r304285 - [sanitizer] Avoid possible deadlock in child process after fork
r304297 - [sanitizer] Trying to fix MAC buildbots after r304285
These changes create deadlock when Tcl calls pthread_create from a
pthread_atfork child handler. More info in the original review at
https://reviews.llvm.org/D33325
llvm-svn: 304735
This patch addresses https://github.com/google/sanitizers/issues/774. When we
fork a multi-threaded process it's possible to deadlock if some thread acquired
StackDepot or allocator internal lock just before fork. In this case the lock
will never be released in child process causing deadlock on following memory alloc/dealloc
routine. While calling alloc/dealloc routines after multi-threaded fork is not allowed,
most of modern allocators (Glibc, tcmalloc, jemalloc) are actually fork safe. Let's do the same
for sanitizers except TSan that has complex locking rules.
Differential Revision: https://reviews.llvm.org/D33325
llvm-svn: 304285
This reverts commit r250823.
Replacing at least some of empty
constructors with "= default" variants is a semantical change which we
don't want. E.g. __tsan::ClockBlock contains a union of large arrays,
and it's critical for correctness and performance that we don't memset()
these arrays in the constructor.
llvm-svn: 251717