Merge pull request #21180 from lrusak/atomicspinlock

threads: replace CAtomicSpinLock usage with std::lock_guard

10 files changed, 50 insertions, 83 deletions

diff --git a/xbmc/network/Zeroconf.cpp b/xbmc/network/Zeroconf.cpp
index cf850202ab..311ecfb089 100644
--- a/xbmc/network/Zeroconf.cpp
+++ b/xbmc/network/Zeroconf.cpp
@@ -15,7 +15,6 @@
 #endif
 #include "settings/Settings.h"
 #include "settings/SettingsComponent.h"
-#include "threads/Atomics.h"
 #include "threads/CriticalSection.h"
 #include "utils/JobManager.h"
 
@@ -31,6 +30,13 @@
 #include <cassert>
 #include <utility>
 
+namespace
+{
+
+std::mutex singletonMutex;
+
+}
+
 #ifndef HAS_ZEROCONF
 //dummy implementation used if no zeroconf is present
 //should be optimized away
@@ -47,7 +53,6 @@ class CZeroconfDummy : public CZeroconf
 };
 #endif
 
-std::atomic_flag CZeroconf::sm_singleton_guard = ATOMIC_FLAG_INIT;
 CZeroconf* CZeroconf::smp_instance = 0;
 
 CZeroconf::CZeroconf():mp_crit_sec(new CCriticalSection)
@@ -134,7 +139,7 @@ void CZeroconf::Stop()
 
 CZeroconf*  CZeroconf::GetInstance()
 {
-  CAtomicSpinLock lock(sm_singleton_guard);
+  std::lock_guard<std::mutex> lock(singletonMutex);
   if(!smp_instance)
   {
 #ifndef HAS_ZEROCONF
@@ -157,7 +162,7 @@ CZeroconf*  CZeroconf::GetInstance()
 
 void CZeroconf::ReleaseInstance()
 {
-  CAtomicSpinLock lock(sm_singleton_guard);
+  std::lock_guard<std::mutex> lock(singletonMutex);
   delete smp_instance;
   smp_instance = 0;
 }
diff --git a/xbmc/network/Zeroconf.h b/xbmc/network/Zeroconf.h
index f91f0fc3c3..bed66c936b 100644
--- a/xbmc/network/Zeroconf.h
+++ b/xbmc/network/Zeroconf.h
@@ -10,7 +10,6 @@
 
 #include "utils/Job.h"
 
-#include <atomic>
 #include <map>
 #include <string>
 #include <utility>
@@ -123,8 +122,6 @@ private:
   tServiceMap m_service_map;
   bool m_started = false;
 
-  //protects singleton creation/destruction
-  static std::atomic_flag sm_singleton_guard;
   static CZeroconf* smp_instance;
 
   class CPublish : public CJob
diff --git a/xbmc/network/ZeroconfBrowser.cpp b/xbmc/network/ZeroconfBrowser.cpp
index c08dbac250..2d1b8c6686 100644
--- a/xbmc/network/ZeroconfBrowser.cpp
+++ b/xbmc/network/ZeroconfBrowser.cpp
@@ -25,7 +25,13 @@
 #endif
 
 #include "threads/CriticalSection.h"
-#include "threads/Atomics.h"
+
+namespace
+{
+
+std::mutex singletonMutex;
+
+}
 
 #if !defined(HAS_ZEROCONF)
 //dummy implementation used if no zeroconf is present
@@ -39,7 +45,6 @@ class CZeroconfBrowserDummy : public CZeroconfBrowser
 };
 #endif
 
-std::atomic_flag CZeroconfBrowser::sm_singleton_guard = ATOMIC_FLAG_INIT;
 CZeroconfBrowser* CZeroconfBrowser::smp_instance = 0;
 
 CZeroconfBrowser::CZeroconfBrowser():mp_crit_sec(new CCriticalSection)
@@ -131,27 +136,24 @@ bool CZeroconfBrowser::ResolveService(ZeroconfService& fr_service, double f_time
 
