similar to: [LLVMdev] Use of statics and ManagedStatics in LLVM

The mutex could be made an actual global static instead of a ManagedStatic. This guarantees it would be constructed before main, and live until the end of main. So even in PassRegistry's destructor, which would get call during llvm_shutdown(), it would always have the same mutex. Ideally I'd like to just delete the mutex, as it doesn't seem like anyone is using it in a

I actually had an idea about how to fix this in a relatively painless manner. Although given my experience over the past 4 days, it might not be best to call it painless without first trying :) The idea is to make a StaticPassRegistry. RegisterPass<> only touches the StaticPassRegistry, and nothing else touches the StaticPassRegistry. So once you enter main(), StaticPassRegistry can be

Hi, We have been investigating an issue when running LTO with our proprietary linker, which links against libLTO dynamically. The issue is that when we pass -time-passes via the lto_codegen_debug_options function in the LTO C API, no time information is produced during compilation. The reason for this is that time information is stored in state owned by a ManagedStatic instance, and is only

+cc original authors of these changes. Is PassRegistry intended to be thread-safe? The header file explicitly says that PassRegistry is not thread-safe, but there are mutexes and locking used in the code. This is actually creating a problem, because of a subtle bug involving static initialization order and shutdown. In particular, the RegisterPass<> static template will get invoked

2017-05-02 8:42 GMT-07:00 Duncan P. N. Exon Smith <dexonsmith at apple.com>: > +Teresa, Mehdi > > On May 2, 2017, at 08:31, James Henderson <jh7370.2008 at my.bristol.ac.uk> > wrote: > > Hi, > > We have been investigating an issue when running LTO with our proprietary > linker, which links against libLTO dynamically. The issue is that when we > pass

Right, I'm suggesting we keep llvm_shutdown() for users who want this control, but also destroy still-live ManagedStatic instances if llvm_shutdown() is not called. This helps in the case where there is not a clear time when llvm_shutdown() can be called, especially given that LLVM cannot be resurrected in the same process due to current limitations in the pass registry, and perhaps

I'm curious about the design rationale for how ManagedStatic instances are cleaned up, and I'm hoping someone can shed some light on it. Currently, ManagedStatic objects are cleaned up when llvm_shutdown() traverses the global list of initialized objects and calls destroy() on each. This leads to two questions: 1. An assertion enforces that the objects are deleted in reverse order of

Hi llvmdev! In our project (Windows, Visual Studio compiler) we've got some frontend which generates LLVM IR. Now I'm observing strange *llvm_shutdown* behavior. If I called it when I was done using the LLVM APIs I saw that destructors of static objects created new ManagedStatic objects, which was never freed. Then I tried to use static global llvm_shutdown_obj to cause destruction

On Thu, May 15, 2014 at 05:39:08PM +0200, mzatko@redhat.com wrote: > + > + pr "gl_recursive_lock_define_initialized(static, global_lock)\n"; static? I suspect this only allows one libguestfs handle per process into the critical section at once. I think the lock needs to be per-handle unless I'm misunderstanding what this is for. Rich. > + pr "\n"; > +

I am trying to figure out how to free up some memory that seems to be lost when running valgrind under our internal application. The stack traces I get are: ==19966== 4 bytes in 1 blocks are still reachable in loss record 1 of 12 ==19966== at 0x402569A: operator new(unsigned int) (vg_replace_malloc.c:255) ==19966== by 0x5D9BBE8: void* llvm::object_creator<llvm::PassRegistry>()

Hi, I found that building LLVM in single-threaded mode with CMake is failing because some object files still have references to pthread routines. There are two instances of the build failure happening. $ cmake .../llvm/ -DLLVM_ENABLE_THREADS=0 $ make -j8 check-all % Linking CXX executable IRTests ../../lib/libgtest.a(gtest.cc.o): In function

Hi, We use LLVM libraries to compile C++ code and noticed slow downs when multiple threads of a process were compiling at once. *perf *indicated that most of the CPU time was spent in a spin lock, which was being locked/unlocked from llvm::PassRegistry::getPassInfo(). We read the relevant LLVM code and found out that PassRegistry is a ManagedStatic and is shared among all threads in case of a

Manish Verma <manish.avtaar at gmail.com> writes: > I am attaching a patch which fixes the above mentioned failures. Could you > please review the patch? [snip] > index 79eb098..6419653 100644 > --- a/unittests/Support/ManagedStatic.cpp > +++ b/unittests/Support/ManagedStatic.cpp > @@ -9,7 +9,7 @@ > #include "llvm/Support/ManagedStatic.h" > #include

Hi all, I observe that r220932 (Removing the static initializer in ManagedStatic.cpp by using llvm_call_once to initialize the ManagedStatic mutex.) is causing tablegen to segfault in PPC platforms during static initialization. The crash happens while calling std::call_once introduced by this patch in the wrapper used in getManagedStaticMutex. I understand this call is buggy for some platforms

From: Maros Zatko <mzatko@redhat.com> Patch adds recursive mutex around C calls, which tries to fix potential race condition in guestfs_umount_local (see [1]). [1] - https://bugzilla.redhat.com/show_bug.cgi?id=917706 Maros Zatko (1): generator: c.ml - wrap non deamon function with recursive mutex generator/c.ml | 12 ++++++++++++ 1 file changed, 12 insertions(+) -- 1.8.5.3

Hi Bill, You can find the same issue in the buildbot: http://lab.llvm.org:8011/builders/clang-ppc64-elf-linux2/builds/16444/steps/compile.llvm.stage2/logs/stdio It is failing for me both in BE (gcc 4.8.2) and LE(4.9.1). I am compiling with clang 3.5, but those are the gcc toolchains I am using. What do you think is the best way to fix this? Thanks! Samuel Bill Schmidt <wschmidt at

On May 17, 2009, at 5:23 AM, Luke Dalessandro wrote: > Owen Anderson wrote: >> >> On May 16, 2009, at 7:47 PM, Luke Dalessandro wrote: >> >>> Also, atomic ops are usually pretty low level things used for >>> nonblocking algorithms or to build higher level locking >>> constructs. Is >>> that the plan here too? It seems like you'd want

Apologies for the noop question in advance (just getting started with LLVM), and I'm not entirely sure if this is the right list to post to. is it? I have some lambda functions as member variables that I want to have my LLVM language make calls to. I've added a mapping to them, but this doesn't seem to enable LLVM to resolve the functions. I asked on stackoverflow but the suggestion

Ok, I'll put a patch together to fix this later today. I'll probably do what Reid was suggesting and use what is already in there for Windows. Thanks, Samuel Bill Schmidt <wschmidt at linux.vnet.ibm.com> wrote on 11/04/2014 12:11:08 PM: > From: Bill Schmidt <wschmidt at linux.vnet.ibm.com> > To: Samuel F Antao/Watson/IBM at IBMUS > Cc: azanella at

On May 16, 2009, at 10:01 PM, Owen Anderson wrote: > OK, I've enhanced Atomic.h by pulling in a bunch of implementations > from libatomic_ops, and others that I could figure out on my own. > > Again, my plea: PLEASE TRY THIS OUT ON YOUR PLATFORM, AND SEND ME > PATCHES IF IT DOESN'T WORK! Similarly, if you think the > implementation could be improved for your