forked from lix-project/lix
1984 lines
52 KiB
C++
1984 lines
52 KiB
C++
#include <map>
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#include <boost/shared_ptr.hpp>
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#include <boost/weak_ptr.hpp>
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#include <boost/enable_shared_from_this.hpp>
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#include <sys/types.h>
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#include <sys/stat.h>
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#include <sys/time.h>
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#include <fcntl.h>
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#include <unistd.h>
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#include <errno.h>
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#include <utime.h>
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#include "normalise.hh"
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#include "references.hh"
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#include "pathlocks.hh"
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#include "globals.hh"
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/* !!! TODO storeExprFromPath shouldn't be used here */
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static string pathNullDevice = "/dev/null";
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/* Forward definition. */
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class Worker;
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/* A pointer to a goal. */
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class Goal;
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typedef shared_ptr<Goal> GoalPtr;
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typedef weak_ptr<Goal> WeakGoalPtr;
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/* Set of goals. */
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typedef set<GoalPtr> Goals;
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typedef set<WeakGoalPtr> WeakGoals;
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/* A map of paths to goals (and the other way around). */
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typedef map<Path, WeakGoalPtr> WeakGoalMap;
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class Goal : public enable_shared_from_this<Goal>
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{
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protected:
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/* Backlink to the worker. */
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Worker & worker;
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/* Goals that this goal is waiting for. */
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Goals waitees;
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/* Goals waiting for this one to finish. Must use weak pointers
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here to prevent cycles. */
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WeakGoals waiters;
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/* Number of goals we are/were waiting for that have failed. */
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unsigned int nrFailed;
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/* Whether amDone() has been called. */
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bool done;
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Goal(Worker & _worker) : worker(_worker)
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{
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done = false;
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nrFailed = 0;
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}
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virtual ~Goal()
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{
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printMsg(lvlVomit, "goal destroyed");
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}
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public:
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virtual void work() = 0;
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virtual string name() = 0;
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void addWaitee(GoalPtr waitee);
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virtual void waiteeDone(GoalPtr waitee, bool success);
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virtual void writeLog(int fd, const unsigned char * buf, size_t count)
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{
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abort();
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}
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void trace(const format & f);
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protected:
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void amDone(bool success = true);
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};
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/* A mapping used to remember for each child process to what goal it
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belongs, and a file descriptor for receiving log data. */
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struct Child
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{
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WeakGoalPtr goal;
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int fdOutput;
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bool inBuildSlot;
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};
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typedef map<pid_t, Child> Children;
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/* The worker class. */
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class Worker
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{
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private:
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/* Note: the worker should only have strong pointers to the
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top-level goals. */
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/* The top-level goals of the worker. */
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Goals topGoals;
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/* Goals that are ready to do some work. */
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WeakGoals awake;
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/* Goals waiting for a build slot. */
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WeakGoals wantingToBuild;
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/* Child processes currently running. */
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Children children;
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/* Number of build slots occupied. Not all child processes
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(namely build hooks) count as occupied build slots. */
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unsigned int nrChildren;
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/* Maps used to prevent multiple instantiation of a goal for the
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same expression / path. */
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WeakGoalMap normalisationGoals;
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WeakGoalMap realisationGoals;
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WeakGoalMap substitutionGoals;
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public:
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Worker();
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~Worker();
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/* Make a goal (with caching). */
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GoalPtr makeNormalisationGoal(const Path & nePath);
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GoalPtr makeRealisationGoal(const Path & nePath);
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GoalPtr makeSubstitutionGoal(const Path & storePath);
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/* Remove a dead goal. */
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void removeGoal(GoalPtr goal);
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/* Wake up a goal (i.e., there is something for it to do). */
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void wakeUp(GoalPtr goal);
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/* Can we start another child process? */
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bool canBuildMore();
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/* Registers / unregisters a running child process. */
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void childStarted(GoalPtr goal, pid_t pid, int fdOutput,
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bool inBuildSlot);
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void childTerminated(pid_t pid, bool wakeSleepers = true);
