Import LLVM 10.0.0 release including clang, lld and lldb.

ok hackroom
tested by plenty

1 files changed, 754 insertions, 0 deletions

diff --git a/gnu/llvm/lldb/source/Target/ThreadList.cpp b/gnu/llvm/lldb/source/Target/ThreadList.cpp
new file mode 100644
index 00000000000..183b39c2cfa
--- /dev/null
+++ b/gnu/llvm/lldb/source/Target/ThreadList.cpp
@@ -0,0 +1,754 @@
+//===-- ThreadList.cpp ------------------------------------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include <stdlib.h>
+
+#include <algorithm>
+
+#include "lldb/Target/Process.h"
+#include "lldb/Target/RegisterContext.h"
+#include "lldb/Target/Thread.h"
+#include "lldb/Target/ThreadList.h"
+#include "lldb/Target/ThreadPlan.h"
+#include "lldb/Utility/LLDBAssert.h"
+#include "lldb/Utility/Log.h"
+#include "lldb/Utility/State.h"
+
+using namespace lldb;
+using namespace lldb_private;
+
+ThreadList::ThreadList(Process *process)
+    : ThreadCollection(), m_process(process), m_stop_id(0),
+      m_selected_tid(LLDB_INVALID_THREAD_ID) {}
+
+ThreadList::ThreadList(const ThreadList &rhs)
+    : ThreadCollection(), m_process(rhs.m_process), m_stop_id(rhs.m_stop_id),
+      m_selected_tid() {
+  // Use the assignment operator since it uses the mutex
+  *this = rhs;
+}
+
+const ThreadList &ThreadList::operator=(const ThreadList &rhs) {
+  if (this != &rhs) {
+    // Lock both mutexes to make sure neither side changes anyone on us while
+    // the assignment occurs
+    std::lock(GetMutex(), rhs.GetMutex());
+    std::lock_guard<std::recursive_mutex> guard(GetMutex(), std::adopt_lock);
+    std::lock_guard<std::recursive_mutex> rhs_guard(rhs.GetMutex(), 
+                                                    std::adopt_lock);
+
+    m_process = rhs.m_process;
+    m_stop_id = rhs.m_stop_id;
+    m_threads = rhs.m_threads;
+    m_selected_tid = rhs.m_selected_tid;
+  }
+  return *this;
+}
+
+ThreadList::~ThreadList() {
+  // Clear the thread list. Clear will take the mutex lock which will ensure
+  // that if anyone is using the list they won't get it removed while using it.
+  Clear();
+}
+
+lldb::ThreadSP ThreadList::GetExpressionExecutionThread() {
+  if (m_expression_tid_stack.empty())
+    return GetSelectedThread();
+  ThreadSP expr_thread_sp = FindThreadByID(m_expression_tid_stack.back());
+  if (expr_thread_sp)
+    return expr_thread_sp;
+  else
+    return GetSelectedThread();
+}
+
+void ThreadList::PushExpressionExecutionThread(lldb::tid_t tid) {
+  m_expression_tid_stack.push_back(tid);
+}
+
+void ThreadList::PopExpressionExecutionThread(lldb::tid_t tid) {
+  assert(m_expression_tid_stack.back() == tid);
+  m_expression_tid_stack.pop_back();
+}
+
+uint32_t ThreadList::GetStopID() const { return m_stop_id; }
+
+void ThreadList::SetStopID(uint32_t stop_id) { m_stop_id = stop_id; }
+
+uint32_t ThreadList::GetSize(bool can_update) {
+  std::lock_guard<std::recursive_mutex> guard(GetMutex());
+
+  if (can_update)
+    m_process->UpdateThreadListIfNeeded();
+  return m_threads.size();
+}
+
+ThreadSP ThreadList::GetThreadAtIndex(uint32_t idx, bool can_update) {
+  std::lock_guard<std::recursive_mutex> guard(GetMutex());
+
+  if (can_update)
+    m_process->UpdateThreadListIfNeeded();
+
+  ThreadSP thread_sp;
+  if (idx < m_threads.size())
+    thread_sp = m_threads[idx];
+  return thread_sp;
+}
+
+ThreadSP ThreadList::FindThreadByID(lldb::tid_t tid, bool can_update) {
