refactor(fs): now it is time to get rid of fs_loop and fs_loop_mutex

Here's the headline: when run in sync mode (last argument cb=NULL),
these functions don't actually use the uv_loop_t.

An earlier version of this patch instead replaced fs_loop with
using main_loop.uv on the main thread and luv_loop() on luv worker
threads. However this made the code more complicated for no reason.

Also arbitrarily, half of these functions would attempt to handle
UV_ENOMEM by try_to_free_memory(). This would mostly happen
on windows because it needs to allocate a converted WCHAR buffer.
This should be a quite rare situation. Your system is pretty
much hosed already if you cannot allocate like 50 WCHAR:s.
Therefore, take the liberty of simply removing this fallback.

In addition, we tried to "recover" from ENOMEM in read()/readv()
this way which doesn't make any sense. The read buffer(s) are already
allocated at this point.

This would also be an issue when using these functions on a worker
thread, as try_to_free_memory() is not thread-safe. Currently
os_file_is_readable() and os_is_dir() is used by worker threads
(as part of nvim__get_runtime(), to implement require from 'rtp' in
threads).

In the end, these changes makes _all_ os/fs.c functions thread-safe,
and we thus don't need to document and maintain a thread-safe subset.

1 files changed, 0 insertions, 1 deletions

diff --git a/test/unit/helpers.lua b/test/unit/helpers.lua
index 8fa6378d10..52769cd9e9 100644
--- a/test/unit/helpers.lua
+++ b/test/unit/helpers.lua
@@ -97,7 +97,6 @@ local init = only_separate(function()
   for _, c in ipairs(child_calls_init) do
     c.func(unpack(c.args))
   end
-  libnvim.fs_init()
   libnvim.event_init()
   libnvim.early_init(nil)
   if child_calls_mod then