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/* Add a goal to the set of goals waiting for a build slot. */
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void waitForBuildSlot(GoalPtr goal, bool reallyWait = false);
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/* Loop until the specified top-level goal has finished. Returns
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true if it has finished succesfully. */
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bool run(GoalPtr topGoal);
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/* Wait for input to become available. */
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void waitForInput();
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};
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class SubstError : public Error
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{
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public:
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SubstError(const format & f) : Error(f) { };
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};
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class BuildError : public Error
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{
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public:
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BuildError(const format & f) : Error(f) { };
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};
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//////////////////////////////////////////////////////////////////////
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void Goal::addWaitee(GoalPtr waitee)
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{
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waitees.insert(waitee);
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waitee->waiters.insert(shared_from_this());
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}
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void Goal::waiteeDone(GoalPtr waitee, bool success)
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{
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assert(waitees.find(waitee) != waitees.end());
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waitees.erase(waitee);
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if (!success) ++nrFailed;
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if (waitees.empty() || (!success && !keepGoing)) {
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/* If we failed and keepGoing is not set, we remove all
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remaining waitees. */
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for (Goals::iterator i = waitees.begin(); i != waitees.end(); ++i) {
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GoalPtr goal = *i;
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WeakGoals waiters2;
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for (WeakGoals::iterator j = goal->waiters.begin();
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j != goal->waiters.end(); ++j)
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if (j->lock() != shared_from_this())
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waiters2.insert(*j);
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goal->waiters = waiters2;
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}
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waitees.clear();
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worker.wakeUp(shared_from_this());
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}
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}
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void Goal::amDone(bool success)
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{
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trace("done");
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assert(!done);
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done = true;
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for (WeakGoals::iterator i = waiters.begin(); i != waiters.end(); ++i) {
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GoalPtr goal = i->lock();
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if (goal) goal->waiteeDone(shared_from_this(), success);
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}
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waiters.clear();
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worker.removeGoal(shared_from_this());
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}
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void Goal::trace(const format & f)
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{
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debug(format("%1%: %2%") % name() % f);
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}
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//////////////////////////////////////////////////////////////////////
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/* Common initialisation performed in child processes. */
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void commonChildInit(Pipe & logPipe)
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{
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/* Put the child in a separate process group so that it doesn't
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receive terminal signals. */
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if (setpgid(0, 0) == -1)
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throw SysError(format("setting process group"));
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/* Dup the write side of the logger pipe into stderr. */
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if (dup2(logPipe.writeSide, STDERR_FILENO) == -1)
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throw SysError("cannot pipe standard error into log file");
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logPipe.readSide.close();
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/* Dup stderr to stdin. */
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if (dup2(STDERR_FILENO, STDOUT_FILENO) == -1)
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throw SysError("cannot dup stderr into stdout");
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/* Reroute stdin to /dev/null. */
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int fdDevNull = open(pathNullDevice.c_str(), O_RDWR);
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if (fdDevNull == -1)
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throw SysError(format("cannot open `%1%'") % pathNullDevice);
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if (dup2(fdDevNull, STDIN_FILENO) == -1)
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throw SysError("cannot dup null device into stdin");
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}
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/* Convert a string list to an array of char pointers. Careful: the
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string list should outlive the array. */
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const char * * strings2CharPtrs(const Strings & ss)
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{
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const char * * arr = new const char * [ss.size() + 1];
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const char * * p = arr;
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for (Strings::const_iterator i = ss.begin(); i != ss.end(); ++i)
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*p++ = i->c_str();
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*p = 0;
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return arr;
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}
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/* Should only be called after an expression has been normalised. */
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Path queryNormalForm(const Path & nePath)
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{
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Path nfPath;
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if (querySuccessor(nePath, nfPath)) return nfPath;
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/* If there is no successor, than nePath must be a normal form
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itself. */
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StoreExpr ne = storeExprFromPath(nePath);
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if (ne.type != StoreExpr::neClosure) abort();
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return nePath;
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}
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/* "Fix", or canonicalise, the meta-data of the files in a store path
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after it has been built. In particular:
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- the last modification date on each file is set to 0 (i.e.,
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00:00:00 1/1/1970 UTC)
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- the permissions are set of 444 or 555 (i.e., read-only with or
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without execute permission; setuid bits etc. are cleared)
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- the owner and group are set to the Nix user and group, if we're
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in a setuid Nix installation
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*/
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void canonicalisePathMetaData(const Path & path)
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{
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checkInterrupt();
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struct stat st;
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if (lstat(path.c_str(), &st))
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throw SysError(format("getting attributes of path `%1%'") % path);
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if (!S_ISLNK(st.st_mode)) {
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/* Mask out all type related bits. */
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mode_t mode = st.st_mode & ~S_IFMT;
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if (mode != 0444 && mode != 0555) {
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mode = (st.st_mode & S_IFMT)
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| 0444
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| (st.st_mode & S_IXUSR ? 0111 : 0);
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if (chmod(path.c_str(), mode) == -1)
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throw SysError(format("changing mode of `%1%' to %2$o") % path % mode);
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}
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if (st.st_uid != getuid() || st.st_gid != getgid()) {
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if (chown(path.c_str(), getuid(), getgid()) == -1)
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throw SysError(format("changing owner/group of `%1%' to %2%/%3%")
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% path % getuid() % getgid());
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}
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if (st.st_mtime != 0) {
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struct utimbuf utimbuf;
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utimbuf.actime = st.st_atime;
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utimbuf.modtime = 0;
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if (utime(path.c_str(), &utimbuf) == -1)
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throw SysError(format("changing modification time of `%1%'") % path);
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}
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}
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if (S_ISDIR(st.st_mode)) {
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Strings names = readDirectory(path);
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for (Strings::iterator i = names.begin(); i != names.end(); ++i)
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canonicalisePathMetaData(path + "/" + *i);
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}
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}
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//////////////////////////////////////////////////////////////////////
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class NormalisationGoal : public Goal
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{
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private:
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/* The path of the derivation store expression. */
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Path nePath;
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/* The store expression stored at nePath. */
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StoreExpr expr;
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/* The remainder is state held during the build. */
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/* Locks on the output paths. */
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PathLocks outputLocks;
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/* Input paths, with their closure elements. */
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ClosureElems inClosures;
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/* Referenceable paths (i.e., input and output paths). */
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PathSet allPaths;
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/* The normal forms of the input store expressions. */
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PathSet inputNFs;
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/* The successor mappings for the input store expressions. */
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map<Path, Path> inputSucs;
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/* The process ID of the builder. */
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Pid pid;
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/* The temporary directory. */
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Path tmpDir;
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/* File descriptor for the log file. */
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AutoCloseFD fdLogFile;
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/* Pipe for the builder's standard output/error. */
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Pipe logPipe;
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/* Pipes for talking to the build hook (if any). */
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Pipe toHook;
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Pipe fromHook;
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typedef void (NormalisationGoal::*GoalState)();
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GoalState state;
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public:
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NormalisationGoal(const Path & _nePath, Worker & _worker);
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~NormalisationGoal();
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void work();
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private:
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/* The states. */
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void init();
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void haveStoreExpr();
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void inputRealised();
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void tryToBuild();
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void buildDone();
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/* Is the build hook willing to perform the build? */
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typedef enum {rpAccept, rpDecline, rpPostpone, rpDone} HookReply;
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HookReply tryBuildHook();
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/* Synchronously wait for a build hook to finish. */
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void terminateBuildHook();
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/* Acquires locks on the output paths and gathers information
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about the build (e.g., the input closures). During this
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process its possible that we find out that the build is
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unnecessary, in which case we return false (this is not an
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error condition!). */
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bool prepareBuild();
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/* Start building a derivation. */
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void startBuilder();
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/* Must be called after the output paths have become valid (either
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due to a successful build or hook, or because they already
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were). */
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void createClosure();
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/* Open a log file and a pipe to it. */
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void openLogFile();
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/* Common initialisation to be performed in child processes (i.e.,