+  std::lock_guard<std::recursive_mutex> guard(GetMutex());
+
+  if (can_update)
+    m_process->UpdateThreadListIfNeeded();
+
+  ThreadSP thread_sp;
+  uint32_t idx = 0;
+  const uint32_t num_threads = m_threads.size();
+  for (idx = 0; idx < num_threads; ++idx) {
+    if (m_threads[idx]->GetID() == tid) {
+      thread_sp = m_threads[idx];
+      break;
+    }
+  }
+  return thread_sp;
+}
+
+ThreadSP ThreadList::FindThreadByProtocolID(lldb::tid_t tid, bool can_update) {
+  std::lock_guard<std::recursive_mutex> guard(GetMutex());
+
+  if (can_update)
+    m_process->UpdateThreadListIfNeeded();
+
+  ThreadSP thread_sp;
+  uint32_t idx = 0;
+  const uint32_t num_threads = m_threads.size();
+  for (idx = 0; idx < num_threads; ++idx) {
+    if (m_threads[idx]->GetProtocolID() == tid) {
+      thread_sp = m_threads[idx];
+      break;
+    }
+  }
+  return thread_sp;
+}
+
+ThreadSP ThreadList::RemoveThreadByID(lldb::tid_t tid, bool can_update) {
+  std::lock_guard<std::recursive_mutex> guard(GetMutex());
+
+  if (can_update)
+    m_process->UpdateThreadListIfNeeded();
+
+  ThreadSP thread_sp;
+  uint32_t idx = 0;
+  const uint32_t num_threads = m_threads.size();
+  for (idx = 0; idx < num_threads; ++idx) {
+    if (m_threads[idx]->GetID() == tid) {
+      thread_sp = m_threads[idx];
+      m_threads.erase(m_threads.begin() + idx);
+      break;
+    }
+  }
+  return thread_sp;
+}
+
+ThreadSP ThreadList::RemoveThreadByProtocolID(lldb::tid_t tid,
+                                              bool can_update) {
+  std::lock_guard<std::recursive_mutex> guard(GetMutex());
+
+  if (can_update)
+    m_process->UpdateThreadListIfNeeded();
+
+  ThreadSP thread_sp;
+  uint32_t idx = 0;
+  const uint32_t num_threads = m_threads.size();
+  for (idx = 0; idx < num_threads; ++idx) {
+    if (m_threads[idx]->GetProtocolID() == tid) {
+      thread_sp = m_threads[idx];
+      m_threads.erase(m_threads.begin() + idx);
+      break;
+    }
+  }
+  return thread_sp;
+}
+
+ThreadSP ThreadList::GetThreadSPForThreadPtr(Thread *thread_ptr) {
+  ThreadSP thread_sp;
+  if (thread_ptr) {
+    std::lock_guard<std::recursive_mutex> guard(GetMutex());
+
+    uint32_t idx = 0;
+    const uint32_t num_threads = m_threads.size();
+    for (idx = 0; idx < num_threads; ++idx) {
+      if (m_threads[idx].get() == thread_ptr) {
+        thread_sp = m_threads[idx];
+        break;
+      }
+    }
+  }
+  return thread_sp;
+}
+
+ThreadSP ThreadList::GetBackingThread(const ThreadSP &real_thread) {
+  std::lock_guard<std::recursive_mutex> guard(GetMutex());
+
+  ThreadSP thread_sp;
+  const uint32_t num_threads = m_threads.size();
+  for (uint32_t idx = 0; idx < num_threads; ++idx) {
+    if (m_threads[idx]->GetBackingThread() == real_thread) {
+      thread_sp = m_threads[idx];
+      break;
+    }
+  }
+  return thread_sp;
+}
+
+ThreadSP ThreadList::FindThreadByIndexID(uint32_t index_id, bool can_update) {
+  std::lock_guard<std::recursive_mutex> guard(GetMutex());
+
+  if (can_update)
+    m_process->UpdateThreadListIfNeeded();
+
+  ThreadSP thread_sp;
+  const uint32_t num_threads = m_threads.size();
+  for (uint32_t idx = 0; idx < num_threads; ++idx) {
+    if (m_threads[idx]->GetIndexID() == index_id) {
+      thread_sp = m_threads[idx];
+      break;
+    }
+  }
+  return thread_sp;
+}
+
+bool ThreadList::ShouldStop(Event *event_ptr) {
+  // Running events should never stop, obviously...
