Ring buffer: use shmp (shared-memory pointers) for per-channel shm structures

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

diff --git a/libringbuffer/frontend_types.h b/libringbuffer/frontend_types.h
index c9f98cb79810dd9385e578da5f520c60e8582340..d1a3d200be7130076805a2c0ef019b6054bf281f 100644 (file)
--- a/libringbuffer/frontend_types.h
+++ b/libringbuffer/frontend_types.h
@@ -16,6 +16,8 @@
  * Dual LGPL v2.1/GPL v2 license.
  */
 
+#include <string.h>
+
 #include <urcu/list.h>
 #include <urcu/uatomic.h>
 #include <urcu/ref.h>
@@ -25,6 +27,7 @@
 #include "usterr_signal_safe.h"
 #include "config.h"
 #include "backend_types.h"
+#include "shm.h"
 
 /*
  * A switch is done during tracing or as a final flush after tracing (so it
@@ -49,24 +52,25 @@ struct channel {
        //wait_queue_head_t read_wait;          /* reader wait queue */
        int finalized;                          /* Has channel been finalized */
        struct urcu_ref ref;                    /* Reference count */
-};
+       DECLARE_SHMP(struct shm_header, shm_header);
+} ____cacheline_aligned;
 
 /* Per-subbuffer commit counters used on the hot path */
 struct commit_counters_hot {
        union v_atomic cc;              /* Commit counter */
        union v_atomic seq;             /* Consecutive commits */
-};
+} ____cacheline_aligned;
 
 /* Per-subbuffer commit counters used only on cold paths */
 struct commit_counters_cold {
        union v_atomic cc_sb;           /* Incremented _once_ at sb switch */
-};
+} ____cacheline_aligned;
 
 /* ring buffer state */
 struct lib_ring_buffer {
        /* First 32 bytes cache-hot cacheline */
        union v_atomic offset;          /* Current offset in the buffer */
-       struct commit_counters_hot *commit_hot;
+       DECLARE_SHMP(struct commit_counters_hot, commit_hot);
                                        /* Commit count per sub-buffer */
        long consumed;                  /*
                                         * Current offset in the buffer
@@ -80,7 +84,7 @@ struct lib_ring_buffer {
 
        struct lib_ring_buffer_backend backend; /* Associated backend */
 
-       struct commit_counters_cold *commit_cold;
+       DECLARE_SHMP(struct commit_counters_cold, commit_cold);
                                        /* Commit count per sub-buffer */
        long active_readers;            /*
                                         * Active readers count
@@ -102,7 +106,7 @@ struct lib_ring_buffer {
        int get_subbuf:1;               /* Sub-buffer being held by reader */
        int switch_timer_enabled:1;     /* Protected by ring_buffer_nohz_lock */
        int read_timer_enabled:1;       /* Protected by ring_buffer_nohz_lock */
-};
+} ____cacheline_aligned;
 
 static inline
 void *channel_get_private(struct channel *chan)