user propagator

Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>

scripts/update_api.py

@@ -1843,7 +1843,7 @@ _lib.Z3_set_error_handler.argtypes = [ContextObj, _error_handler_type]
 
 push_eh_type  = ctypes.CFUNCTYPE(None, ctypes.c_void_p)
 pop_eh_type   = ctypes.CFUNCTYPE(None, ctypes.c_void_p, ctypes.c_uint)
-fresh_eh_type = ctypes.CFUNCTYPE(ctypes.c_void_p, ctypes.c_void_p)
+fresh_eh_type = ctypes.CFUNCTYPE(ctypes.c_void_p, ctypes.c_void_p, ctypes.c_void_p)
 
 fixed_eh_type = ctypes.CFUNCTYPE(None, ctypes.c_void_p, ctypes.c_void_p, ctypes.c_uint, ctypes.c_void_p)
 final_eh_type = ctypes.CFUNCTYPE(None, ctypes.c_void_p, ctypes.c_void_p)

src/api/api_context.cpp

@@ -116,6 +116,8 @@ namespace api {
             DEBUG_CODE(warning_msg("Uncollected memory: %d: %s", kv.m_key, typeid(*val).name()););
             dealloc(val);
         }
+        if (m_params.owns_manager())
+            m_manager.detach();
     }
 
     context::set_interruptable::set_interruptable(context & ctx, event_handler & i):

src/api/api_solver.cpp

@@ -896,9 +896,15 @@ extern "C" {
         Z3_TRY;
         RESET_ERROR_CODE();
         init_solver(c, s);
-        std::function<void(void*)> _push = push_eh;
+        solver::push_eh_t _push = push_eh;
-        std::function<void(void*,unsigned)> _pop = pop_eh;
+        solver::pop_eh_t _pop = pop_eh;
-        std::function<void*(void*)> _fresh = fresh_eh;
+        solver::fresh_eh_t _fresh = [&](void * user_ctx, ast_manager& m, void*& _ctx) {
+            context_params params;
+            params.set_foreign_manager(&m);
+            auto* ctx = reinterpret_cast<Z3_context>(alloc(api::context, &params, false));
+            _ctx = ctx;
+            return fresh_eh(user_ctx, ctx);
+        };
         to_solver_ref(s)->user_propagate_init(user_context, _push, _pop, _fresh);
         Z3_CATCH;
     }
@@ -955,11 +961,11 @@ extern "C" {
         Z3_CATCH_RETURN(0);
     }
 
-    void Z3_API Z3_solver_propagate_consequence(Z3_context c, Z3_solver_callback s, unsigned sz, unsigned const* ids, Z3_ast conseq) {
+    void Z3_API Z3_solver_propagate_consequence(Z3_context c, Z3_solver_callback s, unsigned num_fixed, unsigned const* fixed_ids, unsigned num_eqs, unsigned const* eq_lhs, unsigned const* eq_rhs, Z3_ast conseq) {
         Z3_TRY;
-        LOG_Z3_solver_propagate_consequence(c, s, sz, ids, conseq);
+        LOG_Z3_solver_propagate_consequence(c, s, num_fixed, fixed_ids, num_eqs, eq_lhs, eq_rhs, conseq);
         RESET_ERROR_CODE();
-        reinterpret_cast<solver::propagate_callback*>(s)->propagate(sz, ids, to_expr(conseq));
+        reinterpret_cast<solver::propagate_callback*>(s)->propagate(num_fixed, fixed_ids, num_eqs, eq_lhs, eq_rhs, to_expr(conseq));
         Z3_CATCH;        
     }
 

src/api/python/z3/z3.py

@@ -10506,30 +10506,39 @@ def TransitiveClosure(f):
 
 
 class PropClosures:
-#    import thread
     def __init__(self):
         self.bases = {}
-#        self.lock = thread.Lock()
+        self.lock = None
+
+    def set_threaded():
+        if self.lock is None:
+            import threading
+            self.lock = threading.thread.Lock()
 
     def get(self, ctx):
-#        self.lock.acquire()
+        if self.lock: self.lock.acquire()
         r = self.bases[ctx]
-#        self.lock.release()
+        if self.lock: self.lock.release()
         return r
 
     def set(self, ctx, r):
-#        self.lock.acquire()
+        if self.lock: self.lock.acquire()
         self.bases[ctx] = r
-#        self.lock.release()
+        if self.lock: self.lock.release()
 
     def insert(self, r):
-#        self.lock.acquire()
+        if self.lock: self.lock.acquire()
         id = len(self.bases) + 3
         self.bases[id] = r
-#       self.lock.release()
+        if self.lock: self.lock.release()
         return id
 