+
+  Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_STEP));
+
+  // The ShouldStop method of the threads can do a whole lot of work, figuring
+  // out whether the thread plan conditions are met.  So we don't want to keep
+  // the ThreadList locked the whole time we are doing this.
+  // FIXME: It is possible that running code could cause new threads
+  // to be created.  If that happens, we will miss asking them whether they
+  // should stop.  This is not a big deal since we haven't had a chance to hang
+  // any interesting operations on those threads yet.
+
+  collection threads_copy;
+  {
+    // Scope for locker
+    std::lock_guard<std::recursive_mutex> guard(GetMutex());
+
+    m_process->UpdateThreadListIfNeeded();
+    for (lldb::ThreadSP thread_sp : m_threads) {
+      // This is an optimization...  If we didn't let a thread run in between
+      // the previous stop and this one, we shouldn't have to consult it for
+      // ShouldStop.  So just leave it off the list we are going to inspect. On
+      // Linux, if a thread-specific conditional breakpoint was hit, it won't
+      // necessarily be the thread that hit the breakpoint itself that
+      // evaluates the conditional expression, so the thread that hit the
+      // breakpoint could still be asked to stop, even though it hasn't been
+      // allowed to run since the previous stop.
+      if (thread_sp->GetTemporaryResumeState() != eStateSuspended ||
+          thread_sp->IsStillAtLastBreakpointHit())
+        threads_copy.push_back(thread_sp);
+    }
+
+    // It is possible the threads we were allowing to run all exited and then
+    // maybe the user interrupted or something, then fall back on looking at
+    // all threads:
+
+    if (threads_copy.size() == 0)
+      threads_copy = m_threads;
+  }
+
+  collection::iterator pos, end = threads_copy.end();
+
+  if (log) {
+    log->PutCString("");
+    LLDB_LOGF(log,
+              "ThreadList::%s: %" PRIu64 " threads, %" PRIu64
+              " unsuspended threads",
+              __FUNCTION__, (uint64_t)m_threads.size(),
+              (uint64_t)threads_copy.size());
+  }
+
+  bool did_anybody_stop_for_a_reason = false;
+
+  // If the event is an Interrupt event, then we're going to stop no matter
+  // what.  Otherwise, presume we won't stop.
+  bool should_stop = false;
+  if (Process::ProcessEventData::GetInterruptedFromEvent(event_ptr)) {
+    LLDB_LOGF(
+        log, "ThreadList::%s handling interrupt event, should stop set to true",
+        __FUNCTION__);
+
+    should_stop = true;
+  }
+
+  // Now we run through all the threads and get their stop info's.  We want to
+  // make sure to do this first before we start running the ShouldStop, because
+  // one thread's ShouldStop could destroy information (like deleting a thread
+  // specific breakpoint another thread had stopped at) which could lead us to
+  // compute the StopInfo incorrectly. We don't need to use it here, we just
+  // want to make sure it gets computed.
+
+  for (pos = threads_copy.begin(); pos != end; ++pos) {
+    ThreadSP thread_sp(*pos);
+    thread_sp->GetStopInfo();
+  }
+
+  for (pos = threads_copy.begin(); pos != end; ++pos) {
+    ThreadSP thread_sp(*pos);
+
+    // We should never get a stop for which no thread had a stop reason, but
+    // sometimes we do see this - for instance when we first connect to a
+    // remote stub.  In that case we should stop, since we can't figure out the
+    // right thing to do and stopping gives the user control over what to do in
+    // this instance.
+    //
+    // Note, this causes a problem when you have a thread specific breakpoint,
+    // and a bunch of threads hit the breakpoint, but not the thread which we
+    // are waiting for.  All the threads that are not "supposed" to hit the
+    // breakpoint are marked as having no stop reason, which is right, they
+    // should not show a stop reason.  But that triggers this code and causes
+    // us to stop seemingly for no reason.
+    //
+    // Since the only way we ever saw this error was on first attach, I'm only
+    // going to trigger set did_anybody_stop_for_a_reason to true unless this
+    // is the first stop.
+    //
+    // If this becomes a problem, we'll have to have another StopReason like
+    // "StopInfoHidden" which will look invalid everywhere but at this check.
