Commit Graph

11 Commits

Author SHA1 Message Date
51fc5ed28d fix loop variable usage 2022-11-17 14:33:09 +01:00
d15586390a Lock access to S.cache 2020-01-21 13:38:26 +01:00
d800683dce RunEvery() and better Error-handling added
1. symbolyze.Scanner now implements the RunEvery(time.Duration) method
   that will call scanner.Run() periodically.  It should be called to
   run in its own goroutine.  The loop can be stopped by calling
   scanner.Stop().

2. The scanner now collects all errors from all observers in a private
   error type `errors []error`. It's Error() returns a cumulated list of
   errors, seperated by a newline.
2020-01-18 20:27:23 +01:00
de5bcf9913 Cleanup of the comments 2020-01-16 15:47:16 +01:00
4ba4442100 Better handling of concurrent calls to observers
We now call wg.Add(n) before we loop over n observers.  We also run the
loop inside a goroutine and therefore more quickly handle all (pid,
offset) pairs.
2020-01-16 13:30:41 +01:00
6eebe8c9f4 Only log the errors from observers
Because we call the observers concurrently, we must not write to S.err
inside the goroutines.  For now, we simply log an error from an
observer.
2020-01-16 10:28:01 +01:00
65a8d52b7a Syncronize all observers in Run()
With the introduction of a sync.WaitGroup we now wait for all observers
to finished before Run() returns
2020-01-16 10:18:07 +01:00
edd9212e89 Rename symbolyze.New -> symbolze.NewScanner 2020-01-16 00:13:03 +01:00
32981d6a55 Don't export *log.Logger in Scanner
By introducing a lowercase type alias 'logger' for *log.Logger we can
now embed 'logger' in Scanner and not export it:

 % go doc Scanner
package symbolyze // import "."

type Scanner struct {
	// Has unexported fields.
}
2020-01-15 23:50:09 +01:00
7af1728eed Cleanup done and documtation added
symbolyze.go has been simplified and cleaned up.  It now also is documented,
f.e.:

 % go doc Scanner
package symbolyze // import "."

type Scanner struct {
	*log.Logger // Embedded logger

	// Has unexported fields.
}
    Scanner represents an engine for scanning for a specific symbol in all
    ELF-files matching a certain pattern. The pattern is described in
    fileapth.Match().

    Once a Scanner is created with New(), it should be populated with Observer
    functions using OnFound(). Optionally, the scanner can be put into debugging
    mode by a call to DebugOn() prior to a call to Run().

    A call to Scanner.Run() then starts the engine and it will scan all pids in
    /proc. Whenever a match is found, all observers will be called with the
    (pid, offset), concurrently.

func New(symbol, pathglob string) *Scanner
func (S *Scanner) DebugOn()
func (S *Scanner) OnFound(fun Observer)
func (S *Scanner) Run() error
2020-01-15 23:26:30 +01:00
fb59ca1072 modular solution, first working draft
symbolyze/ now contains a module that exposes a Finder type with a
simple API, like:

	finder := symbolyze.New("_PyRuntime", "*python3*")
	finder.Debug(true)
	finder.OnFound(mapFD.Set)
	finder.Run()

Instead of writing (pid, offset) directly to a eBPF-map, it implements
an observer-pattern and expects a callback.

TODOs/next steps:

	- Write documentation
	- Add tests
	- Experiment and re-evaluate design
2020-01-15 20:42:53 +01:00