This is a similar concept as `nullptr` is to a pointer.
`BlocksRingBuffer` now skips the first byte in the buffer, so that no entries
start at 0 (the internal default `BlockIndex` value).
All `BlocksRingBuffer` public APIs handle this default value, and do nothing
and/or return Nothing (as if it pointed at an already-deleted entry).
Added tests for this, and for all BlockIndex operations.
Differential Revision: https://phabricator.services.mozilla.com/D38667
--HG--
extra : moz-landing-system : lando
Without declaring them, ModuloBuffer had its copy&move constructor&assignments
defaulted. This means it could have been copied, and then both objects would now
own the same resource and attempt to free it on destruction!
So now:
- Copy construction&assignment are now explicitly disallowed.
- Move assignment is disallowed, to keep some members `const`.
- Move construction is allowed (so a function can return a ModuloBuffer), and
ensures that the moved-from object won't free the resource anymore.
Bonus: `mBuffer` is now `const`, to ensure that it cannot point at something
else, but note the pointed-at bytes are *not* const.
So ModuloBuffer is like an unchanging resource, but it allows to be moved-from
as an xvalue that should not be used after the move.
Differential Revision: https://phabricator.services.mozilla.com/D38665
--HG--
extra : moz-landing-system : lando
By default `ModuloBuffer` allocates its own buffer on the heap.
Now `ModuloBuffer` adds two alternatives:
- Take ownership of a pre-allocated `UniquePtr<uint8_t>` buffer.
- Work over an unowned `uint8_t*` array. The caller is responsible for
ownership, and ensuring that the array lives at least as long as the
`ModuloBuffer`/`BlocksRingBuffer`.
`BlocksRingBuffer` can pass along these new options to its underlying
`ModuloBuffer`.
The main use will be for small on-stack `BlocksRingBuffer` that can store a
stack trace, or to more easily collect data (without allocating anything on the
heap) that can then go into the upcoming `ProfileBuffer`'s `BlocksRingBuffer`.
Differential Revision: https://phabricator.services.mozilla.com/D38285
--HG--
extra : moz-landing-system : lando
This adds to the byte-oriented ModuloBuffer from bug 1563425:
- Thread-safety: All APIs may be called at any time from any thread.
- Structure: The buffer will be divided in "blocks" of different size, with some
block meta-data and space for the user "entry".
- Capable of handling user resources: The user may provide a "deleter" that will
be informed about soon-to-be-destroyed entries; so if some entries reference
outside resources, these references may be properly released.
Note: This first implementation still only allows the user to manipulate bytes
and trivially-copyable objects (same as with the ModuloBuffer iterators). A
follow-up bug will introduce better serialization capabilities, with the aim to
eventually store everything that current Profiler Markers and their payloads
contain.
Differential Revision: https://phabricator.services.mozilla.com/D37702
--HG--
extra : moz-landing-system : lando
As we are increasingly moving toward enabling new types of DLL blocking across
our various process types, we need to be able to generate various headers in
various distinct formats.
This script enables us to use a unified DLL blocklist input that generates
these distinct headers. From WindowsDllBlocklistDefs.in, we generate:
WindowsDllBlocklistA11yDefs.h - definitions for a11y
WindowsDllBlocklistLauncherDefs.h - definitions for the launcher process
WindowsDllBlocklistLegacyDefs.h - definitions for the legacy mozglue blocklist
WindowsDllBlocklistTestDefs.h - test-only definitions
These headers are then exported to mozilla.
Note that not all headers use the same format, as not all consumers of these
headers have identical workings. There will be additional header types added
in the future which diverge even more from the standard blocklist format. While
this work may seem a bit pointless at the moment, it will become more necessary
in the future. In particular, this work is a prerequisite for bug 1238735.
Differential Revision: https://phabricator.services.mozilla.com/D36993
--HG--
extra : moz-landing-system : lando
Since higher-level APIs that we test may depend on lower-level APIs that we
also test, and since those higher-level APIs may spin up background threads
that call those lower-level APIs, we should ensure that tests are ordered
such that the lower-level APIs are hooked first, thus preventing races where
higher-level background threads call lower-level APIs while the test's main
thread is in the midst of hooking a lower-level API.
I also added some fflush calls to the test so that, the next time we see lots
of crashes in this test, the log output is more complete.
Differential Revision: https://phabricator.services.mozilla.com/D37497
--HG--
extra : moz-landing-system : lando
Basic usage:
- Create buffer: `ModuloBuffer mb(PowerOfTwo);`
- Get iterator: `auto writer = mb.WriterAt(Index);` (or `ReaderAt()`)
- Basic iterator functions on bytes: `*++writer = 'x';`
- Write: `writer.WriteULEB128(sizeof(int)); writer.WriteObject<int>(42);`
- Comparisons, move: `while (writer > reader) { --writer; }`
- Read: `size_t s = reader.ReadULEB128<size_t>(); int i = ReadObject<int>();`
There are no safety checks, it will be up to the caller to ensure thread-safety,
and data safety when wrapping around the buffer.
