llvm-project/lldb/source/Core/PluginManager.cpp

//===-- PluginManager.cpp ---------------------------------------*- C++ -*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//

#include "lldb/Core/PluginManager.h"

#include <string>
#include <vector>

#include "lldb/Core/Error.h"
#include "lldb/Host/FileSpec.h"
#include "lldb/Host/Host.h"
#include "lldb/Host/Mutex.h"

using namespace lldb;
using namespace lldb_private;

enum PluginAction
{
    ePluginRegisterInstance,
    ePluginUnregisterInstance,
    ePluginGetInstanceAtIndex
};

struct PluginInfo
{
    void *plugin_handle;
    void *plugin_init_callback;
    void *plugin_term_callback;
};

typedef std::map<FileSpec, PluginInfo> PluginTerminateMap;

static Mutex &
GetPluginMapMutex ()
{
    static Mutex g_plugin_map_mutex (Mutex::eMutexTypeRecursive);
    return g_plugin_map_mutex;
}

static PluginTerminateMap &
GetPluginMap ()
{
    static PluginTerminateMap g_plugin_map;
    return g_plugin_map;
}

static bool
PluginIsLoaded (const FileSpec &plugin_file_spec)
{
    Mutex::Locker locker (GetPluginMapMutex ());
    PluginTerminateMap &plugin_map = GetPluginMap ();
    return plugin_map.find (plugin_file_spec) != plugin_map.end();
}
    
static void
SetPluginInfo (const FileSpec &plugin_file_spec, const PluginInfo &plugin_info)
{
    Mutex::Locker locker (GetPluginMapMutex ());
    PluginTerminateMap &plugin_map = GetPluginMap ();
    assert (plugin_map.find (plugin_file_spec) != plugin_map.end());
    plugin_map[plugin_file_spec] = plugin_info;
}


static FileSpec::EnumerateDirectoryResult 
LoadPluginCallback 
(
    void *baton,
    FileSpec::FileType file_type,
    const FileSpec &file_spec
)
{
//    PluginManager *plugin_manager = (PluginManager *)baton;
    Error error;
    
    // If we have a regular file, a symbolic link or unknown file type, try
    // and process the file. We must handle unknown as sometimes the directory 
    // enumeration might be enumerating a file system that doesn't have correct
    // file type information.
    if (file_type == FileSpec::eFileTypeRegular         ||
        file_type == FileSpec::eFileTypeSymbolicLink    ||
        file_type == FileSpec::eFileTypeUnknown          )
    {
        FileSpec plugin_file_spec (file_spec);
        plugin_file_spec.ResolvePath();
        
        if (PluginIsLoaded (plugin_file_spec))
            return FileSpec::eEnumerateDirectoryResultNext;
        else
        {
            PluginInfo plugin_info = { NULL, NULL, NULL };
            uint32_t flags = Host::eDynamicLibraryOpenOptionLazy |
                             Host::eDynamicLibraryOpenOptionLocal |
                             Host::eDynamicLibraryOpenOptionLimitGetSymbol;

            plugin_info.plugin_handle = Host::DynamicLibraryOpen (plugin_file_spec, flags, error);
            if (plugin_info.plugin_handle)
            {
                bool success = false;
                plugin_info.plugin_init_callback = Host::DynamicLibraryGetSymbol (plugin_info.plugin_handle, "LLDBPluginInitialize", error);
                if (plugin_info.plugin_init_callback)
                {
                    // Call the plug-in "bool LLDBPluginInitialize(void)" function
                    success = ((bool (*)(void))plugin_info.plugin_init_callback)();
                }

                if (success)
                {
                    // It is ok for the "LLDBPluginTerminate" symbol to be NULL
                    plugin_info.plugin_term_callback = Host::DynamicLibraryGetSymbol (plugin_info.plugin_handle, "LLDBPluginTerminate", error);
                }
                else 
                {
                    // The initialize function returned FALSE which means the
                    // plug-in might not be compatible, or might be too new or
                    // too old, or might not want to run on this machine.
                    Host::DynamicLibraryClose (plugin_info.plugin_handle);
                    plugin_info.plugin_handle = NULL;
                    plugin_info.plugin_init_callback = NULL;
                }

                // Regardless of success or failure, cache the plug-in load
                // in our plug-in info so we don't try to load it again and 
                // again.
                SetPluginInfo (plugin_file_spec, plugin_info);

                return FileSpec::eEnumerateDirectoryResultNext;
            }
        }
    }
    
    if (file_type == FileSpec::eFileTypeUnknown     ||
        file_type == FileSpec::eFileTypeDirectory   ||
        file_type == FileSpec::eFileTypeSymbolicLink )
    {
        // Try and recurse into anything that a directory or symbolic link. 
        // We must also do this for unknown as sometimes the directory enumeration
        // might be enurating a file system that doesn't have correct file type
        // information.
        return FileSpec::eEnumerateDirectoryResultEnter;
    }

    return FileSpec::eEnumerateDirectoryResultNext;
}


void
PluginManager::Initialize ()
{
#if 1
    FileSpec dir_spec;
    const bool find_directories = true;
    const bool find_files = true;
    const bool find_other = true;
    char dir_path[PATH_MAX];
    if (Host::GetLLDBPath (ePathTypeLLDBSystemPlugins, dir_spec))
    {
        if (dir_spec.Exists() && dir_spec.GetPath(dir_path, sizeof(dir_path)))
        {
            FileSpec::EnumerateDirectory (dir_path, 
                                          find_directories,
                                          find_files,
                                          find_other,
                                          LoadPluginCallback,
                                          NULL);
        }
    }

    if (Host::GetLLDBPath (ePathTypeLLDBUserPlugins, dir_spec))
    {
        if (dir_spec.Exists() && dir_spec.GetPath(dir_path, sizeof(dir_path)))
        {
            FileSpec::EnumerateDirectory (dir_path, 
                                          find_directories,
                                          find_files,
                                          find_other,
                                          LoadPluginCallback,
                                          NULL);
        }
    }
#endif
}

void
PluginManager::Terminate ()
{
    Mutex::Locker locker (GetPluginMapMutex ());
    PluginTerminateMap &plugin_map = GetPluginMap ();
    
