Add support for advanced closing callbacks to unixmessage_sender_flush.

(Typically, this will be used for refcounting when broadcasting copies of
the same fd.)

5 files changed, 39 insertions, 11 deletions

diff --git a/src/include/skalibs/unixmessage.h b/src/include/skalibs/unixmessage.h
index 51d48bc..f971a65 100644
--- a/src/include/skalibs/unixmessage.h
+++ b/src/include/skalibs/unixmessage.h
@@ -49,6 +49,9 @@ extern unixmessage_v_t const unixmessage_v_zero ;
 
  /* Sender */
 
+typedef void unixmessage_sender_closecb_func_t (int, void *) ;
+typedef unixmessage_sender_closecb_func_t *unixmessage_sender_closecb_func_t_ref ;
+
 typedef struct unixmessage_sender_s unixmessage_sender_t, *unixmessage_sender_t_ref ;
 struct unixmessage_sender_s
 {
@@ -58,12 +61,17 @@ struct unixmessage_sender_s
   genalloc offsets ; /* diuint */
   unsigned int head ;
   unsigned int shorty ;
+  unixmessage_sender_closecb_func_t_ref closecb ;
+  void *closecbdata ;
 } ;
 #define UNIXMESSAGE_SENDER_ZERO UNIXMESSAGE_SENDER_INIT(-1)
-#define UNIXMESSAGE_SENDER_INIT(s) { .fd = (s), .data = STRALLOC_ZERO, .fds = GENALLOC_ZERO, .offsets = GENALLOC_ZERO, .head = 0, .shorty = 0 }
+#define UNIXMESSAGE_SENDER_INIT(s) UNIXMESSAGE_SENDER_INIT_WITHCLOSECB((s), &unixmessage_sender_closecb, 0)
+#define UNIXMESSAGE_SENDER_INIT_WITHCLOSECB(s, f, p) { .fd = (s), .data = STRALLOC_ZERO, .fds = GENALLOC_ZERO, .offsets = GENALLOC_ZERO, .head = 0, .shorty = 0, .closecb = (f), .closecbdata = (p) }
 
 extern unixmessage_sender_t const unixmessage_sender_zero ;
+extern unixmessage_sender_closecb_func_t unixmessage_sender_closecb ;
 extern void unixmessage_sender_init (unixmessage_sender_t *, int) ;
+extern void unixmessage_sender_init_withclosecb (unixmessage_sender_t *, int, unixmessage_sender_closecb_func_t_ref, void *) ;
 extern void unixmessage_sender_free (unixmessage_sender_t *) ;
 #define unixmessage_sender_fd(b) ((b)->fd)
 extern int unixmessage_sender_getfd (unixmessage_sender_t const *) gccattr_pure ;
diff --git a/src/libunixonacid/unixmessage_sender_closecb.c b/src/libunixonacid/unixmessage_sender_closecb.c
new file mode 100644
index 0000000..1234ff5
--- /dev/null
+++ b/src/libunixonacid/unixmessage_sender_closecb.c
@@ -0,0 +1,10 @@
+/* ISC license. */
+
+#include <skalibs/djbunix.h>
+#include <skalibs/unixmessage.h>
+
+void unixmessage_sender_closecb (int fd, void *p)
+{
+  fd_close(fd) ;
+  (void)p ;
+}
diff --git a/src/libunixonacid/unixmessage_sender_flush.c b/src/libunixonacid/unixmessage_sender_flush.c
index 75412fb..6559083 100644
--- a/src/libunixonacid/unixmessage_sender_flush.c
+++ b/src/libunixonacid/unixmessage_sender_flush.c
@@ -97,13 +97,13 @@ int unixmessage_sender_flush (unixmessage_sender_t *b)
     while (r < 0 && errno == EINTR) ;
     if (r <= 0) return 0 ;
 #ifndef SKALIBS_HASANCILAUTOCLOSE
-    if (nfds)
+    if (nfds && b->closecb)
     {
       register unsigned int i = 0 ;
       for (; i < nfds ; i++)
       {
         register int fd = genalloc_s(int, &b->fds)[offsets[b->head].right + i] ;
-        if (fd < 0) fd_close(-(fd+1)) ;
+        if (fd < 0) (*b->closecb)(-(fd+1), b->closecbdata) ;
       }
     }
 #endif
diff --git a/src/libunixonacid/unixmessage_sender_init.c b/src/libunixonacid/unixmessage_sender_init.c
index d986f29..71a8b3b 100644
--- a/src/libunixonacid/unixmessage_sender_init.c
+++ b/src/libunixonacid/unixmessage_sender_init.c
@@ -1,15 +1,8 @@
 /* ISC license. */
 
-#include <skalibs/stralloc.h>
-#include <skalibs/genalloc.h>
 #include <skalibs/unixmessage.h>
 
 void unixmessage_sender_init (unixmessage_sender_t *b, int fd)
 {
-  b->fd = fd ;
-  b->data = stralloc_zero ;
-  b->fds = genalloc_zero ;
-  b->offsets = genalloc_zero ;
-  b->head = 0 ;
-  b->shorty = 0 ;
+  unixmessage_sender_init_withclosecb(b, fd, &unixmessage_sender_closecb, 0) ;
 }
diff --git a/src/libunixonacid/unixmessage_sender_init_withclosecb.c b/src/libunixonacid/unixmessage_sender_init_withclosecb.c
new file mode 100644
index 0000000..32743ec
--- /dev/null
+++ b/src/libunixonacid/unixmessage_sender_init_withclosecb.c
@@ -0,0 +1,17 @@
+/* ISC license. */
+
+#include <skalibs/stralloc.h>
+#include <skalibs/genalloc.h>
+#include <skalibs/unixmessage.h>
+
+void unixmessage_sender_init_withclosecb (unixmessage_sender_t *b, int fd, unixmessage_sender_closecb_func_t_ref f, void *p)
+{
+  b->fd = fd ;
+  b->data = stralloc_zero ;
+  b->fds = genalloc_zero ;
+  b->offsets = genalloc_zero ;
+  b->head = 0 ;
+  b->shorty = 0 ;
+  b->closecb = f ;
+  b->closecbdata = 0 ;
+}