From bff26063438c93079acfd8dd929de14000b5fb58 Mon Sep 17 00:00:00 2001
From: Silvio Traversaro <silvio@traversaro.it>
Date: Fri, 18 Oct 2024 08:35:04 +0200
Subject: [PATCH] Add general mutex for ShmemInputStreamImpl

To avoid failures like https://github.com/robotology/icub-tech-support/issues/1937
---
 src/carriers/shmem_carrier/ShmemInputStream.cpp | 10 ++++++++++
 src/carriers/shmem_carrier/ShmemInputStream.h   |  3 +++
 2 files changed, 13 insertions(+)

diff --git a/src/carriers/shmem_carrier/ShmemInputStream.cpp b/src/carriers/shmem_carrier/ShmemInputStream.cpp
index 7ea612ffeda..fb427f5d8f8 100644
--- a/src/carriers/shmem_carrier/ShmemInputStream.cpp
+++ b/src/carriers/shmem_carrier/ShmemInputStream.cpp
@@ -43,6 +43,8 @@ bool ShmemInputStreamImpl::isOk() const
 
 bool ShmemInputStreamImpl::open(int port, ACE_SOCK_Stream* pSock, int size)
 {
+    std::lock_guard<std::recursive_mutex> l_guard(m_generalMutex);
+
     m_pSock = pSock;
 
     m_pAccessMutex = m_pWaitDataMutex = nullptr;
@@ -102,6 +104,8 @@ bool ShmemInputStreamImpl::open(int port, ACE_SOCK_Stream* pSock, int size)
 
 bool ShmemInputStreamImpl::Resize()
 {
+    std::lock_guard<std::recursive_mutex> l_guard(m_generalMutex);
+
     ++m_ResizeNum;
 
     ACE_Shared_Memory* pNewMap;
@@ -155,6 +159,8 @@ bool ShmemInputStreamImpl::Resize()
 
 int ShmemInputStreamImpl::read(char* data, int len)
 {
+    std::lock_guard<std::recursive_mutex> l_guard(m_generalMutex);
+
     m_pAccessMutex->acquire();
 
     if (m_pHeader->close) {
@@ -193,6 +199,8 @@ int ShmemInputStreamImpl::read(char* data, int len)
 
 yarp::conf::ssize_t ShmemInputStreamImpl::read(yarp::os::Bytes& b)
 {
+    std::lock_guard<std::recursive_mutex> l_guard(m_generalMutex);
+
     m_ReadSerializerMutex.lock();
 
     if (!m_bOpen) {
@@ -230,6 +238,8 @@ yarp::conf::ssize_t ShmemInputStreamImpl::read(yarp::os::Bytes& b)
 
 void ShmemInputStreamImpl::close()
 {
+    std::lock_guard<std::recursive_mutex> l_guard(m_generalMutex);
+
     if (!m_bOpen) {
         return;
     }
diff --git a/src/carriers/shmem_carrier/ShmemInputStream.h b/src/carriers/shmem_carrier/ShmemInputStream.h
index 96099ec377b..d7b4aa69580 100644
--- a/src/carriers/shmem_carrier/ShmemInputStream.h
+++ b/src/carriers/shmem_carrier/ShmemInputStream.h
@@ -63,6 +63,9 @@ class ShmemInputStreamImpl
 
     std::mutex m_ReadSerializerMutex;
 
+    // Mutex for the whole class, to avoid concurrent close and read
+    std::recursive_mutex m_generalMutex;
+
     ACE_Shared_Memory* m_pMap;
     char* m_pData;
     ShmemHeader_t* m_pHeader;