Index: source/Plugins/OperatingSystem/Python/OperatingSystemPython.cpp
===================================================================
--- source/Plugins/OperatingSystem/Python/OperatingSystemPython.cpp
+++ source/Plugins/OperatingSystem/Python/OperatingSystemPython.cpp
@@ -156,9 +156,10 @@
 
   Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_OS));
 
-  // First thing we have to do is to try to get the API lock, and the run lock.
-  // We're going to change the thread content of the process, and we're going
-  // to use python, which requires the API lock to do it.
+  // First thing we have to do is to try to get the API lock, and the
+  // interpreter lock. We're going to change the thread content of the process,
+  // and we're going to use python, which requires the API lock to do it. We
+  // need the interpreter lock to make sure thread_info_dict stays alive.
   //
   // If someone already has the API lock, that is ok, we just want to avoid
   // external code from making new API calls while this call is happening.
@@ -166,9 +167,10 @@
   // This is a recursive lock so we can grant it to any Python code called on
   // the stack below us.
   Target &target = m_process->GetTarget();
-  std::unique_lock<std::recursive_mutex> lock(target.GetAPIMutex(),
-                                              std::defer_lock);
-  lock.try_lock();
+  std::unique_lock<std::recursive_mutex> api_lock(target.GetAPIMutex(),
+                                                  std::defer_lock);
+  api_lock.try_lock();
+  auto interpreter_lock = m_interpreter->AcquireInterpreterLock();
 
   if (log)
     log->Printf("OperatingSystemPython::UpdateThreadList() fetching thread "
@@ -176,12 +178,8 @@
                 m_process->GetID());
 
   // The threads that are in "new_thread_list" upon entry are the threads from
-  // the
-  // lldb_private::Process subclass, no memory threads will be in this list.
-
-  auto interpreter_lock =
-      m_interpreter
-          ->AcquireInterpreterLock(); // to make sure threads_list stays alive
+  // the lldb_private::Process subclass, no memory threads will be in this
+  // list.
   StructuredData::ArraySP threads_list =
       m_interpreter->OSPlugin_ThreadsInfo(m_python_object_sp);
 
@@ -301,20 +299,24 @@
   if (!IsOperatingSystemPluginThread(thread->shared_from_this()))
     return reg_ctx_sp;
 
-  // First thing we have to do is get the API lock, and the run lock.  We're
-  // going to change the thread
-  // content of the process, and we're going to use python, which requires the
-  // API lock to do it.
-  // So get & hold that.  This is a recursive lock so we can grant it to any
-  // Python code called on the stack below us.
+  // First thing we have to do is to try to get the API lock, and the
+  // interpreter lock. We're going to change the thread content of the process,
+  // and we're going to use python, which requires the API lock to do it. We
+  // need the interpreter lock to make sure thread_info_dict stays alive.
+  //
+  // If someone already has the API lock, that is ok, we just want to avoid
+  // external code from making new API calls while this call is happening.
+  //
+  // This is a recursive lock so we can grant it to any Python code called on
+  // the stack below us.
   Target &target = m_process->GetTarget();
-  std::lock_guard<std::recursive_mutex> guard(target.GetAPIMutex());
+  std::unique_lock<std::recursive_mutex> api_lock(target.GetAPIMutex(),
+                                                  std::defer_lock);
+  api_lock.try_lock();
+  auto interpreter_lock = m_interpreter->AcquireInterpreterLock();
 
   Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_THREAD));
 
-  auto lock =
-      m_interpreter
-          ->AcquireInterpreterLock(); // to make sure python objects stays alive
   if (reg_data_addr != LLDB_INVALID_ADDRESS) {
     // The registers data is in contiguous memory, just create the register
     // context using the address provided
@@ -383,18 +385,21 @@
                 tid, context);
 
   if (m_interpreter && m_python_object_sp) {
-    // First thing we have to do is get the API lock, and the run lock.  We're
-    // going to change the thread
-    // content of the process, and we're going to use python, which requires the
-    // API lock to do it.
-    // So get & hold that.  This is a recursive lock so we can grant it to any
-    // Python code called on the stack below us.
+    // First thing we have to do is to try to get the API lock, and the
+    // interpreter lock. We're going to change the thread content of the
+    // process, and we're going to use python, which requires the API lock to
+    // do it. We need the interpreter lock to make sure thread_info_dict stays
+    // alive.
+    //
+    // If someone already has the API lock, that is ok, we just want to avoid
+    // external code from making new API calls while this call is happening.
+    //
+    // This is a recursive lock so we can grant it to any Python code called on
+    // the stack below us.
     Target &target = m_process->GetTarget();
     std::lock_guard<std::recursive_mutex> guard(target.GetAPIMutex());
+    auto interpreter_lock = m_interpreter->AcquireInterpreterLock();
 
-    auto lock = m_interpreter->AcquireInterpreterLock(); // to make sure
-                                                         // thread_info_dict
-                                                         // stays alive
     StructuredData::DictionarySP thread_info_dict =
         m_interpreter->OSPlugin_CreateThread(m_python_object_sp, tid, context);
     std::vector<bool> core_used_map;