Add a function ‘valueSize’

It returns the size of value, including all other values and
environments reachable from it. It is intended for debugging memory
consumption issues.
This commit is contained in:
Eelco Dolstra 2014-09-22 14:46:42 +02:00
parent 68cf98c4d2
commit eff120d1b9
4 changed files with 99 additions and 2 deletions

View file

@ -404,9 +404,12 @@ Value * EvalState::allocValue()
Env & EvalState::allocEnv(unsigned int size) Env & EvalState::allocEnv(unsigned int size)
{ {
assert(size <= std::numeric_limits<decltype(Env::size)>::max());
nrEnvs++; nrEnvs++;
nrValuesInEnvs += size; nrValuesInEnvs += size;
Env * env = (Env *) GC_MALLOC(sizeof(Env) + size * sizeof(Value *)); Env * env = (Env *) GC_MALLOC(sizeof(Env) + size * sizeof(Value *));
env->size = size;
/* Clear the values because maybeThunk() and lookupVar fromWith expects this. */ /* Clear the values because maybeThunk() and lookupVar fromWith expects this. */
for (unsigned i = 0; i < size; ++i) for (unsigned i = 0; i < size; ++i)
@ -1488,4 +1491,81 @@ void EvalState::printCanaries()
} }
size_t valueSize(Value & v)
{
std::set<const void *> 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<size_t(Value & v)> doValue;
std::function<size_t(Env & v)> 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);
}
} }

View file

@ -95,8 +95,9 @@ struct PrimOp
struct Env struct Env
{ {
Env * up; Env * up;
unsigned short prevWith; // nr of levels up to next `with' environment unsigned short size; // used by valueSize
bool haveWithAttrs; unsigned short prevWith:15; // nr of levels up to next `with' environment
unsigned short haveWithAttrs:1;
Value * values[0]; Value * values[0];
}; };

View file

@ -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 * Derivations
*************************************************************/ *************************************************************/
@ -1416,8 +1423,11 @@ void EvalState::createBaseEnv()
addPrimOp("__addErrorContext", 2, prim_addErrorContext); addPrimOp("__addErrorContext", 2, prim_addErrorContext);
addPrimOp("__tryEval", 1, prim_tryEval); addPrimOp("__tryEval", 1, prim_tryEval);
addPrimOp("__getEnv", 1, prim_getEnv); addPrimOp("__getEnv", 1, prim_getEnv);
// Debugging
addPrimOp("__trace", 2, prim_trace); addPrimOp("__trace", 2, prim_trace);
addPrimOp("__gcCanary", 1, prim_gcCanary); addPrimOp("__gcCanary", 1, prim_gcCanary);
addPrimOp("__valueSize", 1, prim_valueSize);
// Paths // Paths
addPrimOp("__toPath", 1, prim_toPath); addPrimOp("__toPath", 1, prim_toPath);

View file

@ -159,4 +159,10 @@ static inline void mkPathNoCopy(Value & v, const char * s)
void mkPath(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);
} }