libshiboken: Fix hangs introduced by mutex

Use a recursive mutex since nested locks can occur in
~BindingManager.
Amends e141ea41cf6f2840281ab6e52b0861a6d1dcc137.

Change-Id: I2dee3da70fe855859b3917e6ac775b8c5cdf5da7
Reviewed-by: Christian Tismer <tismer@stackless.com>
(cherry picked from commit a2005503162fd707d71027712f13f6b9454e78ad)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>

1 files changed, 7 insertions, 7 deletions

diff --git a/sources/shiboken6/libshiboken/bindingmanager.cpp b/sources/shiboken6/libshiboken/bindingmanager.cpp
index a9e7028e1..3820107d0 100644
--- a/sources/shiboken6/libshiboken/bindingmanager.cpp
+++ b/sources/shiboken6/libshiboken/bindingmanager.cpp
@@ -146,7 +146,7 @@ struct BindingManager::BindingManagerPrivate {
     // QObject::metaObject() and elsewhere from threads without GIL, causing
     // crashes for example in retrieveWrapper(). std::shared_mutex was rejected due to:
     // https://stackoverflow.com/questions/50972345/when-is-stdshared-timed-mutex-slower-than-stdmutex-and-when-not-to-use-it
-    std::mutex wrapperMapLock;
+    std::recursive_mutex wrapperMapLock;
     Graph classHierarchy;
     DestructorEntries deleteInMainThread;
     bool destroying;
@@ -162,7 +162,7 @@ bool BindingManager::BindingManagerPrivate::releaseWrapper(void *cptr, SbkObject
     // The wrapper argument is checked to ensure that the correct wrapper is released.
     // Returns true if the correct wrapper is found and released.
     // If wrapper argument is NULL, no such check is performed.
-    std::lock_guard<std::mutex> guard(wrapperMapLock);
+    std::lock_guard<std::recursive_mutex> guard(wrapperMapLock);
     auto iter = wrapperMapper.find(cptr);
     if (iter != wrapperMapper.end() && (wrapper == nullptr || iter->second == wrapper)) {
         wrapperMapper.erase(iter);
@@ -174,7 +174,7 @@ bool BindingManager::BindingManagerPrivate::releaseWrapper(void *cptr, SbkObject
 void BindingManager::BindingManagerPrivate::assignWrapper(SbkObject *wrapper, const void *cptr)
 {
     assert(cptr);
-    std::lock_guard<std::mutex> guard(wrapperMapLock);
+    std::lock_guard<std::recursive_mutex> guard(wrapperMapLock);
     auto iter = wrapperMapper.find(cptr);
     if (iter == wrapperMapper.end())
         wrapperMapper.insert(std::make_pair(cptr, wrapper));
@@ -201,7 +201,7 @@ BindingManager::~BindingManager()
      * the BindingManager is being destroyed the interpreter is alredy
      * shutting down. */
     if (Py_IsInitialized()) {  // ensure the interpreter is still valid
-        std::lock_guard<std::mutex> guard(m_d->wrapperMapLock);
+        std::lock_guard<std::recursive_mutex> guard(m_d->wrapperMapLock);
         while (!m_d->wrapperMapper.empty()) {
             Object::destroy(m_d->wrapperMapper.begin()->second, const_cast<void *>(m_d->wrapperMapper.begin()->first));
         }
@@ -217,7 +217,7 @@ BindingManager &BindingManager::instance() {
 
 bool BindingManager::hasWrapper(const void *cptr)
 {
-    std::lock_guard<std::mutex> guard(m_d->wrapperMapLock);
+    std::lock_guard<std::recursive_mutex> guard(m_d->wrapperMapLock);
     return m_d->wrapperMapper.find(cptr) != m_d->wrapperMapper.end();
 }
 
@@ -278,7 +278,7 @@ void BindingManager::addToDeletionInMainThread(const DestructorEntry &e)
 
 SbkObject *BindingManager::retrieveWrapper(const void *cptr)
 {
-    std::lock_guard<std::mutex> guard(m_d->wrapperMapLock);
+    std::lock_guard<std::recursive_mutex> guard(m_d->wrapperMapLock);
     auto iter = m_d->wrapperMapper.find(cptr);
     if (iter == m_d->wrapperMapper.end())
         return nullptr;
@@ -388,7 +388,7 @@ PyTypeObject *BindingManager::resolveType(void **cptr, PyTypeObject *type)
 std::set<PyObject *> BindingManager::getAllPyObjects()
 {
     std::set<PyObject *> pyObjects;
-    std::lock_guard<std::mutex> guard(m_d->wrapperMapLock);
+    std::lock_guard<std::recursive_mutex> guard(m_d->wrapperMapLock);
     const WrapperMap &wrappersMap = m_d->wrapperMapper;
     auto it = wrappersMap.begin();
     for (; it != wrappersMap.end(); ++it)