    PluginTerminateMap::const_iterator pos, end = plugin_map.end();
    for (pos = plugin_map.begin(); pos != end; ++pos)
    {
        // Call the plug-in "void LLDBPluginTerminate (void)" function if there
        // is one (if the symbol was not NULL).
        if (pos->second.plugin_handle)
        {
            if (pos->second.plugin_term_callback)
                ((void (*)(void))pos->second.plugin_term_callback)();
            Host::DynamicLibraryClose (pos->second.plugin_handle);
        }
    }
    plugin_map.clear();
}


#pragma mark ABI


struct ABIInstance
{
    ABIInstance() :
        name(),
        description(),
        create_callback(NULL)
    {
    }

    std::string name;
    std::string description;
    ABICreateInstance create_callback;
};

typedef std::vector<ABIInstance> ABIInstances;

static Mutex &
GetABIInstancesMutex ()
{
    static Mutex g_instances_mutex (Mutex::eMutexTypeRecursive);
    return g_instances_mutex;
}

static ABIInstances &
GetABIInstances ()
{
    static ABIInstances g_instances;
    return g_instances;
}

bool
PluginManager::RegisterPlugin
(
    const char *name,
    const char *description,
    ABICreateInstance create_callback
)
{
    if (create_callback)
    {
        ABIInstance instance;
        assert (name && name[0]);
        instance.name = name;
        if (description && description[0])
            instance.description = description;
        instance.create_callback = create_callback;
        Mutex::Locker locker (GetABIInstancesMutex ());
        GetABIInstances ().push_back (instance);
        return true;
    }
    return false;
}

bool
PluginManager::UnregisterPlugin (ABICreateInstance create_callback)
{
    if (create_callback)
    {
        Mutex::Locker locker (GetABIInstancesMutex ());
        ABIInstances &instances = GetABIInstances ();

        ABIInstances::iterator pos, end = instances.end();
        for (pos = instances.begin(); pos != end; ++ pos)
        {
            if (pos->create_callback == create_callback)
            {
                instances.erase(pos);
                return true;
            }
        }
    }
    return false;
}

ABICreateInstance
PluginManager::GetABICreateCallbackAtIndex (uint32_t idx)
{
    Mutex::Locker locker (GetABIInstancesMutex ());
    ABIInstances &instances = GetABIInstances ();

    if (idx < instances.size())
        return instances[idx].create_callback;
    return NULL;
}

ABICreateInstance
PluginManager::GetABICreateCallbackForPluginName (const char *name)
{
    if (name && name[0])
    {
        Mutex::Locker locker (GetABIInstancesMutex ());
        std::string ss_name(name);
        ABIInstances &instances = GetABIInstances ();

        ABIInstances::iterator pos, end = instances.end();
        for (pos = instances.begin(); pos != end; ++ pos)
        {
            if (pos->name == ss_name)
                return pos->create_callback;
        }
    }
    return NULL;
}


#pragma mark Disassembler


struct DisassemblerInstance
{
    DisassemblerInstance() :
        name(),
        description(),
        create_callback(NULL)
    {
    }

    std::string name;
    std::string description;
    DisassemblerCreateInstance create_callback;
};

typedef std::vector<DisassemblerInstance> DisassemblerInstances;

static bool
AccessDisassemblerInstances (PluginAction action, DisassemblerInstance &instance, uint32_t index)
{
    static DisassemblerInstances g_plugin_instances;

    switch (action)
    {
    case ePluginRegisterInstance:
        if (instance.create_callback)
        {
            g_plugin_instances.push_back (instance);
            return true;
        }
        break;

    case ePluginUnregisterInstance:
        if (instance.create_callback)
        {
            DisassemblerInstances::iterator pos, end = g_plugin_instances.end();
            for (pos = g_plugin_instances.begin(); pos != end; ++ pos)
            {
                if (pos->create_callback == instance.create_callback)
                {
                    g_plugin_instances.erase(pos);
                    return true;
                }
            }
        }
        break;

    case ePluginGetInstanceAtIndex:
        if (index < g_plugin_instances.size())
        {
            instance = g_plugin_instances[index];
            return true;
        }
        break;

    default:
        break;
    }
    return false;
}


bool
PluginManager::RegisterPlugin
(
    const char *name,
    const char *description,
    DisassemblerCreateInstance create_callback
)
{
    if (create_callback)
    {
        DisassemblerInstance instance;
        assert (name && name[0]);
        instance.name = name;
        if (description && description[0])
            instance.description = description;
        instance.create_callback = create_callback;
        return AccessDisassemblerInstances (ePluginRegisterInstance, instance, 0);
    }
    return false;
}

bool
PluginManager::UnregisterPlugin (DisassemblerCreateInstance create_callback)
{
    if (create_callback)
    {
        DisassemblerInstance instance;
        instance.create_callback = create_callback;
        return AccessDisassemblerInstances (ePluginUnregisterInstance, instance, 0);
    }
    return false;
}

DisassemblerCreateInstance
PluginManager::GetDisassemblerCreateCallbackAtIndex (uint32_t idx)
{
    DisassemblerInstance instance;
    if (AccessDisassemblerInstances (ePluginGetInstanceAtIndex, instance, idx))
        return instance.create_callback;
    return NULL;
}

DisassemblerCreateInstance
PluginManager::GetDisassemblerCreateCallbackForPluginName (const char *name)
{
    if (name && name[0])
    {
        DisassemblerInstance instance;
        std::string ss_name(name);
        for (uint32_t idx = 0; AccessDisassemblerInstances (ePluginGetInstanceAtIndex, instance, idx); ++idx)
        {
            if (instance.name == ss_name)
                return instance.create_callback;
        }
    }
    return NULL;
}



