nixos/nix
1
1
Fork 0
mirror of https://github.com/NixOS/nix.git synced 2025-12-06 17:11:00 +01:00
Code Activity

Make restarting state machines explicit

Browse source 
If my memory is correct, @edolstra objected to modifying `wantedOutputs`
upon falling back to doing a build (as we did before), because we should
only modify it in response to new requests --- *actual* wants --- and
not because we are "incidentally" building all the outptus beyond what
may have been requested.

That's a fair point, and the alternative is to replace the boolean soup
with proper enums: Instead of modifying `wantedOuputs` som more, we'll
modify `needsRestart` to indicate we are passed the need.
This commit is contained in:
John Ericson 2023-02-14 13:25:55 -05:00
parent 37fca662b0
commit 0f2b5146c7
2 changed files with 83 additions and 18 deletions
Download patch file Download diff file Expand all files Collapse all files

49
src/libstore/build/derivation-goal.cc
View file

@ -145,8 +145,20 @@ void DerivationGoal::work()
void DerivationGoal::addWantedOutputs(const OutputsSpec & outputs)
{
auto newWanted = wantedOutputs.union_(outputs);
if (!newWanted.isSubsetOf(wantedOutputs))
needRestart = true;
switch (needRestart) {
case NeedRestartForMoreOutputs::OutputsUnmodifedDontNeed:
if (!newWanted.isSubsetOf(wantedOutputs))
needRestart = NeedRestartForMoreOutputs::OutputsAddedDoNeed;
break;
case NeedRestartForMoreOutputs::OutputsAddedDoNeed:
/* No need to check whether we added more outputs, because a
restart is already queued up. */
break;
case NeedRestartForMoreOutputs::BuildInProgressWillNotNeed:
/* We are already building all outputs, so it doesn't matter if
we now want more. */
break;
};
wantedOutputs = newWanted;
}
@ -297,12 +309,29 @@ void DerivationGoal::outputsSubstitutionTried()
In particular, it may be the case that the hole in the closure is
an output of the current derivation, which causes a loop if retried.
*/
if (nrIncompleteClosure > 0 && nrIncompleteClosure == nrFailed) retrySubstitution = true;
{
bool substitutionFailed =
nrIncompleteClosure > 0 &&
nrIncompleteClosure == nrFailed;
switch (retrySubstitution) {
case RetrySubstitution::NoNeed:
if (substitutionFailed)
retrySubstitution = RetrySubstitution::YesNeed;
break;
case RetrySubstitution::YesNeed:
// Should not be able to reach this state from here.
assert(false);
break;
case RetrySubstitution::AlreadyRetried:
debug("substitution failed again, but we already retried once. Not retrying again.");
break;
}
}
nrFailed = nrNoSubstituters = nrIncompleteClosure = 0;
if (needRestart) {
needRestart = false;
if (needRestart == NeedRestartForMoreOutputs::OutputsAddedDoNeed) {
needRestart = NeedRestartForMoreOutputs::OutputsUnmodifedDontNeed;
haveDerivation();
return;
}
@ -330,9 +359,9 @@ void DerivationGoal::outputsSubstitutionTried()
produced using a substitute. So we have to build instead. */
void DerivationGoal::gaveUpOnSubstitution()
{
/* Make sure checkPathValidity() from now on checks all
outputs. */
wantedOutputs = OutputsSpec::All { };
/* At this point we are building all outputs, so if more are wanted there
is no need to restart. */
needRestart = NeedRestartForMoreOutputs::BuildInProgressWillNotNeed;
/* The inputs must be built before we can build this goal. */
inputDrvOutputs.clear();
@ -455,8 +484,8 @@ void DerivationGoal::inputsRealised()
return;
}
if (retrySubstitution && !retriedSubstitution) {
retriedSubstitution = true;
if (retrySubstitution == RetrySubstitution::YesNeed) {
retrySubstitution = RetrySubstitution::AlreadyRetried;
haveDerivation();
return;
}