From eff120d1b93b99d6ae61b20e18c31a5324a2be4f Mon Sep 17 00:00:00 2001 From: Eelco Dolstra Date: Mon, 22 Sep 2014 14:46:42 +0200 Subject: [PATCH] =?UTF-8?q?Add=20a=20function=20=E2=80=98valueSize?= =?UTF-8?q?=E2=80=99?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit It returns the size of value, including all other values and environments reachable from it. It is intended for debugging memory consumption issues. --- src/libexpr/eval.cc | 80 ++++++++++++++++++++++++++++++++++++++++++ src/libexpr/eval.hh | 5 +-- src/libexpr/primops.cc | 10 ++++++ src/libexpr/value.hh | 6 ++++ 4 files changed, 99 insertions(+), 2 deletions(-) diff --git a/src/libexpr/eval.cc b/src/libexpr/eval.cc index cf8aafa8f..bd49cec4f 100644 --- a/src/libexpr/eval.cc +++ b/src/libexpr/eval.cc @@ -404,9 +404,12 @@ Value * EvalState::allocValue() Env & EvalState::allocEnv(unsigned int size) { + assert(size <= std::numeric_limits::max()); + nrEnvs++; nrValuesInEnvs += size; Env * env = (Env *) GC_MALLOC(sizeof(Env) + size * sizeof(Value *)); + env->size = size; /* Clear the values because maybeThunk() and lookupVar fromWith expects this. */ for (unsigned i = 0; i < size; ++i) @@ -1488,4 +1491,81 @@ void EvalState::printCanaries() } +size_t valueSize(Value & v) +{ + std::set seen; + + auto doString = [&](const char * s) -> size_t { + if (seen.find(s) != seen.end()) return 0; + seen.insert(s); + return strlen(s) + 1; + }; + + std::function doValue; + std::function doEnv; + + doValue = [&](Value & v) -> size_t { + if (seen.find(&v) != seen.end()) return 0; + seen.insert(&v); + + size_t sz = sizeof(Value); + + switch (v.type) { + case tString: + sz += doString(v.string.s); + if (v.string.context) + for (const char * * p = v.string.context; *p; ++p) + sz += doString(*p); + break; + case tPath: + sz += doString(v.path); + break; + case tAttrs: + for (auto & i : *v.attrs) + sz += doValue(*i.value); + break; + case tList: + for (unsigned int n = 0; n < v.list.length; ++n) + sz += doValue(*v.list.elems[n]); + break; + case tThunk: + sz += doEnv(*v.thunk.env); + break; + case tApp: + sz += doValue(*v.app.left); + sz += doValue(*v.app.right); + break; + case tLambda: + sz += doEnv(*v.lambda.env); + break; + case tPrimOpApp: + sz += doValue(*v.primOpApp.left); + sz += doValue(*v.primOpApp.right); + break; + default: + ; + } + + return sz; + }; + + doEnv = [&](Env & env) -> size_t { + if (seen.find(&env) != seen.end()) return 0; + seen.insert(&env); + + size_t sz = sizeof(Env); + + for (unsigned int i = 0; i < env.size; ++i) + if (env.values[i]) + sz += doValue(*env.values[i]); + + if (env.up) sz += doEnv(*env.up); + + return sz; + }; + + return doValue(v); +} + + } diff --git a/src/libexpr/eval.hh b/src/libexpr/eval.hh index dcd6209e3..d8ea0f0ce 100644 --- a/src/libexpr/eval.hh +++ b/src/libexpr/eval.hh @@ -95,8 +95,9 @@ struct PrimOp struct Env { Env * up; - unsigned short prevWith; // nr of levels up to next `with' environment - bool haveWithAttrs; + unsigned short size; // used by ‘valueSize’ + unsigned short prevWith:15; // nr of levels up to next `with' environment + unsigned short haveWithAttrs:1; Value * values[0]; }; diff --git a/src/libexpr/primops.cc b/src/libexpr/primops.cc index 66321c769..c721a5681 100644 --- a/src/libexpr/primops.cc +++ b/src/libexpr/primops.cc @@ -423,6 +423,13 @@ void prim_gcCanary(EvalState & state, const Pos & pos, Value * * args, Value & v } +void prim_valueSize(EvalState & state, const Pos & pos, Value * * args, Value & v) +{ + /* We're not forcing the argument on purpose. */ + mkInt(v, valueSize(*args[0])); +} + + /************************************************************* * Derivations *************************************************************/ @@ -1416,8 +1423,11 @@ void EvalState::createBaseEnv() addPrimOp("__addErrorContext", 2, prim_addErrorContext); addPrimOp("__tryEval", 1, prim_tryEval); addPrimOp("__getEnv", 1, prim_getEnv); + + // Debugging addPrimOp("__trace", 2, prim_trace); addPrimOp("__gcCanary", 1, prim_gcCanary); + addPrimOp("__valueSize", 1, prim_valueSize); // Paths addPrimOp("__toPath", 1, prim_toPath); diff --git a/src/libexpr/value.hh b/src/libexpr/value.hh index 2feb2f949..227f5e173 100644 --- a/src/libexpr/value.hh +++ b/src/libexpr/value.hh @@ -159,4 +159,10 @@ static inline void mkPathNoCopy(Value & v, const char * s) void mkPath(Value & v, const char * s); +/* Compute the size in bytes of the given value, including all values + and environments reachable from it. Static expressions (Exprs) are + not included. */ +size_t valueSize(Value & v); + + }