#pragma mark DynamicLoader


struct DynamicLoaderInstance
{
    DynamicLoaderInstance() :
        name(),
        description(),
        create_callback(NULL)
    {
    }

    std::string name;
    std::string description;
    DynamicLoaderCreateInstance create_callback;
};

typedef std::vector<DynamicLoaderInstance> DynamicLoaderInstances;

static bool
AccessDynamicLoaderInstances (PluginAction action, DynamicLoaderInstance &instance, uint32_t index)
{
    static DynamicLoaderInstances g_plugin_instances;

    switch (action)
    {
    case ePluginRegisterInstance:
        if (instance.create_callback)
        {
            g_plugin_instances.push_back (instance);
            return true;
        }
        break;

    case ePluginUnregisterInstance:
        if (instance.create_callback)
        {
            DynamicLoaderInstances::iterator pos, end = g_plugin_instances.end();
            for (pos = g_plugin_instances.begin(); pos != end; ++ pos)
            {
                if (pos->create_callback == instance.create_callback)
                {
                    g_plugin_instances.erase(pos);
                    return true;
                }
            }
        }
        break;

    case ePluginGetInstanceAtIndex:
        if (index < g_plugin_instances.size())
        {
            instance = g_plugin_instances[index];
            return true;
        }
        break;

    default:
        break;
    }
    return false;
}


bool
PluginManager::RegisterPlugin
(
    const char *name,
    const char *description,
    DynamicLoaderCreateInstance create_callback
)
{
    if (create_callback)
    {
        DynamicLoaderInstance instance;
        assert (name && name[0]);
        instance.name = name;
        if (description && description[0])
            instance.description = description;
        instance.create_callback = create_callback;
        return AccessDynamicLoaderInstances (ePluginRegisterInstance, instance, 0);
    }
    return false;
}

bool
PluginManager::UnregisterPlugin (DynamicLoaderCreateInstance create_callback)
{
    if (create_callback)
    {
        DynamicLoaderInstance instance;
        instance.create_callback = create_callback;
        return AccessDynamicLoaderInstances (ePluginUnregisterInstance, instance, 0);
    }
    return false;
}

DynamicLoaderCreateInstance
PluginManager::GetDynamicLoaderCreateCallbackAtIndex (uint32_t idx)
{
    DynamicLoaderInstance instance;
    if (AccessDynamicLoaderInstances (ePluginGetInstanceAtIndex, instance, idx))
        return instance.create_callback;
    return NULL;
}

DynamicLoaderCreateInstance
PluginManager::GetDynamicLoaderCreateCallbackForPluginName (const char *name)
{
    if (name && name[0])
    {
        DynamicLoaderInstance instance;
        std::string ss_name(name);
        for (uint32_t idx = 0; AccessDynamicLoaderInstances (ePluginGetInstanceAtIndex, instance, idx); ++idx)
        {
            if (instance.name == ss_name)
                return instance.create_callback;
        }
    }
    return NULL;
}

#pragma mark EmulateInstruction


struct EmulateInstructionInstance
{
    EmulateInstructionInstance() :
    name(),
    description(),
    create_callback(NULL)
    {
    }
    
    std::string name;
    std::string description;
    EmulateInstructionCreateInstance create_callback;
};

typedef std::vector<EmulateInstructionInstance> EmulateInstructionInstances;

static bool
AccessEmulateInstructionInstances (PluginAction action, EmulateInstructionInstance &instance, uint32_t index)
{
    static EmulateInstructionInstances g_plugin_instances;
    
    switch (action)
    {
        case ePluginRegisterInstance:
            if (instance.create_callback)
            {
                g_plugin_instances.push_back (instance);
                return true;
            }
            break;
            
        case ePluginUnregisterInstance:
            if (instance.create_callback)
            {
                EmulateInstructionInstances::iterator pos, end = g_plugin_instances.end();
                for (pos = g_plugin_instances.begin(); pos != end; ++ pos)
                {
                    if (pos->create_callback == instance.create_callback)
                    {
                        g_plugin_instances.erase(pos);
                        return true;
                    }
                }
            }
            break;
            
        case ePluginGetInstanceAtIndex:
            if (index < g_plugin_instances.size())
            {
                instance = g_plugin_instances[index];
                return true;
            }
            break;
            
        default:
            break;
    }
    return false;
}


bool
PluginManager::RegisterPlugin
(
    const char *name,
    const char *description,
    EmulateInstructionCreateInstance create_callback
)
{
    if (create_callback)
    {
        EmulateInstructionInstance instance;
        assert (name && name[0]);
        instance.name = name;
        if (description && description[0])
            instance.description = description;
        instance.create_callback = create_callback;
        return AccessEmulateInstructionInstances (ePluginRegisterInstance, instance, 0);
    }
    return false;
}

bool
PluginManager::UnregisterPlugin (EmulateInstructionCreateInstance create_callback)
{
    if (create_callback)
    {
        EmulateInstructionInstance instance;
        instance.create_callback = create_callback;
        return AccessEmulateInstructionInstances (ePluginUnregisterInstance, instance, 0);
    }
    return false;
}

EmulateInstructionCreateInstance
PluginManager::GetEmulateInstructionCreateCallbackAtIndex (uint32_t idx)
{
    EmulateInstructionInstance instance;
    if (AccessEmulateInstructionInstances (ePluginGetInstanceAtIndex, instance, idx))
        return instance.create_callback;
    return NULL;
}

EmulateInstructionCreateInstance
PluginManager::GetEmulateInstructionCreateCallbackForPluginName (const char *name)
{
    if (name && name[0])
    {
        EmulateInstructionInstance instance;
        std::string ss_name(name);
        for (uint32_t idx = 0; AccessEmulateInstructionInstances (ePluginGetInstanceAtIndex, instance, idx); ++idx)
        {
            if (instance.name == ss_name)
                return instance.create_callback;
        }
    }
    return NULL;
}


#pragma mark LanguageRuntime


struct LanguageRuntimeInstance
{
    LanguageRuntimeInstance() :
        name(),
        description(),
        create_callback(NULL)
    {
    }

    std::string name;
    std::string description;
    LanguageRuntimeCreateInstance create_callback;
};

typedef std::vector<LanguageRuntimeInstance> LanguageRuntimeInstances;

static bool
AccessLanguageRuntimeInstances (PluginAction action, LanguageRuntimeInstance &instance, uint32_t index)
{
    static LanguageRuntimeInstances g_plugin_instances;

    switch (action)
    {
        case ePluginRegisterInstance:
            if (instance.create_callback)
            {
                g_plugin_instances.push_back (instance);
                return true;
            }
            break;

        case ePluginUnregisterInstance:
            if (instance.create_callback)
            {
                LanguageRuntimeInstances::iterator pos, end = g_plugin_instances.end();
                for (pos = g_plugin_instances.begin(); pos != end; ++ pos)
                {
                    if (pos->create_callback == instance.create_callback)
                    {
                        g_plugin_instances.erase(pos);
                        return true;
                    }
                }
            }
            break;

        case ePluginGetInstanceAtIndex:
            if (index < g_plugin_instances.size())
            {
                instance = g_plugin_instances[index];
                return true;
            }
            break;

        default:
            break;
    }
    return false;
}


bool
PluginManager::RegisterPlugin
(
    const char *name,
    const char *description,
    LanguageRuntimeCreateInstance create_callback
)
{
    if (create_callback)
    {
        LanguageRuntimeInstance instance;
        assert (name && name[0]);
        instance.name = name;
        if (description && description[0])
            instance.description = description;
        instance.create_callback = create_callback;
        return AccessLanguageRuntimeInstances (ePluginRegisterInstance, instance, 0);
    }
    return false;
}

bool
PluginManager::UnregisterPlugin (LanguageRuntimeCreateInstance create_callback)
{
    if (create_callback)
    {
        LanguageRuntimeInstance instance;
        instance.create_callback = create_callback;
        return AccessLanguageRuntimeInstances (ePluginUnregisterInstance, instance, 0);
    }
    return false;
}

