daemon: Allow builds to be repeated.

This makes it easy to detect non-deterministic builds.

* nix/libstore/build.cc (DerivationGoal): Remove 'InodesSeen'; add
'curRound', 'nrRound', and 'prevInfos'.
(DerivationGoal::inputsRealised): Initialize 'nrRound'.
(NotDeterministic): New error type.
(DerivationGoal::buildDone): Check whether we need to repeat.
(DerivationGoal::startBuilder): Adjust message.
(DerivationGoal::registerOutputs): Check whether we get the same result.
* nix/libstore/globals.cc (Settings::get(const string & name, int def)):
New method.
* nix/libstore/globals.hh (Settings): Add it.
* nix/libstore/store-api.hh (ValidPathInfo): Add operator ==.
* nix/nix-daemon/nix-daemon.cc (performOp): Allow "build-repeat" for
"untrusted" users.

Co-authored-by: Ludovic Courtès <ludo@gnu.org>
This commit is contained in:
Eelco Dolstra 2015-12-08 22:50:18 +01:00 committed by Ludovic Courtès
parent 7fbee931a5
commit b23b4d394a
5 changed files with 71 additions and 14 deletions

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@ -785,10 +785,16 @@ private:
temporary paths. */
PathSet redirectedBadOutputs;
/* Set of inodes seen during calls to canonicalisePathMetaData()
for this build's outputs. This needs to be shared between
outputs to allow hard links between outputs. */
InodesSeen inodesSeen;
/* The current round, if we're building multiple times. */
unsigned int curRound = 1;
unsigned int nrRounds;
/* Path registration info from the previous round, if we're
building multiple times. Since this contains the hash, it
allows us to compare whether two rounds produced the same
result. */
ValidPathInfos prevInfos;
public:
DerivationGoal(const Path & drvPath, const StringSet & wantedOutputs, Worker & worker, BuildMode buildMode = bmNormal);
@ -1194,8 +1200,12 @@ void DerivationGoal::inputsRealised()
/* Is this a fixed-output derivation? */
fixedOutput = true;
foreach (DerivationOutputs::iterator, i, drv.outputs)
if (i->second.hash == "") fixedOutput = false;
for (auto & i : drv.outputs)
if (i.second.hash == "") fixedOutput = false;
/* Don't repeat fixed-output derivations since they're already
verified by their output hash.*/
nrRounds = fixedOutput ? 1 : settings.get("build-repeat", 0) + 1;
/* Okay, try to build. Note that here we don't wait for a build
slot to become available, since we don't need one if there is a
@ -1371,6 +1381,9 @@ void replaceValidPath(const Path & storePath, const Path tmpPath)
}
MakeError(NotDeterministic, BuildError)
void DerivationGoal::buildDone()
{
trace("build done");
@ -1470,6 +1483,15 @@ void DerivationGoal::buildDone()
deleteTmpDir(true);
/* Repeat the build if necessary. */
if (curRound++ < nrRounds) {
outputLocks.unlock();
buildUser.release();
state = &DerivationGoal::tryToBuild;
worker.wakeUp(shared_from_this());
return;
}
/* It is now safe to delete the lock files, since all future
lockers will see that the output paths are valid; they will
not create new lock files with the same names as the old
@ -1623,10 +1645,13 @@ int childEntry(void * arg)
void DerivationGoal::startBuilder()
{
startNest(nest, lvlInfo, format(
auto f = format(
buildMode == bmRepair ? "repairing path(s) %1%" :
buildMode == bmCheck ? "checking path(s) %1%" :
"building path(s) %1%") % showPaths(missingPaths));
nrRounds > 1 ? "building path(s) %1% (round %2%/%3%)" :
"building path(s) %1%");
f.exceptions(boost::io::all_error_bits ^ boost::io::too_many_args_bit);
startNest(nest, lvlInfo, f % showPaths(missingPaths) % curRound % nrRounds);
/* Right platform? */
if (!canBuildLocally(drv.platform)) {
@ -1638,6 +1663,7 @@ void DerivationGoal::startBuilder()
}
/* Construct the environment passed to the builder. */
env.clear();
/* Most shells initialise PATH to some default (/bin:/usr/bin:...) when
PATH is not set. We don't want this, so we fill it in with some dummy
@ -2267,6 +2293,11 @@ void DerivationGoal::registerOutputs()
ValidPathInfos infos;
/* Set of inodes seen during calls to canonicalisePathMetaData()
for this build's outputs. This needs to be shared between
outputs to allow hard links between outputs. */
InodesSeen inodesSeen;
/* Check whether the output paths were created, and grep each
output path to determine what other paths it references. Also make all
output paths read-only. */
@ -2438,6 +2469,16 @@ void DerivationGoal::registerOutputs()
if (buildMode == bmCheck) return;
if (curRound > 1 && prevInfos != infos)
throw NotDeterministic(
format("result of %1% differs from previous round; rejecting as non-deterministic")
% drvPath);
if (curRound < nrRounds) {
prevInfos = infos;
return;
}
/* Register each output path as valid, and register the sets of
paths referenced by each of them. If there are cycles in the
outputs, this will fail. */

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@ -137,6 +137,13 @@ bool Settings::get(const string & name, bool def)
return res;
}
int Settings::get(const string & name, int def)
{
int res = def;
_get(res, name);
return res;
}
void Settings::update()
{

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@ -27,6 +27,8 @@ struct Settings {
bool get(const string & name, bool def);
int get(const string & name, int def);
void update();
string pack();

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@ -88,10 +88,17 @@ struct ValidPathInfo
Path deriver;
Hash hash;
PathSet references;
time_t registrationTime;
unsigned long long narSize; // 0 = unknown
time_t registrationTime = 0;
unsigned long long narSize = 0; // 0 = unknown
unsigned long long id; // internal use only
ValidPathInfo() : registrationTime(0), narSize(0) { }
bool operator == (const ValidPathInfo & i) const
{
return
path == i.path
&& hash == i.hash
&& references == i.references;
}
};
typedef list<ValidPathInfo> ValidPathInfos;

View File

@ -565,7 +565,7 @@ static void performOp(bool trusted, unsigned int clientVersion,
for (unsigned int i = 0; i < n; i++) {
string name = readString(from);
string value = readString(from);
if (name == "build-timeout" || name == "use-ssh-substituter")
if (name == "build-timeout" || name == "build-repeat" || name == "use-ssh-substituter")
settings.set(name, value);
else
settings.set(trusted ? name : "untrusted-" + name, value);