+
+    if (thread_sp->GetProcess()->GetStopID() > 1)
+      did_anybody_stop_for_a_reason = true;
+    else
+      did_anybody_stop_for_a_reason |= thread_sp->ThreadStoppedForAReason();
+
+    const bool thread_should_stop = thread_sp->ShouldStop(event_ptr);
+    if (thread_should_stop)
+      should_stop |= true;
+  }
+
+  if (!should_stop && !did_anybody_stop_for_a_reason) {
+    should_stop = true;
+    LLDB_LOGF(log,
+              "ThreadList::%s we stopped but no threads had a stop reason, "
+              "overriding should_stop and stopping.",
+              __FUNCTION__);
+  }
+
+  LLDB_LOGF(log, "ThreadList::%s overall should_stop = %i", __FUNCTION__,
+            should_stop);
+
+  if (should_stop) {
+    for (pos = threads_copy.begin(); pos != end; ++pos) {
+      ThreadSP thread_sp(*pos);
+      thread_sp->WillStop();
+    }
+  }
+
+  return should_stop;
+}
+
+Vote ThreadList::ShouldReportStop(Event *event_ptr) {
+  std::lock_guard<std::recursive_mutex> guard(GetMutex());
+
+  Vote result = eVoteNoOpinion;
+  m_process->UpdateThreadListIfNeeded();
+  collection::iterator pos, end = m_threads.end();
+
+  Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_STEP));
+
+  LLDB_LOGF(log, "ThreadList::%s %" PRIu64 " threads", __FUNCTION__,
+            (uint64_t)m_threads.size());
+
+  // Run through the threads and ask whether we should report this event. For
+  // stopping, a YES vote wins over everything.  A NO vote wins over NO
+  // opinion.
+  for (pos = m_threads.begin(); pos != end; ++pos) {
+    ThreadSP thread_sp(*pos);
+    const Vote vote = thread_sp->ShouldReportStop(event_ptr);
+    switch (vote) {
+    case eVoteNoOpinion:
+      continue;
+
+    case eVoteYes:
+      result = eVoteYes;
+      break;
+
+    case eVoteNo:
+      if (result == eVoteNoOpinion) {
+        result = eVoteNo;
+      } else {
+        LLDB_LOG(log,
+          "Thread {0:x} voted {1}, but lost out because result was {2}",
+          thread_sp->GetID(), vote, result);
+      }
+      break;
+    }
+  }
+  LLDB_LOG(log, "Returning {0}", result);
+  return result;
+}
+
+void ThreadList::SetShouldReportStop(Vote vote) {
+  std::lock_guard<std::recursive_mutex> guard(GetMutex());
+
+  m_process->UpdateThreadListIfNeeded();
+  collection::iterator pos, end = m_threads.end();
+  for (pos = m_threads.begin(); pos != end; ++pos) {
+    ThreadSP thread_sp(*pos);
+    thread_sp->SetShouldReportStop(vote);
+  }
+}
+
+Vote ThreadList::ShouldReportRun(Event *event_ptr) {
+
+  std::lock_guard<std::recursive_mutex> guard(GetMutex());
+
+  Vote result = eVoteNoOpinion;
+  m_process->UpdateThreadListIfNeeded();
+  collection::iterator pos, end = m_threads.end();
+
+  // Run through the threads and ask whether we should report this event. The
+  // rule is NO vote wins over everything, a YES vote wins over no opinion.
