poll: Introduce and use BEFOREPOLL_WANT_FDS

[secnet.git] / secnet.h

diff --git a/secnet.h b/secnet.h
index 7d1edb0737d6709714973f9b438a66bddd5a08c5..0e2e1f7819057a17b8911a7c1647cb0cd70508de 100644 (file)
--- a/secnet.h
+++ b/secnet.h
@@ -13,12 +13,15 @@
 #include <assert.h>
 #include <fcntl.h>
 #include <unistd.h>
+#include <errno.h>
 #include <sys/poll.h>
 #include <sys/types.h>
 #include <sys/time.h>
 #include <netinet/in.h>
 #include <arpa/inet.h>
 
+#include <bsd/sys/queue.h>
+
 #define MAX_PEER_ADDRS 5
 /* send at most this many copies; honour at most that many addresses */
 
@@ -198,6 +201,16 @@ typedef int beforepoll_fn(void *st, struct pollfd *fds, int *nfds_io,
                          int *timeout_io);
 typedef void afterpoll_fn(void *st, struct pollfd *fds, int nfds);
 
+/* void BEFOREPOLL_WANT_FDS(int want);
+ *   Expects: int *nfds_io;
+ *   Can perform non-local exit.
+ * Checks whether there is space for want fds.  If so, sets *nfds_io.
+ * If not, sets *nfds_io and returns. */
+#define BEFOREPOLL_WANT_FDS(want) do{                          \
+    if (*nfds_io<(want)) { *nfds_io=(want); return ERANGE; }   \
+    *nfds_io=(want);                                           \
+  }while(0)
+
 /* Register interest in the main loop of the program. Before a call
    to poll() your supplied beforepoll function will be called. After
    the call to poll() the supplied afterpoll function will be called.