-_prop_closures = PropClosures()
+_prop_closures = None
+
+def ensure_prop_closures():
+    global _prop_closures
+    if _prop_closures is None:
+        _prop_closures = PropClosures()
 
 def user_prop_push(ctx):
     _prop_closures.get(ctx).push();
@@ -10537,9 +10546,10 @@ def user_prop_push(ctx):
 def user_prop_pop(ctx, num_scopes):
     _prop_closures.get(ctx).pop(num_scopes)
 
-def user_prop_fresh(ctx):
+def user_prop_fresh(id, ctx):
-    prop = _prop_closures.get(ctx)
+    prop = _prop_closures.get(id)
-    new_prop = UsePropagateBase(None, prop.ctx)
+    _prop_closures.set_threaded()
+    new_prop = UsePropagateBase(None, ctx)
     _prop_closures.set(new_prop.id, new_prop.fresh())
     return ctypes.c_void_p(new_prop.id)
 
@@ -10577,66 +10587,104 @@ _user_prop_diseq = eq_eh_type(user_prop_diseq)
 
 class UserPropagateBase:
 
+    #
+    # Either solver is set or ctx is set.
+    # Propagators that are created throuh callbacks
+    # to "fresh" inherit the context of that is supplied
+    # as argument to the callback.
+    # This context should not be deleted. It is owned by the solver.
+    # 
     def __init__(self, s, ctx = None):
+        assert s is None or ctx is None
+        ensure_prop_closures()
         self.solver = s        
-        self.ctx = s.ctx if s is not None else ctx
+        self._ctx = None
         self.cb = None
         self.id = _prop_closures.insert(self)
         self.fixed = None
         self.final = None
         self.eq    = None
         self.diseq = None
+        if ctx:
+            self._ctx = Context()
+            Z3_del_context(self._ctx.ctx)
+            self._ctx.ctx = ctx
+            self._ctx.eh = Z3_set_error_handler(ctx, z3_error_handler)
+            Z3_set_ast_print_mode(ctx, Z3_PRINT_SMTLIB2_COMPLIANT)
         if s:
-            Z3_solver_propagate_init(s.ctx.ref(),
+            Z3_solver_propagate_init(self.ctx_ref(),
                                      s.solver,
                                      ctypes.c_void_p(self.id),
                                      _user_prop_push,
                                      _user_prop_pop,
                                      _user_prop_fresh)
 
+    def __del__(self):
+        if self._ctx:
+            self._ctx.ctx = None
+
+    def ctx(self):
+        if self._ctx:
+            return self._ctx
+        else:
+            return self.solver.ctx
+        
+    def ctx_ref(self):
+        return self.ctx().ref()
                     
     def add_fixed(self, fixed):
         assert not self.fixed
-        Z3_solver_propagate_fixed(self.ctx.ref(), self.solver.solver, _user_prop_fixed)
+        assert not self._ctx
+        Z3_solver_propagate_fixed(self.ctx_ref(), self.solver.solver, _user_prop_fixed)
         self.fixed = fixed
  
     def add_final(self, final):
         assert not self.final
-        Z3_solver_propagate_final(self.ctx.ref(), self.solver.solver, _user_prop_final)
+        assert not self._ctx
+        Z3_solver_propagate_final(self.ctx_ref(), self.solver.solver, _user_prop_final)
         self.final = final
 
     def add_eq(self, eq):
         assert not self.eq
-        Z3_solver_propagate_eq(self.ctx.ref(), self.solver.solver, _user_prop_eq)
+        assert not self._ctx
+        Z3_solver_propagate_eq(self.ctx_ref(), self.solver.solver, _user_prop_eq)
         self.eq = eq
 
     def add_diseq(self, diseq):
         assert not self.diseq
-        Z3_solver_propagate_diseq(self.ctx.ref(), self.solver.solver, _user_prop_diseq)
+        assert not self._ctx
+        Z3_solver_propagate_diseq(self.ctx_ref(), self.solver.solver, _user_prop_diseq)
         self.diseq = diseq
 
     def push(self):
-        raise Z3Exception("push has not been overwritten")
+        raise Z3Exception("push needs to be overwritten")
 
     def pop(self, num_scopes):
-        raise Z3Exception("pop has not been overwritten")
+        raise Z3Exception("pop needs to be overwritten")
 
     def fresh(self):
-        raise Z3Exception("fresh has not been overwritten")
+        raise Z3Exception("fresh needs to be overwritten")
         
     def add(self, e):
         assert self.solver
-        return Z3_solver_propagate_register(self.ctx.ref(), self.solver.solver, e.ast)
+        assert not self._ctx
+        return Z3_solver_propagate_register(self.ctx_ref(), self.solver.solver, e.ast)
 
