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Diffstat (limited to 'doc/HACKING/Tracing.md')
| -rw-r--r-- | doc/HACKING/Tracing.md | 12 |
1 files changed, 6 insertions, 6 deletions
diff --git a/doc/HACKING/Tracing.md b/doc/HACKING/Tracing.md index 24fa761310..e1e97abe6d 100644 --- a/doc/HACKING/Tracing.md +++ b/doc/HACKING/Tracing.md @@ -1,16 +1,16 @@ -# Tracing # +# Tracing This document describes how the event tracing subsystem works in tor so developers can add events to the code base but also hook them to an event tracing framework. -## Basics ### +## Basics Event tracing is separated in two concepts, trace events and a tracer. The tracing subsystem can be found in `src/trace`. The `events.h` header file is the main file that maps the different tracers to trace events. -### Events ### +### Events A trace event is basically a function from which we can pass any data that we want to collect. In addition, we specify a context for the event such as @@ -39,7 +39,7 @@ How `argc` is collected or used has nothing to do with the instrumentation the trace events and collection framework (tracer) are decoupled. You _can_ have trace events without a tracer. -### Tracer ### +### Tracer In `src/trace/events.h`, we map the `tor_trace()` function to the right tracer. A tracer support is only enabled at compile time. For instance, the @@ -47,7 +47,7 @@ file `src/trace/debug.h` contains the mapping of the generic tracing function `tor_trace()` to the `log_debug()` function. More specialized function can be mapped depending on the tracepoint. -## Build System ## +## Build System This section describes how it is integrated into the build system of tor. @@ -66,7 +66,7 @@ configure option: --enable-tracing-debug -## Instrument Tor ## +## Instrument Tor This is pretty easy. Let's say you want to add a trace event in `src/feature/rend/rendcache.c`, you only have to add this include statement: |