 CZeroconfBrowser*  CZeroconfBrowser::GetInstance()
 {
+  std::lock_guard<std::mutex> lock(singletonMutex);
+
   if(!smp_instance)
   {
-    //use double checked locking
-    CAtomicSpinLock lock(sm_singleton_guard);
-    if(!smp_instance)
-    {
 #if !defined(HAS_ZEROCONF)
-      smp_instance = new CZeroconfBrowserDummy;
+    smp_instance = new CZeroconfBrowserDummy;
 #else
 #if defined(TARGET_DARWIN)
-      smp_instance = new CZeroconfBrowserDarwin;
+    smp_instance = new CZeroconfBrowserDarwin;
 #elif defined(HAS_AVAHI)
-      smp_instance  = new CZeroconfBrowserAvahi;
+    smp_instance = new CZeroconfBrowserAvahi;
 #elif defined(TARGET_ANDROID)
-      // WIP
-      smp_instance  = new CZeroconfBrowserAndroid;
+    // WIP
+    smp_instance = new CZeroconfBrowserAndroid;
 #elif defined(HAS_MDNS)
-      smp_instance  = new CZeroconfBrowserMDNS;
+    smp_instance = new CZeroconfBrowserMDNS;
 #endif
 #endif
-    }
   }
   assert(smp_instance);
   return smp_instance;
@@ -159,7 +161,8 @@ CZeroconfBrowser*  CZeroconfBrowser::GetInstance()
 
 void CZeroconfBrowser::ReleaseInstance()
 {
-  CAtomicSpinLock lock(sm_singleton_guard);
+  std::lock_guard<std::mutex> lock(singletonMutex);
+
   delete smp_instance;
   smp_instance = 0;
 }
diff --git a/xbmc/network/ZeroconfBrowser.h b/xbmc/network/ZeroconfBrowser.h
index 5979e34186..76a4439a11 100644
--- a/xbmc/network/ZeroconfBrowser.h
+++ b/xbmc/network/ZeroconfBrowser.h
@@ -8,7 +8,6 @@
 
 #pragma once
 
-#include <atomic>
 #include <string>
 #include <set>
 #include <vector>
@@ -153,8 +152,6 @@ private:
   tServices m_services;
   bool m_started = false;
 
-  //protects singleton creation/destruction
-  static std::atomic_flag sm_singleton_guard;
   static CZeroconfBrowser* smp_instance;
 };
 #include <iostream>
diff --git a/xbmc/platform/darwin/osx/XBMCHelper.cpp b/xbmc/platform/darwin/osx/XBMCHelper.cpp
index 52bb6acfdb..396c67a969 100644
--- a/xbmc/platform/darwin/osx/XBMCHelper.cpp
+++ b/xbmc/platform/darwin/osx/XBMCHelper.cpp
@@ -19,12 +19,12 @@
 #include "settings/Settings.h"
 #include "settings/SettingsComponent.h"
 #include "settings/lib/Setting.h"
-#include "threads/Atomics.h"
 #include "utils/SystemInfo.h"
 #include "utils/TimeUtils.h"
 #include "utils/log.h"
 
 #include <fstream>
+#include <mutex>
 #include <signal.h>
 #include <sstream>
 
@@ -32,7 +32,13 @@
 
 #include "PlatformDefs.h"
 
-static std::atomic_flag sg_singleton_lock_variable = ATOMIC_FLAG_INIT;
+namespace
+{
+
+std::mutex singletonMutex;
+
+}
+
 XBMCHelper* XBMCHelper::smp_instance = 0;
 
 #define XBMC_HELPER_PROGRAM "XBMCHelper"
@@ -44,7 +50,7 @@ static int GetBSDProcessList(kinfo_proc **procList, size_t *procCount);
 XBMCHelper&
 XBMCHelper::GetInstance()
 {
-  CAtomicSpinLock lock(sg_singleton_lock_variable);
+  std::lock_guard<std::mutex> lock(singletonMutex);
   if( ! smp_instance )
   {
     smp_instance = new XBMCHelper();
diff --git a/xbmc/platform/darwin/tvos/TVOSSettingsHandler.mm b/xbmc/platform/darwin/tvos/TVOSSettingsHandler.mm
index a1a19530f9..5e3df2c8aa 100644
--- a/xbmc/platform/darwin/tvos/TVOSSettingsHandler.mm
+++ b/xbmc/platform/darwin/tvos/TVOSSettingsHandler.mm
@@ -12,18 +12,25 @@
 #include "settings/Settings.h"
 #include "settings/SettingsComponent.h"
 #include "settings/lib/Setting.h"
-#include "threads/Atomics.h"
 
 #import "platform/darwin/tvos/XBMCController.h"
 #import "platform/darwin/tvos/input/LibInputHandler.h"
 #import "platform/darwin/tvos/input/LibInputSettings.h"
 
-static std::atomic_flag sg_singleton_lock_variable = ATOMIC_FLAG_INIT;
+#include <mutex>
+
+namespace
+{
+
+std::mutex singletonMutex;
+
+}
+
 CTVOSInputSettings* CTVOSInputSettings::m_instance = nullptr;
 
