diff options
| -rw-r--r-- | build2/depdb.cxx | 138 | ||||
| -rw-r--r-- | build2/depdb.hxx | 5 |
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 }; } |