From 41c45a9b319a5578e2731505ca3de2b9c50b4988 Mon Sep 17 00:00:00 2001 From: Eelco Dolstra Date: Fri, 22 Oct 2010 14:47:42 +0000 Subject: * Store Value nodes outside of attribute sets. I.e., Attr now stores a pointer to a Value, rather than the Value directly. This improves the effectiveness of garbage collection a lot: if the Value is stored inside the set directly, then any live pointer to the Value causes all other attributes in the set to be live as well. --- src/libexpr/eval.cc | 97 +++++++++++++++++++++++++++++++---------------------- 1 file changed, 56 insertions(+), 41 deletions(-) (limited to 'src/libexpr/eval.cc') diff --git a/src/libexpr/eval.cc b/src/libexpr/eval.cc index c8a031ac6d0a..ea48947258ec 100644 --- a/src/libexpr/eval.cc +++ b/src/libexpr/eval.cc @@ -58,7 +58,7 @@ std::ostream & operator << (std::ostream & str, const Value & v) typedef std::map Sorted; Sorted sorted; foreach (Bindings::iterator, i, *v.attrs) - sorted[i->first] = &i->second.value; + sorted[i->first] = i->second.value; foreach (Sorted::iterator, i, sorted) str << i->first << " = " << *i->second << "; "; str << "}"; @@ -145,24 +145,26 @@ EvalState::~EvalState() void EvalState::addConstant(const string & name, Value & v) { + Value * v2 = allocValue(); + *v2 = v; staticBaseEnv.vars[symbols.create(name)] = baseEnvDispl; baseEnv.values[baseEnvDispl++] = v; string name2 = string(name, 0, 2) == "__" ? string(name, 2) : name; - (*baseEnv.values[0].attrs)[symbols.create(name2)].value = v; + (*baseEnv.values[0].attrs)[symbols.create(name2)].value = v2; } void EvalState::addPrimOp(const string & name, unsigned int arity, PrimOp primOp) { - Value v; + Value * v = allocValue(); string name2 = string(name, 0, 2) == "__" ? string(name, 2) : name; - v.type = tPrimOp; - v.primOp.arity = arity; - v.primOp.fun = primOp; - v.primOp.name = GC_STRDUP(name2.c_str()); + v->type = tPrimOp; + v->primOp.arity = arity; + v->primOp.fun = primOp; + v->primOp.name = GC_STRDUP(name2.c_str()); staticBaseEnv.vars[symbols.create(name)] = baseEnvDispl; - baseEnv.values[baseEnvDispl++] = v; + baseEnv.values[baseEnvDispl++] = *v; (*baseEnv.values[0].attrs)[symbols.create(name2)].value = v; } @@ -265,7 +267,7 @@ Value * EvalState::lookupVar(Env * env, const VarRef & var) while (1) { Bindings::iterator j = env->values[0].attrs->find(var.name); if (j != env->values[0].attrs->end()) - return &j->second.value; + return j->second.value; if (env->prevWith == 0) throwEvalError("undefined variable `%1%'", var.name); for (unsigned int l = env->prevWith; l; --l, env = env->up) ; @@ -275,6 +277,13 @@ Value * EvalState::lookupVar(Env * env, const VarRef & var) } +Value * EvalState::allocValue() +{ + nrValues++; + return (Value *) GC_MALLOC(sizeof(Value)); +} + + Value * EvalState::allocValues(unsigned int count) { nrValues += count; @@ -291,6 +300,14 @@ Env & EvalState::allocEnv(unsigned int size) } +Value * EvalState::allocAttr(Value & vAttrs, const Symbol & name) +{ + Attr & a = (*vAttrs.attrs)[name]; + a.value = allocValue(); + return a.value; +} + + void EvalState::mkList(Value & v, unsigned int length) { v.type = tList; @@ -321,11 +338,8 @@ void EvalState::mkThunk_(Value & v, Expr * expr) void EvalState::cloneAttrs(Value & src, Value & dst) { mkAttrs(dst); - foreach (Bindings::iterator, i, *src.attrs) { - Attr & a = (*dst.attrs)[i->first]; - mkCopy(a.value, i->second.value); - a.pos = i->second.pos; - } + foreach (Bindings::iterator, i, *src.attrs) + (*dst.attrs)[i->first] = i->second; } @@ -449,8 +463,9 @@ void ExprAttrs::eval(EvalState & state, Env & env, Value & v) environment. */ foreach (Attrs::iterator, i, attrs) { nix::Attr & a = (*v.attrs)[i->first]; - mkThunk(a.value, env2, i->second.first); - mkCopy(env2.values[displ++], a.value); + a.value = state.allocValue(); + mkThunk(*a.value, env2, i->second.first); + mkCopy(env2.values[displ++], *a.value); a.pos = &i->second.second; } @@ -459,7 +474,7 @@ void ExprAttrs::eval(EvalState & state, Env & env, Value & v) foreach (list::iterator, i, inherited) { nix::Attr & a = (*v.attrs)[i->first.name]; Value * v2 = state.lookupVar(&env, i->first); - mkCopy(a.value, *v2); + a.value = v2; mkCopy(env2.values[displ++], *v2); a.pos = &i->second; } @@ -474,10 +489,12 @@ void ExprAttrs::eval(EvalState & state, Env & env, Value & v) Hence we need __overrides.) */ Bindings::iterator overrides = v.attrs->find(state.sOverrides); if (overrides != v.attrs->end()) { - state.forceAttrs(overrides->second.value); - foreach (Bindings::iterator, i, *overrides->second.value.attrs) { + state.forceAttrs(*overrides->second.value); + foreach (Bindings::iterator, i, *overrides->second.value->attrs) { nix::Attr & a = (*v.attrs)[i->first]; - mkCopy(a.value, i->second.value); + if (a.value) + mkCopy(env2.values[displs[i->first]], *i->second.value); + a = i->second; } } } @@ -485,13 +502,14 @@ void ExprAttrs::eval(EvalState & state, Env & env, Value & v) else { foreach (Attrs::iterator, i, attrs) { nix::Attr & a = (*v.attrs)[i->first]; - mkThunk(a.value, env, i->second.first); + a.value = state.allocValue(); + mkThunk(*a.value, env, i->second.first); a.pos = &i->second.second; } foreach (list::iterator, i, inherited) { nix::Attr & a = (*v.attrs)[i->first.name]; - mkCopy(a.value, *state.lookupVar(&env, i->first)); + a.value = state.lookupVar(&env, i->first); a.pos = &i->second; } } @@ -548,13 +566,13 @@ void ExprSelect::eval(EvalState & state, Env & env, Value & v) if (i == v2.attrs->end()) throwEvalError("attribute `%1%' missing", name); try { - state.forceValue(i->second.value); + state.forceValue(*i->second.value); } catch (Error & e) { addErrorPrefix(e, "while evaluating the attribute `%1%' at %2%:\n", name, *i->second.pos); throw; } - v = i->second.value; + v = *i->second.value; } @@ -578,9 +596,9 @@ void ExprApp::eval(EvalState & state, Env & env, Value & v) { Value vFun; state.eval(env, e1, vFun); - Value vArg; - mkThunk(vArg, env, e2); // !!! should this be on the heap? - state.callFunction(vFun, vArg, v); + Value * vArg = state.allocValue(); + mkThunk(*vArg, env, e2); + state.callFunction(vFun, *vArg, v); } @@ -656,7 +674,7 @@ void EvalState::callFunction(Value & fun, Value & arg, Value & v) mkThunk(env2.values[displ++], env2, i->def); } else { attrsUsed++; - mkCopy(env2.values[displ++], j->second.value); + mkCopy(env2.values[displ++], *j->second.value); } } @@ -677,7 +695,7 @@ void EvalState::callFunction(Value & fun, Value & arg, Value & v) } -void EvalState::autoCallFunction(const Bindings & args, Value & fun, Value & res) +void EvalState::autoCallFunction(Bindings & args, Value & fun, Value & res) { forceValue(fun); @@ -690,7 +708,7 @@ void EvalState::autoCallFunction(const Bindings & args, Value & fun, Value & res mkAttrs(actualArgs); foreach (Formals::Formals_::iterator, i, fun.lambda.fun->formals->formals) { - Bindings::const_iterator j = args.find(i->name); + Bindings::iterator j = args.find(i->name); if (j != args.end()) (*actualArgs.attrs)[i->name] = j->second; else if (!i->def) @@ -780,11 +798,8 @@ void ExprOpUpdate::eval(EvalState & state, Env & env, Value & v) state.cloneAttrs(v1, v); - foreach (Bindings::iterator, i, *v2.attrs) { - Attr & a = (*v.attrs)[i->first]; - mkCopy(a.value, i->second.value); - a.pos = i->second.pos; - } + foreach (Bindings::iterator, i, *v2.attrs) + (*v.attrs)[i->first] = i->second; state.nrOpUpdateValuesCopied += v.attrs->size(); } @@ -866,7 +881,7 @@ void EvalState::strictForceValue(Value & v) if (v.type == tAttrs) { foreach (Bindings::iterator, i, *v.attrs) - strictForceValue(i->second.value); + strictForceValue(*i->second.value); } else if (v.type == tList) { @@ -957,7 +972,7 @@ bool EvalState::isDerivation(Value & v) { if (v.type != tAttrs) return false; Bindings::iterator i = v.attrs->find(sType); - return i != v.attrs->end() && forceStringNoCtx(i->second.value) == "derivation"; + return i != v.attrs->end() && forceStringNoCtx(*i->second.value) == "derivation"; } @@ -1001,7 +1016,7 @@ string EvalState::coerceToString(Value & v, PathSet & context, Bindings::iterator i = v.attrs->find(sOutPath); if (i == v.attrs->end()) throwTypeError("cannot coerce an attribute set (except a derivation) to a string"); - return coerceToString(i->second.value, context, coerceMore, copyToStore); + return coerceToString(*i->second.value, context, coerceMore, copyToStore); } if (coerceMore) { @@ -1087,9 +1102,9 @@ bool EvalState::eqValues(Value & v1, Value & v2) case tAttrs: { if (v1.attrs->size() != v2.attrs->size()) return false; - Bindings::iterator i, j; - for (i = v1.attrs->begin(), j = v2.attrs->begin(); i != v1.attrs->end(); ++i, ++j) - if (i->first != j->first || !eqValues(i->second.value, j->second.value)) + Bindings::iterator i = v1.attrs->begin(), j = v2.attrs->begin(); + for ( ; i != v1.attrs->end(); ++i, ++j) + if (i->first != j->first || !eqValues(*i->second.value, *j->second.value)) return false; return true; } -- cgit 1.4.1