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[find-all-symbols] Parallelize the merge step. 

There is still more parallelism to get here because we synchonize on the
actual uniquing but just doing YAML parsing in parallel already gives a
significant speedup.

Merging all symbols in LLVM+clang+compiler-rt+lld+libc++, 48 cores.
before: 201.55s user 1.47s system 99% cpu 3:23.04 total
after:  276.99s user 7.63s system 838% cpu 33.947 total

Differential Revision: http://reviews.llvm.org/D19720

llvm-svn: 268037
This commit is contained in:
Benjamin Kramer 2016-04-29 12:46:27 +00:00
parent 9db710a171
commit 683e592ff3
1 changed files with 28 additions and 15 deletions
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43
clang-tools-extra/include-fixer/find-all-symbols/tool/FindAllSymbolsMain.cpp
View File

@ -14,8 +14,9 @@
#include "clang/Tooling/CommonOptionsParser.h"
#include "clang/Tooling/Tooling.h"
#include "llvm/Support/Path.h"
#include "llvm/Support/ThreadPool.h"
#include <map>
#include <mutex>
#include <string>
#include <vector>
@ -76,26 +77,38 @@ private:
bool Merge(llvm::StringRef MergeDir, llvm::StringRef OutputFile) {
std::error_code EC;
std::set<SymbolInfo> UniqueSymbols;
std::mutex SymbolMutex;
auto AddSymbols = [&](ArrayRef<SymbolInfo> Symbols) {
// Synchronize set accesses.
std::unique_lock<std::mutex> LockGuard(SymbolMutex);
UniqueSymbols.insert(Symbols.begin(), Symbols.end());
};
// Load all symbol files in MergeDir.
for (llvm::sys::fs::directory_iterator Dir(MergeDir, EC), DirEnd;
Dir != DirEnd && !EC; Dir.increment(EC)) {
int ReadFD = 0;
if (llvm::sys::fs::openFileForRead(Dir->path(), ReadFD)) {
llvm::errs() << "Cann't open " << Dir->path() << "\n";
continue;
{
llvm::ThreadPool Pool;
for (llvm::sys::fs::directory_iterator Dir(MergeDir, EC), DirEnd;
Dir != DirEnd && !EC; Dir.increment(EC)) {
// Parse YAML files in parallel.
Pool.async(
[&AddSymbols](std::string Path) {
auto Buffer = llvm::MemoryBuffer::getFile(Path);
if (!Buffer) {
llvm::errs() << "Can't open " << Path << "\n";
return;
}
std::vector<SymbolInfo> Symbols =
ReadSymbolInfosFromYAML(Buffer.get()->getBuffer());
// FIXME: Merge without creating such a heavy contention point.
AddSymbols(Symbols);
},
Dir->path());
}
auto Buffer = llvm::MemoryBuffer::getOpenFile(ReadFD, Dir->path(), -1);
if (!Buffer)
continue;
std::vector<SymbolInfo> Symbols =
ReadSymbolInfosFromYAML(Buffer.get()->getBuffer());
for (const auto &Symbol : Symbols)
UniqueSymbols.insert(Symbol);
}
llvm::raw_fd_ostream OS(OutputFile, EC, llvm::sys::fs::F_None);
if (EC) {
llvm::errs() << "Cann't open '" << OutputFile << "': " << EC.message()
llvm::errs() << "Can't open '" << OutputFile << "': " << EC.message()
<< '\n';
return false;
}