introduce a BufferedStackTrace class, which owns this array.
Summary:
This change splits __sanitizer::StackTrace class into a lightweight
__sanitizer::StackTrace, which doesn't own array of PCs, and BufferedStackTrace,
which owns it. This would allow us to simplify the interface of StackDepot,
and eventually merge __sanitizer::StackTrace with __tsan::StackTrace.
Test Plan: regression test suite.
Reviewers: kcc, dvyukov
Reviewed By: dvyukov
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D5985
llvm-svn: 220635
Chained origins make plain memory stores async-signal-unsafe.
We already disable it inside signal handlers.
This change grabs all origin-related locks before fork() and releases
them after fork() to avoid a deadlock in the child process.
llvm-svn: 217140
Generalize StackDepot and create a new specialized instance of it to
efficiently (i.e. without duplicating stack trace data) store the
origin history tree.
This reduces memory usage for chained origins roughly by an order of
magnitude.
Most importantly, this new design allows us to put two limits on
stored history data (exposed in MSAN_OPTIONS) that help avoid
exponential growth in used memory on certain workloads.
See comments in lib/msan/msan_origin.h for more details.
llvm-svn: 209284
Alexey Samsonov