LanguageRuntimeCreateInstance
PluginManager::GetLanguageRuntimeCreateCallbackAtIndex (uint32_t idx)
{
    LanguageRuntimeInstance instance;
    if (AccessLanguageRuntimeInstances (ePluginGetInstanceAtIndex, instance, idx))
        return instance.create_callback;
    return NULL;
}

LanguageRuntimeCreateInstance
PluginManager::GetLanguageRuntimeCreateCallbackForPluginName (const char *name)
{
    if (name && name[0])
    {
        LanguageRuntimeInstance instance;
        std::string ss_name(name);
        for (uint32_t idx = 0; AccessLanguageRuntimeInstances (ePluginGetInstanceAtIndex, instance, idx); ++idx)
        {
            if (instance.name == ss_name)
                return instance.create_callback;
        }
    }
    return NULL;
}

#pragma mark ObjectFile

struct ObjectFileInstance
{
    ObjectFileInstance() :
        name(),
        description(),
        create_callback(NULL)
    {
    }

    std::string name;
    std::string description;
    ObjectFileCreateInstance create_callback;
};

typedef std::vector<ObjectFileInstance> ObjectFileInstances;

static bool
AccessObjectFileInstances (PluginAction action, ObjectFileInstance &instance, uint32_t index)
{
    static ObjectFileInstances g_plugin_instances;

    switch (action)
    {
    case ePluginRegisterInstance:
        if (instance.create_callback)
        {
            g_plugin_instances.push_back (instance);
            return true;
        }
        break;

    case ePluginUnregisterInstance:
        if (instance.create_callback)
        {
            ObjectFileInstances::iterator pos, end = g_plugin_instances.end();
            for (pos = g_plugin_instances.begin(); pos != end; ++ pos)
            {
                if (pos->create_callback == instance.create_callback)
                {
                    g_plugin_instances.erase(pos);
                    return true;
                }
            }
        }
        break;

    case ePluginGetInstanceAtIndex:
        if (index < g_plugin_instances.size())
        {
            instance = g_plugin_instances[index];
            return true;
        }
        break;

    default:
        break;
    }
    return false;
}


bool
PluginManager::RegisterPlugin
(
    const char *name,
    const char *description,
    ObjectFileCreateInstance create_callback
)
{
    if (create_callback)
    {
        ObjectFileInstance instance;
        assert (name && name[0]);
        instance.name = name;
        if (description && description[0])
            instance.description = description;
        instance.create_callback = create_callback;
        return AccessObjectFileInstances (ePluginRegisterInstance, instance, 0);
    }
    return false;
}

bool
PluginManager::UnregisterPlugin (ObjectFileCreateInstance create_callback)
{
    if (create_callback)
    {
        ObjectFileInstance instance;
        instance.create_callback = create_callback;
        return AccessObjectFileInstances (ePluginUnregisterInstance, instance, 0);
    }
    return false;
}

ObjectFileCreateInstance
PluginManager::GetObjectFileCreateCallbackAtIndex (uint32_t idx)
{
    ObjectFileInstance instance;
    if (AccessObjectFileInstances (ePluginGetInstanceAtIndex, instance, idx))
        return instance.create_callback;
    return NULL;
}
ObjectFileCreateInstance
PluginManager::GetObjectFileCreateCallbackForPluginName (const char *name)
{
    if (name && name[0])
    {
        ObjectFileInstance instance;
        std::string ss_name(name);
        for (uint32_t idx = 0; AccessObjectFileInstances (ePluginGetInstanceAtIndex, instance, idx); ++idx)
        {
            if (instance.name == ss_name)
                return instance.create_callback;
        }
    }
    return NULL;
}



#pragma mark ObjectContainer

struct ObjectContainerInstance
{
    ObjectContainerInstance() :
        name(),
        description(),
        create_callback(NULL)
    {
    }

    std::string name;
    std::string description;
    ObjectContainerCreateInstance create_callback;
};

typedef std::vector<ObjectContainerInstance> ObjectContainerInstances;

static bool
AccessObjectContainerInstances (PluginAction action, ObjectContainerInstance &instance, uint32_t index)
{
    static ObjectContainerInstances g_plugin_instances;

    switch (action)
    {
    case ePluginRegisterInstance:
        if (instance.create_callback)
        {
            g_plugin_instances.push_back (instance);
            return true;
        }
        break;

    case ePluginUnregisterInstance:
        if (instance.create_callback)
        {
            ObjectContainerInstances::iterator pos, end = g_plugin_instances.end();
            for (pos = g_plugin_instances.begin(); pos != end; ++ pos)
            {
                if (pos->create_callback == instance.create_callback)
                {
                    g_plugin_instances.erase(pos);
                    return true;
                }
            }
        }
        break;

    case ePluginGetInstanceAtIndex:
        if (index < g_plugin_instances.size())
        {
            instance = g_plugin_instances[index];
            return true;
        }
        break;

    default:
        break;
    }
    return false;
}


bool
PluginManager::RegisterPlugin
(
    const char *name,
    const char *description,
    ObjectContainerCreateInstance create_callback
)
{
    if (create_callback)
    {
        ObjectContainerInstance instance;
        assert (name && name[0]);
        instance.name = name;
        if (description && description[0])
            instance.description = description;
        instance.create_callback = create_callback;
        return AccessObjectContainerInstances (ePluginRegisterInstance, instance, 0);
    }
    return false;
}

bool
PluginManager::UnregisterPlugin (ObjectContainerCreateInstance create_callback)
{
    if (create_callback)
    {
        ObjectContainerInstance instance;
        instance.create_callback = create_callback;
        return AccessObjectContainerInstances (ePluginUnregisterInstance, instance, 0);
    }
    return false;
}

