/*
** Function: 当进程中有多个模块要使用python时，只能公用同一套python环境，此时python环境的初始化和反初始化需要协调，因此提供一个公共模块来对
** python环境的初始化和反初始化进行控制，避免各个模块随意修改改python环境导致模块无法并存。
** Usage: 使用方法，让这些使用python的模块都依赖PythonInst，一些初始化和环境配置的动作统一调PythonInst接口完成。
*/#ifdef PYTHONINST_EXPORTS
#define PYTHONINST_API __declspec(dllexport)
#else
#define PYTHONINST_API __declspec(dllimport)
#endif#define PYTHONINST_CONST_HANDLE 1#ifdef __cplusplus
extern "C"
{
#endif/*** @ Name: Python_Init** @ Brief: Python初始化，如果本接口是被首次调用，将检测Python环境是否已初始化，如果未初始化则执行初始化，否则直接返回PYTHONINST_CONST_HANDLE；** 如果不是首次调用，则返回PYTHONINST_CONST_HANDLE或者返回一个新建句柄。** @ Param: const wchar_t* strPythonHome 设置python工作目录(Python_Init第一次被调用时才生效)。** @ Return: void* 返回引用句柄(接口失败时返回NULL)。该句柄是本模块调用初始化接口的句柄凭证，在模块需要退出时，传递给Fini进行解引用。*/PYTHONINST_API void* __stdcall Python_Init(const wchar_t* strPythonHome);/*** @ Name: Python_Fini** @ Brief: Python反初始化，如果hHandle为有效句柄，则引用计数减少(减到0时将销毁Python解释器)，如果句柄无效则不做任何处理。** @ Param: void* hHandle 由Python_Init创建得到的句柄，hHandle可能是PYTHONINST_CONST_HANDLE / 有效句柄 / NULL** @ Return: void*/PYTHONINST_API void __stdcall Python_Fini(void* hHandle);/*** @ Name: Python_SetGlobalPyHome** @ Brief: 设置全局的Python工作空间，等同于Python_Init传入的参数，在Python_Init首次被调用之前传入有效。** @ Param: const wchar_t* strPath Python工作空间路径，设为NULL时，表示使用默认路径作为Python工作空间。** @ Return: int 返回0表示成功，否则表示错误码。*/PYTHONINST_API int __stdcall Python_SetGlobalPythonHome(const wchar_t* strPath);/*** @ Name: Python_AppendPythonHome** @ Brief: 追加Python工作空间路径。** @ Param: const wchar_t* strPath Python工作空间路径。** @ Return: int 返回0表示成功，否则表示错误码。*/PYTHONINST_API int __stdcall Python_AppendPythonHome(const wchar_t* strPath);/*** @ Name: Python_SetGlobalInstance** @ Brief: 使能/关闭 全局Python实例功能(Python_Init首次被调用之前传入有效)。如果开启，则在Python_Init被调用时，额外创建一个全局的伴生** Handle，即便所有的实例都被Fini(全局Handle除外)，python解释器因为全局实例未销毁从而继续被保留，其他模块还可以继续使用python解释器。** @ Param: int enable 是否开启，1表示开启，0表示关闭。** @ Return: int 返回0表示成功，否则表示错误码。*/PYTHONINST_API int __stdcall Python_SetGlobalInstanceEnable(int enable);/*** @ Name: Python_GetGlobalInstance** @ Brief: 获取全局Python实例句柄。全局实例句柄在运行过程中会失效，外部不要做缓存，需要时来查询一下即可。** @ Param: void** @ Return: void* 全局实例句柄。*/PYTHONINST_API void* __stdcall Python_GetGlobalInstance();#ifdef __cplusplus
}
#endif#include <python.h>
#include <map>
#include <mutex>
#include <memory>
#define PYTHONINST_EXPORTS
#include "PythonInst.h"class PythonInstance
{
public:static PythonInstance* CreateInstance(const wchar_t* strPythonHome);static void DestroyInstance(PythonInstance* handle);~PythonInstance();static int PreparePythonHome(const wchar_t* strPythonHome);static int SetGlobalInstEnable(int bEnable);static int SetPythonHome(const wchar_t* strPythonHome, bool append=false);static PythonInstance* GetGlobalInst();
private:static std::mutex s_PyInitMutex;static std::map<void*, std::shared_ptr<PythonInstance>> s_mapInst;static std::wstring s_strPythonHome;static int s_bGloobalInst;static PythonInstance* s_GlobalHandle;private:PythonInstance();static void SetPythonGlobal();static int CreateGlobalInstWhenEnable();static void ResetIfGlobalInst(void* handle);};class PythonThreadLocker // python lock guard
{
public:PythonThreadLocker() {//if (PyGILState_Check() != 1)state = PyGILState_Ensure();}~PythonThreadLocker() {//if(state != PyGILState_UNLOCKED)PyGILState_Release(state);}
private:PyGILState_STATE state = PyGILState_UNLOCKED;
};typedef std::shared_ptr<PythonInstance> PythonInstancePtr;std::mutex PythonInstance::s_PyInitMutex;
std::map<void*, PythonInstancePtr> PythonInstance::s_mapInst;
std::wstring PythonInstance::s_strPythonHome = L"";
int PythonInstance::s_bGloobalInst = 0;
PythonInstance* PythonInstance::s_GlobalHandle = NULL;PythonInstance::PythonInstance()
{}PythonInstance::~PythonInstance()
{}void PythonInstance::SetPythonGlobal()
{if (0 != s_strPythonHome.compare(L"")){const wchar_t* envStr = Py_GetPythonHome();wchar_t env[1024] = {};if (envStr != NULL){_snwprintf_s(env, 1024,1023, L"%s;%s", envStr, s_strPythonHome.c_str());Py_SetPythonHome(env);}elsePy_SetPythonHome(s_strPythonHome.c_str());}
