ref #6725
fsync() is very slow on some systems. And since the parent commit, Nvim
is smarter about flushing files at certain times (e.g. CursorHold),
regardless of whether 'fsync' is enabled. So it's less risky to disable
'fsync'.
Profiling showed slow (2-4s) :write and :quit caused by fsync():
:quit
shada_write_file(NULL, false);
:write + fsync
0 0x00007f72da567b2d in fsync () at ../sysdeps/unix/syscall-template.S:84
1 0x0000000000638970 in uv__fs_fsync (req=<optimized out>) at /home/vagrant/neovim/.deps/build/src/libuv/src/unix/fs.c:150
2 uv__fs_work (w=<optimized out>) at /home/vagrant/neovim/.deps/build/src/libuv/src/unix/fs.c:953
3 0x0000000000639a70 in uv_fs_fsync (loop=<optimized out>, req=<optimized out>, file=41, cb=0x7f72da567b2d <fsync+45>)
at /home/vagrant/neovim/.deps/build/src/libuv/src/unix/fs.c:1094
4 0x0000000000573694 in os_fsync (fd=41) at ../src/nvim/os/fs.c:631
5 0x00000000004ec9dc in buf_write (buf=<optimized out>, fname=<optimized out>, sfname=<optimized out>, start=1, end=1997, eap=0x7fffc864c570,
append=<optimized out>, forceit=<optimized out>, reset_changed=<optimized out>, filtering=<optimized out>) at ../src/nvim/fileio.c:3387
6 0x00000000004b44ff in do_write (eap=0x7fffc864c570) at ../src/nvim/ex_cmds.c:1745
...
:write + nofsync
0 0x00007f72da567b2d in fsync () at ../sysdeps/unix/syscall-template.S:84
1 0x0000000000638970 in uv__fs_fsync (req=<optimized out>) at /home/vagrant/neovim/.deps/build/src/libuv/src/unix/fs.c:150
2 uv__fs_work (w=<optimized out>) at /home/vagrant/neovim/.deps/build/src/libuv/src/unix/fs.c:953
3 0x0000000000639a70 in uv_fs_fsync (loop=<optimized out>, req=<optimized out>, file=36, cb=0x7f72da567b2d <fsync+45>)
at /home/vagrant/neovim/.deps/build/src/libuv/src/unix/fs.c:1094
4 0x0000000000573694 in os_fsync (fd=36) at ../src/nvim/os/fs.c:631
5 0x0000000000528f5a in mf_sync (mfp=0x7f72d8968d00, flags=5) at ../src/nvim/memfile.c:466
6 0x000000000052d569 in ml_preserve (buf=0x7f72d890f000, message=0) at ../src/nvim/memline.c:1659
7 0x00000000004ebadf in buf_write (buf=<optimized out>, fname=<optimized out>, sfname=<optimized out>, start=1, end=1997, eap=0x7fffc864c570,
append=<optimized out>, forceit=<optimized out>, reset_changed=<optimized out>, filtering=<optimized out>) at ../src/nvim/fileio.c:3071
8 0x00000000004b44ff in do_write (eap=0x7fffc864c570) at ../src/nvim/ex_cmds.c:1745
...
Vim has the 'swapsync' option which we removed in 62d137ce09.
Instead let 'fsync' control swapfile-fsync.
These cases ALWAYS force fsync (ignoring 'fsync' option):
- Idle (CursorHold).
- Exit caused by deadly signal.
- SIGPWR signal.
- Explicit :preserve command.
Avoid a hot loop in retry(), there's no need to retry more than 50/s.
Also use luv.sleep() to implement sleep() instead of spinning the
event-loop, so events are not silently discarded.
plog-converter behaviour is not the best one when creating fullhtml report and
directory already exists: it puts report inside an existing directory. Not sure
what exactly it does if inside exists as well, but if I am not mistaking report
will not be created.
Since `c` there is a result of evaluating `TO_SPECIAL` macros it may be only one
of the following three things:
1. K_SPECIAL
2. K_ZERO (note: not KS_ZERO)
3. negative integer resulting from evaluating TERMCAP2KEY macro.
All variants here are negative and thus fail next !IS_SPECIAL(c) check (negative
is special). If `c` was really NUL it would fall into the `!IS_SPECIAL(c)` block
and use whatever character is third in `<80>{a}{b}` combo. For `<Nul>` it is
X (`<80><ff>X`).