ObjectContainerCreateInstance
PluginManager::GetObjectContainerCreateCallbackAtIndex (uint32_t idx)
{
    ObjectContainerInstance instance;
    if (AccessObjectContainerInstances (ePluginGetInstanceAtIndex, instance, idx))
        return instance.create_callback;
    return NULL;
}
ObjectContainerCreateInstance
PluginManager::GetObjectContainerCreateCallbackForPluginName (const char *name)
{
    if (name && name[0])
    {
        ObjectContainerInstance instance;
        std::string ss_name(name);
        for (uint32_t idx = 0; AccessObjectContainerInstances (ePluginGetInstanceAtIndex, instance, idx); ++idx)
        {
            if (instance.name == ss_name)
                return instance.create_callback;
        }
    }
    return NULL;
}

#pragma mark LogChannel

struct LogChannelInstance
{
    LogChannelInstance() :
        name(),
        description(),
        create_callback(NULL)
    {
    }

    std::string name;
    std::string description;
    LogChannelCreateInstance create_callback;
};

typedef std::vector<LogChannelInstance> LogChannelInstances;

static bool
AccessLogChannelInstances (PluginAction action, LogChannelInstance &instance, uint32_t index)
{
    static LogChannelInstances g_plugin_instances;

    switch (action)
    {
    case ePluginRegisterInstance:
        if (instance.create_callback)
        {
            g_plugin_instances.push_back (instance);
            return true;
        }
        break;

    case ePluginUnregisterInstance:
        if (instance.create_callback)
        {
            LogChannelInstances::iterator pos, end = g_plugin_instances.end();
            for (pos = g_plugin_instances.begin(); pos != end; ++ pos)
            {
                if (pos->create_callback == instance.create_callback)
                {
                    g_plugin_instances.erase(pos);
                    return true;
                }
            }
        }
        break;

    case ePluginGetInstanceAtIndex:
        if (index < g_plugin_instances.size())
        {
            instance = g_plugin_instances[index];
            return true;
        }
        break;

    default:
        break;
    }
    return false;
}


bool
PluginManager::RegisterPlugin
(
    const char *name,
    const char *description,
    LogChannelCreateInstance create_callback
)
{
    if (create_callback)
    {
        LogChannelInstance instance;
        assert (name && name[0]);
        instance.name = name;
        if (description && description[0])
            instance.description = description;
        instance.create_callback = create_callback;
        return AccessLogChannelInstances (ePluginRegisterInstance, instance, 0);
    }
    return false;
}

bool
PluginManager::UnregisterPlugin (LogChannelCreateInstance create_callback)
{
    if (create_callback)
    {
        LogChannelInstance instance;
        instance.create_callback = create_callback;
        return AccessLogChannelInstances (ePluginUnregisterInstance, instance, 0);
    }
    return false;
}

const char *
PluginManager::GetLogChannelCreateNameAtIndex (uint32_t idx)
{
    LogChannelInstance instance;
    if (AccessLogChannelInstances (ePluginGetInstanceAtIndex, instance, idx))
        return instance.name.c_str();
    return NULL;
}


LogChannelCreateInstance
PluginManager::GetLogChannelCreateCallbackAtIndex (uint32_t idx)
{
    LogChannelInstance instance;
    if (AccessLogChannelInstances (ePluginGetInstanceAtIndex, instance, idx))
        return instance.create_callback;
    return NULL;
}

LogChannelCreateInstance
PluginManager::GetLogChannelCreateCallbackForPluginName (const char *name)
{
    if (name && name[0])
    {
        LogChannelInstance instance;
        std::string ss_name(name);
        for (uint32_t idx = 0; AccessLogChannelInstances (ePluginGetInstanceAtIndex, instance, idx); ++idx)
        {
            if (instance.name == ss_name)
                return instance.create_callback;
        }
    }
    return NULL;
}

#pragma mark Platform

struct PlatformInstance
{
    PlatformInstance() :
        name(),
        description(),
        create_callback(NULL)
    {
    }
    
    std::string name;
    std::string description;
    PlatformCreateInstance create_callback;
};

typedef std::vector<PlatformInstance> PlatformInstances;

static Mutex &
GetPlatformInstancesMutex ()
{
    static Mutex g_platform_instances_mutex (Mutex::eMutexTypeRecursive);
    return g_platform_instances_mutex;
}

static PlatformInstances &
GetPlatformInstances ()
{
    static PlatformInstances g_platform_instances;
    return g_platform_instances;
}

bool
PluginManager::RegisterPlugin (const char *name,
                               const char *description,
                               PlatformCreateInstance create_callback)
{
    if (create_callback)
    {
        Mutex::Locker locker (GetPlatformInstancesMutex ());
        
        PlatformInstance instance;
        assert (name && name[0]);
        instance.name = name;
        if (description && description[0])
            instance.description = description;
        instance.create_callback = create_callback;
        GetPlatformInstances ().push_back (instance);
        return true;
    }
    return false;
}

const char *
PluginManager::GetPlatformPluginNameAtIndex (uint32_t idx)
{
    Mutex::Locker locker (GetPlatformInstancesMutex ());
    PlatformInstances &platform_instances = GetPlatformInstances ();
    if (idx < platform_instances.size())
        return platform_instances[idx].name.c_str();
    return NULL;
}

const char *
PluginManager::GetPlatformPluginDescriptionAtIndex (uint32_t idx)
{
    Mutex::Locker locker (GetPlatformInstancesMutex ());
    PlatformInstances &platform_instances = GetPlatformInstances ();
    if (idx < platform_instances.size())
        return platform_instances[idx].description.c_str();
    return NULL;
}

bool
PluginManager::UnregisterPlugin (PlatformCreateInstance create_callback)
{
    if (create_callback)
    {
        Mutex::Locker locker (GetPlatformInstancesMutex ());
        PlatformInstances &platform_instances = GetPlatformInstances ();

        PlatformInstances::iterator pos, end = platform_instances.end();
        for (pos = platform_instances.begin(); pos != end; ++ pos)
        {
            if (pos->create_callback == create_callback)
            {
                platform_instances.erase(pos);
                return true;
            }
        }
    }
    return false;
}

PlatformCreateInstance
PluginManager::GetPlatformCreateCallbackAtIndex (uint32_t idx)
{
    Mutex::Locker locker (GetPlatformInstancesMutex ());
    PlatformInstances &platform_instances = GetPlatformInstances ();
    if (idx < platform_instances.size())
        return platform_instances[idx].create_callback;
    return NULL;
}

