This patch removes the functions llvm_start_multithreaded() and
llvm_stop_multithreaded(), and changes llvm_is_multithreaded()
to return a constant value based on the value of the compile-time
definition LLVM_ENABLE_THREADS.
Previously, it was possible to have compile-time support for
threads on, and runtime support for threads off, in which case
certain mutexes were not allocated or ever acquired. Now, if the
build is created with threads enabled, mutexes are always acquired.
A test before/after patch of compiling a very large TU showed no
noticeable performance impact of this change.
Reviewers: rnk
Differential Revision: http://reviews.llvm.org/D4076
llvm-svn: 210600
Breaks the MSVC build.
DataStream.cpp(44): error C2552: 'llvm::Statistic::Value' : non-aggregates cannot be initialized with initializer list
llvm-svn: 202731
With C++11 we finally have a standardized way to specify atomic operations. Use
them to replace the existing custom implemention. Sadly the translation is not
entirely trivial as std::atomic allows more fine-grained control over the
atomicity. I tried to preserve the old semantics as well as possible.
Differential Revision: http://llvm-reviews.chandlerc.com/D2915
llvm-svn: 202730
This was somewhat tricky because ~PrettyStackTraceEntry() may run after
llvm_shutdown() has been called. This is rare and only happens for a common idiom
used in the main() functions of command-line tools. This works around the idiom by
skipping the stack clean-up if the PrettyStackTraceHead ManagedStatic is not
constructed (i.e. llvm_shutdown() has been called).
llvm-svn: 190730
These annotations are disabled entirely when either ENABLE_THREADS is off, or
building a release build. When enabled, they add calls to functions with no
statements to ManagedStatic's getters.
Use these annotations to inform tsan that the race used inside ManagedStatic
initialization is actually benign. Thanks to Kostya Serebryany for helping
write this patch!
llvm-svn: 144567
