pespin has uploaded this change for review. ( https://gerrit.osmocom.org/c/libosmocore/+/41989?usp=email )

Change subject: osmo_io: Allow fetching maximum value allowed by osmo_iofd_set_io_buffers() ......................................................................

osmo_io: Allow fetching maximum value allowed by osmo_iofd_set_io_buffers()

Before this patch, there's no way for a user of the API to know whether a requested buffers value is actually going to be accepted or not.

Change-Id: Id3d8413c119eb3d9b60aa068295a59561236938c --- M src/core/osmo_io.c 1 file changed, 9 insertions(+), 1 deletion(-)

git pull ssh://gerrit.osmocom.org:29418/libosmocore refs/changes/89/41989/1

diff --git a/src/core/osmo_io.c b/src/core/osmo_io.c index 7c931d3..8ee6967 100644 --- a/src/core/osmo_io.c +++ b/src/core/osmo_io.c @@ -915,15 +915,23 @@ * \param[in] op the osmo_io_op (read or write) to set the number of IO buffers for * \param[in] buffers the number of IO buffer for each specified operation * \returns zero on success, a negative value on error + * + * The minimum valid buffers to set is always 1. + * The maximum valid buffers is implementation defined, and trying to set a + * value greater than the maximum will return an error. + * Passing \ref buffers with a value of 0 can be used to fetch the maximum value allowed. */ int osmo_iofd_set_io_buffers(struct osmo_io_fd *iofd, enum osmo_io_op op, uint8_t buffers) { if (iofd->mode != OSMO_IO_FD_MODE_READ_WRITE) return -EINVAL;

- if (buffers < 1 || buffers > IOFD_MSGHDR_IO_BUFFERS) + if (buffers > IOFD_MSGHDR_IO_BUFFERS) return -EINVAL;

+ if (buffers == 0) + return IOFD_MSGHDR_IO_BUFFERS; + switch (op) { case OSMO_IO_OP_READ: iofd->io_read_buffers = buffers;