PlatformCreateInstance
PluginManager::GetPlatformCreateCallbackForPluginName (const char *name)
{
    if (name && name[0])
    {
        Mutex::Locker locker (GetPlatformInstancesMutex ());
        std::string ss_name(name);
        PlatformInstances &platform_instances = GetPlatformInstances ();

        PlatformInstances::iterator pos, end = platform_instances.end();
        for (pos = platform_instances.begin(); pos != end; ++ pos)
        {
            if (pos->name == ss_name)
                return pos->create_callback;
        }
    }
    return NULL;
}

#pragma mark Process

struct ProcessInstance
{
    ProcessInstance() :
    name(),
    description(),
    create_callback(NULL)
    {
    }
    
    std::string name;
    std::string description;
    ProcessCreateInstance create_callback;
};

typedef std::vector<ProcessInstance> ProcessInstances;

static bool
AccessProcessInstances (PluginAction action, ProcessInstance &instance, uint32_t index)
{
    static ProcessInstances g_plugin_instances;
    
    switch (action)
    {
        case ePluginRegisterInstance:
            if (instance.create_callback)
            {
                g_plugin_instances.push_back (instance);
                return true;
            }
            break;
            
        case ePluginUnregisterInstance:
            if (instance.create_callback)
            {
                ProcessInstances::iterator pos, end = g_plugin_instances.end();
                for (pos = g_plugin_instances.begin(); pos != end; ++ pos)
                {
                    if (pos->create_callback == instance.create_callback)
                    {
                        g_plugin_instances.erase(pos);
                        return true;
                    }
                }
            }
            break;
            
        case ePluginGetInstanceAtIndex:
            if (index < g_plugin_instances.size())
            {
                instance = g_plugin_instances[index];
                return true;
            }
            break;
            
        default:
            break;
    }
    return false;
}


bool
PluginManager::RegisterPlugin
(
 const char *name,
 const char *description,
 ProcessCreateInstance create_callback
 )
{
    if (create_callback)
    {
        ProcessInstance instance;
        assert (name && name[0]);
        instance.name = name;
        if (description && description[0])
            instance.description = description;
        instance.create_callback = create_callback;
        return AccessProcessInstances (ePluginRegisterInstance, instance, 0);
    }
    return false;
}

const char *
PluginManager::GetProcessPluginNameAtIndex (uint32_t idx)
{
    ProcessInstance instance;
    if (AccessProcessInstances (ePluginGetInstanceAtIndex, instance, idx))
        return instance.name.c_str();
    return NULL;
}

const char *
PluginManager::GetProcessPluginDescriptionAtIndex (uint32_t idx)
{
    ProcessInstance instance;
    if (AccessProcessInstances (ePluginGetInstanceAtIndex, instance, idx))
        return instance.description.c_str();
    return NULL;
}

bool
PluginManager::UnregisterPlugin (ProcessCreateInstance create_callback)
{
    if (create_callback)
    {
        ProcessInstance instance;
        instance.create_callback = create_callback;
        return AccessProcessInstances (ePluginUnregisterInstance, instance, 0);
    }
    return false;
}

ProcessCreateInstance
PluginManager::GetProcessCreateCallbackAtIndex (uint32_t idx)
{
    ProcessInstance instance;
    if (AccessProcessInstances (ePluginGetInstanceAtIndex, instance, idx))
        return instance.create_callback;
    return NULL;
}

ProcessCreateInstance
PluginManager::GetProcessCreateCallbackForPluginName (const char *name)
{
    if (name && name[0])
    {
        ProcessInstance instance;
        std::string ss_name(name);
        for (uint32_t idx = 0; AccessProcessInstances (ePluginGetInstanceAtIndex, instance, idx); ++idx)
        {
            if (instance.name == ss_name)
                return instance.create_callback;
        }
    }
    return NULL;
}

#pragma mark SymbolFile

struct SymbolFileInstance
{
    SymbolFileInstance() :
        name(),
        description(),
        create_callback(NULL)
    {
    }

    std::string name;
    std::string description;
    SymbolFileCreateInstance create_callback;
};

typedef std::vector<SymbolFileInstance> SymbolFileInstances;

static bool
AccessSymbolFileInstances (PluginAction action, SymbolFileInstance &instance, uint32_t index)
{
    static SymbolFileInstances g_plugin_instances;

    switch (action)
    {
    case ePluginRegisterInstance:
        if (instance.create_callback)
        {
            g_plugin_instances.push_back (instance);
            return true;
        }
        break;

    case ePluginUnregisterInstance:
        if (instance.create_callback)
        {
            SymbolFileInstances::iterator pos, end = g_plugin_instances.end();
            for (pos = g_plugin_instances.begin(); pos != end; ++ pos)
            {
                if (pos->create_callback == instance.create_callback)
                {
                    g_plugin_instances.erase(pos);
                    return true;
                }
            }
        }
        break;

    case ePluginGetInstanceAtIndex:
        if (index < g_plugin_instances.size())
        {
            instance = g_plugin_instances[index];
            return true;
        }
        break;

    default:
        break;
    }
    return false;
}


bool
PluginManager::RegisterPlugin
(
    const char *name,
    const char *description,
    SymbolFileCreateInstance create_callback
)
{
    if (create_callback)
    {
        SymbolFileInstance instance;
        assert (name && name[0]);
        instance.name = name;
        if (description && description[0])
            instance.description = description;
        instance.create_callback = create_callback;
        return AccessSymbolFileInstances (ePluginRegisterInstance, instance, 0);
    }
    return false;
}

bool
PluginManager::UnregisterPlugin (SymbolFileCreateInstance create_callback)
{
    if (create_callback)
    {
        SymbolFileInstance instance;
        instance.create_callback = create_callback;
        return AccessSymbolFileInstances (ePluginUnregisterInstance, instance, 0);
    }
    return false;
}

SymbolFileCreateInstance
PluginManager::GetSymbolFileCreateCallbackAtIndex (uint32_t idx)
{
    SymbolFileInstance instance;
    if (AccessSymbolFileInstances (ePluginGetInstanceAtIndex, instance, idx))
        return instance.create_callback;
    return NULL;
}
SymbolFileCreateInstance
PluginManager::GetSymbolFileCreateCallbackForPluginName (const char *name)
{
    if (name && name[0])
    {
        SymbolFileInstance instance;
        std::string ss_name(name);
        for (uint32_t idx = 0; AccessSymbolFileInstances (ePluginGetInstanceAtIndex, instance, idx); ++idx)
        {
            if (instance.name == ss_name)
                return instance.create_callback;
        }
    }
    return NULL;
}