     #
     # Propagation can only be invoked as during a fixed-callback.
     # 
-    def propagate(self, ids, e):
+    def propagate(self, e, ids, eqs = []):
-        sz = len(ids)
+        num_fixed = len(ids)
-        _ids = (ctypes.c_uint * sz)()
+        _ids = (ctypes.c_uint * num_fixed)()
-        for i in range(sz):
+        for i in range(num_fixed):
             _ids[i] = ids[i]
-        Z3_solver_propagate_consequence(self.ctx.ref(), ctypes.c_void_p(self.cb), sz, _ids, e.ast)
+        num_eqs = len(eqs)
+        _lhs = (ctypes.c_uint * num_eqs)()
+        _rhs = (ctypes.c_uint * num_eqs)()
+        for i in range(num_eqs):
+            _lhs[i] = eqs[i][0]
+            _rhs[i] = eqs[i][1]
+        Z3_solver_propagate_consequence(self.ctx_ref(), ctypes.c_void_p(self.cb), num_fixed, _ids, num_eqs, _lhs, _rhs, e.ast)
 
     def conflict(self, ids):
-        self.propagate(ids, BoolVal(False, self.ctx))
+        self.propagate(ids, BoolVal(False, self.ctx_ref()))

src/api/z3_api.h

@@ -1420,7 +1420,7 @@ typedef void Z3_error_handler(Z3_context c, Z3_error_code e);
 */
 typedef void Z3_push_eh(void* ctx);
 typedef void Z3_pop_eh(void* ctx, unsigned num_scopes);
-typedef void* Z3_fresh_eh(void* ctx);
+typedef void* Z3_fresh_eh(void* ctx, Z3_context new_context);
 typedef void Z3_fixed_eh(void* ctx, Z3_solver_callback cb, unsigned id, Z3_ast value);
 typedef void Z3_eq_eh(void* ctx, Z3_solver_callback cb, unsigned x, unsigned y);
 typedef void Z3_final_eh(void* ctx, Z3_solver_callback cb);
@@ -6586,10 +6586,10 @@ extern "C" {
        The callback adds a propagation consequence based on the fixed values of the
        \c ids. 
        
-       def_API('Z3_solver_propagate_consequence', VOID, (_in(CONTEXT), _in(SOLVER_CALLBACK), _in(UINT), _in_array(2, UINT), _in(AST)))
+       def_API('Z3_solver_propagate_consequence', VOID, (_in(CONTEXT), _in(SOLVER_CALLBACK), _in(UINT), _in_array(2, UINT), _in(UINT), _in_array(4, UINT), _in_array(4, UINT), _in(AST)))
     */
     
-    void Z3_API Z3_solver_propagate_consequence(Z3_context c, Z3_solver_callback, unsigned sz, unsigned const* ids, Z3_ast conseq);
+    void Z3_API Z3_solver_propagate_consequence(Z3_context c, Z3_solver_callback, unsigned num_fixed, unsigned const* fixed_ids, unsigned num_eqs, unsigned const* eq_lhs, unsigned const* eq_rhs, Z3_ast conseq);
 
     /**
        \brief Check whether the assertions in a given solver are consistent or not.

src/cmd_context/context_params.cpp

@@ -24,19 +24,6 @@ Notes:
 #include "solver/solver.h"
 
 context_params::context_params() {
-    m_unsat_core     = false;
-    m_model          = true;
-    m_model_validate = false;
-    m_dump_models    = false;
-    m_auto_config    = true;
-    m_proof          = false;
-    m_trace          = false;
-    m_debug_ref_count = false;
-    m_smtlib2_compliant = false;
-    m_well_sorted_check = false;
-    m_timeout = UINT_MAX;
-    m_rlimit  = 0;
-    m_statistics = false;
     updt_params();
 }
 
