We were accessing the ModuleList in the target without locking it for tasks like

setting breakpoints.  That's dangerous, since while we are setting a breakpoint,
the target might hit the dyld load notification, and start removing modules from
the list.  This change adds a GetMutex accessor to the ModuleList class, and
uses it whenever we are accessing the target's ModuleList (as returned by GetImages().)

<rdar://problem/11552372>

llvm-svn: 157668

3 files changed, 14 insertions, 10 deletions

diff --git a/lldb/source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCRuntime.cpp b/lldb/source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCRuntime.cpp
index 1cb7ab8eef9..a2bc88872c1 100644
--- a/lldb/source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCRuntime.cpp
+++ b/lldb/source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCRuntime.cpp
@@ -263,11 +263,13 @@ AppleObjCRuntime::GetObjCVersion (Process *process, ModuleSP &objc_module_sp)
         return eObjC_VersionUnknown;
         
     Target &target = process->GetTarget();
-    ModuleList &images = target.GetImages();
-    size_t num_images = images.GetSize();
+    ModuleList &target_modules = target.GetImages();
+    Mutex::Locker modules_locker(target_modules.GetMutex());
+    
+    size_t num_images = target_modules.GetSize();
     for (size_t i = 0; i < num_images; i++)
     {
-        ModuleSP module_sp = images.GetModuleAtIndex(i);
+        ModuleSP module_sp = target_modules.GetModuleAtIndexUnlocked(i);
         // One tricky bit here is that we might get called as part of the initial module loading, but
         // before all the pre-run libraries get winnowed from the module list.  So there might actually
         // be an old and incorrect ObjC library sitting around in the list, and we don't want to look at that.
diff --git a/lldb/source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCSymbolVendor.cpp b/lldb/source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCSymbolVendor.cpp
index ff135806f28..00c90c6eacd 100644
--- a/lldb/source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCSymbolVendor.cpp
+++ b/lldb/source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCSymbolVendor.cpp
@@ -43,13 +43,14 @@ AppleObjCSymbolVendor::FindTypes (const SymbolContext& sc,
     
     uint32_t ret = 0;
     
-    ModuleList &images = m_process->GetTarget().GetImages();
+    ModuleList &target_modules = m_process->GetTarget().GetImages();
+    Mutex::Locker modules_locker(target_modules.GetMutex());
     
-    for (size_t image_index = 0, end_index = images.GetSize();
+    for (size_t image_index = 0, end_index = target_modules.GetSize();
          image_index < end_index;
          ++image_index)
     {
-        Module *image = images.GetModulePointerAtIndex(image_index);
+        Module *image = target_modules.GetModulePointerAtIndexUnlocked(image_index);
         
         if (!image)
             continue;
diff --git a/lldb/source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCTrampolineHandler.cpp b/lldb/source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCTrampolineHandler.cpp
index f8cab06732d..54eda8bddf5 100644
--- a/lldb/source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCTrampolineHandler.cpp
+++ b/lldb/source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCTrampolineHandler.cpp
@@ -334,15 +334,16 @@ AppleObjCTrampolineHandler::AppleObjCVTables::InitializeVTableSymbols ()
         return true;
     Target &target = m_process_sp->GetTarget();
     
-    ModuleList &modules = target.GetImages();
-    size_t num_modules = modules.GetSize();
+    ModuleList &target_modules = target.GetImages();
+    Mutex::Locker modules_locker(target_modules.GetMutex());
+    size_t num_modules = target_modules.GetSize();
     if (!m_objc_module_sp)
     {
         for (size_t i = 0; i < num_modules; i++)
         {
-            if (m_process_sp->GetObjCLanguageRuntime()->IsModuleObjCLibrary (modules.GetModuleAtIndex(i)))
+            if (m_process_sp->GetObjCLanguageRuntime()->IsModuleObjCLibrary (target_modules.GetModuleAtIndexUnlocked(i)))
             {
-                m_objc_module_sp = modules.GetModuleAtIndex(i);
+                m_objc_module_sp = target_modules.GetModuleAtIndexUnlocked(i);
                 break;
             }
         }