This document describes version 2.0 of the Dart Development Service Protocol. This protocol is an extension of the Dart VM Service Protocol and implements it in it's entirety. For details on the VM Service Protocol, see the Dart VM Service Protocol Specification.
The Service Protocol uses JSON-RPC 2.0.
See the corresponding section in the VM Service protocol here.
See the corresponding section in the VM Service protocol here.
See the corresponding section in the VM Service protocol here.
See the corresponding section in the VM Service protocol here.
See the corresponding section in the VM Service protocol here.
For a list of core VM service streams, see streamListen.
DDS will keep a history of events on certain streams and send historical events when a client first subscribes to a stream with history. These streams currently consist of the following:
LoggingStdoutStderrExtensionIn addition, subscribing to the Service stream will result in a ServiceRegistered event being sent to the subscribing client for each existing service extension.
From protocol version 1.4, custom streams of any name can be listened to via DDS.
The DDS Protocol supports all public RPCs defined in the VM Service protocol.
AvailableCachedCpuSamples getAvailableCachedCpuSamples();
The getAvailableCachedCpuSamples RPC is used to determine which caches of CPU samples are available. Caches are associated with individual UserTag names and are specified when DDS is started via the cachedUserTags parameter.
See AvailableCachedCpuSamples.
CachedCpuSamples getCachedCpuSamples(string isolateId, string userTag);
The getCachedCpuSamples RPC is used to retrieve a cache of CPU samples collected under a UserTag with name userTag.
See CachedCpuSamples.
ClientName getClientName()
The getClientName RPC is used to retrieve the name associated with the currently connected VM service client. If no name was previously set through the setClientName RPC, a default name will be returned.
See ClientName
Version getDartDevelopmentServiceVersion()
The getDartDevelopmentServiceVersion RPC is used to determine what version of the Dart Development Service Protocol is served by a DDS instance.
See Version.
Size getLogHistorySize()
The getLogHistorySize RPC is used to retrieve the current size of the log history buffer. If the returned Size is zero, then log history is disabled.
See Size.
PerfettoTimeline getPerfettoVMTimelineWithCpuSamples(int timeOriginMicros [optional],
int timeExtentMicros [optional])
The getPerfettoVMTimelineWithCpuSamples RPC functions nearly identically to the VM Service Protocol's getPerfettoVMTimeline RPC, except the trace field of the PerfettoTimeline response returned by this RPC will be a Base64 string encoding a Perfetto-format trace that includes not only all timeline events in the specified time range, but also all CPU samples from all isolates in the specified time range.
See the documentation of getPerfettoVMTimeline and getPerfettoCpuSamples in the Dart VM Service Protocol Specification.
StreamHistory getStreamHistory(string streamId)
The getStreamHistory RPC is used to retrieve historical events for streams which support event history (see Streams for a list of supported streams).
See StreamHistory.
void postEvent(String stream, String eventKind, Map eventData)
The postEvent RPC is used to send events to custom Event streams.
Success readyToResume(string isolateId)
The readyToResume RPC indicates to DDS that the current client is ready to resume the isolate.
If the current client requires that approval be given before resuming an isolate, this method will:
Returns a collected sentinel if the isolate no longer exists.
See Success.
Success requirePermissionToResume(bool onPauseStart [optional],
bool onPauseReload[optional],
bool onPauseExit [optional])
The requirePermissionToResume RPC is used to change the pause/resume behavior of isolates by providing a way for the VM service to wait for approval to resume from some set of clients. This is useful for clients which want to perform some operation on an isolate after a pause without it being resumed by another client. These clients should invoke readyToResume instead of resume to indicate to DDS that they have finished their work and the isolate can be resumed.
If the onPauseStart parameter is true, isolates will not resume after pausing on start until the client sends a resume request and all other clients which need to provide resume approval for this pause type have done so.
If the onPauseReload parameter is true, isolates will not resume after pausing after a reload until the client sends a resume request and all other clients which need to provide resume approval for this pause type have done so.
If the onPauseExit parameter is true, isolates will not resume after pausing on exit until the client sends a resume request and all other clients which need to provide resume approval for this pause type have done so.
Important Notes:
See Success.
Success requireUserPermissionToResume(bool onPauseStart [optional],
bool onPauseExit [optional])
The requireUserPermissionToResume RPC notifies DDS if it should wait for a resume request to resume isolates paused on start or exit.
This RPC should only be invoked by tooling which launched the target Dart process and knows if the user indicated they wanted isolates paused on start or exit.
See Success.
Success setClientName(string name)
The setClientName RPC is used to set a name to be associated with the currently connected VM service client. If the name parameter is a non-empty string, name will become the new name associated with the client. If name is an empty string, the client's name will be reset to its default name.
See Success.
Success setLogHistorySize(int size)
The setLogHistorySize RPC is used to set the size of the ring buffer used for caching a limited set of historical log messages. If size is 0, logging history will be disabled. The maximum history size is 100,000 messages, with the default set to 10,000 messages.
See Success.
The DDS Protocol supports all public types defined in the VM Service protocol.
class AvailableCachedCpuSamples extends Response {
// A list of UserTag names associated with CPU sample caches.
string[] cacheNames;
}
A collection of [UserTag] names associated with caches of CPU samples.
See getAvailableCachedCpuSamples.
class CachedCpuSamples extends CpuSamples {
// The name of the UserTag associated with this cache of samples.
string userTag;
// Provided if the CPU sample cache has filled and older samples have been
// dropped.
bool truncated [optional];
}
An extension of CpuSamples which represents a set of cached samples, associated with a particular [UserTag] name.
See getCachedCpuSamples.
class ClientName extends Response {
// The name of the currently connected VM service client.
string name;
}
See getClientName and setClientName.
class Size extends Response {
int size;
}
A simple object representing a size response.
class StreamHistory extends Response {
// A list of historical Events for a stream.
List<Event> history;
}
See getStreamHistory.
| version | comments |
|---|---|
| 1.0 | Initial revision |
| 1.1 | Added getDartDevelopmentServiceVersion RPC. |
| 1.2 | Added getStreamHistory RPC. |
| 1.3 | Added getAvailableCachedCpuSamples and getCachedCpuSamples RPCs. |
| 1.4 | Added the ability to subscribe to custom streams (which can be specified when calling dart:developer's postEvent). |
| 1.5 | Added getPerfettoCpuSamples RPC. |
| 1.6 | Added postEvent RPC. |