ContextManager and ProcessEnumerator have the basic functionality done.

Created a test program to validate them and show how to use them.

library/DFContextManager.cpp

@@ -41,23 +41,90 @@ distribution.
 using namespace DFHack;
 namespace DFHack
 {
-    class DFContextMgrPrivate
+    class ContextManager::Private
     {
         public:
-            DFContextMgrPrivate(){};
-            ~DFContextMgrPrivate(){};
+            Private(){};
+            ~Private(){};
             string xml; // path to xml
             vector <Context *> contexts;
             ProcessEnumerator * pEnum;
     };
 }
+class DFHack::BadContexts::Private
+{
+    public:
+        Private(){};
+        vector <Context *> bad;
+};
+
+
+BadContexts::BadContexts():d(new Private()){}
+
+BadContexts::~BadContexts()
+{
+    clear();
+    delete d;
+}
+
+bool BadContexts::Contains(Process* p)
+{
+    for(int i = 0; i < d->bad.size(); i++)
+    {
+        if((d->bad[i])->getProcess() == p)
+            return true;
+    }
+    return false;
+}
+
+bool BadContexts::Contains(Context* c)
+{
+    for(int i = 0; i < d->bad.size(); i++)
+    {
+        if(d->bad[i] == c)
+            return true;
+    }
+        return false;
+}
+
+uint32_t BadContexts::size()
+{
+    return d->bad.size();
+}
+
+void BadContexts::clear()
+{
+    for(int i = 0; i < d->bad.size(); i++)
+    {
+        // delete both Process and Context!
+        // process has to be deleted after context, because Context does some
+        // cleanup on delete (detach, etc.)
+        Process * to_kill = d->bad[i]->getProcess();
+        delete d->bad[i];
+        delete to_kill;
+    }
+    d->bad.clear();
+}
+
+void BadContexts::push_back(Context* c)
+{
+    if(c)
+        d->bad.push_back(c);
+}
+
+Context * BadContexts::operator[](uint32_t index)
+{
+    if(index < d->bad.size())
+        return d->bad[index];
+    return 0;
+}
 
-ContextManager::ContextManager (const string path_to_xml) : d (new DFContextMgrPrivate())
+ContextManager::ContextManager (const string path_to_xml) : d (new Private())
 {
-    d->pEnum = 0;
     d->xml = QUOT (MEMXML_DATA_PATH);
     d->xml += "/";
     d->xml += path_to_xml;
+    d->pEnum = new ProcessEnumerator(d->xml);
 }
 
 ContextManager::~ContextManager()
@@ -66,26 +133,76 @@ ContextManager::~ContextManager()
     delete d;
 }
 
-uint32_t ContextManager::Refresh()
+uint32_t ContextManager::Refresh( BadContexts* bad_contexts )
 {
-    purge();
-    if(d->pEnum != 0)
-        d->pEnum = new ProcessEnumerator(d->xml);
-    else
+    // handle expired processes, remove stale Contexts 
     {
-        delete d->pEnum;
-        d->pEnum = new ProcessEnumerator(d->xml);
+        BadProcesses expired;
+        // get new list od living and expired Process objects
+        d->pEnum->Refresh(&expired);
+
+        // scan expired, kill contexts if necessary
+        vector <Context*>::iterator it = d->contexts.begin();;
+        while(it != d->contexts.end())
+        {
+            Process * test = (*it)->getProcess();
+            if(expired.Contains(test))
+            {
+                // ok. we have an expired context here.
+                if(!bad_contexts)
+                {
+                    // with nowhere to put the context, we have to destroy it
+                    delete *it;
+                    // stop tracking it and advance the iterator
+                    it = d->contexts.erase(it);
+                    continue;
+                }
+                else
+                {
+                    // we stuff the context into bad_contexts
+                    bad_contexts->push_back(*it);
+                    // stop tracking it and advance the iterator
+                    it = d->contexts.erase(it);
+                    // remove process from the 'expired' container, it is tracked by bad_contexts now
+                    // (which is responsible for freeing it).
+                    expired.excise(test);
+                    continue;
+                }
+            }
+            else it++; // not expired, just advance to next one
+        }
+        // no expired contexts are in the d->contexts vector now
+        // all processes remaining in 'expired' are now destroyed along with it
     }
-    d->pEnum->purge();
-    d->pEnum->findProcessess();
+    
     int numProcesses = d->pEnum->size();
+    int numContexts = d->contexts.size();
+    vector <Context *> newContexts;
+    // enumerate valid processes
     for(int i = 0; i < numProcesses; i++)
     {
-        Context * c = new Context(d->pEnum->operator[](i));
-        d->contexts.push_back(c);
+        Process * test = d->pEnum->operator[](i);
+        bool exists = false;
+        // scan context vector for this process
+        for(int j = 0; j < numContexts; j++)
+        {
+            if((d->contexts[j])->getProcess() == test)
+            {
+                // already have that one, skip
+                exists = true;
+            }
+        }
+        if(!exists)
+        {
+            // new process needs a new context
+            Context * c = new Context(d->pEnum->operator[](i));
+            newContexts.push_back(c);
+        }
     }
+    d->contexts.insert(d->contexts.end(), newContexts.begin(), newContexts.end());
     return d->contexts.size();
 }
+
 uint32_t ContextManager::size()
 {
     return d->contexts.size();

