fls: use local namespace to do not clash with FreeBSD string.h

[lttng-ust.git] / libringbuffer / backend_internal.h

diff --git a/libringbuffer/backend_internal.h b/libringbuffer/backend_internal.h
index e3192be7f224e8dadf2a424b5e243ee8a0c182a2..c9ed81be0e5b5c559ba8de23846a6052ecc8ddea 100644 (file)
--- a/libringbuffer/backend_internal.h
+++ b/libringbuffer/backend_internal.h
@@ -32,7 +32,7 @@ void lib_ring_buffer_backend_free(struct lttng_ust_lib_ring_buffer_backend *bufb
 int channel_backend_init(struct channel_backend *chanb,
                         const char *name,
                         const struct lttng_ust_lib_ring_buffer_config *config,
-                        void *priv, size_t subbuf_size,
+                        size_t subbuf_size,
                         size_t num_subbuf, struct lttng_ust_shm_handle *handle);
 void channel_backend_free(struct channel_backend *chanb,
                          struct lttng_ust_shm_handle *handle);
@@ -416,6 +416,10 @@ int update_read_sb_index(const struct lttng_ust_lib_ring_buffer_config *config,
        return 0;
 }
 
+#ifndef inline_memcpy
+#define inline_memcpy(dest, src, n)    memcpy(dest, src, n)
+#endif
+
 /*
  * Use the architecture-specific memcpy implementation for constant-sized
  * inputs, but rely on an inline memcpy for length statically unknown.
@@ -430,4 +434,61 @@ do {                                                               \
                inline_memcpy(dest, src, __len);                \
 } while (0)
 
+/* arch-agnostic implementation */
+
+static inline int lttng_ust_fls(unsigned int x)
+{
+       int r = 32;
+
+       if (!x)
+               return 0;
+       if (!(x & 0xFFFF0000U)) {
+               x <<= 16;
+               r -= 16;
+       }
+       if (!(x & 0xFF000000U)) {
+               x <<= 8;
+               r -= 8;
+       }
+       if (!(x & 0xF0000000U)) {
+               x <<= 4;
+               r -= 4;
+       }
+       if (!(x & 0xC0000000U)) {
+               x <<= 2;
+               r -= 2;
+       }
+       if (!(x & 0x80000000U)) {
+               x <<= 1;
+               r -= 1;
+       }
+       return r;
+}
+
+static inline int get_count_order(unsigned int count)
+{
+       int order;
+
+       order = lttng_ust_fls(count) - 1;
+       if (count & (count - 1))
+               order++;
+       return order;
+}
+
+static inline
+unsigned int hweight32(unsigned int value)
+{
+       unsigned int r;
+
+       r = value;
+       r = r - ((r >> 1) & 0x55555555);
+       r = (r & 0x33333333) + ((r >> 2) & 0x33333333);
+       r += r >> 4;
+       r &= 0x0F0F0F0F;
+       r += r >> 8;
+       r += r >> 16;
+       r &= 0x000000FF;
+       return r;
+}
+
 #endif /* _LINUX_RING_BUFFER_BACKEND_INTERNAL_H */