@@ -204,6 +191,8 @@ void context_params::get_solver_params(ast_manager const & m, params_ref & p, bo
 }
 
 ast_manager * context_params::mk_ast_manager() {
+    if (m_manager)
+        return m_manager;
     ast_manager * r = alloc(ast_manager,
                             m_proof ? PGM_ENABLED : PGM_DISABLED,
                             m_trace ? m_trace_file_name.c_str() : nullptr);

src/cmd_context/context_params.h

@@ -26,24 +26,24 @@ class context_params {
     void set_bool(bool & opt, char const * param, char const * value);
     void set_uint(unsigned & opt, char const * param, char const * value);
 
-    unsigned    m_rlimit;
+    unsigned    m_rlimit { 0 };
+    ast_manager* m_manager { nullptr };
 
 public:
-    bool        m_auto_config;
+    bool        m_auto_config { true };
-    bool        m_proof;
+    bool        m_proof { false };
     std::string m_dot_proof_file;
-    bool        m_interpolants;
+    bool        m_debug_ref_count { false };
-    bool        m_debug_ref_count;
+    bool        m_trace { false };
-    bool        m_trace;
     std::string m_trace_file_name;
-    bool        m_well_sorted_check;
+    bool        m_well_sorted_check { false };
-    bool        m_model;
+    bool        m_model { true };
-    bool        m_model_validate;
+    bool        m_model_validate { false };
-    bool        m_dump_models;
+    bool        m_dump_models { false };
-    bool        m_unsat_core;
+    bool        m_unsat_core { false };
-    bool        m_smtlib2_compliant; // it must be here because it enable/disable the use of coercions in the ast_manager.
+    bool        m_smtlib2_compliant { false }; // it must be here because it enable/disable the use of coercions in the ast_manager.
-    unsigned    m_timeout;
+    unsigned    m_timeout { UINT_MAX } ;
-    bool        m_statistics;
+    bool        m_statistics { false };
 
     unsigned rlimit() const { return m_rlimit; }
     context_params();
@@ -74,6 +74,9 @@ public:
        \brief Create an AST manager using this configuration.
     */
     ast_manager * mk_ast_manager();
+
+    void set_foreign_manager(ast_manager* m) { m_manager = m; }
+    bool owns_manager() const { return m_manager != nullptr; }
 };
 
 

src/smt/smt_context.cpp

@@ -184,12 +184,13 @@ namespace smt {
         dst_ctx.setup_context(dst_ctx.m_fparams.m_auto_config);
         dst_ctx.internalize_assertions();
         
+        dst_ctx.copy_user_propagator(src_ctx);
+
         TRACE("smt_context",
               src_ctx.display(tout);
               dst_ctx.display(tout););
     }
 
-
     context::~context() {
         flush();
         m_asserted_formulas.finalize();
@@ -205,6 +206,19 @@ namespace smt {
         }
     }
 
+    void context::copy_user_propagator(context& src_ctx) {
+        if (!src_ctx.m_user_propagator) 
+            return;
+        ast_translation tr(src_ctx.m, m, false);
+        auto* p = get_theory(m.mk_family_id("user_propagator"));
+        m_user_propagator = reinterpret_cast<user_propagator*>(p);
+        SASSERT(m_user_propagator);
+        for (unsigned i = 0; i < src_ctx.m_user_propagator->get_num_vars(); ++i) {
+            app* e = src_ctx.m_user_propagator->get_expr(i);
+            m_user_propagator->add_expr(tr(e));
+        }
+    }
+
     context * context::mk_fresh(symbol const * l, smt_params * p, params_ref const& pa) {
         context * new_ctx = alloc(context, m, p ? *p : m_fparams, pa);
         new_ctx->m_is_auxiliary = true;
@@ -2950,10 +2964,10 @@ namespace smt {
     }
 
     void context::user_propagate_init(
-        void* ctx, 
+        void*                    ctx, 
-        std::function<void(void*)>&                  push_eh,
+        solver::push_eh_t&       push_eh,
-        std::function<void(void*, unsigned)>&        pop_eh,
+        solver::pop_eh_t&        pop_eh,
-        std::function<void*(void*)>&                 fresh_eh) {
+        solver::fresh_eh_t&      fresh_eh) {
         setup_context(m_fparams.m_auto_config);
         m_user_propagator = alloc(user_propagator, *this);
         m_user_propagator->add(ctx, push_eh, pop_eh, fresh_eh);
@@ -2963,7 +2977,7 @@ namespace smt {
     }
 
     bool context::watches_fixed(enode* n) const {
-        return m_user_propagator && n->get_th_var(m_user_propagator->get_family_id()) != null_theory_var;
+        return m_user_propagator && m_user_propagator->has_fixed() && n->get_th_var(m_user_propagator->get_family_id()) != null_theory_var;
     }
 
     void context::assign_fixed(enode* n, expr* val, unsigned sz, literal const* explain) {

src/smt/smt_context.h

@@ -1573,6 +1573,8 @@ namespace smt {
 
         void log_stats();
 
