Remove shared_pointer from NativeThreadProtocol

Summary:
The NativeThread class is useless without the containing process (and in
some places it is already assuming the process is always around). This
makes it clear that the NativeProcessProtocol is the object owning the
threads, and makes the destruction order deterministic (first threads,
then process). The NativeProcess is the only thing holding a thread
unique_ptr, and methods that used to hand out thread shared pointers now
return raw pointers or references.

Reviewers: krytarowski, eugene

Subscribers: lldb-commits

Differential Revision: https://reviews.llvm.org/D35618

llvm-svn: 316007

2 files changed, 43 insertions, 58 deletions

diff --git a/lldb/source/Plugins/Process/NetBSD/NativeProcessNetBSD.cpp b/lldb/source/Plugins/Process/NetBSD/NativeProcessNetBSD.cpp
index 388989a21f7..4f9a69688fe 100644
--- a/lldb/source/Plugins/Process/NetBSD/NativeProcessNetBSD.cpp
+++ b/lldb/source/Plugins/Process/NetBSD/NativeProcessNetBSD.cpp
@@ -109,10 +109,8 @@ NativeProcessNetBSD::Factory::Launch(ProcessLaunchInfo &launch_info,
   if (status.Fail())
     return status.ToError();
 
-  for (const auto &thread_sp : process_up->m_threads) {
-    static_pointer_cast<NativeThreadNetBSD>(thread_sp)->SetStoppedBySignal(
-        SIGSTOP);
-  }
+  for (const auto &thread : process_up->m_threads)
+    static_cast<NativeThreadNetBSD &>(*thread).SetStoppedBySignal(SIGSTOP);
   process_up->SetState(StateType::eStateStopped);
 
   return std::move(process_up);
@@ -198,9 +196,9 @@ void NativeProcessNetBSD::MonitorSIGSTOP(lldb::pid_t pid) {
     // Handle SIGSTOP from LLGS (LLDB GDB Server)
     if (info.psi_siginfo.si_code == SI_USER &&
         info.psi_siginfo.si_pid == ::getpid()) {
-      /* Stop Tracking All Threads attached to Process */
-      for (const auto &thread_sp : m_threads) {
-        static_pointer_cast<NativeThreadNetBSD>(thread_sp)->SetStoppedBySignal(
+      /* Stop Tracking all Threads attached to Process */
+      for (const auto &thread : m_threads) {
+        static_cast<NativeThreadNetBSD &>(*thread).SetStoppedBySignal(
             SIGSTOP, &info.psi_siginfo);
       }
     }
@@ -221,18 +219,15 @@ void NativeProcessNetBSD::MonitorSIGTRAP(lldb::pid_t pid) {
 
   switch (info.psi_siginfo.si_code) {
   case TRAP_BRKPT:
-    for (const auto &thread_sp : m_threads) {
-      static_pointer_cast<NativeThreadNetBSD>(thread_sp)
-          ->SetStoppedByBreakpoint();
-      FixupBreakpointPCAsNeeded(
-          *static_pointer_cast<NativeThreadNetBSD>(thread_sp));
+    for (const auto &thread : m_threads) {
+      static_cast<NativeThreadNetBSD &>(*thread).SetStoppedByBreakpoint();
+      FixupBreakpointPCAsNeeded(static_cast<NativeThreadNetBSD &>(*thread));
     }
     SetState(StateType::eStateStopped, true);
     break;
   case TRAP_TRACE:
-    for (const auto &thread_sp : m_threads) {
-      static_pointer_cast<NativeThreadNetBSD>(thread_sp)->SetStoppedByTrace();
-    }
+    for (const auto &thread : m_threads)
+      static_cast<NativeThreadNetBSD &>(*thread).SetStoppedByTrace();
     SetState(StateType::eStateStopped, true);
     break;
   case TRAP_EXEC: {
@@ -245,37 +240,34 @@ void NativeProcessNetBSD::MonitorSIGTRAP(lldb::pid_t pid) {
     // Let our delegate know we have just exec'd.
     NotifyDidExec();
 