library/DFProcessEnumerator.cpp

@@ -44,7 +44,76 @@ class DFHack::ProcessEnumerator::Private
         void EnumPIDs (vector <ProcessID> &PIDs);
 };
 
-#ifdef LINUX_BUILD
+class DFHack::BadProcesses::Private
+{
+    public:
+        Private(){};
+        PROC_V bad;
+};
+
+BadProcesses::BadProcesses():d(new Private()){}
+
+BadProcesses::~BadProcesses()
+{
+    clear();
+    delete d;
+}
+
+bool BadProcesses::Contains(Process* p)
+{
+    for(int i = 0; i < d->bad.size(); i++)
+    {
+        if(d->bad[i] == p)
+            return true;
+    }
+    return false;
+}
+
+bool BadProcesses::excise(Process* p)
+{
+    vector<Process*>::iterator it = d->bad.begin();
+    while(it != d->bad.end())
+    {
+        if((*it) == p)
+        {
+            d->bad.erase(it);
+            return true;
+        }
+        else
+        {
+            it++;
+        }
+    }
+    return false;
+}
+
+uint32_t BadProcesses::size()
+{
+    return d->bad.size();
+}
+
+void BadProcesses::clear()
+{
+    for(int i = 0; i < d->bad.size(); i++)
+    {
+        delete d->bad[i];
+    }
+    d->bad.clear();
+}
+
+void BadProcesses::push_back(Process* p)
+{
+    if(p)
+        d->bad.push_back(p);
+}
+
+Process * BadProcesses::operator[](uint32_t index)
+{
+    if(index < d->bad.size())
+        return d->bad[index];
+    return 0;
+}
+
 //FIXME: wasteful
 Process *ProcessEnumerator::Private::GetProcessObject(ProcessID ID)
 {
@@ -54,21 +123,23 @@ Process *ProcessEnumerator::Private::GetProcessObject(ProcessID ID)
         return p1;
     else
         delete p1;
-
+    
     Process *p2 = new NormalProcess(ID.pid,meminfo->meminfo);
     if(p2->isIdentified())
         return p2;
     else
         delete p2;
-
+#ifdef LINUX_BUILD
     Process *p3 = new WineProcess(ID.pid,meminfo->meminfo);
     if(p3->isIdentified())
         return p3;
     else
         delete p3;
     return 0;
+#endif
 }
 
+#ifdef LINUX_BUILD
 void ProcessEnumerator::Private::EnumPIDs (vector <ProcessID> &PIDs)
 {
     DIR *dir_p;
@@ -104,22 +175,6 @@ void ProcessEnumerator::Private::EnumPIDs (vector <ProcessID> &PIDs)
 #endif
 