+        void copy_user_propagator(context& src);
+
     public:
         context(ast_manager & m, smt_params & fp, params_ref const & p = params_ref());
 
@@ -1688,10 +1690,10 @@ namespace smt {
          * user-propagator
          */
         void user_propagate_init(
-            void* ctx, 
+            void*                 ctx, 
-            std::function<void(void*)>&                  push_eh,
+            solver::push_eh_t&    push_eh,
-            std::function<void(void*, unsigned)>&        pop_eh,
+            solver::pop_eh_t&     pop_eh,
-            std::function<void*(void*)>&                 fresh_eh);
+            solver::fresh_eh_t&   fresh_eh);
 
         void user_propagate_register_final(solver::final_eh_t& final_eh) {
             if (!m_user_propagator) 

src/smt/smt_kernel.cpp

@@ -234,10 +234,10 @@ namespace smt {
         }
 
         void user_propagate_init(
-            void* ctx, 
+            void*                    ctx, 
-            std::function<void(void*)>&                  push_eh,
+            solver::push_eh_t&       push_eh,
-            std::function<void(void*, unsigned)>&        pop_eh,
+            solver::pop_eh_t&        pop_eh,
-            std::function<void*(void*)>&                 fresh_eh) {
+            solver::fresh_eh_t&      fresh_eh) {
             m_kernel.user_propagate_init(ctx, push_eh, pop_eh, fresh_eh);
         }
 
@@ -474,10 +474,10 @@ namespace smt {
     }
 
     void kernel::user_propagate_init(
-        void* ctx, 
+        void*                ctx, 
-        std::function<void(void*)>&                  push_eh,
+        solver::push_eh_t&   push_eh,
-        std::function<void(void*, unsigned)>&        pop_eh,
+        solver::pop_eh_t&    pop_eh,
-        std::function<void*(void*)>&                 fresh_eh) {
+        solver::fresh_eh_t&  fresh_eh) {
         m_imp->user_propagate_init(ctx, push_eh, pop_eh, fresh_eh);
     }
 

src/smt/smt_kernel.h

@@ -290,9 +290,9 @@ namespace smt {
         */
         void user_propagate_init(
             void* ctx, 
-            std::function<void(void*)>&                  push_eh,
+            solver::push_eh_t&      push_eh,
-            std::function<void(void*, unsigned)>&        pop_eh,
+            solver::pop_eh_t&       pop_eh,
-            std::function<void*(void*)>&                 fresh_eh);
+            solver::fresh_eh_t&     fresh_eh);
 
         void user_propagate_register_fixed(solver::fixed_eh_t& fixed_eh);
 

src/smt/smt_solver.cpp

@@ -212,7 +212,7 @@ namespace {
             void* ctx, 
             std::function<void(void*)>&                  push_eh,
             std::function<void(void*, unsigned)>&        pop_eh,
-            std::function<void*(void*)>&                 fresh_eh) override {
+            solver::fresh_eh_t&                          fresh_eh) override {
             m_context.user_propagate_init(ctx, push_eh, pop_eh, fresh_eh);
         }
         

src/smt/user_propagator.cpp

@@ -23,11 +23,13 @@ Author:
 using namespace smt;
 
 user_propagator::user_propagator(context& ctx):
-    theory(ctx, ctx.get_manager().mk_family_id("user_propagator")),
+    theory(ctx, ctx.get_manager().mk_family_id("user_propagator"))
-    m_qhead(0),
-    m_num_scopes(0)
 {}
 
+user_propagator::~user_propagator() {
+    dealloc(m_api_context);
+}
+
 void user_propagator::force_push() {
     for (; m_num_scopes > 0; --m_num_scopes) {
         theory::push_scope_eh();
@@ -36,9 +38,6 @@ void user_propagator::force_push() {
     }
 }
 