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both in builders and in build hooks. */
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void initChild();
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/* Delete the temporary directory, if we have one. */
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void deleteTmpDir(bool force);
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/* Callback used by the worker to write to the log. */
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void writeLog(int fd, const unsigned char * buf, size_t count);
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string name();
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};
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NormalisationGoal::NormalisationGoal(const Path & _nePath, Worker & _worker)
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: Goal(_worker)
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{
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nePath = _nePath;
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state = &NormalisationGoal::init;
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}
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NormalisationGoal::~NormalisationGoal()
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{
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if (pid != -1) worker.childTerminated(pid);
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/* Careful: we should never ever throw an exception from a
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destructor. */
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try {
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deleteTmpDir(false);
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} catch (Error & e) {
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printMsg(lvlError, format("error (ignored): %1%") % e.msg());
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}
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}
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void NormalisationGoal::work()
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{
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(this->*state)();
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}
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void NormalisationGoal::init()
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{
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trace("init");
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/* If we already have a successor, then we are done already; don't
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add the expression as a goal. */
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Path nfPath;
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if (querySuccessor(nePath, nfPath)) {
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amDone();
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return;
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}
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/* The first thing to do is to make sure that the store expression
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exists. If it doesn't, it may be created through a
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substitute. */
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addWaitee(worker.makeSubstitutionGoal(nePath));
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state = &NormalisationGoal::haveStoreExpr;
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}
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void NormalisationGoal::haveStoreExpr()
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{
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trace("loading store expression");
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if (nrFailed != 0) {
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printMsg(lvlError,
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format("cannot normalise missing store expression `%1%'")
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% nePath);
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amDone(false);
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return;
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}
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assert(isValidPath(nePath));
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/* Get the store expression. */
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expr = storeExprFromPath(nePath);
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/* If this is a normal form (i.e., a closure) we are also done. */
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if (expr.type == StoreExpr::neClosure) {
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amDone();
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return;
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}
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assert(expr.type == StoreExpr::neDerivation);
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/* Inputs must be realised before we can build this goal. */
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for (PathSet::iterator i = expr.derivation.inputs.begin();
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i != expr.derivation.inputs.end(); ++i)
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addWaitee(worker.makeRealisationGoal(*i));
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state = &NormalisationGoal::inputRealised;
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}
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void NormalisationGoal::inputRealised()
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{
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trace("all inputs realised");
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if (nrFailed != 0) {
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printMsg(lvlError,
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format("cannot normalise derivation `%1%': "
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"%2% closure element(s) could not be realised")
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% nePath % nrFailed);
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amDone(false);
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return;
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}
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/* Okay, try to build. Note that here we don't wait for a build
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slot to become available, since we don't need one if there is a
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build hook. */
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state = &NormalisationGoal::tryToBuild;
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worker.wakeUp(shared_from_this());
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}
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void NormalisationGoal::tryToBuild()
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{
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trace("trying to build");
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try {
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/* Is the build hook willing to accept this job? */
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switch (tryBuildHook()) {
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case rpAccept:
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/* Yes, it has started doing so. Wait until we get
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EOF from the hook. */
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state = &NormalisationGoal::buildDone;
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return;
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case rpPostpone:
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/* Not now; wait until at least one child finishes. */
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worker.waitForBuildSlot(shared_from_this(), true);
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return;
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case rpDecline:
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/* We should do it ourselves. */
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break;
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case rpDone:
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/* Somebody else did it (there is a successor now). */
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amDone();
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return;
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}
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|
|
/* Make sure that we are allowed to start a build. */
|
|
if (!worker.canBuildMore()) {
|
|
worker.waitForBuildSlot(shared_from_this());
|
|
return;
|
|
}
|
|
|
|
/* Acquire locks and such. If we then see that there now is a
|
|
successor, we're done. */
|
|
