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-rw-r--r--build2/depdb.cxx138
-rw-r--r--build2/depdb.hxx5
2 files changed, 25 insertions, 118 deletions
diff --git a/build2/depdb.cxx b/build2/depdb.cxx
index a77a1a8..94b845d 100644
--- a/build2/depdb.cxx
+++ b/build2/depdb.cxx
@@ -121,8 +121,8 @@ namespace build2
//
fdseek (fd.get (), pos_, fdseek_mode::set);
- // @@ Strictly speaking, ofdstream can throw which will leave us
- // in a non-destructible state.
+ // @@ Strictly speaking, ofdstream can throw which will leave us in a
+ // non-destructible state. Unlikely but possible.
//
is_.~ifdstream ();
new (&os_) ofdstream (move (fd),
@@ -250,19 +250,21 @@ namespace build2
//
if (state_ == state::read_eof)
{
+ if (!touch)
+ {
+ is_.close ();
+ return;
+ }
+
// While there are utime(2)/utimensat(2) (and probably something similar
// for Windows), for now we just overwrite the "end marker". Hopefully
// no implementation will be smart enough to recognize this is a no-op
// and skip updating mtime (which would probably be incorrect, spec-
// wise). And this could even be faster since we already have the file
- // descriptor. @@ Might still be faster since we are in reading mode?
+ // descriptor. Or it might be slower since so far we've only been
+ // reading.
//
- // It would be interesting to one day write an implementation that uses
- // POSIX file IO, futimens(), and ftruncate() and see how much better it
- // performs.
- //
- if (touch)
- change (false /* truncate */); // Write end marker below.
+ change (false /* truncate */); // Write end marker below.
}
else if (state_ != state::write)
{
@@ -270,10 +272,17 @@ namespace build2
change (true /* truncate */);
}
- // On some platforms (currently confirmed on Windows and FreeBSD, both
- // running as VMs) one can sometimes end up with a modification time that
- // is quite a bit after the call to close(). And this messes with our
- // arrangement that a valid depdb should be no older than the target it is
+#ifdef BUILD2_MTIME_CHECK
+ start_ = system_clock::now ();
+#endif
+
+ os_.put ('\0'); // The "end marker".
+ os_.close ();
+
+ // On some platforms (currently confirmed on FreeBSD running as VMs) one
+ // can sometimes end up with a modification time that is a bit after the
+ // call to close(). And in some tight cases this can mess with our
+ // "protocol" that a valid depdb should be no older than the target it is
// for.
//
// Note that this does not seem to be related to clock adjustments but
@@ -282,100 +291,8 @@ namespace build2
// driver). One workaround that appears to work is to query the
// mtime. This seems to force that layer to commit to a timestamp.
//
- // Well, this seems to work on FreeBSD but on Windows we may still end up
- // getting the old mtime if we ask for it too soon. For such cases we are
- // going to just set it ourselves.
- //
- /*
-#ifdef _WIN32
- timestamp mt (timestamp_unknown);
-
- // See libbutl/filesystem.cxx for details.
- //
- auto to_timestamp = [] (const FILETIME& t) -> timestamp
- {
- uint64_t nsec ((static_cast<uint64_t> (t.dwHighDateTime) << 32) |
- t.dwLowDateTime);
- nsec -= 11644473600ULL * 10000000;
- nsec *= 100;
-
- return timestamp (
- chrono::duration_cast<duration> (chrono::nanoseconds (nsec)));
- };
-#endif
- */
-
- if (state_ == state::write)
- {
-#ifdef BUILD2_MTIME_CHECK
- start_ = system_clock::now ();
-#endif
-
- /*
-#ifdef _WIN32
- //
- // On Windows there are two times, the precise time (which is what we
- // get with system_clock::now()) and what we will call "filesystem time"
- // which can lag the precise time by as much as couple of milliseconds.
- //
- FILETIME ft;
- GetSystemTimeAsFileTime (&ft);
- mt = to_timestamp (ft);
-
-#ifdef BUILD2_MTIME_CHECK
- wtime_ = mt; // Save for check below.
-#endif
-#endif
- */
-
- os_.put ('\0'); // The "end marker".
- os_.close ();
- }
- else
- is_.close ();
-
-#if /*defined(_WIN32) ||*/ defined(__FreeBSD__)
- if (state_ == state::write)
- {
- /*
-#ifdef _WIN32
- auto file_mtime_h = [&to_timestamp] (const path_type& p) -> timestamp
- {
- HANDLE h (CreateFile (p.string ().c_str (),
- FILE_READ_ATTRIBUTES,
- FILE_SHARE_READ | FILE_SHARE_WRITE,
- NULL,
- OPEN_EXISTING,
- 0,
- NULL));
-
- assert (h != INVALID_HANDLE_VALUE);
-
- BY_HANDLE_FILE_INFORMATION fi;
- if (!GetFileInformationByHandle (h, &fi))
- assert (false);
-
- timestamp r (to_timestamp (fi.ftLastWriteTime));
- CloseHandle (h);
- return r;
- };
-
- mtime = file_mtime_h (path); // Save for check below.
-
- if (mtime < mt)
- {
- file_mtime (path, mt);
- assert (file_mtime_h (path) == mt);
- }
-#else
- */
-
- mtime = file_mtime (path); // Save for check below.
-
- /*
-#endif
- */
- }
+#if defined(__FreeBSD__)
+ mtime = file_mtime (path); // Save for debugging/check below.
#endif
}
@@ -399,14 +316,9 @@ namespace build2
fail << "backwards modification times detected:\n"
<< start_ << " sequence start\n"
- /*
-#if defined(_WIN32)
- << wtime_ << " write time\n"
-#endif
-#if defined(_WIN32) || defined(__FreeBSD__)
+#if defined(__FreeBSD__)
<< mtime << " close mtime\n"
#endif
- */
<< d_mt << " " << path.string () << '\n'
<< t_mt << " " << t.string () << '\n'
<< e << " sequence end";
diff --git a/build2/depdb.hxx b/build2/depdb.hxx
index d00418f..66d89e9 100644
--- a/build2/depdb.hxx
+++ b/build2/depdb.hxx
@@ -257,11 +257,6 @@ namespace build2
#ifdef BUILD2_MTIME_CHECK
timestamp start_;
- /*
-#ifdef _WIN32
- timestamp wtime_;
-#endif
- */
#endif
};
}