-    for (const auto &thread_sp : m_threads) {
-      static_pointer_cast<NativeThreadNetBSD>(thread_sp)->SetStoppedByExec();
-    }
+    for (const auto &thread : m_threads)
+      static_cast<NativeThreadNetBSD &>(*thread).SetStoppedByExec();
     SetState(StateType::eStateStopped, true);
   } break;
   case TRAP_DBREG: {
     // If a watchpoint was hit, report it
     uint32_t wp_index;
-    Status error =
-        static_pointer_cast<NativeThreadNetBSD>(m_threads[info.psi_lwpid])
-            ->GetRegisterContext()
-            ->GetWatchpointHitIndex(wp_index,
-                                    (uintptr_t)info.psi_siginfo.si_addr);
+    Status error = static_cast<NativeThreadNetBSD &>(*m_threads[info.psi_lwpid])
+                       .GetRegisterContext()
+                       ->GetWatchpointHitIndex(
+                           wp_index, (uintptr_t)info.psi_siginfo.si_addr);
     if (error.Fail())
       LLDB_LOG(log,
                "received error while checking for watchpoint hits, pid = "
                "{0}, LWP = {1}, error = {2}",
                GetID(), info.psi_lwpid, error);
     if (wp_index != LLDB_INVALID_INDEX32) {
-      for (const auto &thread_sp : m_threads) {
-        static_pointer_cast<NativeThreadNetBSD>(thread_sp)
-            ->SetStoppedByWatchpoint(wp_index);
-      }
+      for (const auto &thread : m_threads)
+        static_cast<NativeThreadNetBSD &>(*thread).SetStoppedByWatchpoint(
+            wp_index);
       SetState(StateType::eStateStopped, true);
       break;
     }
 
     // If a breakpoint was hit, report it
     uint32_t bp_index;
-    error = static_pointer_cast<NativeThreadNetBSD>(m_threads[info.psi_lwpid])
-                ->GetRegisterContext()
+    error = static_cast<NativeThreadNetBSD &>(*m_threads[info.psi_lwpid])
+                .GetRegisterContext()
                 ->GetHardwareBreakHitIndex(bp_index,
                                            (uintptr_t)info.psi_siginfo.si_addr);
     if (error.Fail())
@@ -284,10 +276,8 @@ void NativeProcessNetBSD::MonitorSIGTRAP(lldb::pid_t pid) {
                "breakpoint hits, pid = {0}, LWP = {1}, error = {2}",
                GetID(), info.psi_lwpid, error);
     if (bp_index != LLDB_INVALID_INDEX32) {
-      for (const auto &thread_sp : m_threads) {
-        static_pointer_cast<NativeThreadNetBSD>(thread_sp)
-            ->SetStoppedByBreakpoint();
-      }
+      for (const auto &thread : m_threads)
+        static_cast<NativeThreadNetBSD &>(*thread).SetStoppedByBreakpoint();
       SetState(StateType::eStateStopped, true);
       break;
     }
@@ -300,8 +290,8 @@ void NativeProcessNetBSD::MonitorSignal(lldb::pid_t pid, int signal) {
   const auto siginfo_err =
       PtraceWrapper(PT_GET_SIGINFO, pid, &info, sizeof(info));
 
-  for (const auto &thread_sp : m_threads) {
-    static_pointer_cast<NativeThreadNetBSD>(thread_sp)->SetStoppedBySignal(
+  for (const auto &thread : m_threads) {
+    static_cast<NativeThreadNetBSD &>(*thread).SetStoppedBySignal(
         info.psi_siginfo.si_signo, &info.psi_siginfo);
   }
   SetState(StateType::eStateStopped, true);
@@ -433,13 +423,13 @@ Status NativeProcessNetBSD::Resume(const ResumeActionList &resume_actions) {
   Log *log(ProcessPOSIXLog::GetLogIfAllCategoriesSet(POSIX_LOG_PROCESS));
   LLDB_LOG(log, "pid {0}", GetID());
 
-  const auto &thread_sp = m_threads[0];
+  const auto &thread = m_threads[0];
   const ResumeAction *const action =
-      resume_actions.GetActionForThread(thread_sp->GetID(), true);
+      resume_actions.GetActionForThread(thread->GetID(), true);
 
   if (action == nullptr) {
     LLDB_LOG(log, "no action specified for pid {0} tid {1}", GetID(),
-             thread_sp->GetID());
+             thread->GetID());
     return Status();
   }
 
@@ -452,9 +442,8 @@ Status NativeProcessNetBSD::Resume(const ResumeActionList &resume_actions) {
                                                action->signal);
     if (!error.Success())
       return error;
-    for (const auto &thread_sp : m_threads) {
-      static_pointer_cast<NativeThreadNetBSD>(thread_sp)->SetRunning();
-    }
+    for (const auto &thread : m_threads)
+      static_cast<NativeThreadNetBSD &>(*thread).SetRunning();
     SetState(eStateRunning, true);
     break;
   }
@@ -464,9 +453,8 @@ Status NativeProcessNetBSD::Resume(const ResumeActionList &resume_actions) {
                                                action->signal);
     if (!error.Success())
       return error;
-    for (const auto &thread_sp : m_threads) {
-      static_pointer_cast<NativeThreadNetBSD>(thread_sp)->SetStepping();
-    }
+    for (const auto &thread : m_threads)
+      static_cast<NativeThreadNetBSD &>(*thread).SetStepping();
     SetState(eStateStepping, true);
     break;
 
