[PATCH v2 12/42] tools/nolibc/types: make FD_SETSIZE configurable

From: Willy Tarreau
Date: Sun Feb 13 2022 - 03:53:10 EST


The macro was hard-coded to 256 but it's common to see it redefined.
Let's support this and make sure we always allocate enough entries for
the cases where it wouldn't be multiple of 32.

Signed-off-by: Willy Tarreau <w@xxxxxx>

---
v2:
- rebase on top of v2 of previous patch
---
tools/include/nolibc/types.h | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/tools/include/nolibc/types.h b/tools/include/nolibc/types.h
index a4dda0a22fc2..563dbbad0496 100644
--- a/tools/include/nolibc/types.h
+++ b/tools/include/nolibc/types.h
@@ -45,7 +45,9 @@
#define DT_SOCK 0xc

/* commonly an fd_set represents 256 FDs */
+#ifndef FD_SETSIZE
#define FD_SETSIZE 256
+#endif

/* Special FD used by all the *at functions */
#ifndef AT_FDCWD
@@ -72,7 +74,7 @@

/* for select() */
typedef struct {
- uint32_t fd32[FD_SETSIZE / 32];
+ uint32_t fd32[(FD_SETSIZE + 31) / 32];
} fd_set;

#define FD_CLR(fd, set) do { \
@@ -101,7 +103,7 @@ typedef struct {
#define FD_ZERO(set) do { \
fd_set *__set = (set); \
int __idx; \
- for (__idx = 0; __idx < FD_SETSIZE / 32; __idx ++) \
+ for (__idx = 0; __idx < (FD_SETSIZE+31) / 32; __idx ++) \
__set->fd32[__idx] = 0; \
} while (0)

--
2.35.1