Differential Revision: https://phabricator.services.mozilla.com/D36869
--HG--
extra : moz-landing-system : lando
Bug 1556993 fixed the crash in PoisonIOInterposer (due to missing stdout&stderr
fd's), and bug 1559379 fixed the mozglue memory issue that the unit test
experienced.
So now Base Profiler can be enabled by default on Windows, still using
`MOZ_BASE_PROFILER_...` env-vars for now (upcoming bug will merge these with
non-BASE env-vars soon).
Differential Revision: https://phabricator.services.mozilla.com/D37355
--HG--
extra : moz-landing-system : lando
Now that Gecko Profiler only registers its entry&exit functions when running,
and it ensures that Base Profiler is stopped beforehand, Base Profiler can now
register its own entry&exit functions to capture labels before xpcom starts.
Differential Revision: https://phabricator.services.mozilla.com/D34810
--HG--
extra : moz-landing-system : lando
Profilers will soon be able to set/reset entry&exit functions at different
times, but simultaneously other code may want to use AutoProfilerLabel, so we
need to make this all thread-safe.
All shared static information is now encapsulated in an RAII class that enforces
proper locking before giving access to this information.
Also added a "generation" count, so that if an AutoProfilerLabel is in-flight
when entry&exit functions are changed, the context given by the old entry
function will not be passed to a mismatched new exit function.
Differential Revision: https://phabricator.services.mozilla.com/D34807
--HG--
extra : moz-landing-system : lando
`ProfilingStack*` happens to be the information that the current Gecko Profiler
entry function wants to forward to the exit function, but AutoProfilerLabel does
not really need to know about that.
Changing it to `void*`, so that we can later use different entry/exit functions
that use different context types.
Differential Revision: https://phabricator.services.mozilla.com/D34806
--HG--
extra : moz-landing-system : lando
The new ProfileBuffer data structure will need to store block sizes (usually
small, LEB128 uses fewer bytes for small numbers), and the circular buffer will
provide iterators that hide the wrapping-around.
Differential Revision: https://phabricator.services.mozilla.com/D36473
--HG--
extra : moz-landing-system : lando
PowerOfTwo makes for a cleaner and more expressive interface, showing that the
profiler will use a power-of-2 storage size.
Using PowerOfTwoMask in ProfilerBuffer also makes it more obvious that we want
cheap modulo operations.
And we don't need to keep the original capacity, as it's only used once and can
easily be recomputed from the mask.
Differential Revision: https://phabricator.services.mozilla.com/D36027
--HG--
extra : moz-landing-system : lando
PowerOfTwo stores a power of 2 value, i.e., 2^N.
PowerOfTwoMask stores a mask corresponding to a power of 2, i.e., 2^N-1.
These should be used in places where a power of 2 (or its mask) is stored or
expected.
`% PowerOfTwo{,Mask}` and `& PowerOfTwoMask` operations are optimal.
MakePowerOfTwo{,Mask}<T, Value>() may be used to create statically-checked
constants.
{,Make}PowerOfTwo{,Mask}{32,64} shortcuts for common 32- and 64-bit types.
Differential Revision: https://phabricator.services.mozilla.com/D36026
--HG--
extra : moz-landing-system : lando
PowerOfTwo makes for a cleaner and more expressive interface, showing that the
profiler will use a power-of-2 storage size.
Using PowerOfTwoMask in ProfilerBuffer also makes it more obvious that we want
cheap modulo operations.
And we don't need to keep the original capacity, as it's only used once and can
easily be recomputed from the mask.
Differential Revision: https://phabricator.services.mozilla.com/D36027
--HG--
extra : moz-landing-system : lando
PowerOfTwo stores a power of 2 value, i.e., 2^N.
PowerOfTwoMask stores a mask corresponding to a power of 2, i.e., 2^N-1.
These should be used in places where a power of 2 (or its mask) is stored or
expected.
`% PowerOfTwo{,Mask}` and `& PowerOfTwoMask` operations are optimal.
MakePowerOfTwo{,Mask}<T, Value>() may be used to create statically-checked
constants.
{,Make}PowerOfTwo{,Mask}{32,64} shortcuts for common 32- and 64-bit types.
Differential Revision: https://phabricator.services.mozilla.com/D36026
--HG--
extra : moz-landing-system : lando
BIONIC is only platform that actually supports gettid. Easiest
solution is to check for linux and disable for BIONIC platform. This
includes the change requested by Gerald to keep the two profilers sync'd.
Differential Revision: https://phabricator.services.mozilla.com/D34919
--HG--
extra : moz-landing-system : lando
Update the tests for ARM64 to include additional functions that are now
supported via 4 byte patching.
We also convert the TEST macros to accept the DLL names as strings, as this
works better with clang-format.