+
+  Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_STEP));
+
+  for (pos = m_threads.begin(); pos != end; ++pos) {
+    if ((*pos)->GetResumeState() != eStateSuspended) {
+      switch ((*pos)->ShouldReportRun(event_ptr)) {
+      case eVoteNoOpinion:
+        continue;
+      case eVoteYes:
+        if (result == eVoteNoOpinion)
+          result = eVoteYes;
+        break;
+      case eVoteNo:
+        LLDB_LOGF(log,
+                  "ThreadList::ShouldReportRun() thread %d (0x%4.4" PRIx64
+                  ") says don't report.",
+                  (*pos)->GetIndexID(), (*pos)->GetID());
+        result = eVoteNo;
+        break;
+      }
+    }
+  }
+  return result;
+}
+
+void ThreadList::Clear() {
+  std::lock_guard<std::recursive_mutex> guard(GetMutex());
+  m_stop_id = 0;
+  m_threads.clear();
+  m_selected_tid = LLDB_INVALID_THREAD_ID;
+}
+
+void ThreadList::Destroy() {
+  std::lock_guard<std::recursive_mutex> guard(GetMutex());
+  const uint32_t num_threads = m_threads.size();
+  for (uint32_t idx = 0; idx < num_threads; ++idx) {
+    m_threads[idx]->DestroyThread();
+  }
+}
+
+void ThreadList::RefreshStateAfterStop() {
+  std::lock_guard<std::recursive_mutex> guard(GetMutex());
+
+  m_process->UpdateThreadListIfNeeded();
+
+  Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_STEP));
+  if (log && log->GetVerbose())
+    LLDB_LOGF(log,
+              "Turning off notification of new threads while single stepping "
+              "a thread.");
+
+  collection::iterator pos, end = m_threads.end();
+  for (pos = m_threads.begin(); pos != end; ++pos)
+    (*pos)->RefreshStateAfterStop();
+}
+
+void ThreadList::DiscardThreadPlans() {
+  // You don't need to update the thread list here, because only threads that
+  // you currently know about have any thread plans.
+  std::lock_guard<std::recursive_mutex> guard(GetMutex());
+
+  collection::iterator pos, end = m_threads.end();
+  for (pos = m_threads.begin(); pos != end; ++pos)
+    (*pos)->DiscardThreadPlans(true);
+}
+
+bool ThreadList::WillResume() {
+  // Run through the threads and perform their momentary actions. But we only
+  // do this for threads that are running, user suspended threads stay where
+  // they are.
+
+  std::lock_guard<std::recursive_mutex> guard(GetMutex());
+  m_process->UpdateThreadListIfNeeded();
+
+  collection::iterator pos, end = m_threads.end();
+
+  // See if any thread wants to run stopping others.  If it does, then we won't
+  // setup the other threads for resume, since they aren't going to get a
+  // chance to run.  This is necessary because the SetupForResume might add
+  // "StopOthers" plans which would then get to be part of the who-gets-to-run
+  // negotiation, but they're coming in after the fact, and the threads that
+  // are already set up should take priority.
+
+  bool wants_solo_run = false;
+
+  for (pos = m_threads.begin(); pos != end; ++pos) {
+    lldbassert((*pos)->GetCurrentPlan() &&
+               "thread should not have null thread plan");
+    if ((*pos)->GetResumeState() != eStateSuspended &&
+        (*pos)->GetCurrentPlan()->StopOthers()) {
+      if ((*pos)->IsOperatingSystemPluginThread() &&
+          !(*pos)->GetBackingThread())
+        continue;
+      wants_solo_run = true;
+      break;
+    }
+  }
+
+  if (wants_solo_run) {
+    Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_STEP));
+    if (log && log->GetVerbose())
+      LLDB_LOGF(log, "Turning on notification of new threads while single "
+                     "stepping a thread.");
+    m_process->StartNoticingNewThreads();
+  } else {
+    Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_STEP));
+    if (log && log->GetVerbose())
+      LLDB_LOGF(log, "Turning off notification of new threads while single "
+                     "stepping a thread.");
+    m_process->StopNoticingNewThreads();
+  }
+
+  // Give all the threads that are likely to run a last chance to set up their
+  // state before we negotiate who is actually going to get a chance to run...
+  // Don't set to resume suspended threads, and if any thread wanted to stop
+  // others, only call setup on the threads that request StopOthers...
+
+  for (pos = m_threads.begin(); pos != end; ++pos) {
+    if ((*pos)->GetResumeState() != eStateSuspended &&
+        (!wants_solo_run || (*pos)->GetCurrentPlan()->StopOthers())) {
+      if ((*pos)->IsOperatingSystemPluginThread() &&
+          !(*pos)->GetBackingThread())
+        continue;
+      (*pos)->SetupForResume();
+    }
+  }
+
+  // Now go through the threads and see if any thread wants to run just itself.
+  // if so then pick one and run it.
