diff options
| -rw-r--r-- | nix/libstore/build.cc | 118 | ||||
| -rw-r--r-- | nix/libutil/util.cc | 84 | ||||
| -rw-r--r-- | nix/libutil/util.hh | 25 |
3 files changed, 111 insertions, 116 deletions
diff --git a/nix/libstore/build.cc b/nix/libstore/build.cc index 346f92a8c3..88f8d11103 100644 --- a/nix/libstore/build.cc +++ b/nix/libstore/build.cc @@ -80,9 +80,6 @@ namespace nix { using std::map; -static string pathNullDevice = "/dev/null"; - - /* Forward definition. */ class Worker; struct Agent; @@ -397,33 +394,6 @@ void Goal::trace(const format & f) ////////////////////////////////////////////////////////////////////// -/* Common initialisation performed in child processes. */ -static void commonChildInit(Pipe & logPipe) -{ - /* Put the child in a separate session (and thus a separate - process group) so that it has no controlling terminal (meaning - that e.g. ssh cannot open /dev/tty) and it doesn't receive - terminal signals. */ - if (setsid() == -1) - throw SysError(format("creating a new session")); - - /* Dup the write side of the logger pipe into stderr. */ - if (dup2(logPipe.writeSide, STDERR_FILENO) == -1) - throw SysError("cannot pipe standard error into log file"); - - /* Dup stderr to stdout. */ - if (dup2(STDERR_FILENO, STDOUT_FILENO) == -1) - throw SysError("cannot dup stderr into stdout"); - - /* Reroute stdin to /dev/null. */ - int fdDevNull = open(pathNullDevice.c_str(), O_RDWR); - if (fdDevNull == -1) - throw SysError(format("cannot open `%1%'") % pathNullDevice); - if (dup2(fdDevNull, STDIN_FILENO) == -1) - throw SysError("cannot dup null device into stdin"); - close(fdDevNull); -} - /* Restore default handling of SIGPIPE, otherwise some programs will randomly say "Broken pipe". */ static void restoreSIGPIPE() @@ -586,91 +556,6 @@ void UserLock::kill() killUser(uid); } - -////////////////////////////////////////////////////////////////////// - - -/* An "agent" is a helper program that runs in the background and that we talk - to over pipes, such as the "guix offload" program. */ -struct Agent -{ - /* Pipes for talking to the agent. */ - Pipe toAgent; - - /* Pipe for the agent's standard output/error. */ - Pipe fromAgent; - - /* Pipe for build standard output/error--e.g., for build processes started - by "guix offload". */ - Pipe builderOut; - - /* The process ID of the agent. */ - Pid pid; - - /* The 'guix' sub-command and arguments passed to the agent. */ - Agent(const string &command, const Strings &args); - - ~Agent(); -}; - - -Agent::Agent(const string &command, const Strings &args) -{ - debug(format("starting agent '%1%'") % command); - - const Path &buildHook = settings.guixProgram; - - /* Create a pipe to get the output of the child. */ - fromAgent.create(); - - /* Create the communication pipes. */ - toAgent.create(); - - /* Create a pipe to get the output of the builder. */ - builderOut.create(); - - /* Fork the hook. */ - pid = startProcess([&]() { - - commonChildInit(fromAgent); - - if (chdir("/") == -1) throw SysError("changing into `/"); - - /* Dup the communication pipes. */ - if (dup2(toAgent.readSide, STDIN_FILENO) == -1) - throw SysError("dupping to-hook read side"); - - /* Use fd 4 for the builder's stdout/stderr. */ - if (dup2(builderOut.writeSide, 4) == -1) - throw SysError("dupping builder's stdout/stderr"); - - Strings allArgs; - allArgs.push_back(buildHook); - allArgs.push_back(command); - allArgs.insert(allArgs.end(), args.begin(), args.end()); // append - - execv(buildHook.c_str(), stringsToCharPtrs(allArgs).data()); - - throw SysError(format("executing `%1% %2%'") % buildHook % command); - }); - - pid.setSeparatePG(true); - fromAgent.writeSide.close(); - toAgent.readSide.close(); -} - - -Agent::~Agent() -{ - try { - toAgent.writeSide.close(); - pid.kill(true); - } catch (...) { - ignoreException(); - } -} - - ////////////////////////////////////////////////////////////////////// @@ -1593,13 +1478,14 @@ HookReply DerivationGoal::tryBuildHook() if (!worker.hook) { Strings args = { + "offload", settings.thisSystem.c_str(), (format("%1%") % settings.maxSilentTime).str().c_str(), (format("%1%") % settings.printBuildTrace).str().c_str(), (format("%1%") % settings.buildTimeout).str().c_str() }; - worker.hook = std::make_shared<Agent>("offload", args); + worker.hook = std::make_shared<Agent>(settings.guixProgram, args); } /* Tell the hook about system features (beyond the system type) diff --git a/nix/libutil/util.cc b/nix/libutil/util.cc index 17d145b4c6..59a2981359 100644 --- a/nix/libutil/util.cc +++ b/nix/libutil/util.cc @@ -1142,5 +1142,89 @@ void ignoreException() } } +static const string pathNullDevice = "/dev/null"; + +/* Common initialisation performed in child processes. */ +void commonChildInit(Pipe & logPipe) +{ + /* Put the child in a separate session (and thus a separate + process group) so that it has no controlling terminal (meaning + that e.g. ssh cannot open /dev/tty) and it doesn't receive + terminal signals. */ + if (setsid() == -1) + throw SysError(format("creating a new session")); + + /* Dup the write side of the logger pipe into stderr. */ + if (dup2(logPipe.writeSide, STDERR_FILENO) == -1) + throw SysError("cannot pipe standard error into log file"); + + /* Dup stderr to stdout. */ + if (dup2(STDERR_FILENO, STDOUT_FILENO) == -1) + throw SysError("cannot dup stderr into stdout"); + + /* Reroute stdin to /dev/null. */ + int fdDevNull = open(pathNullDevice.c_str(), O_RDWR); + if (fdDevNull == -1) + throw SysError(format("cannot open `%1%'") % pathNullDevice); + if (dup2(fdDevNull, STDIN_FILENO) == -1) + throw SysError("cannot dup null device into stdin"); + close(fdDevNull); +} + +////////////////////////////////////////////////////////////////////// + +Agent::Agent(const string &command, const Strings &args) +{ + debug(format("starting agent '%1%'") % command); + + /* Create a pipe to get the output of the child. */ + fromAgent.create(); + + /* Create the communication pipes. */ + toAgent.create(); + + /* Create a pipe to get the output of the builder. */ + builderOut.create(); + + /* Fork the hook. */ + pid = startProcess([&]() { + + commonChildInit(fromAgent); + + if (chdir("/") == -1) throw SysError("changing into `/"); + + /* Dup the communication pipes. */ + if (dup2(toAgent.readSide, STDIN_FILENO) == -1) + throw SysError("dupping to-hook read side"); + + /* Use fd 4 for the builder's stdout/stderr. */ + if (dup2(builderOut.writeSide, 4) == -1) + throw SysError("dupping builder's stdout/stderr"); + + Strings allArgs; + allArgs.push_back(command); + allArgs.insert(allArgs.end(), args.begin(), args.end()); // append + + execv(command.c_str(), stringsToCharPtrs(allArgs).data()); + + throw SysError(format("executing `%1%'") % command); + }); + + pid.setSeparatePG(true); + fromAgent.writeSide.close(); + toAgent.readSide.close(); +} + + +Agent::~Agent() +{ + try { + toAgent.writeSide.close(); + pid.kill(true); + } catch (...) { + ignoreException(); + } +} + } diff --git a/nix/libutil/util.hh b/nix/libutil/util.hh index 9e3c14bdd4..13cff44316 100644 --- a/nix/libutil/util.hh +++ b/nix/libutil/util.hh @@ -264,6 +264,29 @@ public: void setKillSignal(int signal); }; +/* An "agent" is a helper program that runs in the background and that we talk + to over pipes, such as the "guix offload" program. */ +struct Agent +{ + /* Pipes for talking to the agent. */ + Pipe toAgent; + + /* Pipe for the agent's standard output/error. */ + Pipe fromAgent; + + /* Pipe for build standard output/error--e.g., for build processes started + by "guix offload". */ + Pipe builderOut; + + /* The process ID of the agent. */ + Pid pid; + + /* The command and arguments passed to the agent. */ + Agent(const string &command, const Strings &args); + + ~Agent(); +}; + /* Kill all processes running under the specified uid by sending them a SIGKILL. */ @@ -295,6 +318,8 @@ void closeMostFDs(const set<int> & exceptions); /* Set the close-on-exec flag for the given file descriptor. */ void closeOnExec(int fd); +/* Common initialisation performed in child processes. */ +void commonChildInit(Pipe & logPipe); /* User interruption. */ |