-// TODO: check type of 'e', either Bool or Bit-vector.
-//
-
 unsigned user_propagator::add_expr(expr* e) {
     force_push();
     enode* n = ensure_enode(e);
@@ -49,13 +48,13 @@ unsigned user_propagator::add_expr(expr* e) {
     return v;
 }
 
-void user_propagator::propagate(unsigned sz, unsigned const* ids, expr* conseq) {
+void user_propagator::propagate(unsigned num_fixed, unsigned const* fixed_ids, unsigned num_eqs, unsigned const* eq_lhs, unsigned const* eq_rhs, expr* conseq) {
-    m_prop.push_back(prop_info(sz, ids, expr_ref(conseq, m)));
+    m_prop.push_back(prop_info(num_fixed, fixed_ids, num_eqs, eq_lhs, eq_rhs, expr_ref(conseq, m)));
 }
 
 theory * user_propagator::mk_fresh(context * new_ctx) { 
     auto* th = alloc(user_propagator, *new_ctx); 
-    void* ctx = m_fresh_eh(m_user_context);
+    void* ctx = m_fresh_eh(m_user_context, new_ctx->get_manager(), th->m_api_context);
     th->add(ctx, m_push_eh, m_pop_eh, m_fresh_eh);
     if ((bool)m_fixed_eh) th->register_fixed(m_fixed_eh);
     if ((bool)m_final_eh) th->register_final(m_final_eh);
@@ -111,8 +110,11 @@ void user_propagator::propagate() {
     while (qhead < m_prop.size() && !ctx.inconsistent()) {
         auto const& prop = m_prop[qhead];
         m_lits.reset();   
+        eqs.reset();
         for (unsigned id : prop.m_ids)
             m_lits.append(m_id2justification[id]);
+        for (auto const& p : prop.m_eqs)
+            eqs.push_back(enode_pair(get_enode(p.first), get_enode(p.second)));
         if (m.is_false(prop.m_conseq)) {
             js = ctx.mk_justification(
                 ext_theory_conflict_justification(
@@ -126,10 +128,16 @@ void user_propagator::propagate() {
                     get_id(), ctx.get_region(), m_lits.size(), m_lits.c_ptr(), eqs.size(), eqs.c_ptr(), lit));
             ctx.assign(lit, js);
         }
+        ++m_stats.m_num_propagations;
         ++qhead;
     }
     ctx.push_trail(value_trail<context, unsigned>(m_qhead));
     m_qhead = qhead;
 }
 
+void user_propagator::collect_statistics(::statistics & st) const {
+    st.update("user-propagations", m_stats.m_num_propagations);
+    st.update("user-watched",      get_num_vars());
+}
+
 

src/smt/user_propagator.h

@@ -29,45 +29,59 @@ Notes:
 
 namespace smt {
     class user_propagator : public theory, public solver::propagate_callback {
-        void* m_user_context;
-        std::function<void(void*)>                  m_push_eh;
-        std::function<void(void*, unsigned)>        m_pop_eh;
-        std::function<void*(void*)>                 m_fresh_eh;
-        solver::final_eh_t  m_final_eh;
-        solver::fixed_eh_t  m_fixed_eh;
-        solver::eq_eh_t     m_eq_eh;
-        solver::eq_eh_t     m_diseq_eh;
 
         struct prop_info {
             unsigned_vector m_ids;
             expr_ref        m_conseq;
-            prop_info(unsigned sz, unsigned const* ids, expr_ref const& c):
+            svector<std::pair<unsigned, unsigned>> m_eqs;
-                m_ids(sz, ids),
+            prop_info(unsigned num_fixed, unsigned const* fixed_ids, unsigned num_eqs, unsigned const* eq_lhs, unsigned const* eq_rhs, expr_ref const& c):
+                m_ids(num_fixed, fixed_ids),
                 m_conseq(c)
-            {}
+            {
+                for (unsigned i = 0; i < num_eqs; ++i)
+                    m_eqs.push_back(std::make_pair(eq_lhs[i], eq_rhs[i]));
+            }
         };
-        unsigned               m_qhead;
+
+        struct stats {
+            unsigned m_num_propagations;
+            stats() { reset(); }
+            void reset() { memset(this, 0, sizeof(*this)); }
+        };
+
+        void*               m_user_context;
+        solver::push_eh_t   m_push_eh;
+        solver::pop_eh_t    m_pop_eh;
+        solver::fresh_eh_t  m_fresh_eh;
+        solver::final_eh_t  m_final_eh;
+        solver::fixed_eh_t  m_fixed_eh;
+        solver::eq_eh_t     m_eq_eh;
+        solver::eq_eh_t     m_diseq_eh;
+        void*               m_api_context { nullptr };
+
+        unsigned               m_qhead { 0 };
         vector<prop_info>      m_prop;
         unsigned_vector        m_prop_lim;
         vector<literal_vector> m_id2justification;
-        unsigned               m_num_scopes;
+        unsigned               m_num_scopes { 0 };
         literal_vector         m_lits;
+        stats                  m_stats;
 
