This is the start of a ring buffer to coordinate between processes without
the overhead of writing directly to files within the inferior process.
Instead, the parent process can monitor the ring buffer for framing
information and pass that along to the capture writer.
This brings over some of the techniques from the old memprof design.
Sysprof and memprof shared a lot of code, so it is pretty natural to
bring back the same callgraph view based on memory allocations.
This reuses the StackStash just like it did in memprof. While it
would be nice to reuse some existing tools out there, the fit of
memprof with sysprof is so naturally aligned, it's not really a
big deal to bring back the LD_PRELOAD. The value really comes
from seeing all this stuff together instead of multiple apps.
There are plenty of things we can implement on top of this that
we are not doing yet such as temporary allocations, cross-thread
frees, graphing the heap, and graphing differences between the
heap at to points in time. I'd like all of these things, given
enough time to make them useful.
This is still a bit slow though due to the global lock we take
to access the writer. To improve the speed here we need to get
rid of that lock and head towards a design that allows a thread
to request a new writer from Sysprof and save it in TLS (to be
destroyed when the thread exits).
The goal here is to be able to locate all of the debug directories for
active flatpak runtimes so that we can possibly decode debug libraries
from them (after verifying build-id/CRC).
The goal of this helper is to simplify the process of parsing information
about mounts and the mountinfo for per-process maps. We should be able
to change sysprof-proc-source to use this and have better support for
getting the libraries within different mount namespaces.
This comprises a massive rewrite of the UI for browsing captures. We use
the SysprofAid class to scan capture files for content and then auto-
matically add visualizers and details pages.
To avoid breaking things incrementally, we just land this as a very large
commit. Not necessarily ideal, but given the amount of stuff that could
break, this is easier.
As part of this process, we're removing a lot of the surface API so that
we can limit how much we need to maintain in terms of ABI.
This doesn't make profiling useful in any way, but it does get things
to the point where I can actually open a capture file. And it would
be nice if we could progress to the point of loading capture files
(with correct data in-tact) and this helps us move down that path.
To really do that correctly, we should make some of the widgetry
disabled when it isn't useful. We also need to ensure that we add extra
decoding information to capture files during shutdown so that any
platform can read it back. This would also help the situation of
running and reading on separate architectures.
The big thing going on here is that we are going to split up the libraries
a bit better, and remove GObject from the capture library. The libsysprof
library will bring in the capture library statically, so we can export the
symbols we want.
Eventually, we will bump the version to sysprof-3, but not yet.
