The goal here is to break up libsysprof into a library for recording
profiles (using libsysprof-capture) and a library for analyzing profiles
(both used by the sysprof UI).
This adds a GListModel that we can use to load capture files. The goal here
is to map the entire capture into memory so we can avoid reading lots of
buffers. That also allows for the model items to live as long as the model
is alive (or underlying file map, really).
The next goal is to stack features on top of this such as implementing the
callgraph as a filter of the model, or generic filters between the
callgraph model and the actual data source model.
Really what we want to deal with here is tracking an overlay that we may
need to be able to decode after the fact (in case processes exit or we
need to do post-processing symbol resolution).
For the podman case, that is $some_path mapped to root (/), generally
speaking. For flatpak though, that would have two mappings, one for
/app and another for /usr (possibly more).
It turns out that /proc/cpuinfo changes out from under us rather frequently
and that makes it a bad use-case for a unit test. This uses meson.build
which presumably wont change while running the tests.
This is all aimed at making it so that sysprof can be built as a
subproject within GLib, with only `libsysprof-capture-4.a` being
produced as output.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
This avoids making the project depend on all its dependencies, some of
which are optional, when being built as a Meson subproject.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
Some minor changes were necessary so that we could change the ABI in
libsysprof-capture to be free from GLib (and therefore used by GLib).
This also adds some wrappers for capture API in libsysprof so that we
can continue to use GError from UI code.
Use `errno` instead, which is icky, but given that all of the failure
modes are from POSIX I/O functions, it’s at least in keeping with them.
This is a major API break.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
Helps: #40
Use `errno` instead, which is icky, but given that all of the failure
modes are from POSIX I/O functions, it’s at least in keeping with them.
This is a major API break.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
Helps: #40
Change `sysprof_capture_reader_read_jitmap()` to return a `const
SysprofCaptureJitmap *` (like the other `read` functions), and add a new
`SysprofCaptureJitmapIter` type to allow easy iteration over the jitmap.
This allows a use of `GHashTable` to be removed from the API. It breaks
the libsysprof-capture API and ABI.
All the callers iterate over the jitmap rather than looking up elements
by key. If that functionality is needed in future, additional API can be
added to allow it on `SysprofCaptureJitmap`.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
Helps: #40
This changes its API and ABI: it now returns an allocated array of const
strings, rather than an allocated array of allocated strings.
The call sites in the source tree have been adjusted accordingly.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
Helps: #40
Another step towards dropping GLib as a dependency of
libsysprof-capture.
Unlike the previous commit which replaced GLib integer types with the
bitwise equivalent C standard types, `stdbool` is potentially a different
width from `gboolean`, so this is an ABI break.
It therefore involves some changes to callback functions in the tests
and tools, and in libsysprof.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
Helps: #40
It has previously been implicitly pulled in by libsysprof-capture, but
that will change in future.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
Helps: #40
This removes the 8 bytes of framing data from the MappedRingBuffer which
means we can write more data without racing. But also this means that we
can eventually use the mapped ring buffer as our normal buffer for
capture writing (to be done later).
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).
