diff options
| author | Stefan Sauer <ensonic@users.sf.net> | 2013-10-23 18:16:54 +0200 |
|---|---|---|
| committer | Stefan Sauer <ensonic@users.sf.net> | 2013-10-25 20:05:03 +0200 |
| commit | 0089bcd3e211b2d250a66b2faaffef120e8f4cbd (patch) | |
| tree | effddc9d5b23eb2c6e4a7ed8efb5c8155bba5e05 | |
| parent | bbc26fffc26b38dc6c83702d1ff1c969f33e60dc (diff) | |
design: flesh out the tracing design a little more
| -rw-r--r-- | docs/design/draft-tracing.txt | 15 |
1 files changed, 12 insertions, 3 deletions
diff --git a/docs/design/draft-tracing.txt b/docs/design/draft-tracing.txt index 39c20fbdf..6867d4fa9 100644 --- a/docs/design/draft-tracing.txt +++ b/docs/design/draft-tracing.txt @@ -27,18 +27,27 @@ GST_TRACER_PUSH_BUFFER (pad, buffer) If tracing is disable at compile time the macro will evaluate to nothing. Otherwise it will become something along the lines of: -if (__tracer) { +if (__tracer && __tracer_hook_is_used) { gst_tracer_push_buffer (pad, buffer); } +TODO(ensonic): we should eval if we can use something like jump_label in the kernel +- http://lwn.net/Articles/412072/ + http://lwn.net/Articles/435215/ +- http://lxr.free-electrons.com/source/kernel/jump_label.c +- http://lxr.free-electrons.com/source/include/linux/jump_label.h +- http://lxr.free-electrons.com/source/arch/x86/kernel/jump_label.c +TODO(ensonic): liblttng-ust provides such a mechanism for user-space +- but this is mostly about logging traces +- it is linux specific :/ + In addition to api hooks we should also provide timer hooks. Interval timers are useful to get e.g. resource usage snapshots. Also absolute timers might make sense. Plugins can attach handlers to one or more hooks. When a hook such as gst_tracer_push_buffer () is called it will take a timestamp and call all attached handlers. Hooks will be called from misc threads. The trace plugins should only -consume the provided data. Most trace plugins will log data to a trace channel. - +consume (=read) the provided data. Most trace plugins will log data to a trace +channel. TODO(ensonic): use GSignal for the hooks? |