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/*
* Copyright (c) 2011-2014, Intel Corporation
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without modification,
* are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation and/or
* other materials provided with the distribution.
*
* 3. Neither the name of the copyright holder nor the names of its contributors
* may be used to endorse or promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
* ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
* ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <dlfcn.h>
#include <dirent.h>
#include <algorithm>
#include <ctype.h>
#include "SystemClass.h"
#include "SubsystemLibrary.h"
#include "AutoLog.h"
#include "VirtualSubsystem.h"
#include "NamedElementBuilderTemplate.h"
#include <assert.h>
#include "PluginLocation.h"
#include "Utility.h"
#define base CConfigurableElement
using std::list;
using std::string;
/**
* A plugin file name is of the form:
* lib<type>-subsystem.so or lib<type>-subsystem._host.so
*
* The plugin symbol is of the form:
* get<TYPE>SubsystemBuilder
*/
// Plugin file naming
const char* gpcPluginSuffix = "-subsystem";
const char* gpcPluginPrefix = "lib";
// Plugin symbol naming
const char* gpcPluginSymbolPrefix = "get";
const char* gpcPluginSymbolSuffix = "SubsystemBuilder";
// Used by subsystem plugins
typedef void (*GetSubsystemBuilder)(CSubsystemLibrary*);
CSystemClass::CSystemClass() : _pSubsystemLibrary(new CSubsystemLibrary)
{
}
CSystemClass::~CSystemClass()
{
delete _pSubsystemLibrary;
// Destroy child subsystems *before* unloading the libraries (otherwise crashes will occur
// as unmapped code will be referenced)
clean();
// Close all previously opened subsystem libraries
list<void*>::const_iterator it;
for (it = _subsystemLibraryHandleList.begin(); it != _subsystemLibraryHandleList.end(); ++it) {
dlclose(*it);
}
}
bool CSystemClass::childrenAreDynamic() const
{
return true;
}
string CSystemClass::getKind() const
{
return "SystemClass";
}
bool CSystemClass::loadSubsystems(string& strError,
const CSubsystemPlugins* pSubsystemPlugins,
bool bVirtualSubsystemFallback)
{
CAutoLog autoLog_info(this, "Loading subsystem plugins");
// Start clean
_pSubsystemLibrary->clean();
// Add virtual subsystem builder
_pSubsystemLibrary->addElementBuilder("Virtual",
new TNamedElementBuilderTemplate<CVirtualSubsystem>());
// Set virtual subsytem as builder fallback if required
_pSubsystemLibrary->enableDefaultMechanism(bVirtualSubsystemFallback);
// Add subsystem defined in shared libraries
list<string> lstrError;
bool bLoadPluginsSuccess = loadSubsystemsFromSharedLibraries(lstrError, pSubsystemPlugins);
if (bLoadPluginsSuccess) {
log_info("All subsystem plugins successfully loaded");
} else {
// Log plugin as warning if no fallback available
log_table(!bVirtualSubsystemFallback, lstrError);
}
if (!bVirtualSubsystemFallback) {
// Any problem reported is an error as there is no fallback.
// Fill strError for caller.