if (!prepareBuild()) {
|
|
amDone();
|
|
return;
|
|
}
|
|
|
|
/* Okay, we have to build. */
|
|
startBuilder();
|
|
|
|
} catch (BuildError & e) {
|
|
printMsg(lvlError, e.msg());
|
|
amDone(false);
|
|
return;
|
|
}
|
|
|
|
/* This state will be reached when we get EOF on the child's
|
|
log pipe. */
|
|
state = &NormalisationGoal::buildDone;
|
|
}
|
|
|
|
|
|
void NormalisationGoal::buildDone()
|
|
{
|
|
trace("build done");
|
|
|
|
/* Since we got an EOF on the logger pipe, the builder is presumed
|
|
to have terminated. In fact, the builder could also have
|
|
simply have closed its end of the pipe --- just don't do that
|
|
:-) */
|
|
/* !!! this could block! */
|
|
pid_t savedPid = pid;
|
|
int status = pid.wait(true);
|
|
|
|
/* So the child is gone now. */
|
|
worker.childTerminated(savedPid);
|
|
|
|
/* Close the read side of the logger pipe. */
|
|
logPipe.readSide.close();
|
|
|
|
/* Close the log file. */
|
|
fdLogFile.close();
|
|
|
|
debug(format("builder process for `%1%' finished") % nePath);
|
|
|
|
/* Check the exit status. */
|
|
if (!statusOk(status)) {
|
|
deleteTmpDir(false);
|
|
printMsg(lvlError, format("builder for `%1%' %2%")
|
|
% nePath % statusToString(status));
|
|
amDone(false);
|
|
return;
|
|
}
|
|
|
|
deleteTmpDir(true);
|
|
|
|
/* Compute a closure store expression, and register it as our
|
|
successor. */
|
|
try {
|
|
createClosure();
|
|
} catch (BuildError & e) {
|
|
printMsg(lvlError, e.msg());
|
|
amDone(false);
|
|
return;
|
|
}
|
|
|
|
amDone();
|
|
}
|
|
|
|
|
|
static string readLine(int fd)
|
|
{
|
|
string s;
|
|
while (1) {
|
|
char ch;
|
|
ssize_t rd = read(fd, &ch, 1);
|
|
if (rd == -1) {
|
|
if (errno != EINTR)
|
|
throw SysError("reading a line");
|
|
} else if (rd == 0)
|
|
throw Error("unexpected EOF reading a line");
|
|
else {
|
|
if (ch == '\n') return s;
|
|
s += ch;
|
|
}
|
|
}
|
|
}
|
|
|
|
|
|
static void writeLine(int fd, string s)
|
|
{
|
|
s += '\n';
|
|
writeFull(fd, (const unsigned char *) s.c_str(), s.size());
|
|
}
|
|
|
|
|
|
/* !!! ugly hack */
|
|
static void drain(int fd)
|
|
{
|
|
unsigned char buffer[1024];
|
|
while (1) {
|
|
ssize_t rd = read(fd, buffer, sizeof buffer);
|
|
if (rd == -1) {
|
|
if (errno != EINTR)
|
|
throw SysError("draining");
|
|
} else if (rd == 0) break;
|
|
else writeFull(STDERR_FILENO, buffer, rd);
|
|
}
|
|
}
|
|
|
|
|
|
NormalisationGoal::HookReply NormalisationGoal::tryBuildHook()
|
|
{
|
|
Path buildHook = getEnv("NIX_BUILD_HOOK");
|
|
if (buildHook == "") return rpDecline;
|
|
buildHook = absPath(buildHook);
|
|
|
|
/* Create a directory where we will store files used for
|
|
communication between us and the build hook. */
|
|
tmpDir = createTempDir();
|
|
|
|
/* Create the log file and pipe. */
|
|
openLogFile();
|
|
|
|
/* Create the communication pipes. */
|
|
toHook.create();
|
|
fromHook.create();
|
|
|
|
/* Fork the hook. */
|
|
pid = fork();
|
|
switch (pid) {
|
|
|
|
case -1:
|
|
throw SysError("unable to fork");
|
|
|
|
case 0:
|
|
try { /* child */
|
|
|
|
initChild();
|
|
|
|
execl(buildHook.c_str(), buildHook.c_str(),
|
|
(worker.canBuildMore() ? (string) "1" : "0").c_str(),
|
|
thisSystem.c_str(),
|
|
expr.derivation.platform.c_str(),
|
|
nePath.c_str(), 0);
|
|
|
|
throw SysError(format("executing `%1%'") % buildHook);
|
|
|
|
} catch (exception & e) {
|
|
cerr << format("build error: %1%\n") % e.what();
|
|
}
|
|
_exit(1);
|
|
}
|
|
|
|
/* parent */
|
|
logPipe.writeSide.close();
|
|
worker.childStarted(shared_from_this(),
|
|
pid, logPipe.readSide, false);
|
|
|
|
fromHook.writeSide.close();
|
|
toHook.readSide.close();
|
|
|
|
/* Read the first line of input, which should be a word indicating
|
|
whether the hook wishes to perform the build. !!! potential
|
|
for deadlock here: we should also read from the child's logger
|
|
pipe. */
|
|
string reply;
|
|
try {
|
|
reply = readLine(fromHook.readSide);
|
|
} catch (Error & e) {
|
|
drain(logPipe.readSide);
|
|
throw;
|
|
}
|
|
|
|
debug(format("hook reply is `%1%'") % reply);
|
|
|
|
if (reply == "decline" || reply == "postpone") {
|
|
/* Clean up the child. !!! hacky / should verify */
|
|
drain(logPipe.readSide);
|
|
terminateBuildHook();
|
|
return reply == "decline" ? rpDecline : rpPostpone;
|
|
}
|
|
|
|
else if (reply == "accept") {
|
|
|
|
/* Acquire locks and such. If we then see that there now is a
|
|
successor, we're done. */
|
|
if (!prepareBuild()) {
|
|
/* Tell the hook to exit. */
|
|
writeLine(toHook.writeSide, "cancel");
|
|
terminateBuildHook();
|
|
return rpDone;
|
|
}
|
|
|
|
printMsg(lvlInfo, format("running hook to build path `%1%'")
|
|
% *expr.derivation.outputs.begin());
|
|
|
|
/* Write the information that the hook needs to perform the
|
|
build, i.e., the set of input paths (including closure
|
|
expressions), the set of output paths, and the successor
|
|
mappings for the input expressions. */
|
|
|
|
Path inputListFN = tmpDir + "/inputs";
|
|
Path outputListFN = tmpDir + "/outputs";
|
|
Path successorsListFN = tmpDir + "/successors";
|
|
|
|
string s;
|
|
for (ClosureElems::iterator i = inClosures.begin();
|
|
i != inClosures.end(); ++i)
|
|
s += i->first + "\n";
|
|
for (PathSet::iterator i = inputNFs.begin();
|
|
i != inputNFs.end(); ++i)
|
|
s += *i + "\n";
|
|
writeStringToFile(inputListFN, s);
|
|
|
|
s = "";
|
|
for (PathSet::iterator i = expr.derivation.outputs.begin();
|
|
i != expr.derivation.outputs.end(); ++i)
|
|
s += *i + "\n";
|
|
writeStringToFile(outputListFN, s);
|
|
|
|
s = "";
|
|
for (map<Path, Path>::iterator i = inputSucs.begin();
|
|
i != inputSucs.end(); ++i)
|
|
s += i->first + " " + i->second + "\n";
|
|
writeStringToFile(successorsListFN, s);
|
|
|
|
/* Tell the hook to proceed. */
|
|
writeLine(toHook.writeSide, "okay");
|
|
|
|
return rpAccept;
|
|
}
|
|
|
|
else throw Error(format("bad hook reply `%1%'") % reply);
|
|
}
|
|
|
|
|
|
void NormalisationGoal::terminateBuildHook()
|
|
{
|
|
/* !!! drain stdout of hook */
|
|
debug("terminating build hook");
|
|
pid_t savedPid = pid;
|
|
pid.wait(true);
|
|
worker.childTerminated(savedPid, false);
|
|
fromHook.readSide.close();
|
|
toHook.writeSide.close();
|
|
fdLogFile.close();
|
|
logPipe.readSide.close();
|
|
deleteTmpDir(true); /* get rid of the hook's temporary directory */
|
|
}
|
|
|
|
|
|
bool NormalisationGoal::prepareBuild()
|
|
{
|
|
/* Obtain locks on all output paths. The locks are automatically
|
|
released when we exit this function or Nix crashes. */
|
|
/* !!! BUG: this could block, which is not allowed. */
|
|
outputLocks.lockPaths(expr.derivation.outputs);
|
|
|
|
/* Now check again whether there is a successor. This is because
|
|
another process may have started building in parallel. After
|
|
it has finished and released the locks, we can (and should)
|
|
reuse its results. (Strictly speaking the first successor
|
|
check can be omitted, but that would be less efficient.) Note
|
|
that since we now hold the locks on the output paths, no other
|
|
process can build this expression, so no further checks are
|
|
necessary. */
|
|
Path nfPath;
|
|
if (querySuccessor(nePath, nfPath)) {
|
|
debug(format("skipping build of expression `%1%', someone beat us to it")
|
|
% nePath);
|
|
outputLocks.setDeletion(true);
|
|
return false;
|
|
}
|
|
|
|
/* Gather information necessary for computing the closure and/or
|
|
running the build hook. */
|
|
|
|
/* The outputs are referenceable paths. */
|
|
for (PathSet::iterator i = expr.derivation.outputs.begin();
|
|
i != expr.derivation.outputs.end(); ++i)
|
|
{
|
|
debug(format("building path `%1%'") % *i);
|
|
allPaths.insert(*i);
|
|
}
|
|
|
|
/* Get information about the inputs (these all exist now). */
|
|
for (PathSet::iterator i = expr.derivation.inputs.begin();
|
|
i != expr.derivation.inputs.end(); ++i)
|
|
{
|
|
checkInterrupt();
|
|
Path nePath = *i;
|
|
Path nfPath = queryNormalForm(nePath);
|
|
inputNFs.insert(nfPath);
|
|
if (nfPath != nePath) inputSucs[nePath] = nfPath;
|
|
/* !!! nfPath should be a root of the garbage collector while
|
|
we are building */
|
|
StoreExpr ne = storeExprFromPath(nfPath);
|
|
if (ne.type != StoreExpr::neClosure) abort();
|
|
for (ClosureElems::iterator j = ne.closure.elems.begin();
|
|
j != ne.closure.elems.end(); ++j)
|
|
{
|
|
inClosures[j->first] = j->second;
|
|
allPaths.insert(j->first);
|
|
}
|
|
}
|
|
|
|
/* We can skip running the builder if all output paths are already
|
|
valid. */
|
|
bool fastBuild = true;
|
|
for (PathSet::iterator i = expr.derivation.outputs.begin();
|
|
i != expr.derivation.outputs.end(); ++i)
|
|
if (!isValidPath(*i)) {
|
|
fastBuild = false;
|
|
break;
|
|
}
|
|
|
|
if (fastBuild) {
|
|
printMsg(lvlChatty, format("skipping build; output paths already exist"));
|
|
createClosure();
|
|
return false;
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
|
|
void NormalisationGoal::startBuilder()
|
|
{
|
|
startNest(nest, lvlInfo,
|
|
format("building path `%1%'") % *expr.derivation.outputs.begin());
|
|
|
|
/* Right platform? */
|
|
if (expr.derivation.platform != thisSystem)
|
|
throw BuildError(
|
|
