[Lldb-commits] [lldb] [debugserver] Migrate RNBRemote away from PThreadMutex (NFC) (PR #137547)

[Jonas Devlieghere via lldb-commits]

https://github.com/JDevlieghere created https://github.com/llvm/llvm-project/pull/137547

The debugserver code predates modern C++, but with C++11 and later there's no need to have something like PThreadMutex. This migrates RNBRemote away from PThreadMutex in preparation for removing it.

>From 10a1f5b8f615f502a92e23a39e233265cca6d8ba Mon Sep 17 00:00:00 2001
From: Jonas Devlieghere <jonas at devlieghere.com>
Date: Sun, 27 Apr 2025 13:39:07 -0700
Subject: [PATCH] [debugserver] Migrate RNBRemote away from PThreadMutex (NFC)

The debugserver code predates modern C++, but with C++11 and later
there's no need to have something like PThreadMutex. This migrates
RNBRemote away from PThreadMutex in preparation for removing it.
---
 lldb/tools/debugserver/source/RNBRemote.cpp | 4 ++--
 lldb/tools/debugserver/source/RNBRemote.h   | 4 +---
 2 files changed, 3 insertions(+), 5 deletions(-)

diff --git a/lldb/tools/debugserver/source/RNBRemote.cpp b/lldb/tools/debugserver/source/RNBRemote.cpp
index eb7c5ca32c02a..e0831023e7ae4 100644
--- a/lldb/tools/debugserver/source/RNBRemote.cpp
+++ b/lldb/tools/debugserver/source/RNBRemote.cpp
@@ -820,7 +820,7 @@ rnb_err_t RNBRemote::GetPacketPayload(std::string &return_packet) {
   // (uint32_t)m_comm.Timer().ElapsedMicroSeconds(true), __FUNCTION__);
 
   {
-    PThreadMutex::Locker locker(m_mutex);
+    std::lock_guard<std::mutex> guard(m_mutex);
     if (m_rx_packets.empty()) {
       // Only reset the remote command available event if we have no more
       // packets
@@ -1052,7 +1052,7 @@ void RNBRemote::CommDataReceived(const std::string &new_data) {
   //  (uint32_t)m_comm.Timer().ElapsedMicroSeconds(true), __FUNCTION__);
 
   // Put the packet data into the buffer in a thread safe fashion
-  PThreadMutex::Locker locker(m_mutex);
+  std::lock_guard<std::mutex> guard(m_mutex);
 
   std::string data;
   // See if we have any left over data from a previous call to this
diff --git a/lldb/tools/debugserver/source/RNBRemote.h b/lldb/tools/debugserver/source/RNBRemote.h
index c552713551013..ad254ae90e2f7 100644
--- a/lldb/tools/debugserver/source/RNBRemote.h
+++ b/lldb/tools/debugserver/source/RNBRemote.h
@@ -14,7 +14,6 @@
 #define LLDB_TOOLS_DEBUGSERVER_SOURCE_RNBREMOTE_H
 
 #include "DNB.h"
-#include "PThreadMutex.h"
 #include "RNBContext.h"
 #include "RNBDefs.h"
 #include "RNBSocket.h"
@@ -25,7 +24,6 @@
 
 class RNBSocket;
 class RNBContext;
-class PThreadEvents;
 
 enum event_loop_mode { debug_nub, gdb_remote_protocol, done };
 
@@ -379,7 +377,7 @@ class RNBRemote {
   std::string m_arch;
   nub_thread_t m_continue_thread; // thread to continue; 0 for any, -1 for all
   nub_thread_t m_thread;          // thread for other ops; 0 for any, -1 for all
-  PThreadMutex m_mutex;           // Mutex that protects
+  std::mutex m_mutex;             // Mutex that protects
   DispatchQueueOffsets m_dispatch_queue_offsets;
   nub_addr_t m_dispatch_queue_offsets_addr;
   uint32_t m_qSymbol_index;