[geom] Added optional persistence for TGeoTessellated optimization

[agheata]

Persistence capability of the bvh::v2::Bvh data structure is now enabled. It can be controlled by TGeoTessellated::fgStreamOptimization, which is set to false (not streaming) by default, because although there is a gain in speed (2-3x faster), it is still fast to create the optimization on the fly, even for complex cases (1M facets).

co-authored by @pcanal

This Pull request:

Changes or fixes:

Optionally enables persistence for the tessellated acceleration structure

Checklist:

• tested changes locally
• updated the docs (if necessary)

This PR fixes #

[github-actions]

Test Results

     4 files       4 suites   11h 31m 45s ⏱️
 3 767 tests  3 767 ✅ 0 💤 0 ❌
13 283 runs  13 283 ✅ 0 💤 0 ❌

Results for commit 970b15e.

♻️ This comment has been updated with latest results.

[dpiparo]

The changes seem to have triggered a problem in the creation of the precompiled modules. A proposal to move forward could be to

1. isolate the behaviour in a reproducer, open an issue
2. if possible, simplify the template used in this PR to converge towards its merging

Does it make sense?

[agheata]

The changes seem to have triggered a problem in the creation of the precompiled modules. A proposal to move forward could be to

1. isolate the behaviour in a reproducer, open an issue
2. if possible, simplify the template used in this PR to converge towards its merging

Does it make sense?

The simplification of the template is not an option, as this optimization package is meant to remain an opaque external implementation for BVH. @pcanal is looking into this. If it really does not work, I think we will drop the persistence because the creation of the data structure on the fly is quite fast, so persistence would only benefit setups with a very large number of complex tessellations.

[pcanal]

@aaronj0 The PR fails during the generation of the modules.idx triggers the assert:

#9  0x00007f426d5135e4 in DefinitionFinder::Register (this=0x7ffdae8f8be8, ND=0x37d5998, AddSingleEntry=false) at /github/home/ROOT-CI/src/core/metacling/src/TCling.cxx:1186
1186                      assert(FE->getName().contains("input_line_"));
(gdb) p FE
$6 = {Storage = {<clang::FileMgr::MapEntryOptionalStorage<clang::FileEntryRef>> = {MaybeRef = {ME = 0x2e18a80}}, <No data fields>}}
(gdb) l
1181    #ifndef NDEBUG
1182                      SourceManager &SM = ND->getASTContext().getSourceManager();
1183                      SourceLocation Loc = ND->getLocation();
1184                      OptionalFileEntryRef FE = SM.getFileEntryRefForID(SM.getFileID(Loc));
1185                      (void)FE;
1186                      assert(FE->getName().contains("input_line_"));
1187    #endif
1188                      return;
1189                   }
1190

The stack trace is below. The ND namespace is bvh which is a namespace that contains, intentionally, two forward declared class template (used for one specific instantiation for a persistent pointer).

Do you know how we can solve this issue?

cd /github/home/ROOT-CI/build/lib && ROOT_INCLUDE_PATH= ROOTIGNOREPREFIX=1 ROOT_HIST=0 /github/home/ROOT-CI/build/bin/root.exe -l -q -b
root.exe: /github/home/ROOT-CI/src/core/metacling/src/TCling.cxx:1186: void loadGlobalModuleIndex(cling::Interpreter&)::DefinitionFinder::Register(const clang::NamedDecl*, bool): Assertion `FE->getName().contains("input_line_")' failed.
make[2]: *** [CMakeFiles/modules_idx.dir/build.make:182: lib/modules.idx] Aborted (core dumped)