#pragma mark SymbolVendor

struct SymbolVendorInstance
{
    SymbolVendorInstance() :
        name(),
        description(),
        create_callback(NULL)
    {
    }

    std::string name;
    std::string description;
    SymbolVendorCreateInstance create_callback;
};

typedef std::vector<SymbolVendorInstance> SymbolVendorInstances;

static bool
AccessSymbolVendorInstances (PluginAction action, SymbolVendorInstance &instance, uint32_t index)
{
    static SymbolVendorInstances g_plugin_instances;

    switch (action)
    {
    case ePluginRegisterInstance:
        if (instance.create_callback)
        {
            g_plugin_instances.push_back (instance);
            return true;
        }
        break;

    case ePluginUnregisterInstance:
        if (instance.create_callback)
        {
            SymbolVendorInstances::iterator pos, end = g_plugin_instances.end();
            for (pos = g_plugin_instances.begin(); pos != end; ++ pos)
            {
                if (pos->create_callback == instance.create_callback)
                {
                    g_plugin_instances.erase(pos);
                    return true;
                }
            }
        }
        break;

    case ePluginGetInstanceAtIndex:
        if (index < g_plugin_instances.size())
        {
            instance = g_plugin_instances[index];
            return true;
        }
        break;

    default:
        break;
    }
    return false;
}

bool
PluginManager::RegisterPlugin
(
    const char *name,
    const char *description,
    SymbolVendorCreateInstance create_callback
)
{
    if (create_callback)
    {
        SymbolVendorInstance instance;
        assert (name && name[0]);
        instance.name = name;
        if (description && description[0])
            instance.description = description;
        instance.create_callback = create_callback;
        return AccessSymbolVendorInstances (ePluginRegisterInstance, instance, 0);
    }
    return false;
}

bool
PluginManager::UnregisterPlugin (SymbolVendorCreateInstance create_callback)
{
    if (create_callback)
    {
        SymbolVendorInstance instance;
        instance.create_callback = create_callback;
        return AccessSymbolVendorInstances (ePluginUnregisterInstance, instance, 0);
    }
    return false;
}

SymbolVendorCreateInstance
PluginManager::GetSymbolVendorCreateCallbackAtIndex (uint32_t idx)
{
    SymbolVendorInstance instance;
    if (AccessSymbolVendorInstances (ePluginGetInstanceAtIndex, instance, idx))
        return instance.create_callback;
    return NULL;
}

SymbolVendorCreateInstance
PluginManager::GetSymbolVendorCreateCallbackForPluginName (const char *name)
{
    if (name && name[0])
    {
        SymbolVendorInstance instance;
        std::string ss_name(name);
        for (uint32_t idx = 0; AccessSymbolVendorInstances (ePluginGetInstanceAtIndex, instance, idx); ++idx)
        {
            if (instance.name == ss_name)
                return instance.create_callback;
        }
    }
    return NULL;
}


#pragma mark UnwindAssemblyProfiler

struct UnwindAssemblyProfilerInstance
{
    UnwindAssemblyProfilerInstance() :
        name(),
        description(),
        create_callback(NULL)
    {
    }

    std::string name;
    std::string description;
    UnwindAssemblyProfilerCreateInstance create_callback;
};

typedef std::vector<UnwindAssemblyProfilerInstance> UnwindAssemblyProfilerInstances;

static bool
AccessUnwindAssemblyProfilerInstances (PluginAction action, UnwindAssemblyProfilerInstance &instance, uint32_t index)
{
    static UnwindAssemblyProfilerInstances g_plugin_instances;

    switch (action)
    {
    case ePluginRegisterInstance:
        if (instance.create_callback)
        {
            g_plugin_instances.push_back (instance);
            return true;
        }
        break;

    case ePluginUnregisterInstance:
        if (instance.create_callback)
        {
            UnwindAssemblyProfilerInstances::iterator pos, end = g_plugin_instances.end();
            for (pos = g_plugin_instances.begin(); pos != end; ++ pos)
            {
                if (pos->create_callback == instance.create_callback)
                {
                    g_plugin_instances.erase(pos);
                    return true;
                }
            }
        }
        break;

    case ePluginGetInstanceAtIndex:
        if (index < g_plugin_instances.size())
        {
            instance = g_plugin_instances[index];
            return true;
        }
        break;

    default:
        break;
    }
    return false;
}

bool
PluginManager::RegisterPlugin
(
    const char *name,
    const char *description,
    UnwindAssemblyProfilerCreateInstance create_callback
)
{
    if (create_callback)
    {
        UnwindAssemblyProfilerInstance instance;
        assert (name && name[0]);
        instance.name = name;
        if (description && description[0])
            instance.description = description;
        instance.create_callback = create_callback;
        return AccessUnwindAssemblyProfilerInstances (ePluginRegisterInstance, instance, 0);
    }
    return false;
}

bool
PluginManager::UnregisterPlugin (UnwindAssemblyProfilerCreateInstance create_callback)
{
    if (create_callback)
    {
        UnwindAssemblyProfilerInstance instance;
        instance.create_callback = create_callback;
        return AccessUnwindAssemblyProfilerInstances (ePluginUnregisterInstance, instance, 0);
    }
    return false;
}

UnwindAssemblyProfilerCreateInstance
PluginManager::GetUnwindAssemblyProfilerCreateCallbackAtIndex (uint32_t idx)
{
    UnwindAssemblyProfilerInstance instance;
    if (AccessUnwindAssemblyProfilerInstances (ePluginGetInstanceAtIndex, instance, idx))
        return instance.create_callback;
    return NULL;
}

UnwindAssemblyProfilerCreateInstance
PluginManager::GetUnwindAssemblyProfilerCreateCallbackForPluginName (const char *name)
{
    if (name && name[0])
    {
        UnwindAssemblyProfilerInstance instance;
        std::string ss_name(name);
        for (uint32_t idx = 0; AccessUnwindAssemblyProfilerInstances (ePluginGetInstanceAtIndex, instance, idx); ++idx)
        {
            if (instance.name == ss_name)
                return instance.create_callback;
        }
    }
    return NULL;
}