 #ifndef LINUX_BUILD
-Process *ProcessEnumerator::Private::GetProcessObject(ProcessID ID)
-{
-    
-    Process *p1 = new SHMProcess(ID.pid,meminfo->meminfo);
-    if(p1->isIdentified())
-        return p1;
-    else
-        delete p1;
-
-    Process *p2 = new NormalProcess(ID.pid,meminfo->meminfo);
-    if(p2->isIdentified())
-        return p2;
-    else
-        delete p2;
-    return 0;
-}
 // some magic - will come in handy when we start doing debugger stuff on Windows
 bool EnableDebugPriv()
 {
@@ -199,19 +254,19 @@ void ProcessEnumerator::Private::EnumPIDs (vector <ProcessID> &PIDs)
 }
 #endif
 
-bool ProcessEnumerator::Refresh( PROC_V * invalidated_processes)
+bool ProcessEnumerator::Refresh( BadProcesses* invalidated_processes)
 {
     // PIDs to process
     vector <ProcessID> PIDs;
     // this will be the new process map
     PID2PROC temporary;
-    // clear the vector other access
+    // clear the vector
     d->Processes.clear();
     if(invalidated_processes)
         invalidated_processes->clear();
-    
+
     d->EnumPIDs(PIDs);
-    
+
     for(uint64_t i = 0; i < PIDs.size();i++)
     {
         ProcessID & PID = PIDs[i];

library/include/dfhack/DFContextManager.h

@@ -35,18 +35,36 @@ distribution.
 namespace DFHack
 {
     class Context;
-    class DFContextMgrPrivate;
+    class BadContexts;
+    class Process;
+
     class DFHACK_EXPORT ContextManager
     {
-        DFContextMgrPrivate * const d;
+        class Private;
+        Private * const d;
     public:
         ContextManager(const std::string path_to_xml);
         ~ContextManager();
-        uint32_t Refresh();
+        uint32_t Refresh(BadContexts* bad_contexts = 0);
         uint32_t size();
         Context * operator[](uint32_t index);
         Context * getSingleContext();
         void purge(void);
     };
+    class DFHACK_EXPORT BadContexts
+    {
+        class Private;
+        Private * const d;
+        void push_back(Context * c);
+        friend class ContextManager;
+    public:
+        BadContexts();
+        ~BadContexts();
+        bool Contains(Context* c);
+        bool Contains(Process* p);
+        uint32_t size();
+        void clear();
+        Context * operator[](uint32_t index);
+    };
 } // namespace DFHack
 #endif // CONTEXTMANAGER_H_INCLUDED

library/include/dfhack/DFProcessEnumerator.h

@@ -32,6 +32,7 @@ namespace DFHack
 {
     class memory_info;
     class Process;
+    class BadProcesses;
     /*
      * Process manager
      */
@@ -42,11 +43,26 @@ namespace DFHack
     public:
         ProcessEnumerator( string path_to_xml );
         ~ProcessEnumerator();
-        bool Refresh(vector <Process *> * invalidated_processes = 0);
+        bool Refresh(BadProcesses * invalidated_processes = 0);
         bool findProcessess();
         uint32_t size();
         Process * operator[](uint32_t index);
         void purge(void);
     };
+    class DFHACK_EXPORT BadProcesses
+    {
+        class Private;
+        Private * const d;
+        void push_back(Process * p);
+        friend class ProcessEnumerator;
+    public:
+        BadProcesses();
+        ~BadProcesses();
+        bool Contains(Process* p);
+        bool excise (Process* p);
+        uint32_t size();
+        void clear();
+        Process * operator[](uint32_t index);
+    };
 }
 #endif // PROCESSMANAGER_H_INCLUDED

