Assign event ids after creation from backends

If we want to merge events coming from different sources (in the
future changes, files), we need to be able to label the events
uniquely across sources so assigning an ID right before an item is
added to the array makes more sense.

src/gpuvis.cpp

@@ -713,6 +713,9 @@ int TraceEvents::new_event_cb( const trace_event_t &event )
     // Add event to our m_events array
     m_events.push_back( event );
 
+    // Assign an event id
+    m_events.back().id = m_events.size() - 1;
+
     // If this is a sched_switch event, see if it has comm info we don't know about.
     // This is the reason we're initializing events in two passes to collect all this data.
     if ( event.is_sched_switch() )

src/gpuvis_etl.cpp

@@ -628,7 +628,6 @@ class etl_parser_t
         , mTraceInfo( trace_info )
         , mCallback( cb )
         , mReader( file,  process_event_cb_proxy, this )
-        , mCurrentEventId( 0 )
         , mStartTicks( 0 )
         , mAdapterCount( 0 )
         , mCrtcCount( 0 )
@@ -717,7 +716,6 @@ class etl_parser_t
     EventCallback &mCallback;
 
     etl_reader_t mReader;
-    uint32_t mCurrentEventId;
     uint64_t mStartTicks;
 
     std::unordered_map<uint64_t, int> mAdapterMap;
@@ -827,7 +825,6 @@ class etl_parser_t
         }
 
         event.pid = entry.tid;
-        event.id = mCurrentEventId++;
         event.cpu = entry.cpu;
         event.ts = ticks_to_relative_us( entry.ts );
         event.comm = comm;

src/trace-cmd/trace-read.cpp

@@ -1584,7 +1584,6 @@ class trace_data_t
     trace_info_t &trace_info;
     StrPool &strpool;
 
-    uint32_t events = 0;
     const char *seqno_str;
     const char *crtc_str;
     const char *ip_str;
@@ -1648,7 +1647,6 @@ static int trace_enum_events( trace_data_t &trace_data, tracecmd_input_t *handle
         trace_seq_init( &seq );
 
         trace_event.pid = pid;
-        trace_event.id = trace_data.events++;
         trace_event.cpu = record->cpu;
         trace_event.ts = record->ts - trace_data.trace_info.min_file_ts;