CUtility::asString(lstrError, strError);
}
return bLoadPluginsSuccess || bVirtualSubsystemFallback;
}
bool CSystemClass::loadSubsystemsFromSharedLibraries(list<string>& lstrError,
const CSubsystemPlugins* pSubsystemPlugins)
{
// Plugin list
list<string> lstrPluginFiles;
uint32_t uiPluginLocation;
for (uiPluginLocation = 0; uiPluginLocation < pSubsystemPlugins->getNbChildren(); uiPluginLocation++) {
// Get Folder for current Plugin Location
const CPluginLocation* pPluginLocation = static_cast<const CPluginLocation*>(pSubsystemPlugins->getChild(uiPluginLocation));
string strFolder(pPluginLocation->getFolder());
if (!strFolder.empty()) {
strFolder += "/";
}
// Iterator on Plugin List:
list<string>::const_iterator it;
const list<string>& pluginList = pPluginLocation->getPluginList();
for (it = pluginList.begin(); it != pluginList.end(); ++it) {
// Fill Plugin files list
lstrPluginFiles.push_back(strFolder + *it);
}
}
// Actually load plugins
while (!lstrPluginFiles.empty()) {
// Because plugins might depend on one another, loading will be done
// as an iteration process that finishes successfully when the remaining
// list of plugins to load gets empty or unsuccessfully if the loading
// process failed to load at least one of them
// Attempt to load the complete list
if (!loadPlugins(lstrPluginFiles, lstrError)) {
// Unable to load at least one plugin
break;
}
}
if (!lstrPluginFiles.empty()) {
// Unable to load at least one plugin
string strPluginUnloaded;
CUtility::asString(lstrPluginFiles, strPluginUnloaded, ", ");
lstrError.push_back("Unable to load the following plugins: " + strPluginUnloaded + ".");
return false;
}
return true;
}
// Plugin symbol computation
string CSystemClass::getPluginSymbol(const string& strPluginPath)
{
// Extract plugin type out of file name
string strPluginSuffix = gpcPluginSuffix;
string strPluginPrefix = gpcPluginPrefix;
// Remove folder and library prefix
size_t iPluginTypePos = strPluginPath.rfind('/') + 1 + strPluginPrefix.length();
// Get index of -subsystem.so or -subsystem_host.so suffix
size_t iSubsystemPos = strPluginPath.find(strPluginSuffix, iPluginTypePos);
// Get type (between iPluginTypePos and iSubsystemPos)
string strPluginType = strPluginPath.substr(iPluginTypePos, iSubsystemPos - iPluginTypePos);
// Make it upper case
std::transform(strPluginType.begin(), strPluginType.end(), strPluginType.begin(), ::toupper);
// Get plugin symbol
return gpcPluginSymbolPrefix + strPluginType + gpcPluginSymbolSuffix;
}
// Plugin loading
bool CSystemClass::loadPlugins(list<string>& lstrPluginFiles, list<string>& lstrError)
{
assert(lstrPluginFiles.size());
bool bAtLeastOneSubsystemPluginSuccessfullyLoaded = false;
list<string>::iterator it = lstrPluginFiles.begin();
while (it != lstrPluginFiles.end()) {
string strPluginFileName = *it;
log_info("Attempting to load subsystem plugin path \"%s\"", strPluginFileName.c_str());
// Load attempt
void* lib_handle = dlopen(strPluginFileName.c_str(), RTLD_LAZY);
if (!lib_handle) {
const char *err = dlerror();
// Failed
if (err == NULL) {
lstrError.push_back("dlerror failed");
} else {
lstrError.push_back("Plugin load failed: " + string(err));
}
// Next plugin
++it;
continue;
}
// Store libraries handles
_subsystemLibraryHandleList.push_back(lib_handle);
// Get plugin symbol
string strPluginSymbol = getPluginSymbol(strPluginFileName);
// Load symbol from library
GetSubsystemBuilder pfnGetSubsystemBuilder = (GetSubsystemBuilder)dlsym(lib_handle, strPluginSymbol.c_str());
if (!pfnGetSubsystemBuilder) {
lstrError.push_back("Subsystem plugin " + strPluginFileName +
" does not contain " + strPluginSymbol + " symbol.");
continue;
}
// Account for this success
bAtLeastOneSubsystemPluginSuccessfullyLoaded = true;
// Fill library
pfnGetSubsystemBuilder(_pSubsystemLibrary);
// Remove successfully loaded plugin from list and select next
lstrPluginFiles.erase(it++);
}
return bAtLeastOneSubsystemPluginSuccessfullyLoaded;
}
const CSubsystemLibrary* CSystemClass::getSubsystemLibrary() const
{
return _pSubsystemLibrary;
}
void CSystemClass::checkForSubsystemsToResync(CSyncerSet& syncerSet)
{
size_t uiNbChildren = getNbChildren();
size_t uiChild;
for (uiChild = 0; uiChild < uiNbChildren; uiChild++) {
CSubsystem* pSubsystem = static_cast<CSubsystem*>(getChild(uiChild));
// Collect and consume the need for a resync
if (pSubsystem->needResync(true)) {
log_info("Resynchronizing subsystem: %s", pSubsystem->getName().c_str());
// get all subsystem syncers
pSubsystem->fillSyncerSet(syncerSet);
}
}
}
void CSystemClass::cleanSubsystemsNeedToResync()
{
size_t uiNbChildren = getNbChildren();
size_t uiChild;
for (uiChild = 0; uiChild < uiNbChildren; uiChild++) {
CSubsystem* pSubsystem = static_cast<CSubsystem*>(getChild(uiChild));
// Consume the need for a resync
pSubsystem->needResync(true);
}
}
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