tools/examples/processenum.cpp

@@ -13,42 +13,113 @@ using namespace std;
 using namespace DFHack;
 #ifndef LINUX_BUILD
 #endif
+
+void printhelp ()
+{
+    cout << "enter empty line for next try." << endl;
+    cout << "enter 'next' or 'n' for next test." << endl;
+    cout << "enter 'help' to show this text again." << endl;
+}
+
+int inputwait (const char * prompt)
+{
+inputwait_reset:
+    string command = "";
+    cout <<"[" << prompt << "]# ";
+    getline(cin, command);
+    if(command == "help")
+    {
+        printhelp();
+        goto inputwait_reset;
+    }
+    else if(command == "")
+    {
+        return 1;
+    }
+    else if(command == "next")
+    {
+        return 0;
+    }
+    else
+    {
+        cout << "Command not recognized. Try 'help' for a list of valid commands." << endl;
+        goto inputwait_reset;
+    }
+    return 0;
+}
+
 int main (void)
 {
-    vector<Process*> inval;
-    ProcessEnumerator Penum("Memory.xml");
-    memory_info * mem;
-    for(int cnt = 0; cnt < 100; cnt++)
+    printhelp();
+    cout << endl;
+    // first test ProcessEnumerator and BadProcesses
     {
-        // make the ProcessEnumerator update its list of Processes
-        // by passing the pointer to 'inval', we make it export expired
-        // processes instead of destroying them outright
-        // (processes expire when the OS kills them for whatever reason)
-        Penum.Refresh(&inval);
-        int nProc = Penum.size();
-        int nInval = inval.size();
-
-        cout << "Processes:" << endl;
-        for(int i = 0; i < nProc; i++)
+        cout << "Testing ProcessEnumerator" << endl;
+        ProcessEnumerator Penum("Memory.xml");
+        memory_info * mem;
+        do
         {
-            mem = Penum[i]->getDescriptor();
-            cout << "DF instance: " << Penum[i]->getPID()
-                 << ", " << mem->getVersion() << endl;
-        }
+            // make the ProcessEnumerator update its list of Processes
+            // by passing the pointer to 'inval', we make it export expired
+            // processes instead of destroying them outright
+            // (processes expire when the OS kills them for whatever reason)
+            BadProcesses inval;
+            Penum.Refresh(&inval);
+            int nProc = Penum.size();
+            int nInval = inval.size();
+
+            cout << "Processes:" << endl;
+            for(int i = 0; i < nProc; i++)
+            {
+                mem = Penum[i]->getDescriptor();
+                cout << "DF instance: " << Penum[i]->getPID()
+                     << ", " << mem->getVersion() << endl;
+            }
 
-        cout << "Invalidated:" << endl;
-        for(int i = 0; i < nInval; i++)
+            cout << "Invalidated:" << endl;
+            for(int i = 0; i < nInval; i++)
+            {
+                mem = inval[i]->getDescriptor();
+                cout << "DF instance: " << inval[i]->getPID()
+                     << ", " << mem->getVersion() << endl;
+            }
+        }
+        while(inputwait("ProcessEnumerator"));
+    }
+    // next test ContextManager and BadContexts
+    {
+        cout << "Testing ProcessEnumerator" << endl;
+        ContextManager Cman("Memory.xml");
+        memory_info * mem;
+        do
         {
-            mem = inval[i]->getDescriptor();
-            cout << "DF instance: " << inval[i]->getPID()
-                 << ", " << mem->getVersion() << endl;
-            // we own the expired process, we must take care of freeing its resources
-            delete inval[i];
+            // make the ProcessEnumerator update its list of Processes
+            // by passing the pointer to 'inval', we make it export expired
+            // processes instead of destroying them outright
+            // (processes expire when the OS kills them for whatever reason)
+            BadContexts inval;
+            Cman.Refresh(&inval);
+            int nCont = Cman.size();
+            int nInval = inval.size();
+
+            cout << "Contexts:" << endl;
+            for(int i = 0; i < nCont; i++)
+            {
+                mem = Cman[i]->getMemoryInfo();
+                cout << "DF instance: " << Cman[i]->getProcess()->getPID()
+                     << ", " << mem->getVersion() << endl;
+            }
+
+            cout << "Invalidated:" << endl;
+            for(int i = 0; i < nInval; i++)
+            {
+                mem = inval[i]->getMemoryInfo();
+                cout << "DF instance: " << inval[i]->getProcess()->getPID()
+                     << ", " << mem->getVersion() << endl;
+            }
         }
-        cout << "<-* Press Enter to refresh *->" << endl << endl;
-        cin.ignore();
+        while(inputwait("ContextManager"));
     }
-    
     #ifndef LINUX_BUILD
         cout << "Done. Press any key to continue" << endl;
         cin.ignore();