         void force_push();
 
     public:
         user_propagator(context& ctx);
         
-        ~user_propagator() override {}
+        ~user_propagator() override;
 
         /*
          * \brief initial setup for user propagator.
          */
         void add(
-            void* ctx, 
+            void*                ctx, 
-            std::function<void(void*)>&                  push_eh,
+            solver::push_eh_t&    push_eh,
-            std::function<void(void*, unsigned)>&        pop_eh,
+            solver::pop_eh_t&     pop_eh,
-            std::function<void*(void*)>&                 fresh_eh) {
+            solver::fresh_eh_t&   fresh_eh) {
             m_user_context = ctx;
             m_push_eh      = push_eh;
             m_pop_eh       = pop_eh;
@@ -81,7 +95,9 @@ namespace smt {
         void register_eq(solver::eq_eh_t& eq_eh) { m_eq_eh = eq_eh; }
         void register_diseq(solver::eq_eh_t& diseq_eh) { m_diseq_eh = diseq_eh; }
 
-        void propagate(unsigned sz, unsigned const* ids, expr* conseq) override;
+        bool has_fixed() const { return (bool)m_fixed_eh; }
+
+        void propagate(unsigned num_fixed, unsigned const* fixed_ids, unsigned num_eqs, unsigned const* lhs, unsigned const* rhs, expr* conseq) override;
 
         void new_fixed_eh(theory_var v, expr* value, unsigned num_lits, literal const* jlits);
 
@@ -99,7 +115,7 @@ namespace smt {
         void push_scope_eh() override;
         void pop_scope_eh(unsigned num_scopes) override;
         void restart_eh() override {}
-        void collect_statistics(::statistics & st) const override {}
+        void collect_statistics(::statistics & st) const override;
         model_value_proc * mk_value(enode * n, model_generator & mg) override { return nullptr; }
         void init_model(model_generator & m) override {}
         bool include_func_interp(func_decl* f) override { return false; }

src/solver/solver.h

@@ -239,22 +239,26 @@ public:
 
     virtual expr_ref get_implied_upper_bound(expr* e) = 0;
 
-    virtual void user_propagate_init(
-        void* ctx, 
-        std::function<void(void*)>&                  push_eh,
-        std::function<void(void*, unsigned)>&        pop_eh,
-        std::function<void*(void*)>&                 fresh_eh) {
-        throw default_exception("user-propagators are only supported on the SMT solver");
-    }
-
     class propagate_callback {
     public:
-        virtual void propagate(unsigned sz, unsigned const* ids, expr* conseq) = 0;
+        virtual void propagate(unsigned num_fixed, unsigned const* fixed_ids, unsigned num_eqs, unsigned const* eq_lhs, unsigned const* eq_rhs, expr* conseq) = 0;
     };
     
     typedef std::function<void(void*, solver::propagate_callback*)> final_eh_t;
     typedef std::function<void(void*, solver::propagate_callback*, unsigned, expr*)> fixed_eh_t;
     typedef std::function<void(void*, solver::propagate_callback*, unsigned, unsigned)> eq_eh_t;
+    typedef std::function<void*(void*, ast_manager&, void*&)> fresh_eh_t;
+    typedef std::function<void(void*)>                 push_eh_t;
+    typedef std::function<void(void*,unsigned)>        pop_eh_t;
+
+    virtual void user_propagate_init(
+        void* ctx, 
+        push_eh_t&                                   push_eh,
+        pop_eh_t&                                    pop_eh,
+        fresh_eh_t&                                  fresh_eh) {
+        throw default_exception("user-propagators are only supported on the SMT solver");
+    }
+
 
     virtual void user_propagate_register_fixed(fixed_eh_t& fixed_eh) {
         throw default_exception("user-propagators are only supported on the SMT solver");