[Lldb-commits] [PATCH] D122975: parallelize calling of Module::PreloadSymbols()

[Luboš Luňák via Phabricator via lldb-commits]

llunak updated this revision to Diff 420492.
llunak retitled this revision from "parallelize module loading in  DynamicLoaderPOSIXDYLD()" to "parallelize calling of Module::PreloadSymbols()".
llunak edited the summary of this revision.
llunak added a reviewer: jingham.
llunak added a comment.

Ok, parallelizing of only Module::PreloadSymbols() was simpler than I expected and it also works, so I've reworked the patch to do that.

This change now requires D123128 <https://reviews.llvm.org/D123128> and also adding the grouping ability to ThreadPool, which I haven't done yet.


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D122975/new/

https://reviews.llvm.org/D122975

Files:
  lldb/source/Target/Target.cpp


Index: lldb/source/Target/Target.cpp
===================================================================
--- lldb/source/Target/Target.cpp
+++ lldb/source/Target/Target.cpp
@@ -62,6 +62,7 @@
 
 #include "llvm/ADT/ScopeExit.h"
 #include "llvm/ADT/SetVector.h"
+#include "llvm/Support/ThreadPool.h"
 
 #include <memory>
 #include <mutex>
@@ -1623,6 +1624,17 @@
 void Target::ModulesDidLoad(ModuleList &module_list) {
   const size_t num_images = module_list.GetSize();
   if (m_valid && num_images) {
+    if (GetPreloadSymbols()) {
+      // Try to preload symbols in parallel.
+      llvm::ThreadPool pool(llvm::optimal_concurrency(num_images));
+      auto preload_symbols_fn = [&](size_t idx) {
+        ModuleSP module_sp(module_list.GetModuleAtIndex(idx));
+        module_sp->PreloadSymbols();
+      };
+      for (size_t idx = 0; idx < num_images; ++idx)
+        pool.async(preload_symbols_fn, idx);
+      pool.wait();
+    }
     for (size_t idx = 0; idx < num_images; ++idx) {
       ModuleSP module_sp(module_list.GetModuleAtIndex(idx));
       LoadScriptingResourceForModule(module_sp, this);
@@ -2170,11 +2182,6 @@
           });
         }
 
-        // Preload symbols outside of any lock, so hopefully we can do this for
-        // each library in parallel.
-        if (GetPreloadSymbols())
-          module_sp->PreloadSymbols();
-
         llvm::SmallVector<ModuleSP, 1> replaced_modules;
         for (ModuleSP &old_module_sp : old_modules) {
           if (m_images.GetIndexForModule(old_module_sp.get()) !=


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