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authorLudovic Courtès <ludo@gnu.org>2020-09-10 16:28:11 +0200
committerLudovic Courtès <ludo@gnu.org>2020-09-14 15:42:55 +0200
commit7809071c822589dfc3c65c539760e92936c41073 (patch)
tree8be8ec42b6d4198fbdf2b2d8ef1bb2a7d9956248 /nix
parent735808b12cc23909b421e10e212a07e7aa69a5eb (diff)
daemon: Generalize 'HookInstance' to 'Agent'.
* nix/libstore/build.cc (HookInstance): Rename to... (Agent): ... this. Rename 'toHook' and 'fromHook' similarly and update users. Change constructor to require a command and an argument list. (DerivationGoal::tryBuildHook): Pass arguments to the 'Agent' constructor.
Diffstat (limited to 'nix')
-rw-r--r--nix/libstore/build.cc90
1 files changed, 51 insertions, 39 deletions
diff --git a/nix/libstore/build.cc b/nix/libstore/build.cc
index 29266f1dd6..346f92a8c3 100644
--- a/nix/libstore/build.cc
+++ b/nix/libstore/build.cc
@@ -85,7 +85,7 @@ static string pathNullDevice = "/dev/null";
/* Forward definition. */
class Worker;
-struct HookInstance;
+struct Agent;
/* A pointer to a goal. */
@@ -265,7 +265,7 @@ public:
LocalStore & store;
- std::shared_ptr<HookInstance> hook;
+ std::shared_ptr<Agent> hook;
Worker(LocalStore & store);
~Worker();
@@ -590,37 +590,41 @@ void UserLock::kill()
//////////////////////////////////////////////////////////////////////
-struct HookInstance
+/* 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 build hook. */
- Pipe toHook;
+ /* Pipes for talking to the agent. */
+ Pipe toAgent;
- /* Pipe for the hook's standard output/error. */
- Pipe fromHook;
+ /* Pipe for the agent's standard output/error. */
+ Pipe fromAgent;
- /* Pipe for the builder's standard output/error. */
+ /* Pipe for build standard output/error--e.g., for build processes started
+ by "guix offload". */
Pipe builderOut;
- /* The process ID of the hook. */
+ /* The process ID of the agent. */
Pid pid;
- HookInstance();
+ /* The 'guix' sub-command and arguments passed to the agent. */
+ Agent(const string &command, const Strings &args);
- ~HookInstance();
+ ~Agent();
};
-HookInstance::HookInstance()
+Agent::Agent(const string &command, const Strings &args)
{
- debug("starting build hook");
+ debug(format("starting agent '%1%'") % command);
const Path &buildHook = settings.guixProgram;
/* Create a pipe to get the output of the child. */
- fromHook.create();
+ fromAgent.create();
/* Create the communication pipes. */
- toHook.create();
+ toAgent.create();
/* Create a pipe to get the output of the builder. */
builderOut.create();
@@ -628,38 +632,38 @@ HookInstance::HookInstance()
/* Fork the hook. */
pid = startProcess([&]() {
- commonChildInit(fromHook);
+ commonChildInit(fromAgent);
if (chdir("/") == -1) throw SysError("changing into `/");
/* Dup the communication pipes. */
- if (dup2(toHook.readSide, STDIN_FILENO) == -1)
+ 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");
- execl(buildHook.c_str(), buildHook.c_str(), "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(),
- NULL);
+ 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% offload'") % buildHook);
+ throw SysError(format("executing `%1% %2%'") % buildHook % command);
});
pid.setSeparatePG(true);
- fromHook.writeSide.close();
- toHook.readSide.close();
+ fromAgent.writeSide.close();
+ toAgent.readSide.close();
}
-HookInstance::~HookInstance()
+Agent::~Agent()
{
try {
- toHook.writeSide.close();
+ toAgent.writeSide.close();
pid.kill(true);
} catch (...) {
ignoreException();
@@ -760,7 +764,7 @@ private:
Pipe builderOut;
/* The build hook. */
- std::shared_ptr<HookInstance> hook;
+ std::shared_ptr<Agent> hook;
/* Whether we're currently doing a chroot build. */
bool useChroot;
@@ -1440,7 +1444,7 @@ void DerivationGoal::buildDone()
/* Close the read side of the logger pipe. */
if (hook) {
hook->builderOut.readSide.close();
- hook->fromHook.readSide.close();
+ hook->fromAgent.readSide.close();
}
else builderOut.readSide.close();
@@ -1587,8 +1591,16 @@ HookReply DerivationGoal::tryBuildHook()
{
if (!settings.useBuildHook) return rpDecline;
- if (!worker.hook)
- worker.hook = std::shared_ptr<HookInstance>(new HookInstance);
+ if (!worker.hook) {
+ Strings args = {
+ 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);
+ }
/* Tell the hook about system features (beyond the system type)
required from the build machine. (The hook could parse the
@@ -1597,7 +1609,7 @@ HookReply DerivationGoal::tryBuildHook()
foreach (Strings::iterator, i, features) checkStoreName(*i); /* !!! abuse */
/* Send the request to the hook. */
- writeLine(worker.hook->toHook.writeSide, (format("%1% %2% %3% %4%")
+ writeLine(worker.hook->toAgent.writeSide, (format("%1% %2% %3% %4%")
% (worker.getNrLocalBuilds() < settings.maxBuildJobs ? "1" : "0")
% drv.platform % drvPath % concatStringsSep(",", features)).str());
@@ -1605,7 +1617,7 @@ HookReply DerivationGoal::tryBuildHook()
whether the hook wishes to perform the build. */
string reply;
while (true) {
- string s = readLine(worker.hook->fromHook.readSide);
+ string s = readLine(worker.hook->fromAgent.readSide);
if (string(s, 0, 2) == "# ") {
reply = string(s, 2);
break;
@@ -1637,21 +1649,21 @@ HookReply DerivationGoal::tryBuildHook()
string s;
foreach (PathSet::iterator, i, allInputs) { s += *i; s += ' '; }
- writeLine(hook->toHook.writeSide, s);
+ writeLine(hook->toAgent.writeSide, s);
/* Tell the hooks the missing outputs that have to be copied back
from the remote system. */
s = "";
foreach (PathSet::iterator, i, missingPaths) { s += *i; s += ' '; }
- writeLine(hook->toHook.writeSide, s);
+ writeLine(hook->toAgent.writeSide, s);
- hook->toHook.writeSide.close();
+ hook->toAgent.writeSide.close();
/* Create the log file and pipe. */
Path logFile = openLogFile();
set<int> fds;
- fds.insert(hook->fromHook.readSide);
+ fds.insert(hook->fromAgent.readSide);
fds.insert(hook->builderOut.readSide);
worker.childStarted(shared_from_this(), hook->pid, fds, false, true);
@@ -2785,7 +2797,7 @@ void DerivationGoal::handleChildOutput(int fd, const string & data)
writeFull(fdLogFile, data);
}
- if (hook && fd == hook->fromHook.readSide)
+ if (hook && fd == hook->fromAgent.readSide)
writeToStderr(prefix + data);
}