#9  0x00007f426d5135e4 in DefinitionFinder::Register (this=0x7ffdae8f8be8, ND=0x37d5998, AddSingleEntry=false) at /github/home/ROOT-CI/src/core/metacling/src/TCling.cxx:1186
#10 0x00007f426d513489 in DefinitionFinder::VisitNamedDecl (this=0x7ffdae8f8be8, ND=0x37d5998) at /github/home/ROOT-CI/src/core/metacling/src/TCling.cxx:1167
#11 0x00007f426d5b137c in clang::RecursiveASTVisitor<loadGlobalModuleIndex(cling::Interpreter&)::DefinitionFinder>::WalkUpFromNamedDecl (this=0x7ffdae8f8be8, D=0x37d5998)
    at /github/home/ROOT-CI/build/interpreter/llvm-project/llvm/tools/clang/include/clang/AST/DeclNodes.inc:120
#12 0x00007f426d567dc6 in clang::RecursiveASTVisitor<loadGlobalModuleIndex(cling::Interpreter&)::DefinitionFinder>::WalkUpFromNamespaceDecl (this=0x7ffdae8f8be8, D=0x37d5998)
    at /github/home/ROOT-CI/build/interpreter/llvm-project/llvm/tools/clang/include/clang/AST/DeclNodes.inc:176
#13 0x00007f426d53e128 in clang::RecursiveASTVisitor<loadGlobalModuleIndex(cling::Interpreter&)::DefinitionFinder>::TraverseNamespaceDecl (this=0x7ffdae8f8be8, D=0x37d5998)
    at /github/home/ROOT-CI/src/interpreter/llvm-project/clang/include/clang/AST/RecursiveASTVisitor.h:1685
#14 0x00007f426d535ec8 in clang::RecursiveASTVisitor<loadGlobalModuleIndex(cling::Interpreter&)::DefinitionFinder>::TraverseDecl (this=0x7ffdae8f8be8, D=0x37d5998)
    at /github/home/ROOT-CI/build/interpreter/llvm-project/llvm/tools/clang/include/clang/AST/DeclNodes.inc:176
#15 0x00007f426d55da26 in clang::RecursiveASTVisitor<loadGlobalModuleIndex(cling::Interpreter&)::DefinitionFinder>::TraverseDeclContextHelper (this=0x7ffdae8f8be8, DC=0x1e16f40)
    at /github/home/ROOT-CI/src/interpreter/llvm-project/clang/include/clang/AST/RecursiveASTVisitor.h:1544
#16 0x00007f426d53b05b in clang::RecursiveASTVisitor<loadGlobalModuleIndex(cling::Interpreter&)::DefinitionFinder>::TraverseTranslationUnitDecl (this=0x7ffdae8f8be8, D=0x1e16f18)
    at /github/home/ROOT-CI/src/interpreter/llvm-project/clang/include/clang/AST/RecursiveASTVisitor.h:1649
#17 0x00007f426d535a66 in clang::RecursiveASTVisitor<loadGlobalModuleIndex(cling::Interpreter&)::DefinitionFinder>::TraverseDecl (this=0x7ffdae8f8be8, D=0x1e16f18)
    at /github/home/ROOT-CI/build/interpreter/llvm-project/llvm/tools/clang/include/clang/AST/DeclNodes.inc:24
#18 0x00007f426d51338c in DefinitionFinder::DefinitionFinder (this=0x7ffdae8f8be8, IDs=..., TU=0x1e16f18) at /github/home/ROOT-CI/src/core/metacling/src/TCling.cxx:1152
#19 0x00007f426d513965 in loadGlobalModuleIndex (interp=...) at /github/home/ROOT-CI/src/core/metacling/src/TCling.cxx:1203
#20 0x00007f426d513e35 in RegisterCxxModules (clingInterp=...) at /github/home/ROOT-CI/src/core/metacling/src/TCling.cxx:1274
#21 0x00007f426d516494 in TCling::TCling (this=0x1d89f00, name=0x7f4276062f2b "C++", title=0x7f4276062f15 "cling C++ Interpreter", argv=0x7ffdae8f9be0, interpLibHandle=0x1d17ec0)
    at /github/home/ROOT-CI/src/core/metacling/src/TCling.cxx:1612