@@ -478,7 +466,7 @@ Status NativeProcessNetBSD::Resume(const ResumeActionList &resume_actions) {
     return Status("NativeProcessNetBSD::%s (): unexpected state %s specified "
                   "for pid %" PRIu64 ", tid %" PRIu64,
                   __FUNCTION__, StateAsCString(action->state), GetID(),
-                  thread_sp->GetID());
+                  thread->GetID());
   }
 
   return Status();
@@ -764,9 +752,9 @@ void NativeProcessNetBSD::SigchldHandler() {
 }
 
 bool NativeProcessNetBSD::HasThreadNoLock(lldb::tid_t thread_id) {
-  for (auto thread_sp : m_threads) {
-    assert(thread_sp && "thread list should not contain NULL threads");
-    if (thread_sp->GetID() == thread_id) {
+  for (const auto &thread : m_threads) {
+    assert(thread && "thread list should not contain NULL threads");
+    if (thread->GetID() == thread_id) {
       // We have this thread.
       return true;
     }
@@ -776,7 +764,7 @@ bool NativeProcessNetBSD::HasThreadNoLock(lldb::tid_t thread_id) {
   return false;
 }
 
-NativeThreadNetBSDSP NativeProcessNetBSD::AddThread(lldb::tid_t thread_id) {
+NativeThreadNetBSD &NativeProcessNetBSD::AddThread(lldb::tid_t thread_id) {
 
   Log *log(ProcessPOSIXLog::GetLogIfAllCategoriesSet(POSIX_LOG_THREAD));
   LLDB_LOG(log, "pid {0} adding thread with tid {1}", GetID(), thread_id);
@@ -788,9 +776,8 @@ NativeThreadNetBSDSP NativeProcessNetBSD::AddThread(lldb::tid_t thread_id) {
   if (m_threads.empty())
     SetCurrentThreadID(thread_id);
 
-  auto thread_sp = std::make_shared<NativeThreadNetBSD>(*this, thread_id);
-  m_threads.push_back(thread_sp);
-  return thread_sp;
+  m_threads.push_back(llvm::make_unique<NativeThreadNetBSD>(*this, thread_id));
+  return static_cast<NativeThreadNetBSD &>(*m_threads.back());
 }
 
 Status NativeProcessNetBSD::Attach() {
@@ -811,10 +798,8 @@ Status NativeProcessNetBSD::Attach() {
   if (status.Fail())
     return status;
 
-  for (const auto &thread_sp : m_threads) {
-    static_pointer_cast<NativeThreadNetBSD>(thread_sp)->SetStoppedBySignal(
-        SIGSTOP);
-  }
+  for (const auto &thread : m_threads)
+    static_cast<NativeThreadNetBSD &>(*thread).SetStoppedBySignal(SIGSTOP);
 
   // Let our process instance know the thread has stopped.
   SetState(StateType::eStateStopped);
@@ -928,7 +913,7 @@ Status NativeProcessNetBSD::ReinitializeThreads() {
   }
   // Reinitialize from scratch threads and register them in process
   while (info.pl_lwpid != 0) {
-    NativeThreadNetBSDSP thread_sp = AddThread(info.pl_lwpid);
+    AddThread(info.pl_lwpid);
     error = PtraceWrapper(PT_LWPINFO, GetID(), &info, sizeof(info));
     if (error.Fail()) {
       return error;
diff --git a/lldb/source/Plugins/Process/NetBSD/NativeProcessNetBSD.h b/lldb/source/Plugins/Process/NetBSD/NativeProcessNetBSD.h
index 2cbd5e30ab2..5ecf4623572 100644
--- a/lldb/source/Plugins/Process/NetBSD/NativeProcessNetBSD.h
+++ b/lldb/source/Plugins/Process/NetBSD/NativeProcessNetBSD.h
@@ -121,7 +121,7 @@ private:
 
   bool HasThreadNoLock(lldb::tid_t thread_id);
 
-  NativeThreadNetBSDSP AddThread(lldb::tid_t thread_id);
+  NativeThreadNetBSD &AddThread(lldb::tid_t thread_id);
 
   void MonitorCallback(lldb::pid_t pid, int signal);
   void MonitorExited(lldb::pid_t pid, WaitStatus status);