For reasons which are unclear, but possibly due to lack of any known use cases
when the code was written, LUL on i686/x86_64-linux only accepts CFA (canonical
frame address) expressions of the form SP+offset or FP+offset. However, on
Fedora 25 x86_64 and Ubuntu 16.10 x86_64, at least one address range per object
uses a Dwarf expression for the CFA, for example:
00000018 000000000024 0000001c FDE cie=00000000 pc=0000000031e0..0000000031f0
DW_CFA_def_cfa_offset: 16
DW_CFA_advance_loc: 6 to 00000000000031e6
DW_CFA_def_cfa_offset: 24
DW_CFA_advance_loc: 10 to 00000000000031f0
DW_CFA_def_cfa_expression(
DW_OP_breg7 (rsp): 8; DW_OP_breg16 (rip): 0; DW_OP_lit15; DW_OP_and;
DW_OP_lit11; DW_OP_ge; DW_OP_lit3; DW_OP_shl; DW_OP_plus)
producing the following complaint from LUL:
can't summarise: SVMA=0x31f0: rule for DW_REG_CFA: invalid |how|, expr=LExpr(PFXEXPR,0,0)
Given that LUL is capable of handling such a CFA expression, it seems artificial
to stop it doing so. This patch changes Summariser::Rule() so as to allow such
expressions.
PseudoStack requires that startJSSampling() and stopJSSampling() calls be
interleaved. But currently the conditions guarding those calls don't match:
startJSSampling() is guarded by ShouldProfileThread(), and stopJSSampling() is
guarded by HasProfile().
It's possible for HasProfile() to be true when ShouldProfileThread() is not
true -- e.g. profile many threads, then restart and profile fewer threads, and
we end up with live threads that have a profile but aren't being profiled right
now -- which leads to assertion failures in stopJSSampling().
This patch makes the stopJSSampling() condition use ShouldProfileThread(), just
like the startJSSampling() condition, which fixes the assertion failure.
--HG--
extra : rebase_source : e9931928c8ac1301f5018f9da319bc478722b98e
LUL doesn't read CFI from the main executable on x86_64-linux, and possibly
other Linux variants, because SharedLibraryInfo::GetInfoForSelf() doesn't
produce a name for the main executable object, even though it does notice the
mapping.
This causes noticeable unwind breakage because the main executable on Linux
contains various wrapper functions pertaining to memory allocation and locking,
such as
moz_xmalloc, moz_xcalloc, moz_xrealloc
mozilla::detail::MutexImpl::lock, mozilla::detail::MutexImpl::unlock
and is generally observable on x86_64-Linux as unwinding failures out of
functions with addresses around 0x40xxxx, since that's the traditional load
address for the main executable.
This patch modifies the Linux implementation of GetInfoForSelf() so as to
harvest the main executable's name from /proc/self/maps. This is then added
into the information acquired from dl_iterate_phdr. As a result
GetInfoForSelf() does correctly report the executable name, so LUL reads Dwarf
unwind info from it, and the abovementioned unwinding failures disappear.
--HG--
extra : rebase_source : 267c6d7c3967a4d29f8ff0b4a91d339a6625085d
Pick up autofix improvements in 3.19.0. Upgrade eslint-plugin-react. Also fix issues with the package.json file and the ESLint node_modules upload script.
MozReview-Commit-ID: IDZ1n4qTTuv
--HG--
extra : rebase_source : aa97cd6f314ce10d16d12446e50a27d6f994a9f1
shared-linux-libraries.cc is a maze of ifdefs which is hard to navigate, hard to
reason about and gets in the way of making a proper fix for bug 1354546. This
bug is for cleanup only. It should not change any functionality.
The following changes are made:
* adds emacs/vi tab-width lines
* removes the ARRAY_SIZE macro as it appears to be unused
* documents the 3 different configurations, splits #includes accordingly
* comments SharedLibraryInfo::GetInfoForSelf accordingly
* wraps some long lines
* documents in which cases dl_iterate_phdr is used and in which cases
/proc/<pid>/maps is used
* Puts /proc/<pid>/maps reading in its own scope
* Makes the LOG messages on failure clearer
Currently, ThreadInfos for live and dead threads are stored in a single vector.
This patch separates them into two separate vectors.
This ensures that the two kinds of ThreadInfos can't be mixed up. It also means
ThreadInfo::mPendingDelete can be removed.
Currently, when the profiler is active we hold onto the ThreadInfo of all
threads that die. Then when capturing a profile we ignore all threads that
aren't being profiled.
This patch changes things so we only hold onto the ThreadInfos of threads that
die if they are being profiled. In effect it removes state 3 from the following
list of possible ThreadInfo states:
1. !PendingDelete + !HasProfile
2. !PendingDelete + HasProfile
3. PendingDelete + !HasProfile (no longer used)
4. PendingDelete + HasProfile
Now that ThreadResponsiveness is only used on the main thread, we can refactor
ThreadInfo a bit. This patch does the following.
- Removes ThreadInfo::mThread, which is unused.
- Changes ThreadInfo::mRespInfo to a Maybe<>, and moves the is-main-thread
checking outside of ThreadInfo and ThreadResponsiveness.
- Renames {ThreadInfo,TickSample}::mRespInfo as mResponsiveness, to better
match the class name.
The state management is better done within nsProfiler::GetProfileDataAsync()
and nsProfiler::DumpProfileToFileAsync(). (The latter function is new in this
patch.)
This fixes a deadlock.
Other notes:
- The patch moves ProfileGatherer from ProfilerState to nsProfiler. This is
nice because the former is shared between threads but the latter is main
thread only. (This is how the deadlock is avoided.)
- ProfilerStateMutex and PSLockRef are no longer required in platform.h. Those
types and variables are now only used in platform.cpp and platform-*.cpp.
- ProfilerGatherer now calls profiler_get_profile() instead of ToJSON(). Which
means that ToJSON() now has a single caller, so the patch inlines it at the
callsite and removes it.
- profiler_save_profile_to_file_async() dispatched a Runnable to the main
thread. But this wasn't necessary, because it always ran on the main thread
itself. So the new function nsProfiler::DumpProfileToFileAsync() doesn't do
that.
- profiler_will_gather_OOP_profile(), profiler_gathered_OOP_profile(), and
profiler_OOP_exit_profile() are all moved into nsProfiler as well. This
removes the need for the horrible fake lock in
profiler_will_gather_OOP_profile(), hooray!
The conversion to a JSObject is better done within
nsProfiler::GetProfileData().
--HG--
extra : rebase_source : 4a0ba97d99681fca96f2d26b609bafe188095787
This reduces the amount of places where we need to specify the mozilla/frame-script environment. It does have
the side effect of allowing those globals in the whole file, but that is what specifying the environment would
do, and this is also for mochitest test files only.
MozReview-Commit-ID: 1LLFbn6fFJR
--HG--
extra : rebase_source : 82a6934d90bbbbd25f91b7b06bf4f9354e38865a
This retains the advantage of running only once per process, while
avoiding the per-process overhead of a jsm.
MozReview-Commit-ID: 1N53MvRwUpg
--HG--
rename : browser/modules/ContentObservers.jsm => browser/modules/ContentObservers.js
extra : rebase_source : 6a502cff26fcb55526f97385274bbae871f5cc6c
