chore(3p/nix): unvendor tvix 0.1 r/4098

Nothing is using this now, and we'll likely never pick this up again,
but we learned a lot in the process.

Every now and then this breaks in some bizarre way on channel bumps
and it's just a waste of time to maintain that.

Change-Id: Idcf2f5acd4ca7070ce18d7149cbfc0d967dc0a44
Reviewed-on: https://cl.tvl.fyi/c/depot/+/5632
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
Reviewed-by: lukegb <lukegb@tvl.fyi>
Autosubmit: tazjin <tazjin@tvl.su>

1 files changed, 0 insertions, 172 deletions

diff --git a/third_party/nix/src/libstore/pathlocks.cc b/third_party/nix/src/libstore/pathlocks.cc
deleted file mode 100644
index 09dec08c458c..000000000000
--- a/third_party/nix/src/libstore/pathlocks.cc
+++ /dev/null
@@ -1,172 +0,0 @@
-#include "libstore/pathlocks.hh"
-
-#include <cerrno>
-#include <cstdlib>
-
-#include <fcntl.h>
-#include <glog/logging.h>
-#include <sys/file.h>
-#include <sys/stat.h>
-#include <sys/types.h>
-
-#include "libutil/sync.hh"
-#include "libutil/util.hh"
-
-namespace nix {
-
-AutoCloseFD openLockFile(const Path& path, bool create) {
-  AutoCloseFD fd(
-      open(path.c_str(), O_CLOEXEC | O_RDWR | (create ? O_CREAT : 0), 0600));
-
-  if (!fd && (create || errno != ENOENT)) {
-    throw SysError(format("opening lock file '%1%'") % path);
-  }
-
-  return fd;
-}
-
-void deleteLockFile(const Path& path, int fd) {
-  /* Get rid of the lock file.  Have to be careful not to introduce
-     races.  Write a (meaningless) token to the file to indicate to
-     other processes waiting on this lock that the lock is stale
-     (deleted). */
-  unlink(path.c_str());
-  writeFull(fd, "d");
-  /* Note that the result of unlink() is ignored; removing the lock
-     file is an optimisation, not a necessity. */
-}
-
-bool lockFile(int fd, LockType lockType, bool wait) {
-  int type;
-  if (lockType == ltRead) {
-    type = LOCK_SH;
-  } else if (lockType == ltWrite) {
-    type = LOCK_EX;
-  } else if (lockType == ltNone) {
-    type = LOCK_UN;
-  } else {
-    abort();
-  }
-
-  if (wait) {
-    while (flock(fd, type) != 0) {
-      checkInterrupt();
-      if (errno != EINTR) {
-        throw SysError(format("acquiring/releasing lock"));
-      }
-      return false;
-    }
-  } else {
-    while (flock(fd, type | LOCK_NB) != 0) {
-      checkInterrupt();
-      if (errno == EWOULDBLOCK) {
-        return false;
-      }
-      if (errno != EINTR) {
-        throw SysError(format("acquiring/releasing lock"));
-      }
-    }
-  }
-
-  return true;
-}
-
-PathLocks::PathLocks() : deletePaths(false) {}
-
-PathLocks::PathLocks(const PathSet& paths, const std::string& waitMsg)
-    : deletePaths(false) {
-  lockPaths(paths, waitMsg);
-}
-
-bool PathLocks::lockPaths(const PathSet& paths, const std::string& waitMsg,
-                          bool wait) {
-  assert(fds.empty());
-
-  /* Note that `fds' is built incrementally so that the destructor
-     will only release those locks that we have already acquired. */
-
-  /* Acquire the lock for each path in sorted order. This ensures
-     that locks are always acquired in the same order, thus
-     preventing deadlocks. */
-  for (auto& path : paths) {
-    checkInterrupt();
-    Path lockPath = path + ".lock";
-
-    VLOG(2) << "locking path '" << path << "'";
-
-    AutoCloseFD fd;
-
-    while (true) {
-      /* Open/create the lock file. */
-      fd = openLockFile(lockPath, true);
-
-      /* Acquire an exclusive lock. */
-      if (!lockFile(fd.get(), ltWrite, false)) {
-        if (wait) {
-          if (!waitMsg.empty()) {
-            LOG(WARNING) << waitMsg;
-          }
-          lockFile(fd.get(), ltWrite, true);
-        } else {
-          /* Failed to lock this path; release all other
-             locks. */
-          unlock();
-          return false;
-        }
-      }
-
-      VLOG(2) << "lock acquired on '" << lockPath << "'";
-
-      /* Check that the lock file hasn't become stale (i.e.,
-         hasn't been unlinked). */
-      struct stat st;
-      if (fstat(fd.get(), &st) == -1) {
-        throw SysError(format("statting lock file '%1%'") % lockPath);
-      }
-      if (st.st_size != 0) {
-        /* This lock file has been unlinked, so we're holding
-           a lock on a deleted file.  This means that other
-           processes may create and acquire a lock on
-           `lockPath', and proceed.  So we must retry. */
-        DLOG(INFO) << "open lock file '" << lockPath << "' has become stale";
-      } else {
-        break;
-      }
-    }
-
-    /* Use borrow so that the descriptor isn't closed. */
-    fds.emplace_back(fd.release(), lockPath);
-  }
-
-  return true;
-}
-
-PathLocks::~PathLocks() {
-  try {
-    unlock();
-  } catch (...) {
-    ignoreException();
-  }
-}
-
-void PathLocks::unlock() {
-  for (auto& i : fds) {
-    if (deletePaths) {
-      deleteLockFile(i.second, i.first);
-    }
-
-    if (close(i.first) == -1) {
-      LOG(WARNING) << "cannot close lock file on '" << i.second << "'";
-    }
-
-    VLOG(2) << "lock released on '" << i.second << "'";
-  }
-
-  fds.clear();
-}
-
-void PathLocks::setDeletion(bool deletePaths) {
-  this->deletePaths = deletePaths;
-}
-
-}  // namespace nix