ThreadClosureVariableStack.h

/* -*- mode: c++; indent-tabs-mode: nil -*- */
/*
    ThreadClosureVariableStack.h

    Qore Programming Language

    Copyright (C) 2003 - 2020 Qore Technologies, s.r.o.

    Permission is hereby granted, free of charge, to any person obtaining a
    copy of this software and associated documentation files (the "Software"),
    to deal in the Software without restriction, including without limitation
    the rights to use, copy, modify, merge, publish, distribute, sublicense,
    and/or sell copies of the Software, and to permit persons to whom the
    Software is furnished to do so, subject to the following conditions:

    The above copyright notice and this permission notice shall be included in
    all copies or substantial portions of the Software.

    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
    AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
    FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
    DEALINGS IN THE SOFTWARE.

    Note that the Qore library is released under a choice of three open-source
    licenses: MIT (as above), LGPL 2+, or GPL 2+; see README-LICENSE for more
    information.
*/

#ifndef _QORE_INTERN_THREADCLOSUREVARIABLESTACK_H
#define _QORE_INTERN_THREADCLOSUREVARIABLESTACK_H

class ThreadClosureVariableStack : public ThreadLocalData<ClosureVarValue*> {
private:
    DLLLOCAL void instantiateIntern(ClosureVarValue* cvar) {
        //printd(5, "ThreadClosureVariableStack::instantiateIntern(%p = '%s') this: %p pgm: %p\n", cvar->id, cvar->id, this, getProgram());

        if (curr->pos == QORE_THREAD_STACK_BLOCK) {
            if (curr->next)
                curr = curr->next;
            else {
                curr->next = new Block(curr);
                //printf("this: %p: add curr: %p, curr->next: %p\n", this, curr, curr->next);
                curr = curr->next;
            }
        }
        curr->var[curr->pos++] = cvar;
    }

public:
    // clears and marks all variables as finalized on the stack
    DLLLOCAL void finalize(arg_vec_t*& cl) {
        ThreadClosureVariableStack::iterator i(curr);
        while (i.next()) {
            ValueHolder n(i.get()->finalize(), nullptr);
            if (n->derefCanThrowException()) {
                if (!cl) {
                    cl = new arg_vec_t;
                }
                cl->push_back(n.release());
            }
        }
    }

    // deletes everything on the stack
    DLLLOCAL void del(ExceptionSink* xsink) {
        while (curr->prev || curr->pos)
            uninstantiate(xsink);
    }

    DLLLOCAL ClosureVarValue* instantiate(const char* id, const QoreTypeInfo* typeInfo, QoreValue& nval, bool assign) {
        ClosureVarValue* cvar = new ClosureVarValue(id, typeInfo, nval, assign);
        instantiateIntern(cvar);
        return cvar;
    }

    DLLLOCAL void instantiate(ClosureVarValue* cvar) {
        instantiateIntern(cvar);
    }

    DLLLOCAL void uninstantiateIntern() {
#if 0
        if (!curr->pos)
            printd(5, "ThreadClosureVariableStack::uninstantiate() this: %p pos: %d %p %s\n", this, curr->prev->pos - 1, curr->prev->var[curr->prev->pos - 1]->id, curr->prev->var[curr->prev->pos - 1]->id);
        else
            printd(5, "ThreadClosureVariableStack::uninstantiate() this: %p pos: %d %p %s\n", this, curr->pos - 1, curr->var[curr->pos - 1]->id, curr->var[curr->pos - 1]->id);
#endif
        if (!curr->pos) {
            if (curr->next) {
                //printf("this %p: del curr: %p, curr->next: %p\n", this, curr, curr->next);
                delete curr->next;
                curr->next = 0;
            }
            curr = curr->prev;
            assert(curr);
        }
        --curr->pos;
    }

    DLLLOCAL void uninstantiate(ExceptionSink* xsink) {
        uninstantiateIntern();
        assert(curr->var[curr->pos]);
        curr->var[curr->pos]->deref(xsink);
    }

    DLLLOCAL ClosureVarValue* find(const char* id) {
        printd(5, "ThreadClosureVariableStack::find() this: %p id: %p\n", this, id);
        Block* w = curr;
        while (true) {
            int p = w->pos;
            while (p) {
                --p;
                ClosureVarValue* rv = w->var[p];
                //printd(5, "ThreadClosureVariableStack::find(%p '%s') this: %p checking %p '%s'\n", id, id, this, rv ? rv->id : nullptr, rv ? rv->id : "n/a");
                if (rv && rv->id == id) {
                    //printd(5, "ThreadClosureVariableStack::find(%p '%s') this: %p returning: %p\n", id, id, this, rv);
                    return rv;
                }
            }
            w = w->prev;
#ifdef DEBUG
            if (!w) {
                printd(0, "ThreadClosureVariableStack::find() this: %p no closure-bound local variable '%s' (%p) on stack (pgm: %p) p: %d curr->prev: %p\n", this, id, id, getProgram(), p, curr->prev);
                w = curr;
                while (w) {
                    p = w->pos;
                    while (p) {
                        --p;
                        ClosureVarValue* cvv = w->var[p];
                        printd(0, "var p: %d: %s (%p)\n", p, cvv ? cvv->id : "frame boundary", cvv ? cvv->id : nullptr);
                    }
                    w = w->prev;
                }
            }
#endif
            assert(w);
        }
        // to avoid a warning on most compilers - note that this generates a warning on aCC!
        return nullptr;
    }

    DLLLOCAL cvv_vec_t* getAll() const {
        cvv_vec_t* cv = 0;
        Block* w = curr;
        while (w) {
            int p = w->pos;
            while (p) {
                --p;
                ClosureVarValue* cvv = w->var[p];
                // skip frame boundaries
                if (!cvv)
                    continue;
                if (!cv)
                    cv = new cvv_vec_t;
                cv->push_back(cvv->refSelf());
            }
            w = w->prev;
        }
        //printd(5, "ThreadClosureVariableStack::getAll() this: %p cv: %p size: %d\n", this, cv, cv ? cv->size() : 0);
        return cv;
    }

    DLLLOCAL void pushFrameBoundary() {
        ++frame_count;
        //printd(5, "ThreadClosureVariableStack::pushFrameBoundary(): fc:%d\n", frame_count);
        instantiateIntern(nullptr);
    }

    DLLLOCAL void popFrameBoundary() {
        assert(frame_count >= 0);
        --frame_count;
        //printd(5, "ThreadClosureVariableStack::popFrameBoundary(): fc:%d\n", frame_count);
        uninstantiateIntern();
        assert(!curr->var[curr->pos]);
    }

    DLLLOCAL int getFrame(int frame, Block*& w, int& p);

    DLLLOCAL void getLocalVars(QoreHashNode& h, int frame, ExceptionSink* xsink);

    // returns 0 = OK, 1 = no such variable, -1 exception setting variable
    DLLLOCAL int setVarValue(int frame, const char* name, const QoreValue& val, ExceptionSink* xsink);
};

#endif