 CTVOSInputSettings& CTVOSInputSettings::GetInstance()
 {
-  CAtomicSpinLock lock(sg_singleton_lock_variable);
+  std::lock_guard<std::mutex> lock(singletonMutex);
   if (!m_instance)
     m_instance = new CTVOSInputSettings();
 
diff --git a/xbmc/platform/posix/XTimeUtils.cpp b/xbmc/platform/posix/XTimeUtils.cpp
index bbec474e86..e78e5cff48 100644
--- a/xbmc/platform/posix/XTimeUtils.cpp
+++ b/xbmc/platform/posix/XTimeUtils.cpp
@@ -11,14 +11,11 @@
 #include "PosixTimezone.h"
 
 #include <errno.h>
+#include <mutex>
 #include <time.h>
 
 #include <sys/times.h>
 
-#if defined(TARGET_DARWIN)
-#include "threads/Atomics.h"
-#endif
-
 #if defined(TARGET_ANDROID) && !defined(__LP64__)
 #include <time64.h>
 #endif
@@ -92,7 +89,7 @@ int SystemTimeToFileTime(const SystemTime* systemTime, FileTime* fileTime)
 {
   static const int dayoffset[12] = {0, 31, 59, 90, 120, 151, 182, 212, 243, 273, 304, 334};
 #if defined(TARGET_DARWIN)
-  static std::atomic_flag timegm_lock = ATOMIC_FLAG_INIT;
+  static std::mutex timegm_lock;
 #endif
 
   struct tm sysTime = {};
@@ -111,7 +108,7 @@ int SystemTimeToFileTime(const SystemTime* systemTime, FileTime* fileTime)
     sysTime.tm_yday++;
 
 #if defined(TARGET_DARWIN)
-  CAtomicSpinLock lock(timegm_lock);
+  std::lock_guard<std::mutex> lock(timegm_lock);
 #endif
 
 #if defined(TARGET_ANDROID) && !defined(__LP64__)
diff --git a/xbmc/threads/Atomics.cpp b/xbmc/threads/Atomics.cpp
deleted file mode 100644
index 28d5d4c33f..0000000000
--- a/xbmc/threads/Atomics.cpp
+++ /dev/null
@@ -1,22 +0,0 @@
-/*
- *  Copyright (C) 2005-2018 Team Kodi
- *  This file is part of Kodi - https://kodi.tv
- *
- *  SPDX-License-Identifier: GPL-2.0-or-later
- *  See LICENSES/README.md for more information.
- */
-
-#include "Atomics.h"
-
-///////////////////////////////////////////////////////////////////////////
-// Fast spinlock implementation. No backoff when busy
-///////////////////////////////////////////////////////////////////////////
-CAtomicSpinLock::CAtomicSpinLock(std::atomic_flag& lock) : m_Lock(lock)
-{
-  while (atomic_flag_test_and_set(&m_Lock)) {} // Lock
-}
-
-CAtomicSpinLock::~CAtomicSpinLock()
-{
-  std::atomic_flag_clear(&m_Lock); // Unlock
-}
diff --git a/xbmc/threads/Atomics.h b/xbmc/threads/Atomics.h
deleted file mode 100644
index 9a403fae65..0000000000
--- a/xbmc/threads/Atomics.h
+++ /dev/null
@@ -1,21 +0,0 @@
-/*
- *  Copyright (C) 2005-2018 Team Kodi
- *  This file is part of Kodi - https://kodi.tv
- *
- *  SPDX-License-Identifier: GPL-2.0-or-later
- *  See LICENSES/README.md for more information.
- */
-
-#pragma once
-
-#include <atomic>
-
-class CAtomicSpinLock
-{
-public:
-  explicit CAtomicSpinLock(std::atomic_flag& lock);
-  ~CAtomicSpinLock();
-private:
-  std::atomic_flag& m_Lock;
-};
-
diff --git a/xbmc/threads/CMakeLists.txt b/xbmc/threads/CMakeLists.txt
index 0202ca4514..de9007d684 100644
--- a/xbmc/threads/CMakeLists.txt
+++ b/xbmc/threads/CMakeLists.txt
@@ -1,10 +1,8 @@
-set(SOURCES Atomics.cpp
-            Event.cpp
+set(SOURCES Event.cpp
             Thread.cpp
             Timer.cpp)
 
-set(HEADERS Atomics.h
-            Condition.h
+set(HEADERS Condition.h
             CriticalSection.h
             Event.h
             Lockables.h