+
+  ThreadList run_me_only_list(m_process);
+
+  run_me_only_list.SetStopID(m_process->GetStopID());
+
+  bool run_only_current_thread = false;
+
+  for (pos = m_threads.begin(); pos != end; ++pos) {
+    ThreadSP thread_sp(*pos);
+    if (thread_sp->GetResumeState() != eStateSuspended &&
+        thread_sp->GetCurrentPlan()->StopOthers()) {
+      if ((*pos)->IsOperatingSystemPluginThread() &&
+          !(*pos)->GetBackingThread())
+        continue;
+
+      // You can't say "stop others" and also want yourself to be suspended.
+      assert(thread_sp->GetCurrentPlan()->RunState() != eStateSuspended);
+
+      if (thread_sp == GetSelectedThread()) {
+        // If the currently selected thread wants to run on its own, always let
+        // it.
+        run_only_current_thread = true;
+        run_me_only_list.Clear();
+        run_me_only_list.AddThread(thread_sp);
+        break;
+      }
+
+      run_me_only_list.AddThread(thread_sp);
+    }
+  }
+
+  bool need_to_resume = true;
+
+  if (run_me_only_list.GetSize(false) == 0) {
+    // Everybody runs as they wish:
+    for (pos = m_threads.begin(); pos != end; ++pos) {
+      ThreadSP thread_sp(*pos);
+      StateType run_state;
+      if (thread_sp->GetResumeState() != eStateSuspended)
+        run_state = thread_sp->GetCurrentPlan()->RunState();
+      else
+        run_state = eStateSuspended;
+      if (!thread_sp->ShouldResume(run_state))
+        need_to_resume = false;
+    }
+  } else {
+    ThreadSP thread_to_run;
+
+    if (run_only_current_thread) {
+      thread_to_run = GetSelectedThread();
+    } else if (run_me_only_list.GetSize(false) == 1) {
+      thread_to_run = run_me_only_list.GetThreadAtIndex(0);
+    } else {
+      int random_thread =
+          (int)((run_me_only_list.GetSize(false) * (double)rand()) /
+                (RAND_MAX + 1.0));
+      thread_to_run = run_me_only_list.GetThreadAtIndex(random_thread);
+    }
+
+    for (pos = m_threads.begin(); pos != end; ++pos) {
+      ThreadSP thread_sp(*pos);
+      if (thread_sp == thread_to_run) {
+        if (!thread_sp->ShouldResume(thread_sp->GetCurrentPlan()->RunState()))
+          need_to_resume = false;
+      } else
+        thread_sp->ShouldResume(eStateSuspended);
+    }
+  }
+
+  return need_to_resume;
+}
+
+void ThreadList::DidResume() {
+  std::lock_guard<std::recursive_mutex> guard(GetMutex());
+  collection::iterator pos, end = m_threads.end();
+  for (pos = m_threads.begin(); pos != end; ++pos) {
+    // Don't clear out threads that aren't going to get a chance to run, rather
+    // leave their state for the next time around.
+    ThreadSP thread_sp(*pos);
+    if (thread_sp->GetResumeState() != eStateSuspended)
+      thread_sp->DidResume();
+  }
+}
+
+void ThreadList::DidStop() {
+  std::lock_guard<std::recursive_mutex> guard(GetMutex());
+  collection::iterator pos, end = m_threads.end();
+  for (pos = m_threads.begin(); pos != end; ++pos) {
+    // Notify threads that the process just stopped. Note, this currently
+    // assumes that all threads in the list stop when the process stops.  In
+    // the future we will want to support a debugging model where some threads
+    // continue to run while others are stopped.  We either need to handle that
+    // somehow here or create a special thread list containing only threads
+    // which will stop in the code that calls this method (currently
+    // Process::SetPrivateState).