#pragma mark ArchDefaultUnwindPlan

struct ArchDefaultUnwindPlanInstance
{
    ArchDefaultUnwindPlanInstance() :
        name(),
        description(),
        create_callback(NULL)
    {
    }

    std::string name;
    std::string description;
    ArchDefaultUnwindPlanCreateInstance create_callback;
};

typedef std::vector<ArchDefaultUnwindPlanInstance> ArchDefaultUnwindPlanInstances;

static bool
AccessArchDefaultUnwindPlanInstances (PluginAction action, ArchDefaultUnwindPlanInstance &instance, uint32_t index)
{
    static ArchDefaultUnwindPlanInstances g_plugin_instances;

    switch (action)
    {
    case ePluginRegisterInstance:
        if (instance.create_callback)
        {
            g_plugin_instances.push_back (instance);
            return true;
        }
        break;

    case ePluginUnregisterInstance:
        if (instance.create_callback)
        {
            ArchDefaultUnwindPlanInstances::iterator pos, end = g_plugin_instances.end();
            for (pos = g_plugin_instances.begin(); pos != end; ++ pos)
            {
                if (pos->create_callback == instance.create_callback)
                {
                    g_plugin_instances.erase(pos);
                    return true;
                }
            }
        }
        break;

    case ePluginGetInstanceAtIndex:
        if (index < g_plugin_instances.size())
        {
            instance = g_plugin_instances[index];
            return true;
        }
        break;

    default:
        break;
    }
    return false;
}

bool
PluginManager::RegisterPlugin
(
    const char *name,
    const char *description,
    ArchDefaultUnwindPlanCreateInstance create_callback
)
{
    if (create_callback)
    {
        ArchDefaultUnwindPlanInstance instance;
        assert (name && name[0]);
        instance.name = name;
        if (description && description[0])
            instance.description = description;
        instance.create_callback = create_callback;
        return AccessArchDefaultUnwindPlanInstances (ePluginRegisterInstance, instance, 0);
    }
    return false;
}

bool
PluginManager::UnregisterPlugin (ArchDefaultUnwindPlanCreateInstance create_callback)
{
    if (create_callback)
    {
        ArchDefaultUnwindPlanInstance instance;
        instance.create_callback = create_callback;
        return AccessArchDefaultUnwindPlanInstances (ePluginUnregisterInstance, instance, 0);
    }
    return false;
}

ArchDefaultUnwindPlanCreateInstance
PluginManager::GetArchDefaultUnwindPlanCreateCallbackAtIndex (uint32_t idx)
{
    ArchDefaultUnwindPlanInstance instance;
    if (AccessArchDefaultUnwindPlanInstances (ePluginGetInstanceAtIndex, instance, idx))
        return instance.create_callback;
    return NULL;
}

ArchDefaultUnwindPlanCreateInstance
PluginManager::GetArchDefaultUnwindPlanCreateCallbackForPluginName (const char *name)
{
    if (name && name[0])
    {
        ArchDefaultUnwindPlanInstance instance;
        std::string ss_name(name);
        for (uint32_t idx = 0; AccessArchDefaultUnwindPlanInstances (ePluginGetInstanceAtIndex, instance, idx); ++idx)
        {
            if (instance.name == ss_name)
                return instance.create_callback;
        }
    }
    return NULL;
}

#pragma mark ArchVolatileRegs

struct ArchVolatileRegsInstance
{
    ArchVolatileRegsInstance() :
        name(),
        description(),
        create_callback(NULL)
    {
    }

    std::string name;
    std::string description;
    ArchVolatileRegsCreateInstance create_callback;
};

typedef std::vector<ArchVolatileRegsInstance> ArchVolatileRegsInstances;

static bool
AccessArchVolatileRegsInstances (PluginAction action, ArchVolatileRegsInstance &instance, uint32_t index)
{
    static ArchVolatileRegsInstances g_plugin_instances;

    switch (action)
    {
    case ePluginRegisterInstance:
        if (instance.create_callback)
        {
            g_plugin_instances.push_back (instance);
            return true;
        }
        break;

    case ePluginUnregisterInstance:
        if (instance.create_callback)
        {
            ArchVolatileRegsInstances::iterator pos, end = g_plugin_instances.end();
            for (pos = g_plugin_instances.begin(); pos != end; ++ pos)
            {
                if (pos->create_callback == instance.create_callback)
                {
                    g_plugin_instances.erase(pos);
                    return true;
                }
            }
        }
        break;

    case ePluginGetInstanceAtIndex:
        if (index < g_plugin_instances.size())
        {
            instance = g_plugin_instances[index];
            return true;
        }
        break;

    default:
        break;
    }
    return false;
}

bool
PluginManager::RegisterPlugin
(
    const char *name,
    const char *description,
    ArchVolatileRegsCreateInstance create_callback
)
{
    if (create_callback)
    {
        ArchVolatileRegsInstance instance;
        assert (name && name[0]);
        instance.name = name;
        if (description && description[0])
            instance.description = description;
        instance.create_callback = create_callback;
        return AccessArchVolatileRegsInstances (ePluginRegisterInstance, instance, 0);
    }
    return false;
}

bool
PluginManager::UnregisterPlugin (ArchVolatileRegsCreateInstance create_callback)
{
    if (create_callback)
    {
        ArchVolatileRegsInstance instance;
        instance.create_callback = create_callback;
        return AccessArchVolatileRegsInstances (ePluginUnregisterInstance, instance, 0);
    }
    return false;
}

ArchVolatileRegsCreateInstance
PluginManager::GetArchVolatileRegsCreateCallbackAtIndex (uint32_t idx)
{
    ArchVolatileRegsInstance instance;
    if (AccessArchVolatileRegsInstances (ePluginGetInstanceAtIndex, instance, idx))
        return instance.create_callback;
    return NULL;
}

ArchVolatileRegsCreateInstance
PluginManager::GetArchVolatileRegsCreateCallbackForPluginName (const char *name)
{
    if (name && name[0])
    {
        ArchVolatileRegsInstance instance;
        std::string ss_name(name);
        for (uint32_t idx = 0; AccessArchVolatileRegsInstances (ePluginGetInstanceAtIndex, instance, idx); ++idx)
        {
            if (instance.name == ss_name)
                return instance.create_callback;
        }
    }
    return NULL;
}