[lld] [lld][MachO]Multi-threaded i/o. Twice as fast linking a large project. (PR #147134)

[John Holdsworth via llvm-commits]

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@@ -282,11 +284,83 @@ static void saveThinArchiveToRepro(ArchiveFile const *file) {
           ": Archive::children failed: " + toString(std::move(e)));
 }
 
-static InputFile *addFile(StringRef path, LoadType loadType,
-                          bool isLazy = false, bool isExplicit = true,
-                          bool isBundleLoader = false,
-                          bool isForceHidden = false) {
-  std::optional<MemoryBufferRef> buffer = readFile(path);
+class DeferredFile {
+public:
+  StringRef path;
+  bool isLazy;
+  std::optional<MemoryBufferRef> buffer;
+  const char *start;
+  size_t size;
+};
+using DeferredFiles = std::vector<DeferredFile>;
+
+class PageInState {
+  DeferredFiles deferred;
+  size_t counter = 0, total = 0, pageSize;
+  std::mutex mutex, *busy;
+
+public:
+  PageInState(DeferredFiles &deferred, std::mutex *busy) {
+    this->deferred = deferred;
+    this->busy = busy;
+    pageSize = llvm::sys::Process::getPageSizeEstimate();
+  }
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johnno1962 wrote:

Thanks for you detailed feedback. I've addressed your points below.

https://github.com/llvm/llvm-project/pull/147134