}int PythonInstance::SetPythonHome(const wchar_t* strPythonHome, bool append )
{if (NULL != strPythonHome && Py_IsInitialized()){PythonThreadLocker lock;if (append) {const wchar_t* envStr = Py_GetPythonHome();if (envStr != NULL){wchar_t env[1024] = {};_snwprintf_s(env, 1024, 1023, L"%s;%s", envStr, strPythonHome);Py_SetPythonHome(env);}elsePy_SetPythonHome(strPythonHome);}elsePy_SetPythonHome(strPythonHome);return 0;}return -1;
}int PythonInstance::CreateGlobalInstWhenEnable()
{if (0 != s_bGloobalInst){std::shared_ptr<PythonInstance> pInst(new PythonInstance());if (nullptr == pInst){return -1;}s_mapInst[pInst.get()] = pInst;ResetIfGlobalInst(s_GlobalHandle);s_GlobalHandle = pInst.get();}return 0;
}void PythonInstance::ResetIfGlobalInst(void* handle)
{if (handle == s_GlobalHandle){auto it = s_mapInst.find(s_GlobalHandle);if (it != s_mapInst.end())s_mapInst.erase(s_GlobalHandle);s_GlobalHandle = NULL;}
}#define GLOBAL_MODE_RETURN() {if(s_GlobalHandle != NULL) \
{\auto it = s_mapInst.find(s_GlobalHandle); \if(it != s_mapInst.end()) \{\return (PythonInstance*)PYTHONINST_CONST_HANDLE;\}\
}\
}PythonInstance* PythonInstance::CreateInstance(const wchar_t* strPythonHome)
{std::lock_guard<std::mutex> cLock(s_PyInitMutex);PythonInstancePtr pInst = PythonInstancePtr(new PythonInstance);if (NULL == pInst)return NULL;if (0 == s_mapInst.size()){if (Py_IsInitialized()){// 这种情况说明模块没有调用本库的Python_Init接口完成python初始化，而是在其他地方对python环境初始化了，本// 库不负责引用计数管理，直接返回(避免Destroy接口内部在销毁句柄时报错，返回非NULL)return (PythonInstance*)PYTHONINST_CONST_HANDLE;}// 先进行全局设置SetPythonGlobal();//如果入参提供了工作空间，则更新为用户指定的工作空间SetPythonHome(strPythonHome);// 初始化Py_Initialize();if (!Py_IsInitialized())return NULL;/*if (!PyEval_ThreadsInitialized()) // depreacted from python 3.7 使能多线程，自3.7以后，该接口功能合并到了Py_Initialize{PyEval_InitThreads();}*/CreateGlobalInstWhenEnable();//如果开启了全局实例，则额外创建一个全局伴生实例}GLOBAL_MODE_RETURN();s_mapInst[pInst.get()] = pInst;return pInst.get();
}void PythonInstance::DestroyInstance(PythonInstance* handle)
{std::lock_guard<std::mutex> cLock(s_PyInitMutex);if (NULL == handle)return;auto it = s_mapInst.find(handle);if (it != s_mapInst.end())s_mapInst.erase(it);ResetIfGlobalInst(handle);if (0 != s_mapInst.size())return;try {PyGILState_STATE gilOk=PyGILState_Ensure();Py_Finalize();s_GlobalHandle = NULL;//PyGILState_Release(gilOk);//no need to release, because things has been deinitialized by Py_Finalize.}catch (...){PyErr_SetString(PyExc_RuntimeError,"PythonInstance Deinitialization Failed.");}
}int PythonInstance::PreparePythonHome(const wchar_t* strPythonHome)
{std::lock_guard<std::mutex> cLock(s_PyInitMutex);if (NULL == strPythonHome)s_strPythonHome = L"";elses_strPythonHome = strPythonHome;return 0;
}int PythonInstance::SetGlobalInstEnable(int bEnable)
{std::lock_guard<std::mutex> cLock(s_PyInitMutex);s_bGloobalInst = bEnable;return 0;
}PythonInstance* PythonInstance::GetGlobalInst()
{std::lock_guard<std::mutex> cLock(s_PyInitMutex);return s_GlobalHandle;
}PYTHONINST_API void* __stdcall Python_Init(const wchar_t* strPythonHome)
{return PythonInstance::CreateInstance(strPythonHome);
}PYTHONINST_API void __stdcall Python_Fini(void* hHandle)
{return PythonInstance::DestroyInstance((PythonInstance*)hHandle);
}PYTHONINST_API int __stdcall Python_SetGlobalPythonHome(const wchar_t* strPath)
{return PythonInstance::PreparePythonHome(strPath);
}PYTHONINST_API int __stdcall Python_AppendPythonHome(const wchar_t* strPath)
{return PythonInstance::SetPythonHome(strPath,true);
}PYTHONINST_API int __stdcall Python_SetGlobalInstanceEnable(int enable)
{return PythonInstance::SetGlobalInstEnable(enable);
}PYTHONINST_API void* __stdcall Python_GetGlobalInstance()
{return PythonInstance::GetGlobalInst();
}众所周知，cc++中调用任何python 接口前，必须对python 解释器进行初始化，并进行必要的环境配置，这些初始化和环境配置是全局生效的，如果这些接口放到各个模块内部执行，将不利于管理，所以需要提炼一个公共模块，对python的全局环境进行初始化和配置，增加防护措施，以使各个模块和谐共存。