format("a `%1%' is required to build `%3%', but I am a `%2%'")
|
|
% expr.derivation.platform % thisSystem % nePath);
|
|
|
|
/* If any of the outputs already exist but are not registered,
|
|
delete them. */
|
|
for (PathSet::iterator i = expr.derivation.outputs.begin();
|
|
i != expr.derivation.outputs.end(); ++i)
|
|
{
|
|
Path path = *i;
|
|
if (isValidPath(path))
|
|
throw Error(format("obstructed build: path `%1%' exists") % path);
|
|
if (pathExists(path)) {
|
|
debug(format("removing unregistered path `%1%'") % path);
|
|
deletePath(path);
|
|
}
|
|
}
|
|
|
|
/* Construct the environment passed to the builder. */
|
|
typedef map<string, string> Environment;
|
|
Environment env;
|
|
|
|
/* 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
|
|
value. */
|
|
env["PATH"] = "/path-not-set";
|
|
|
|
/* Set HOME to a non-existing path to prevent certain programs from using
|
|
/etc/passwd (or NIS, or whatever) to locate the home directory (for
|
|
example, wget looks for ~/.wgetrc). I.e., these tools use /etc/passwd
|
|
if HOME is not set, but they will just assume that the settings file
|
|
they are looking for does not exist if HOME is set but points to some
|
|
non-existing path. */
|
|
env["HOME"] = "/homeless-shelter";
|
|
|
|
/* Tell the builder where the Nix store is. Usually they
|
|
shouldn't care, but this is useful for purity checking (e.g.,
|
|
the compiler or linker might only want to accept paths to files
|
|
in the store or in the build directory). */
|
|
env["NIX_STORE"] = nixStore;
|
|
|
|
/* Add all bindings specified in the derivation expression. */
|
|
for (StringPairs::iterator i = expr.derivation.env.begin();
|
|
i != expr.derivation.env.end(); ++i)
|
|
env[i->first] = i->second;
|
|
|
|
/* Create a temporary directory where the build will take
|
|
place. */
|
|
tmpDir = createTempDir();
|
|
|
|
/* For convenience, set an environment pointing to the top build
|
|
directory. */
|
|
env["NIX_BUILD_TOP"] = tmpDir;
|
|
|
|
/* Also set TMPDIR and variants to point to this directory. */
|
|
env["TMPDIR"] = env["TEMPDIR"] = env["TMP"] = env["TEMP"] = tmpDir;
|
|
|
|
/* Run the builder. */
|
|
printMsg(lvlChatty, format("executing builder `%1%'") %
|
|
expr.derivation.builder);
|
|
|
|
/* Create the log file and pipe. */
|
|
openLogFile();
|
|
|
|
/* Fork a child to build the package. Note that while we
|
|
currently use forks to run and wait for the children, it
|
|
shouldn't be hard to use threads for this on systems where
|
|
fork() is unavailable or inefficient. */
|
|
pid = fork();
|
|
switch (pid) {
|
|
|
|
case -1:
|
|
throw SysError("unable to fork");
|
|
|
|
case 0:
|
|
|
|
/* Warning: in the child we should absolutely not make any
|
|
Berkeley DB calls! */
|
|
|
|
try { /* child */
|
|
|
|
initChild();
|
|
|
|
/* Fill in the arguments. */
|
|
Strings args(expr.derivation.args);
|
|
args.push_front(baseNameOf(expr.derivation.builder));
|
|
const char * * argArr = strings2CharPtrs(args);
|
|
|
|
/* Fill in the environment. */
|
|
Strings envStrs;
|
|
for (Environment::const_iterator i = env.begin();
|
|
i != env.end(); ++i)
|
|
envStrs.push_back(i->first + "=" + i->second);
|
|
const char * * envArr = strings2CharPtrs(envStrs);
|
|
|
|
/* Execute the program. This should not return. */
|
|
execve(expr.derivation.builder.c_str(),
|
|
(char * *) argArr, (char * *) envArr);
|
|
|
|
throw SysError(format("executing `%1%'")
|
|
% expr.derivation.builder);
|
|
|
|
} catch (exception & e) {
|
|
cerr << format("build error: %1%\n") % e.what();
|
|
}
|
|
_exit(1);
|
|
}
|
|
|
|
/* parent */
|
|
pid.setSeparatePG(true);
|
|
logPipe.writeSide.close();
|
|
worker.childStarted(shared_from_this(),
|
|
pid, logPipe.readSide, true);
|
|
}
|
|
|
|
|
|
void NormalisationGoal::createClosure()
|
|
{
|
|
/* The resulting closure expression. */
|
|
StoreExpr nf;
|
|
nf.type = StoreExpr::neClosure;
|
|
|
|
startNest(nest, lvlTalkative,
|
|
format("computing closure for `%1%'") % nePath);
|
|
|
|
/* 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. */
|
|
PathSet usedPaths;
|
|
for (PathSet::iterator i = expr.derivation.outputs.begin();
|
|
i != expr.derivation.outputs.end(); ++i)
|
|
{
|
|
Path path = *i;
|
|
if (!pathExists(path)) {
|
|
throw BuildError(
|
|
format("builder for `%1%' failed to produce output path `%2%'")
|
|
% nePath % path);
|
|
}
|
|
nf.closure.roots.insert(path);
|
|
|
|
canonicalisePathMetaData(path);
|
|
|
|
/* For this output path, find the references to other paths contained
|
|
in it. */
|
|
startNest(nest2, lvlChatty,
|
|
format("scanning for store references in `%1%'") % path);
|
|
Strings refPaths;
|
|
if (!pathExists(path + "/nix-support/no-scan")) {
|
|
refPaths = filterReferences(path,
|
|
Strings(allPaths.begin(), allPaths.end()));
|
|
}
|
|
nest2.close();
|
|
|
|
/* Construct a closure element for this output path. */
|
|
ClosureElem elem;
|
|
|
|
/* For each path referenced by this output path, add its id to the
|
|
closure element and add the id to the `usedPaths' set (so that the
|
|
elements referenced by *its* closure are added below). */
|
|
for (Paths::iterator j = refPaths.begin();
|
|
j != refPaths.end(); ++j)
|
|
{
|
|
checkInterrupt();
|
|
Path path = *j;
|
|
elem.refs.insert(path);
|
|
if (inClosures.find(path) != inClosures.end())
|
|
usedPaths.insert(path);
|
|
else if (expr.derivation.outputs.find(path) ==
|
|
expr.derivation.outputs.end())
|
|
abort();
|
|
}
|
|
|
|
nf.closure.elems[path] = elem;
|
|
}
|
|
|
|
/* Close the closure. That is, for any referenced path, add the paths
|
|
referenced by it. */
|
|
PathSet donePaths;
|
|
|
|
while (!usedPaths.empty()) {
|
|
checkInterrupt();
|
|
PathSet::iterator i = usedPaths.begin();
|
|
Path path = *i;
|
|
usedPaths.erase(i);
|
|
|
|
if (donePaths.find(path) != donePaths.end()) continue;
|
|
donePaths.insert(path);
|
|
|
|
ClosureElems::iterator j = inClosures.find(path);
|
|
if (j == inClosures.end()) abort();
|
|
|
|
nf.closure.elems[path] = j->second;
|
|
|
|
for (PathSet::iterator k = j->second.refs.begin();
|
|
k != j->second.refs.end(); k++)
|
|
usedPaths.insert(*k);
|
|
}
|
|
|
|
/* For debugging, print out the referenced and unreferenced paths. */
|
|
for (ClosureElems::iterator i = inClosures.begin();
|
|
i != inClosures.end(); ++i)
|
|
{
|
|
PathSet::iterator j = donePaths.find(i->first);
|
|
if (j == donePaths.end())
|
|
debug(format("unreferenced input: `%1%'") % i->first);
|
|
else
|
|
debug(format("referenced input: `%1%'") % i->first);
|
|
}
|
|
|
|
/* Write the normal form. This does not have to occur in the
|
|
transaction below because writing terms is idem-potent. */
|
|
ATerm nfTerm = unparseStoreExpr(nf);
|
|
Path nfPath = writeTerm(nfTerm, "-s");
|
|
|
|
/* Register each output path, and register the normal form. This
|
|
is wrapped in one database transaction to ensure that if we
|
|
crash, either everything is registered or nothing is. This is
|
|
for recoverability: unregistered paths in the store can be
|
|
deleted arbitrarily, while registered paths can only be deleted
|
|
by running the garbage collector. */
|
|
Transaction txn;
|
|
createStoreTransaction(txn);
|
|
for (PathSet::iterator i = expr.derivation.outputs.begin();
|
|
i != expr.derivation.outputs.end(); ++i)
|
|
registerValidPath(txn, *i);
|
|
registerSuccessor(txn, nePath, nfPath);
|
|
txn.commit();
|
|
|
|
/* It is now safe to delete the lock files, since all future
|
|
lockers will see the successor; they will not create new lock
|
|
files with the same names as the old (unlinked) lock files. */
|
|
outputLocks.setDeletion(true);
|
|
}
|
|
|
|
|
|
void NormalisationGoal::openLogFile()
|
|
{
|
|
/* Create a log file. */
|
|
Path logFileName = nixLogDir + "/" + baseNameOf(nePath);
|
|
fdLogFile = open(logFileName.c_str(),
|
|
O_CREAT | O_WRONLY | O_TRUNC, 0666);
|
|
if (fdLogFile == -1)
|
|
throw SysError(format("creating log file `%1%'") % logFileName);
|
|
|
|
/* Create a pipe to get the output of the child. */
|
|
logPipe.create();
|
|
}
|
|
|
|
|
|
void NormalisationGoal::initChild()
|
|
{
|
|
commonChildInit(logPipe);
|
|
|
|
if (chdir(tmpDir.c_str()) == -1)
|
|
throw SysError(format("changing into `%1%'") % tmpDir);
|
|
|
|
/* When running a hook, dup the communication pipes. */
|
|
bool inHook = fromHook.writeSide.isOpen();
|
|
if (inHook) {
|
|
fromHook.readSide.close();
|
|
if (dup2(fromHook.writeSide, 3) == -1)
|
|
throw SysError("dupping from-hook write side");
|
|
|
|
toHook.writeSide.close();
|
|
if (dup2(toHook.readSide, 4) == -1)
|
|
throw SysError("dupping to-hook read side");
|
|
}
|
|
|
|
/* Close all other file descriptors. */
|
|
int maxFD = 0;
|
|
maxFD = sysconf(_SC_OPEN_MAX);
|
|
for (int fd = 0; fd < maxFD; ++fd)
|
|
if (fd != STDIN_FILENO && fd != STDOUT_FILENO && fd != STDERR_FILENO
|
|
&& (!inHook || (fd != 3 && fd != 4)))
|
|
close(fd); /* ignore result */
|
|
}
|
|
|
|
|
|
void NormalisationGoal::deleteTmpDir(bool force)
|
|
{
|
|
if (tmpDir != "") {
|
|
if (keepFailed && !force)
|
|
printMsg(lvlError,
|
|
format("builder for `%1%' failed; keeping build directory `%2%'")
|
|
% nePath % tmpDir);
|
|
else
|
|
deletePath(tmpDir);
|
|
