Skip to content

src: raise the maximum open files limit on Windows #63643

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
medns wants to merge 1 commit into
base: main
Choose a base branch
from
+20 −0
Open

src: raise the maximum open files limit on Windows #63643

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
20 changes: 20 additions & 0 deletions src/node.cc
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -638,6 +638,26 @@ static void PlatformInit(ProcessInitializationFlags::Flags flags) {
}
#endif // __POSIX__
#ifdef _WIN32
if (!(flags & ProcessInitializationFlags::kNoAdjustResourceLimits)) {
// Raise the CRT maxstdio / stdio streams limit on Windows.
// By default, up to 512 files can be open simultaneously at the
// stream I/O level. We increase this limit to the maximum possible
// (up to 8192) using `_setmaxstdio`. Since libuv internally calls
// _open_osfhandle when opening files on Windows, which is provided
// by the CRT and constrained by the maxstdio limit, raising this
// limit helps prevent "EMFILE: too many open files" errors.
// We try to set the limit starting from 8192 down to 512.
static constexpr int MIN_OPEN_FILES_LIMIT = 512;
static constexpr int MAX_OPEN_FILES_LIMIT = 8192;
static constexpr int STEP_OPEN_FILES_LIMIT = 512;
for (int i = MAX_OPEN_FILES_LIMIT; i >= MIN_OPEN_FILES_LIMIT;
i -= STEP_OPEN_FILES_LIMIT) {
if (_setmaxstdio(i) != -1) {
break;
}
}
}

if (!(flags & ProcessInitializationFlags::kNoStdioInitialization)) {
for (int fd = 0; fd <= 2; ++fd) {
auto handle = reinterpret_cast<HANDLE>(_get_osfhandle(fd));
Expand Down
Loading