+    ThreadSP thread_sp(*pos);
+    if (StateIsRunningState(thread_sp->GetState()))
+      thread_sp->DidStop();
+  }
+}
+
+ThreadSP ThreadList::GetSelectedThread() {
+  std::lock_guard<std::recursive_mutex> guard(GetMutex());
+  ThreadSP thread_sp = FindThreadByID(m_selected_tid);
+  if (!thread_sp.get()) {
+    if (m_threads.size() == 0)
+      return thread_sp;
+    m_selected_tid = m_threads[0]->GetID();
+    thread_sp = m_threads[0];
+  }
+  return thread_sp;
+}
+
+bool ThreadList::SetSelectedThreadByID(lldb::tid_t tid, bool notify) {
+  std::lock_guard<std::recursive_mutex> guard(GetMutex());
+  ThreadSP selected_thread_sp(FindThreadByID(tid));
+  if (selected_thread_sp) {
+    m_selected_tid = tid;
+    selected_thread_sp->SetDefaultFileAndLineToSelectedFrame();
+  } else
+    m_selected_tid = LLDB_INVALID_THREAD_ID;
+
+  if (notify)
+    NotifySelectedThreadChanged(m_selected_tid);
+
+  return m_selected_tid != LLDB_INVALID_THREAD_ID;
+}
+
+bool ThreadList::SetSelectedThreadByIndexID(uint32_t index_id, bool notify) {
+  std::lock_guard<std::recursive_mutex> guard(GetMutex());
+  ThreadSP selected_thread_sp(FindThreadByIndexID(index_id));
+  if (selected_thread_sp.get()) {
+    m_selected_tid = selected_thread_sp->GetID();
+    selected_thread_sp->SetDefaultFileAndLineToSelectedFrame();
+  } else
+    m_selected_tid = LLDB_INVALID_THREAD_ID;
+
+  if (notify)
+    NotifySelectedThreadChanged(m_selected_tid);
+
+  return m_selected_tid != LLDB_INVALID_THREAD_ID;
+}
+
+void ThreadList::NotifySelectedThreadChanged(lldb::tid_t tid) {
+  ThreadSP selected_thread_sp(FindThreadByID(tid));
+  if (selected_thread_sp->EventTypeHasListeners(
+          Thread::eBroadcastBitThreadSelected))
+    selected_thread_sp->BroadcastEvent(
+        Thread::eBroadcastBitThreadSelected,
+        new Thread::ThreadEventData(selected_thread_sp));
+}
+
+void ThreadList::Update(ThreadList &rhs) {
+  if (this != &rhs) {
+    // Lock both mutexes to make sure neither side changes anyone on us while
+    // the assignment occurs
+    std::lock_guard<std::recursive_mutex> guard(GetMutex());
+
+    m_process = rhs.m_process;
+    m_stop_id = rhs.m_stop_id;
+    m_threads.swap(rhs.m_threads);
+    m_selected_tid = rhs.m_selected_tid;
+
+    // Now we look for threads that we are done with and make sure to clear
+    // them up as much as possible so anyone with a shared pointer will still
+    // have a reference, but the thread won't be of much use. Using
+    // std::weak_ptr for all backward references (such as a thread to a
+    // process) will eventually solve this issue for us, but for now, we need
+    // to work around the issue
+    collection::iterator rhs_pos, rhs_end = rhs.m_threads.end();
+    for (rhs_pos = rhs.m_threads.begin(); rhs_pos != rhs_end; ++rhs_pos) {
+      const lldb::tid_t tid = (*rhs_pos)->GetID();
+      bool thread_is_alive = false;
+      const uint32_t num_threads = m_threads.size();
+      for (uint32_t idx = 0; idx < num_threads; ++idx) {
+        ThreadSP backing_thread = m_threads[idx]->GetBackingThread();
+        if (m_threads[idx]->GetID() == tid ||
+            (backing_thread && backing_thread->GetID() == tid)) {
+          thread_is_alive = true;
+          break;
+        }
+      }
+      if (!thread_is_alive)
+        (*rhs_pos)->DestroyThread();
+    }
+  }
+}
+
+void ThreadList::Flush() {
+  std::lock_guard<std::recursive_mutex> guard(GetMutex());
+  collection::iterator pos, end = m_threads.end();
+  for (pos = m_threads.begin(); pos != end; ++pos)
+    (*pos)->Flush();
+}
+
+std::recursive_mutex &ThreadList::GetMutex() const {
+  return m_process->m_thread_mutex;
+}
+
+ThreadList::ExpressionExecutionThreadPusher::ExpressionExecutionThreadPusher(
+    lldb::ThreadSP thread_sp)
+    : m_thread_list(nullptr), m_tid(LLDB_INVALID_THREAD_ID) {
+  if (thread_sp) {
+    m_tid = thread_sp->GetID();
+    m_thread_list = &thread_sp->GetProcess()->GetThreadList();
+    m_thread_list->PushExpressionExecutionThread(m_tid);
+  }
+}