tmpDir = "";
|
|
}
|
|
}
|
|
|
|
|
|
void NormalisationGoal::writeLog(int fd,
|
|
const unsigned char * buf, size_t count)
|
|
{
|
|
assert(fd == logPipe.readSide);
|
|
writeFull(fdLogFile, buf, count);
|
|
}
|
|
|
|
|
|
string NormalisationGoal::name()
|
|
{
|
|
return (format("normalisation of `%1%'") % nePath).str();
|
|
}
|
|
|
|
|
|
|
|
//////////////////////////////////////////////////////////////////////
|
|
|
|
|
|
class RealisationGoal : public Goal
|
|
{
|
|
private:
|
|
/* The path of the store expression. */
|
|
Path nePath;
|
|
|
|
/* The normal form. */
|
|
Path nfPath;
|
|
|
|
/* Whether we should try to delete a broken successor mapping. */
|
|
bool tryFallback;
|
|
|
|
/* The store expression stored at nePath. */
|
|
StoreExpr expr;
|
|
|
|
typedef void (RealisationGoal::*GoalState)();
|
|
GoalState state;
|
|
|
|
public:
|
|
RealisationGoal(const Path & _nePath, Worker & _worker);
|
|
~RealisationGoal();
|
|
|
|
void work();
|
|
|
|
/* The states. */
|
|
void init();
|
|
void isNormalised();
|
|
void haveStoreExpr();
|
|
void elemFinished();
|
|
|
|
void fallBack(const format & error);
|
|
|
|
string name();
|
|
};
|
|
|
|
|
|
RealisationGoal::RealisationGoal(const Path & _nePath, Worker & _worker)
|
|
: Goal(_worker)
|
|
{
|
|
nePath = _nePath;
|
|
tryFallback = ::tryFallback;
|
|
state = &RealisationGoal::init;
|
|
}
|
|
|
|
|
|
RealisationGoal::~RealisationGoal()
|
|
{
|
|
}
|
|
|
|
|
|
void RealisationGoal::work()
|
|
{
|
|
(this->*state)();
|
|
}
|
|
|
|
|
|
void RealisationGoal::init()
|
|
{
|
|
trace("init");
|
|
|
|
if (querySuccessor(nePath, nfPath)) {
|
|
nrFailed = 0;
|
|
isNormalised();
|
|
return;
|
|
}
|
|
|
|
/* First normalise the expression (which is a no-op if the
|
|
expression is already a closure). */
|
|
addWaitee(worker.makeNormalisationGoal(nePath));
|
|
|
|
/* Since there is no successor right now, the normalisation goal
|
|
will perform an actual build. So there is no sense in trying a
|
|
fallback if the realisation of the closure fails (it can't
|
|
really fail). */
|
|
tryFallback = false;
|
|
|
|
state = &RealisationGoal::isNormalised;
|
|
}
|
|
|
|
|
|
void RealisationGoal::isNormalised()
|
|
{
|
|
trace("has been normalised");
|
|
|
|
if (nrFailed != 0) {
|
|
amDone(false);
|
|
return;
|
|
}
|
|
|
|
nfPath = queryNormalForm(nePath);
|
|
|
|
/* Now make sure that the store expression exists. If it doesn't,
|
|
it may be created through a substitute. */
|
|
addWaitee(worker.makeSubstitutionGoal(nfPath));
|
|
|
|
state = &RealisationGoal::haveStoreExpr;
|
|
}
|
|
|
|
|
|
void RealisationGoal::haveStoreExpr()
|
|
{
|
|
trace("loading store expression");
|
|
|
|
if (nrFailed != 0) {
|
|
fallBack(format("cannot realise closure `%1%' since that file is missing") % nfPath);
|
|
return;
|
|
}
|
|
|
|
assert(isValidPath(nfPath));
|
|
|
|
/* Get the store expression. */
|
|
expr = storeExprFromPath(nfPath);
|
|
|
|
/* If this is a normal form (i.e., a closure) we are also done. */
|
|
if (expr.type != StoreExpr::neClosure)
|
|
throw Error(format("expected closure in `%1%'") % nfPath);
|
|
|
|
/* Each path in the closure should exist, or should be creatable
|
|
through a substitute. */
|
|
for (ClosureElems::const_iterator i = expr.closure.elems.begin();
|
|
i != expr.closure.elems.end(); ++i)
|
|
addWaitee(worker.makeSubstitutionGoal(i->first));
|
|
|
|
state = &RealisationGoal::elemFinished;
|
|
}
|
|
|
|
|
|
void RealisationGoal::elemFinished()
|
|
{
|
|
trace("all closure elements present");
|
|
|
|
if (nrFailed != 0) {
|
|
fallBack(
|
|
format("cannot realise closure `%1%': "
|
|
"%2% closure element(s) are not present "
|
|
"and could not be substituted")
|
|
% nfPath % nrFailed);
|
|
return;
|
|
}
|
|
|
|
amDone();
|
|
}
|
|
|
|
|
|
void RealisationGoal::fallBack(const format & error)
|
|
{
|
|
if (tryFallback && nePath != nfPath) {
|
|
printMsg(lvlError, format("%1%; trying to normalise derivation instead")
|
|
% error);
|
|
tryFallback = false;
|
|
unregisterSuccessor(nePath);
|
|
nrFailed = 0;
|
|
init();
|
|
} else {
|
|
printMsg(lvlError, format("%1%; maybe `--fallback' will help") % error);
|
|
amDone(false);
|
|
}
|
|
}
|
|
|
|
|
|
string RealisationGoal::name()
|
|
{
|
|
return (format("realisation of `%1%'") % nePath).str();
|
|
}
|
|
|
|
|
|
|
|
//////////////////////////////////////////////////////////////////////
|
|
|
|
|
|
class SubstitutionGoal : public Goal
|
|
{
|
|
private:
|
|
/* The store path that should be realised through a substitute. */
|
|
Path storePath;
|
|
|
|
/* The remaining substitutes for this path. */
|
|
Substitutes subs;
|
|
|
|
/* The current substitute. */
|
|
Substitute sub;
|
|
|
|
/* Pipe for the substitute's standard output/error. */
|
|
Pipe logPipe;
|
|
|
|
/* The process ID of the builder. */
|
|
Pid pid;
|
|
|
|
/* Lock on the store path. */
|
|
shared_ptr<PathLocks> outputLock;
|
|
|
|
typedef void (SubstitutionGoal::*GoalState)();
|
|
GoalState state;
|
|
|
|
public:
|
|
SubstitutionGoal(const Path & _nePath, Worker & _worker);
|
|
~SubstitutionGoal();
|
|
|
|
void work();
|
|
|
|
/* The states. */
|
|
void init();
|
|
void tryNext();
|
|
void tryToRun();
|
|
void finished();
|
|
|
|
/* Callback used by the worker to write to the log. */
|
|
void writeLog(int fd, const unsigned char * buf, size_t count);
|
|
|
|
string name();
|
|
};
|
|
|
|
|
|
SubstitutionGoal::SubstitutionGoal(const Path & _storePath, Worker & _worker)
|
|
: Goal(_worker)
|
|
{
|
|
storePath = _storePath;
|
|
state = &SubstitutionGoal::init;
|
|
}
|
|
|
|
|
|
SubstitutionGoal::~SubstitutionGoal()
|
|
{
|
|
if (pid != -1) worker.childTerminated(pid);
|
|
}
|
|
|
|
|
|
void SubstitutionGoal::work()
|
|
{
|
|
(this->*state)();
|
|
}
|
|
|
|
|
|
void SubstitutionGoal::init()
|
|
{
|
|
trace("init");
|
|
|
|
/* If the path already exists we're done. */
|
|
if (isValidPath(storePath)) {
|
|
amDone();
|
|
return;
|
|
}
|
|
|
|
/* Otherwise, get the substitutes. */
|
|
subs = querySubstitutes(storePath);
|
|
|
|
/* Try the first one. */
|
|
tryNext();
|
|
}
|
|
|
|
|
|
void SubstitutionGoal::tryNext()
|
|
{
|
|
trace("trying next substitute");
|
|
|
|
if (subs.size() == 0) {
|
|
/* None left. Terminate this goal and let someone else deal
|
|
with it. */
|
|
printMsg(lvlError,
|
|
format("path `%1%' is required, but it has no (remaining) substitutes")
|
|
% storePath);
|
|
amDone(false);
|
|
return;
|
|
}
|
|
sub = subs.front();
|
|
subs.pop_front();
|
|
|
|
/* Wait until we can run the substitute program. */
|
|
state = &SubstitutionGoal::tryToRun;
|
|
worker.waitForBuildSlot(shared_from_this());
|
|
}
|
|
|
|
|
|
void SubstitutionGoal::tryToRun()
|
|
{
|
|
trace("trying to run");
|
|
|
|
/* Make sure that we are allowed to start a build. */
|
|
if (!worker.canBuildMore()) {
|
|
worker.waitForBuildSlot(shared_from_this());
|
|
return;
|
|
}
|
|
|
|
/* Acquire a lock on the output path. */
|
|
PathSet lockPath;
|
|
lockPath.insert(storePath);
|
|
outputLock = shared_ptr<PathLocks>(new PathLocks);
|
|
outputLock->lockPaths(lockPath);
|
|
|
|
/* Check again whether the path is invalid. */
|
|
if (isValidPath(storePath)) {
|
|
debug(format("store path `%1%' has become valid") % storePath);
|
|
outputLock->setDeletion(true);
|
|
amDone();
|
|
return;
|
|
}
|
|
|
|
printMsg(lvlInfo,
|
|
format("substituting path `%1%' using substituter `%2%'")
|
|
% storePath % sub.program);
|
|
|
|
logPipe.create();
|
|
|
|
/* Remove the (stale) output path if it exists. */
|
|
if (pathExists(storePath))
|
|
deletePath(storePath);
|
|
|
|
/* Fork the substitute program. */
|
|
pid = fork();
|
|
switch (pid) {
|
|
|
|
case -1:
|
|
throw SysError("unable to fork");
|
|
|
|
case 0:
|
|
try { /* child */
|
|
|
|
logPipe.readSide.close();
|
|
|
|
/* !!! close other handles */
|
|
|
|
commonChildInit(logPipe);
|
|
|
|
/* Fill in the arguments. */
|
|
Strings args(sub.args);
|
|
args.push_front(storePath);
|
|
args.push_front(baseNameOf(sub.program));
|
|
const char * * argArr = strings2CharPtrs(args);
|
|
|
|
execv(sub.program.c_str(), (char * *) argArr);
|
|
|
|
throw SysError(format("executing `%1%'") % sub.program);
|
|
|
|
} catch (exception & e) {
|
|
cerr << format("substitute error: %1%\n") % e.what();
|
|
}
|
|
_exit(1);
|
|
}
|
|
|
|
/* parent */
|
|
pid.setSeparatePG(true);
|
|
logPipe.writeSide.close();
|
|
worker.childStarted(shared_from_this(),
|
|
pid, logPipe.readSide, true);
|
|
|
|
state = &SubstitutionGoal::finished;
|
|
}
|
|
|
|
|
|
void SubstitutionGoal::finished()
|
|
{
|
|
trace("substitute finished");
|
|
|
|
/* Since we got an EOF on the logger pipe, the substitute is
|
|
presumed to have terminated. */
|
|
/* !!! this could block! */
|
|
pid_t savedPid = pid;
|
|
int status = pid.wait(true);
|
|
|
|
/* So the child is gone now. */
|
|
worker.childTerminated(savedPid);
|
|
|
|
/* Close the read side of the logger pipe. */
|
|
logPipe.readSide.close();
|
|
|
|
debug(format("substitute for `%1%' finished") % storePath);
|
|
|
|
/* Check the exit status and the build result. */
|
|
try {
|
|
|
|
if (!statusOk(status))
|
|
throw SubstError(format("builder for `%1%' %2%")
|
|
