initEventTraceProps builds the trace properties descriptor which influences the behaviour of event publishing to the trace session buffers.
(c config.EventSourceConfig)
| 35 | // influences the behaviour of event publishing to the trace session |
| 36 | // buffers. |
| 37 | func initEventTraceProps(c config.EventSourceConfig) etw.EventTraceProperties { |
| 38 | bufferSize := c.BufferSize |
| 39 | if bufferSize > maxBufferSize { |
| 40 | bufferSize = maxBufferSize |
| 41 | } |
| 42 | // validate min/max buffers. The minimal |
| 43 | // number of buffers is 2 per CPU logical core |
| 44 | minBuffers := c.MinBuffers |
| 45 | if minBuffers < uint32(runtime.NumCPU()*2) { |
| 46 | minBuffers = uint32(runtime.NumCPU() * 2) |
| 47 | } |
| 48 | maxBuffers := c.MaxBuffers |
| 49 | maxBuffersAllowed := minBuffers + 20 |
| 50 | if maxBuffers > maxBuffersAllowed { |
| 51 | maxBuffers = maxBuffersAllowed |
| 52 | } |
| 53 | if minBuffers > maxBuffers { |
| 54 | minBuffers = maxBuffers - 20 |
| 55 | } |
| 56 | flushTimer := c.FlushTimer |
| 57 | if flushTimer < time.Second { |
| 58 | flushTimer = time.Second |
| 59 | } |
| 60 | |
| 61 | mode := uint32(etw.ProcessTraceModeRealtime) |
| 62 | |
| 63 | return etw.EventTraceProperties{ |
| 64 | Wnode: etw.WnodeHeader{ |
| 65 | BufferSize: uint32(unsafe.Sizeof(etw.EventTraceProperties{})) + maxTracePropsSize, |
| 66 | Flags: etw.WnodeTraceFlagGUID, |
| 67 | ClientContext: 1, // QPC clock resolution |
| 68 | }, |
| 69 | BufferSize: bufferSize, |
| 70 | LogFileMode: mode, |
| 71 | MinimumBuffers: minBuffers, |
| 72 | MaximumBuffers: maxBuffers, |
| 73 | FlushTimer: uint32(flushTimer.Seconds()), |
| 74 | } |
| 75 | } |
| 76 | |
| 77 | // ProviderInfo describes ETW provider metadata. |
| 78 | type ProviderInfo struct { |