope of a call. +// +// See the Context type for complete details. package context import ( + "context" + "time" + "gvisor.dev/gvisor/pkg/amutex" "gvisor.dev/gvisor/pkg/log" ) @@ -59,6 +69,7 @@ func ThreadGroupIDFromContext(ctx Context) (tgid int32, ok bool) { type Context interface { log.Logger amutex.Sleeper + context.Context // UninterruptibleSleepStart indicates the beginning of an uninterruptible // sleep state (equivalent to Linux's TASK_UNINTERRUPTIBLE). If deactivate @@ -72,19 +83,36 @@ type Context interface { // AddressSpace is activated. Normally activate is the same value as the // deactivate parameter passed to UninterruptibleSleepStart. UninterruptibleSleepFinish(activate bool) +} + +// NoopSleeper is a noop implementation of amutex.Sleeper and UninterruptibleSleep +// methods for anonymous embedding in other types that do not implement sleeps. +type NoopSleeper struct { + amutex.NoopSleeper +} + +// UninterruptibleSleepStart does nothing. +func (NoopSleeper) UninterruptibleSleepStart(bool) {} + +// UninterruptibleSleepFinish does nothing. +func (NoopSleeper) UninterruptibleSleepFinish(bool) {} + +// Deadline returns zero values, meaning no deadline. +func (NoopSleeper) Deadline() (time.Time, bool) { + return time.Time{}, false +} + +// Done returns nil. +func (NoopSleeper) Done() <-chan struct{} { + return nil +} - // Value returns the value associated with this Context for key, or nil if - // no value is associated with key. Successive calls to Value with the same - // key returns the same result. - // - // A key identifies a specific value in a Context. Functions that wish to - // retrieve values from Context typically allocate a key in a global - // variable then use that key as the argument to Context.Value. A key can - // be any type that supports equality; packages should define keys as an - // unexported type to avoid collisions. - Value(key interface{}) interface{} +// Err returns nil. +func (NoopSleeper) Err() error { + return nil } +// logContext implements basic logging. type logContext struct { log.Logger NoopSleeper @@ -95,19 +123,6 @@ func (logContext) Value(key interface{}) interface{} { return nil } -// NoopSleeper is a noop implementation of amutex.Sleeper and -// Context.UninterruptibleSleep* methods for anonymous embedding in other types -// that do not want to notify kernel.Task about sleeps. -type NoopSleeper struct { - amutex.NoopSleeper -} - -// UninterruptibleSleepStart does nothing. -func (NoopSleeper) UninterruptibleSleepStart(bool) {} - -// UninterruptibleSleepFinish does nothing. -func (NoopSleeper) UninterruptibleSleepFinish(bool) {} - // bgContext is the context returned by context.Background. var bgContext = &logContext{Logger: log.Log()} |