Replace std::mutex with DefaultUnnamedMutex to avoid named mutex exhaustion (#950)

* DefaultUnnamedMutex migration

* Migrating from DefaultUnnamedMutex to Mutex

* Revert renaming

* Using macro instead of HC_PLATFORM

---------

Co-authored-by: Raul Gomez Rodriguez <raulalbertog@microsoft.com>

Author: rgomez391

Include/httpClient/pal.h

@@ -13,6 +13,7 @@
 #include <stdbool.h>
 #include <stddef.h>
 #include <stdint.h>
+#include <mutex>
 
 #include <httpClient/config.h>
 
@@ -494,3 +495,23 @@ enum class HCWebSocketCloseStatus : uint32_t
 };
 
 }
+
+// On some platforms, std::mutex default construction creates named mutexes which have a low
+// system-wide limit. DefaultUnnamedMutex forces unnamed mutex construction on affected platforms.
+// Define HC_USE_UNNAMED_MUTEX in your platform build props to enable the workaround.
+#if defined(HC_USE_UNNAMED_MUTEX)
+class DefaultUnnamedMutex : public std::mutex
+{
+public:
+    DefaultUnnamedMutex() noexcept : std::mutex(nullptr) {}
+    ~DefaultUnnamedMutex() noexcept = default;
+    DefaultUnnamedMutex(DefaultUnnamedMutex const&) = delete;
+    DefaultUnnamedMutex& operator=(DefaultUnnamedMutex const&) = delete;
+    void lock() { std::mutex::lock(); }
+    bool try_lock() { return std::mutex::try_lock(); }
+    void unlock() { std::mutex::unlock(); }
+    native_handle_type native_handle() { return std::mutex::native_handle(); }
+};
+#else
+using DefaultUnnamedMutex = std::mutex;
+#endif

Source/Global/NetworkState.h

@@ -76,7 +76,7 @@ class NetworkState
     static void CALLBACK HttpProviderCleanupComplete(XAsyncBlock* async);
     bool ScheduleCleanup();
 
-    std::mutex m_mutex;
+    DefaultUnnamedMutex m_mutex;
 
     UniquePtr<IHttpProvider> m_httpProvider;
 

Source/Global/global.cpp

@@ -25,11 +25,11 @@ HRESULT http_singleton::singleton_access(
     _Out_ std::shared_ptr<http_singleton>& singleton
 ) noexcept
 {
-    static std::mutex s_mutex;
+    static DefaultUnnamedMutex s_mutex;
     static std::shared_ptr<http_singleton> s_singleton{ nullptr };
     static uint8_t s_useCount{ 0 };
 
-    std::lock_guard<std::mutex> lock{ s_mutex };
+    std::lock_guard<DefaultUnnamedMutex> lock{ s_mutex };
     switch (mode)
     {
     case singleton_access_mode::create:

Source/Task/AsyncLib.cpp

@@ -45,7 +45,7 @@ struct AsyncState
     XAsyncBlock providerAsyncBlock { };
     XAsyncBlock* userAsyncBlock = nullptr;
     XTaskQueueHandle queue = nullptr;
-    std::mutex waitMutex;
+    DefaultUnnamedMutex waitMutex;
     std::condition_variable waitCondition;
     bool waitSatisfied = false;
 

Source/Task/AtomicVector.h

@@ -94,7 +94,7 @@ class AtomicVector
 
 private:
 
-    std::mutex m_lock;
+    DefaultUnnamedMutex m_lock;
     std::vector<TElement> m_buffers[2];
     std::atomic<uint32_t> m_indexAndRef { 0 };
 };

Source/Task/TaskQueueImpl.h

@@ -114,7 +114,7 @@ class SubmitCallback
     };
 
     std::atomic<uint64_t> m_nextToken{ 0 };
-    std::mutex m_lock;
+    DefaultUnnamedMutex m_lock;
     CallbackRegistration m_buffer1[SUBMIT_CALLBACK_MAX];
     CallbackRegistration m_buffer2[SUBMIT_CALLBACK_MAX];
     CallbackRegistration* m_buffers[2]= { m_buffer1, m_buffer2 };
@@ -149,7 +149,7 @@ class QueueWaitRegistry
 
     std::atomic<uint64_t> m_nextToken{ 0 };
     StaticArray<WaitRegistration, QUEUE_WAIT_MAX> m_callbacks;
-    std::mutex m_lock;
+    DefaultUnnamedMutex m_lock;
 };
 
 class TaskQueuePortImpl: public Api<ApiId::TaskQueuePort, ITaskQueuePort>
@@ -257,12 +257,12 @@ class TaskQueuePortImpl: public Api<ApiId::TaskQueuePort, ITaskQueuePort>
     std::atomic<uint32_t> m_processingSerializedTbCallback{ 0 };
     std::atomic<uint32_t> m_processingCallback{ 0 };
     std::condition_variable m_processingCallbackCv;
-    std::mutex m_lock;
+    DefaultUnnamedMutex m_lock;
     std::unique_ptr<LocklessQueue<QueueEntry>> m_queueList;
     std::unique_ptr<LocklessQueue<QueueEntry>> m_pendingList;
     std::unique_ptr<LocklessQueue<TerminationEntry*>> m_terminationList;
     std::unique_ptr<LocklessQueue<TerminationEntry*>> m_pendingTerminationList;
-    std::mutex m_terminationLock;
+    DefaultUnnamedMutex m_terminationLock;
     OS::WaitTimer m_timer;
     OS::ThreadPool m_threadPool;
     std::atomic<uint64_t> m_timerDue = { UINT64_MAX };
@@ -465,7 +465,7 @@ class TaskQueueImpl : public Api<ApiId::TaskQueue, ITaskQueue>
     struct TerminationData
     {
         bool terminated;
-        std::mutex lock;
+        DefaultUnnamedMutex lock;
         std::condition_variable cv;
     };
 

Source/Task/ThreadPool_stl.cpp

@@ -220,12 +220,12 @@ namespace OS
 
         std::atomic<uint32_t> m_refs{ 1 };
 
-        std::mutex m_wakeLock;
+        DefaultUnnamedMutex m_wakeLock;
         std::condition_variable m_wake;
         uint32_t m_calls{ 0 };
         bool m_terminate{ false };
 
-        std::mutex m_activeLock;
+        DefaultUnnamedMutex m_activeLock;
         std::condition_variable m_active;
         uint32_t m_activeCalls{ 0 };
 

Source/Task/WaitTimer_stl.cpp

@@ -53,7 +53,7 @@ namespace OS
         TimerEntry const& Peek() const noexcept;
         TimerEntry Pop() noexcept;
 
-        std::mutex m_mutex;
+        DefaultUnnamedMutex m_mutex;
         std::condition_variable m_cv;
         std::vector<TimerEntry> m_queue; // used as a heap
         std::thread m_t;
@@ -64,7 +64,7 @@ namespace OS
     namespace
     {
         std::shared_ptr<TimerQueue> g_timerQueue;
-        std::mutex g_timerQueueMutex;
+        DefaultUnnamedMutex g_timerQueueMutex;
     }
 
     TimerQueue::~TimerQueue()

Source/WebSocket/hcwebsocket.h

@@ -181,7 +181,7 @@ class WebSocket : public std::enable_shared_from_this<WebSocket>
         void* context{ nullptr };
     };
 
-    std::mutex m_stateMutex;
+    DefaultUnnamedMutex m_stateMutex;
     enum class State
     {
         Initial,