% storePath % statusToString(status));
|
|
|
|
if (!pathExists(storePath))
|
|
throw SubstError(
|
|
format("substitute did not produce path `%1%'")
|
|
% storePath);
|
|
|
|
} catch (SubstError & e) {
|
|
|
|
printMsg(lvlInfo,
|
|
format("substitution of path `%1%' using substituter `%2%' failed: %3%")
|
|
% storePath % sub.program % e.msg());
|
|
|
|
/* Try the next substitute. */
|
|
state = &SubstitutionGoal::tryNext;
|
|
worker.wakeUp(shared_from_this());
|
|
return;
|
|
}
|
|
|
|
canonicalisePathMetaData(storePath);
|
|
|
|
Transaction txn;
|
|
createStoreTransaction(txn);
|
|
registerValidPath(txn, storePath);
|
|
txn.commit();
|
|
|
|
outputLock->setDeletion(true);
|
|
|
|
printMsg(lvlChatty,
|
|
format("substitution of path `%1%' succeeded") % storePath);
|
|
|
|
amDone();
|
|
}
|
|
|
|
|
|
void SubstitutionGoal::writeLog(int fd,
|
|
const unsigned char * buf, size_t count)
|
|
{
|
|
assert(fd == logPipe.readSide);
|
|
/* Don't write substitution output to a log file for now. We
|
|
probably should, though. */
|
|
}
|
|
|
|
|
|
string SubstitutionGoal::name()
|
|
{
|
|
return (format("substitution of `%1%'") % storePath).str();
|
|
}
|
|
|
|
|
|
|
|
//////////////////////////////////////////////////////////////////////
|
|
|
|
|
|
/* A fake goal used to receive notification of success or failure of
|
|
other goals. */
|
|
class PseudoGoal : public Goal
|
|
{
|
|
private:
|
|
bool success;
|
|
|
|
public:
|
|
PseudoGoal(Worker & _worker) : Goal(_worker)
|
|
{
|
|
success = true;
|
|
}
|
|
|
|
void work()
|
|
{
|
|
abort();
|
|
}
|
|
|
|
void waiteeDone(GoalPtr waitee, bool success)
|
|
{
|
|
if (!success) this->success = false;
|
|
}
|
|
|
|
bool isOkay()
|
|
{
|
|
return success;
|
|
}
|
|
|
|
string name()
|
|
{
|
|
return "pseudo-goal";
|
|
}
|
|
};
|
|
|
|
|
|
|
|
//////////////////////////////////////////////////////////////////////
|
|
|
|
|
|
static bool working = false;
|
|
|
|
|
|
Worker::Worker()
|
|
{
|
|
/* Debugging: prevent recursive workers. */
|
|
if (working) abort();
|
|
working = true;
|
|
nrChildren = 0;
|
|
}
|
|
|
|
|
|
Worker::~Worker()
|
|
{
|
|
working = false;
|
|
|
|
/* Explicitly get rid of all strong pointers now. After this all
|
|
goals that refer to this worker should be gone. (Otherwise we
|
|
are in trouble, since goals may call childTerminated() etc. in
|
|
their destructors). */
|
|
topGoals.clear();
|
|
}
|
|
|
|
|
|
template<class T>
|
|
static GoalPtr addGoal(const Path & path,
|
|
Worker & worker, WeakGoalMap & goalMap)
|
|
{
|
|
GoalPtr goal = goalMap[path].lock();
|
|
if (!goal) {
|
|
goal = GoalPtr(new T(path, worker));
|
|
goalMap[path] = goal;
|
|
worker.wakeUp(goal);
|
|
}
|
|
return goal;
|
|
}
|
|
|
|
|
|
GoalPtr Worker::makeNormalisationGoal(const Path & nePath)
|
|
{
|
|
return addGoal<NormalisationGoal>(nePath, *this, normalisationGoals);
|
|
}
|
|
|
|
|
|
GoalPtr Worker::makeRealisationGoal(const Path & nePath)
|
|
{
|
|
return addGoal<RealisationGoal>(nePath, *this, realisationGoals);
|
|
}
|
|
|
|
|
|
GoalPtr Worker::makeSubstitutionGoal(const Path & storePath)
|
|
{
|
|
return addGoal<SubstitutionGoal>(storePath, *this, substitutionGoals);
|
|
}
|
|
|
|
|
|
static void removeGoal(GoalPtr goal, WeakGoalMap & goalMap)
|
|
{
|
|
/* !!! For now we just let dead goals accumulate. We should
|
|
probably periodically sweep the goalMap to remove dead
|
|
goals. */
|
|
}
|
|
|
|
|
|
void Worker::removeGoal(GoalPtr goal)
|
|
{
|
|
topGoals.erase(goal);
|
|
::removeGoal(goal, normalisationGoals);
|
|
::removeGoal(goal, realisationGoals);
|
|
::removeGoal(goal, substitutionGoals);
|
|
}
|
|
|
|
|
|
void Worker::wakeUp(GoalPtr goal)
|
|
{
|
|
goal->trace("woken up");
|
|
awake.insert(goal);
|
|
}
|
|
|
|
|
|
bool Worker::canBuildMore()
|
|
{
|
|
return nrChildren < maxBuildJobs;
|
|
}
|
|
|
|
|
|
void Worker::childStarted(GoalPtr goal,
|
|
pid_t pid, int fdOutput, bool inBuildSlot)
|
|
{
|
|
Child child;
|
|
child.goal = goal;
|
|
child.fdOutput = fdOutput;
|
|
child.inBuildSlot = inBuildSlot;
|
|
children[pid] = child;
|
|
if (inBuildSlot) nrChildren++;
|
|
}
|
|
|
|
|
|
void Worker::childTerminated(pid_t pid, bool wakeSleepers)
|
|
{
|
|
Children::iterator i = children.find(pid);
|
|
assert(i != children.end());
|
|
|
|
if (i->second.inBuildSlot) {
|
|
assert(nrChildren > 0);
|
|
nrChildren--;
|
|
}
|
|
|
|
children.erase(pid);
|
|
|
|
if (wakeSleepers) {
|
|
|
|
/* Wake up goals waiting for a build slot. */
|
|
for (WeakGoals::iterator i = wantingToBuild.begin();
|
|
i != wantingToBuild.end(); ++i)
|
|
{
|
|
GoalPtr goal = i->lock();
|
|
if (goal) wakeUp(goal);
|
|
}
|
|
|
|
wantingToBuild.clear();
|
|
|
|
}
|
|
}
|
|
|
|
|
|
void Worker::waitForBuildSlot(GoalPtr goal, bool reallyWait)
|
|
{
|
|
debug("wait for build slot");
|
|
if (reallyWait && children.size() == 0)
|
|
throw Error("waiting for a build slot, yet there are no children - "
|
|
"maybe the build hook gave an inappropriate `postpone' reply?");
|
|
if (!reallyWait && canBuildMore())
|
|
wakeUp(goal); /* we can do it right away */
|
|
else
|
|
wantingToBuild.insert(goal);
|
|
}
|
|
|
|
|
|
bool Worker::run(GoalPtr topGoal)
|
|
{
|
|
assert(topGoal);
|
|
|
|
/* Wrap the specified top-level goal in a pseudo-goal so that we
|
|
can check whether it succeeded. */
|
|
shared_ptr<PseudoGoal> pseudo(new PseudoGoal(*this));
|
|
pseudo->addWaitee(topGoal);
|
|
|
|
/* For now, we have only one top-level goal. */
|
|
topGoals.insert(topGoal);
|
|
|
|
startNest(nest, lvlDebug, format("entered goal loop"));
|
|
|
|
while (1) {
|
|
|
|
checkInterrupt();
|
|
|
|
/* Call every wake goal. */
|
|
while (!awake.empty()) {
|
|
WeakGoals awake2(awake);
|
|
awake.clear();
|
|
for (WeakGoals::iterator i = awake2.begin(); i != awake2.end(); ++i) {
|
|
checkInterrupt();
|
|
GoalPtr goal = i->lock();
|
|
if (goal) goal->work();
|
|
}
|
|
}
|
|
|
|
if (topGoals.empty()) break;
|
|
|
|
/* !!! not when we're polling */
|
|
assert(!children.empty());
|
|
|
|
/* Wait for input. */
|
|
waitForInput();
|
|
}
|
|
|
|
/* If --keep-going is not set, it's possible that the main goal
|
|
exited while some of its subgoals were still active. But if
|
|
--keep-going *is* set, then they must all be finished now. */
|
|
assert(!keepGoing || awake.empty());
|
|
assert(!keepGoing || wantingToBuild.empty());
|
|
assert(!keepGoing || children.empty());
|
|
|
|
return pseudo->isOkay();
|
|
}
|
|
|
|
|
|
void Worker::waitForInput()
|
|
{
|
|
printMsg(lvlVomit, "waiting for children");
|
|
|
|
/* Process log output from the children. We also use this to
|
|
detect child termination: if we get EOF on the logger pipe of a
|
|
build, we assume that the builder has terminated. */
|
|
|
|
/* Use select() to wait for the input side of any logger pipe to
|
|
become `available'. Note that `available' (i.e., non-blocking)
|
|
includes EOF. */
|
|
fd_set fds;
|
|
FD_ZERO(&fds);
|
|
int fdMax = 0;
|
|
for (Children::iterator i = children.begin();
|
|
i != children.end(); ++i)
|
|
{
|
|
int fd = i->second.fdOutput;
|
|
FD_SET(fd, &fds);
|
|
if (fd >= fdMax) fdMax = fd + 1;
|
|
}
|
|
|
|
if (select(fdMax, &fds, 0, 0, 0) == -1) {
|
|
if (errno == EINTR) return;
|
|
throw SysError("waiting for input");
|
|
}
|
|
|
|
/* Process all available file descriptors. */
|
|
for (Children::iterator i = children.begin();
|
|
i != children.end(); ++i)
|
|
{
|
|
checkInterrupt();
|
|
GoalPtr goal = i->second.goal.lock();
|
|
assert(goal);
|
|
int fd = i->second.fdOutput;
|
|
if (FD_ISSET(fd, &fds)) {
|
|
unsigned char buffer[4096];
|
|
ssize_t rd = read(fd, buffer, sizeof(buffer));
|
|
if (rd == -1) {
|
|
if (errno != EINTR)
|
|
throw SysError(format("reading from %1%")
|
|
% goal->name());
|
|
} else if (rd == 0) {
|
|
debug(format("%1%: got EOF") % goal->name());
|
|
wakeUp(goal);
|
|
} else {
|
|
printMsg(lvlVomit, format("%1%: read %2% bytes")
|
|
% goal->name() % rd);
|
|
goal->writeLog(fd, buffer, (size_t) rd);
|
|
if (verbosity >= buildVerbosity)
|
|
writeFull(STDERR_FILENO, buffer, rd);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
|
|
//////////////////////////////////////////////////////////////////////
|
|
|
|
|
|
Path normaliseStoreExpr(const Path & nePath)
|
|
{
|
|
startNest(nest, lvlDebug, format("normalising `%1%'") % nePath);
|
|
|
|
Worker worker;
|
|
if (!worker.run(worker.makeNormalisationGoal(nePath)))
|
|
throw Error(format("normalisation of store expression `%1%' failed") % nePath);
|
|
|
|
return queryNormalForm(nePath);
|
|
}
|
|
|
|
|
|
Path realiseStoreExpr(const Path & nePath)
|
|
{
|
|
startNest(nest, lvlDebug, format("realising `%1%'") % nePath);
|
|
|
|
Worker worker;
|
|
if (!worker.run(worker.makeRealisationGoal(nePath)))
|
|
throw Error(format("realisation of store expression `%1%' failed") % nePath);
|
|
|
|
return queryNormalForm(nePath);
|
|
}
|
|
|
|
|
|
void ensurePath(const Path & path)
|
|
{
|
|
/* If the path is already valid, we're done. */
|
|
if (isValidPath(path)) return;
|
|
|
|
Worker worker;
|
|
if (!worker.run(worker.makeSubstitutionGoal(path)))
|
|
throw Error(format("path `%1%' does not exist and cannot be created") % path);
|
|
}
|