xbmc/SectionLoader.cpp

   1 /*
   2  *  Copyright (C) 2005-2018 Team Kodi
   3  *  This file is part of Kodi - https://kodi.tv
   4  *
   5  *  SPDX-License-Identifier: GPL-2.0-or-later
   6  *  See LICENSES/README.md for more information.
   7  */
   8
   9 #include "SectionLoader.h"
  10
  11 #include "cores/DllLoader/DllLoaderContainer.h"
  12 #include "utils/GlobalsHandling.h"
  13 #include "utils/StringUtils.h"
  14 #include "utils/log.h"
  15
  16 #include <mutex>
  17
  18 #define g_sectionLoader XBMC_GLOBAL_USE(CSectionLoader)
  19
  20 //  delay for unloading dll's
  21 #define UNLOAD_DELAY 30*1000 // 30 sec.
  22
  23 //Define this to get logging on all calls to load/unload sections/dlls
  24 //#define LOGALL
  25
  26 CSectionLoader::CSectionLoader(void) = default;
  27
  28 CSectionLoader::~CSectionLoader(void)
  29 {
  30   UnloadAll();
  31 }
  32
  33 LibraryLoader *CSectionLoader::LoadDLL(const std::string &dllname, bool bDelayUnload /*=true*/, bool bLoadSymbols /*=false*/)
  34 {
  35   std::unique_lock<CCriticalSection> lock(g_sectionLoader.m_critSection);
  36
  37   if (dllname.empty()) return NULL;
  38   // check if it's already loaded, and increase the reference count if so
  39   for (int i = 0; i < (int)g_sectionLoader.m_vecLoadedDLLs.size(); ++i)
  40   {
  41     CDll& dll = g_sectionLoader.m_vecLoadedDLLs[i];
  42     if (StringUtils::EqualsNoCase(dll.m_strDllName, dllname))
  43     {
  44       dll.m_lReferenceCount++;
  45       return dll.m_pDll;
  46     }
  47   }
  48
  49   // ok, now load the dll
  50   CLog::Log(LOGDEBUG, "SECTION:LoadDLL({})", dllname);
  51   LibraryLoader* pDll = DllLoaderContainer::LoadModule(dllname.c_str(), NULL, bLoadSymbols);
  52   if (!pDll)
  53     return NULL;
  54
  55   CDll newDLL;
  56   newDLL.m_strDllName = dllname;
  57   newDLL.m_lReferenceCount = 1;
  58   newDLL.m_bDelayUnload=bDelayUnload;
  59   newDLL.m_pDll=pDll;
  60   g_sectionLoader.m_vecLoadedDLLs.push_back(newDLL);
  61
  62   return newDLL.m_pDll;
  63 }
  64
  65 void CSectionLoader::UnloadDLL(const std::string &dllname)
  66 {
  67   std::unique_lock<CCriticalSection> lock(g_sectionLoader.m_critSection);
  68
  69   if (dllname.empty()) return;
  70   // check if it's already loaded, and decrease the reference count if so
  71   for (int i = 0; i < (int)g_sectionLoader.m_vecLoadedDLLs.size(); ++i)
  72   {
  73     CDll& dll = g_sectionLoader.m_vecLoadedDLLs[i];
  74     if (StringUtils::EqualsNoCase(dll.m_strDllName, dllname))
  75     {
  76       dll.m_lReferenceCount--;
  77       if (0 == dll.m_lReferenceCount)
  78       {
  79         if (dll.m_bDelayUnload)
  80           dll.m_unloadDelayStartTick = std::chrono::steady_clock::now();
  81         else
  82         {
  83           CLog::Log(LOGDEBUG, "SECTION:UnloadDll({})", dllname);
  84           if (dll.m_pDll)
  85             DllLoaderContainer::ReleaseModule(dll.m_pDll);
  86           g_sectionLoader.m_vecLoadedDLLs.erase(g_sectionLoader.m_vecLoadedDLLs.begin() + i);
  87         }
  88
  89         return;
  90       }
  91     }
  92   }
  93 }
  94
  95 void CSectionLoader::UnloadDelayed()
  96 {
  97   std::unique_lock<CCriticalSection> lock(g_sectionLoader.m_critSection);
  98
  99   // check if we can unload any unreferenced dlls
 100   for (int i = 0; i < (int)g_sectionLoader.m_vecLoadedDLLs.size(); ++i)
 101   {
 102     CDll& dll = g_sectionLoader.m_vecLoadedDLLs[i];
 103     auto now = std::chrono::steady_clock::now();
 104     auto duration =
 105         std::chrono::duration_cast<std::chrono::milliseconds>(now - dll.m_unloadDelayStartTick);
 106     if (dll.m_lReferenceCount == 0 && duration.count() > UNLOAD_DELAY)
 107     {
 108       CLog::Log(LOGDEBUG, "SECTION:UnloadDelayed(DLL: {})", dll.m_strDllName);
 109
 110       if (dll.m_pDll)
 111         DllLoaderContainer::ReleaseModule(dll.m_pDll);
 112       g_sectionLoader.m_vecLoadedDLLs.erase(g_sectionLoader.m_vecLoadedDLLs.begin() + i);
 113       return;
 114     }
 115   }
 116 }
 117
 118 void CSectionLoader::UnloadAll()
 119 {
 120   // delete the dll's
 121   std::unique_lock<CCriticalSection> lock(g_sectionLoader.m_critSection);
 122   std::vector<CDll>::iterator it = g_sectionLoader.m_vecLoadedDLLs.begin();
 123   while (it != g_sectionLoader.m_vecLoadedDLLs.end())
 124   {
 125     CDll& dll = *it;
 126     if (dll.m_pDll)
 127       DllLoaderContainer::ReleaseModule(dll.m_pDll);
 128     it = g_sectionLoader.m_vecLoadedDLLs.erase(it);
 129   }
 130 }