[net/dns] Refactoring of job dispatch in HostResolverImpl in preparation for DnsTransactionFactory.

net/base/net_log_event_type_list.h

Index: net/base/net_log_event_type_list.h
diff --git a/net/base/net_log_event_type_list.h b/net/base/net_log_event_type_list.h
index 2c273363ce12ee968b9d835789a1e9d27039eb22..2d7520e8bc3241825bcfdd284e69d416bb5383e4 100644
--- a/net/base/net_log_event_type_list.h
+++ b/net/base/net_log_event_type_list.h
@@ -58,32 +58,46 @@ EVENT_TYPE(HOST_RESOLVER_IMPL)
 //     "net_error": <The net error code integer for the failure>,
 //     "os_error": <The exact error code integer that getaddrinfo() returned>,
 //   }
-
 EVENT_TYPE(HOST_RESOLVER_IMPL_REQUEST)
 
 // This event is logged when a request is handled by a cache entry.
 EVENT_TYPE(HOST_RESOLVER_IMPL_CACHE_HIT)
 
-// This event means a request was queued/dequeued for subsequent job creation,
-// because there are already too many active HostResolverImpl::Jobs.
+// This event is created when a new HostResolverImpl::Job is about to be created
+// for a request.
+EVENT_TYPE(HOST_RESOLVER_IMPL_CREATE_JOB)
+
+// The creation/completion of a HostResolverImpl::Job which is created for
+// Requests that cannot be resolved synchronously.
 //
 // The BEGIN phase contains the following parameters:
 //
 //   {
-//     "priority": <Priority of the queued request>,
+//     "host": <Hostname associated with the request>,
+//     "source_dependency": <Source id, if any, of what created the request>,
+//   }
+//
+// On success, the END phase has these parameters:
+//   {
+//     "address_list": <The host name being resolved>,
+//   }
+// If an error occurred, the END phase will contain these parameters:
+//   {
+//     "net_error": <The net error code integer for the failure>,
+//     "os_error": <The exact error code integer that getaddrinfo() returned>,
 //   }
-EVENT_TYPE(HOST_RESOLVER_IMPL_JOB_POOL_QUEUE)
+EVENT_TYPE(HOST_RESOLVER_IMPL_JOB)
 
-// This event is created when a new HostResolverImpl::Request is evicted from
-// JobPool without a Job being created, because the limit on number of queued
-// Requests was reached.
-EVENT_TYPE(HOST_RESOLVER_IMPL_JOB_POOL_QUEUE_EVICTED)
+// This event is created when a HostResolverImpl::Job is evicted from
+// PriorityDispatch before it can start, because the limit on number of queued
+// Jobs was reached.
+EVENT_TYPE(HOST_RESOLVER_IMPL_JOB_EVICTED)
 
-// This event is created when a new HostResolverImpl::Job is about to be created
-// for a request.
-EVENT_TYPE(HOST_RESOLVER_IMPL_CREATE_JOB)
+// This event is created when a HostResolverImpl::Job is started by
+// PriorityDispatch.
+EVENT_TYPE(HOST_RESOLVER_IMPL_JOB_STARTED)
 
-// This event is created when HostResolverImpl::Job is about to start a new
+// This event is created when HostResolverImpl::ProcJob is about to start a new
 // attempt to resolve the host.
 //
 // The ATTEMPT_STARTED event has the parameters:
@@ -93,8 +107,8 @@ EVENT_TYPE(HOST_RESOLVER_IMPL_CREATE_JOB)
 //   }
 EVENT_TYPE(HOST_RESOLVER_IMPL_ATTEMPT_STARTED)
 
-// This event is created when HostResolverImpl::Job has finished resolving the
-// host.
+// This event is created when HostResolverImpl::ProcJob has finished resolving
+// the host.
 //
 // The ATTEMPT_FINISHED event has the parameters:
 //
@@ -109,24 +123,42 @@ EVENT_TYPE(HOST_RESOLVER_IMPL_ATTEMPT_STARTED)
 EVENT_TYPE(HOST_RESOLVER_IMPL_ATTEMPT_FINISHED)
 
 // This is logged for a request when it's attached to a
-// HostResolverImpl::Job.  When this occurs without a preceding
+// HostResolverImpl::Job. When this occurs without a preceding
 // HOST_RESOLVER_IMPL_CREATE_JOB entry, it means the request was attached to an
 // existing HostResolverImpl::Job.
 //
-// If the BoundNetLog used to create the event has a valid source id, the BEGIN
-// phase contains the following parameters:
+// The event contains the following parameters:
 //
 //   {
 //     "source_dependency": <Source identifier for the attached Job>,
 //   }
+//
+// This event is also logged for the job to which the request is attached.
+// In that case, the event contains the following parameters:
+//
+//   {
+//     "source_dependency": <Source identifier for the attached Request>,
+//     "priority": <New priority of the job>,
+//   }
 EVENT_TYPE(HOST_RESOLVER_IMPL_JOB_ATTACH)

[mmenke, 2012/01/26 16:54:10]

nit:  I suggest you use different events for the request and the job.  Maybe
HOST_RESOLVER_IMPL_REQUEST_ATTACH / HOST_RESOLVER_IMPL_REQUEST_DETACH for the
job.  Just makes the relationship a little more explicit.

 
-// The creation/completion of a host resolve (DNS) job.
+// This is logged for a request when it's canceled and detached from a

[mmenke, 2012/01/26 16:54:10]

nit:  It's logged for the job when a request is cancelled and detached.

+// HostResolverImpl::Job.
+//
+// The event contains the following parameters:
+//
+//   {
+//     "source_dependency": <Source identifier for the detached Request>,
+//     "priority": <New priority of the job>,
+//   }
+EVENT_TYPE(HOST_RESOLVER_IMPL_JOB_DETACH)
+
+// The creation/completion of a HostResolverImpl::ProcTask to call getaddrinfo.

[mmenke, 2012/01/26 16:54:10]

There's also an event of the same name logged for the job when we create the
ProcTask, which has yet more parameters not mentioned here.  Suggest you rename
it (And then document it) to keep the docs here from getting too complicated.

 // The BEGIN phase contains the following parameters:
 //
 //   {
-//     "host": <Hostname associated with the request>,
-//     "source_dependency": <Source id, if any, of what created the request>,
+//     "hostname": <Hostname associated with the request>,
+//     "source_dependency": <Source id of parent HostResolverImpl::Job>,
 //   }
 //
 // On success, the END phase has these parameters:
@@ -138,7 +170,7 @@ EVENT_TYPE(HOST_RESOLVER_IMPL_JOB_ATTACH)
 //     "net_error": <The net error code integer for the failure>,
 //     "os_error": <The exact error code integer that getaddrinfo() returned>,
 //   }
-EVENT_TYPE(HOST_RESOLVER_IMPL_JOB)
+EVENT_TYPE(HOST_RESOLVER_IMPL_PROC_TASK)
 
 // ------------------------------------------------------------------------
 // InitProxyResolver