From b288853ffa01fbce1f5831ae6d387520c8882aec Mon Sep 17 00:00:00 2001 From: Philipp Maier Date: Fri, 9 Dec 2016 14:07:18 +0100 Subject: select: add functionality to check socket state osmo_fd_register() is used to register socket file descriptors, after registering a socket, there is no way to test if the socket is still registered or actually registered at all. This commit adds a new function osmo_fd_register_check() that can be used to check in advance, if the socket fd is registered, before performing further operations. Change-Id: I48ec7098d6bba586c81bf0d5c9088108e2c081c6 --- include/osmocom/core/select.h | 2 ++ src/select.c | 30 ++++++++++++++++++++++++------ 2 files changed, 26 insertions(+), 6 deletions(-) diff --git a/include/osmocom/core/select.h b/include/osmocom/core/select.h index 2753637a..c2b51a45 100644 --- a/include/osmocom/core/select.h +++ b/include/osmocom/core/select.h @@ -1,6 +1,7 @@ #pragma once #include +#include /*! \defgroup select Select loop abstraction * @{ @@ -35,6 +36,7 @@ struct osmo_fd { unsigned int priv_nr; }; +bool osmo_fd_is_registered(struct osmo_fd *fd); int osmo_fd_register(struct osmo_fd *fd); void osmo_fd_unregister(struct osmo_fd *fd); int osmo_select_main(int polling); diff --git a/src/select.c b/src/select.c index da273680..ab0734ea 100644 --- a/src/select.c +++ b/src/select.c @@ -23,6 +23,7 @@ #include #include #include +#include #include #include @@ -45,6 +46,23 @@ static int maxfd = 0; static LLIST_HEAD(osmo_fds); static int unregistered_count; + +/*! \brief Check if a file descriptor is already registered + * \param[in] fd osmocom file descriptor to be checked + * \returns true if registered; otherwise false + */ +bool osmo_fd_is_registered(struct osmo_fd *fd) +{ + struct osmo_fd *entry; + llist_for_each_entry(entry, &osmo_fds, list) { + if (entry == fd) { + return true; + } + } + + return false; +} + /*! \brief Register a new file descriptor with select loop abstraction * \param[in] fd osmocom file descriptor to be registered * \returns 0 on success; negative in case of error @@ -76,12 +94,9 @@ int osmo_fd_register(struct osmo_fd *fd) maxfd = fd->fd; #ifdef BSC_FD_CHECK - struct osmo_fd *entry; - llist_for_each_entry(entry, &osmo_fds, list) { - if (entry == fd) { - fprintf(stderr, "Adding a osmo_fd that is already in the list.\n"); - return 0; - } + if (osmo_fd_is_registered(fd)) { + fprintf(stderr, "Adding a osmo_fd that is already in the list.\n"); + return 0; } #endif @@ -95,6 +110,9 @@ int osmo_fd_register(struct osmo_fd *fd) */ void osmo_fd_unregister(struct osmo_fd *fd) { + /* Note: when fd is inside the osmo_fds list (not registered before) + * this function will crash! If in doubt, check file descriptor with + * osmo_fd_is_registered() */ unregistered_count++; llist_del(&fd->list); } -- cgit v1.2.3