Differential Revision: https://phabricator.services.mozilla.com/D32209
--HG--
extra : moz-landing-system : lando
This patch modifies arm64 so that detours are peformed via two passes:
1. The first pass uses a null trampoline to count how many bytes are available
for patching the original function.
2. If we have >= 16 bytes to patch, we reuse existing trampoline space. If we
have less than 16 bytes to patch, we reserve trampoline space within 128MB
of the function, allowing for a 4 byte patch.
3. Then we recurse, this time using a real trampoline.
Note that we still do a single-pass on x86(-64).
Differential Revision: https://phabricator.services.mozilla.com/D32193
--HG--
extra : moz-landing-system : lando
A null trampoline is just a trampoline that is not backed by a VM reservation.
These are used for tracking the number of bytes that are needed to make a patch.
This patch also contains the changes needed to work with TrampolinePool.
Differential Revision: https://phabricator.services.mozilla.com/D32192
--HG--
extra : moz-landing-system : lando
VMSharingPolicyShared needs to become much smarter. This patch modifies that
policy to track different VM reservations and reuse them whenever possible.
We add TrampolinePools to abstract away the differences between VM policies
with respect to the caller who is making the reservation.
Differential Revision: https://phabricator.services.mozilla.com/D32191
--HG--
extra : moz-landing-system : lando
In order to support 4-byte patches on ARM64, we need to be able to reserve
trampoline space within +/- 128 MB of the beginning of a function.
These changes allow us to make such reservations using OS APIs when
available.
Differential Revision: https://phabricator.services.mozilla.com/D32190
--HG--
extra : moz-landing-system : lando
VMSharingPolicyShared needs to become much smarter. This patch modifies that
policy to track different VM reservations and reuse them whenever possible.
We add TrampolinePools to abstract away the differences between VM policies
with respect to the caller who is making the reservation.
Differential Revision: https://phabricator.services.mozilla.com/D32191
--HG--
extra : moz-landing-system : lando
In order to support 4-byte patches on ARM64, we need to be able to reserve
trampoline space within +/- 128 MB of the beginning of a function.
These changes allow us to make such reservations using OS APIs when
available.
Differential Revision: https://phabricator.services.mozilla.com/D32190
--HG--
extra : moz-landing-system : lando
We remove the debugging hooks that were added to check to see whether a DLL
was loaded, as we can just as easily check that by querying the loader itself.
Plus, we shouldn't be exporting a bunch of test-only loader hooks from mozglue
in our release builds, which is what we are currently doing.
We also remove Injector, InjectorDLL, and TestDLLEject, as these tests can
just as easily be done from within TestDllBlocklist by creating a thread with
LoadLibrary* as the entry point. The CreateRemoteThread stuff, while a more
accurate simulation, has no material effect on whether or not the thread
blocking code works.
Differential Revision: https://phabricator.services.mozilla.com/D34444
--HG--
extra : moz-landing-system : lando
We also s/mincore/version/ in OS_LIBS because the former breaks the test on
Windows 7.
Differential Revision: https://phabricator.services.mozilla.com/D34437
--HG--
extra : moz-landing-system : lando
The profiler will require non-fuzzed timers for accuracy. Making the switch early will avoid surprises when FuzzyFox is enabled.
Differential Revision: https://phabricator.services.mozilla.com/D31010
--HG--
extra : moz-landing-system : lando
Start using BaseProfiler in Firefox main(), before&after XPCOM runs.
Also added a BaseProfiler label around Gecko Profiler init/shutdown (so that
samples may be ignored if user is only interested in non-XPCOM profiling).
Main process name changed to "Main Thread (Base Profiler)", so as not to confuse
the front-end, and show where this thread comes from.
Differential Revision: https://phabricator.services.mozilla.com/D31933
--HG--
extra : moz-landing-system : lando
If MOZ_BASE_PROFILER_STARTUP and MOZ_PROFILER_STARTUP are set, this will integrate
a pre-XPCOM startup profile into the main profile.
It is stored as separate threads (in a single JSON string that is moved around),
which will appear as a new track under the main process.
Only adding threads from BaseProfiler means a better integration with Gecko
Profiler profiles, and is more efficient: Less code, and a smaller memory
footprint.
Differential Revision: https://phabricator.services.mozilla.com/D31932
--HG--
extra : moz-landing-system : lando
Running identical (but separate) InitializeWin64ProfilerHooks in both profilers
confuses the DLL interceptor and the 2nd one crashes because of unexpected
opcodes introduced by the 1st one.
If MOZ_BASE_PROFILER is defined, Gecko Profiler will use that implementation of
InitializeWin64ProfilerHooks instead of its own; and that code also has a guard
so that it effectively only run once even if called from both profilers.
Differential Revision: https://phabricator.services.mozilla.com/D31931
--HG--
extra : moz-landing-system : lando
