MINOR: ring: add a flag to indicate a mapped file

Till now we used to rely on a heuristic pointer comparison to check if
a ring was mapped or allocated. Better assign a flag to clarify this
because it's going to become difficult otherwise.

diff --git a/include/haproxy/ring-t.h b/include/haproxy/ring-t.h
index 55867b54b52b9124d447d34014752ad5a8fcc529..ac3e1e1d909fe1330a1e145d74b20861938863db 100644 (file)
--- a/include/haproxy/ring-t.h
+++ b/include/haproxy/ring-t.h
@@ -96,6 +96,9 @@
 #define RING_WF_WAIT_MODE  0x00000001   /* wait for new contents */
 #define RING_WF_SEEK_NEW   0x00000002   /* seek to new contents  */
 
+/* ring flags */
+#define RING_FL_MAPPED     0x00000001 /* mmapped area, must not free() */
+
 /* keep values below in decimal, they may be dumped in error messages */
 #define RING_WRITING_SIZE  255  /* the next message's size is being written */
 #define RING_MAX_READERS   254  /* highest supported value for RC */
@@ -105,6 +108,7 @@ struct ring {
        struct list waiters; // list of waiters, for now, CLI "show event"
        __decl_thread(HA_RWLOCK_T lock);
        int readers_count;
+       uint flags;          // RING_FL_*
 };
 
 #endif /* _HAPROXY_RING_T_H */

diff --git a/src/ring.c b/src/ring.c
index 8d0b704bbac4b376361dbd8c4a72bce1567ddda8..52df2a5cca8e39fa618c0560c5046d1005728563 100644 (file)
--- a/src/ring.c
+++ b/src/ring.c
@@ -43,6 +43,8 @@ void ring_init(struct ring *ring, void *area, size_t size)
        LIST_INIT(&ring->waiters);
        ring->readers_count = 0;
        ring->buf = b_make(area, size, 0, 0);
+       ring->flags = 0;
+
        /* write the initial RC byte */
        b_putchr(&ring->buf, 0);
 }
@@ -83,18 +85,23 @@ struct ring *ring_new(size_t size)
 struct ring *ring_make_from_area(void *area, size_t size)
 {
        struct ring *ring = NULL;
+       uint flags = 0;
 
        if (size < sizeof(*ring))
                return NULL;
 
        if (!area)
                area = malloc(size);
+       else
+               flags |= RING_FL_MAPPED;
+
        if (!area)
                return NULL;
 
        ring = area;
        area += sizeof(*ring);
        ring_init(ring, area, size - sizeof(*ring));
+       ring->flags |= flags;
        return ring;
 }
 
@@ -113,6 +120,7 @@ struct ring *ring_cast_from_area(void *area)
        HA_RWLOCK_INIT(&ring->lock);
        LIST_INIT(&ring->waiters);
        ring->readers_count = 0;
+       ring->flags = RING_FL_MAPPED;
 
        return ring;
 }
@@ -156,7 +164,7 @@ void ring_free(struct ring *ring)
                return;
 
        /* make sure it was not allocated by ring_make_from_area */
-       if (ring->buf.area == (void *)ring + sizeof(*ring))
+       if (ring->flags & RING_FL_MAPPED)
                return;
 
        free(ring_area(ring));