Calculate context length outside of retry loop

[lttng-ust.git] / liblttng-ust / lttng-ring-buffer-client.h

diff --git a/liblttng-ust/lttng-ring-buffer-client.h b/liblttng-ust/lttng-ring-buffer-client.h
index 6ed067105d8e7fd0f8a280e3f09caa0375186836..2f67799e19feb676cb0da2b9eef26e5f74a2c0a3 100644 (file)
--- a/liblttng-ust/lttng-ring-buffer-client.h
+++ b/liblttng-ust/lttng-ring-buffer-client.h
@@ -69,6 +69,10 @@ struct packet_header {
        } ctx;
 };
 
+struct lttng_client_ctx {
+       size_t packet_context_len;
+       size_t event_context_len;
+};
 
 static inline uint64_t lib_ring_buffer_clock_read(struct channel *chan)
 {
@@ -76,15 +80,29 @@ static inline uint64_t lib_ring_buffer_clock_read(struct channel *chan)
 }
 
 static inline
-size_t ctx_get_size(size_t offset, struct lttng_ctx *ctx,
-               enum app_ctx_mode mode)
+size_t ctx_get_aligned_size(size_t offset, struct lttng_ctx *ctx,
+               size_t ctx_len)
 {
-       int i;
        size_t orig_offset = offset;
 
        if (caa_likely(!ctx))
                return 0;
        offset += lib_ring_buffer_align(offset, ctx->largest_align);
+       offset += ctx_len;
+       return offset - orig_offset;
+}
+
+static inline
+void ctx_get_struct_size(struct lttng_ctx *ctx, size_t *ctx_len,
+               enum app_ctx_mode mode)
+{
+       int i;
+       size_t offset = 0;
+
+       if (caa_likely(!ctx)) {
+               *ctx_len = 0;
+               return;
+       }
        for (i = 0; i < ctx->nr_fields; i++) {
                if (mode == APP_CTX_ENABLED) {
                        offset += ctx->fields[i].get_size(&ctx->fields[i], offset);
@@ -106,7 +124,7 @@ size_t ctx_get_size(size_t offset, struct lttng_ctx *ctx,
                        }
                }
        }
-       return offset - orig_offset;
+       *ctx_len = offset;
 }
 
 static inline
@@ -160,7 +178,8 @@ static __inline__
 size_t record_header_size(const struct lttng_ust_lib_ring_buffer_config *config,
                                 struct channel *chan, size_t offset,
                                 size_t *pre_header_padding,
-                                struct lttng_ust_lib_ring_buffer_ctx *ctx)
+                                struct lttng_ust_lib_ring_buffer_ctx *ctx,
+                                struct lttng_client_ctx *client_ctx)
 {
        struct lttng_channel *lttng_chan = channel_get_private(chan);
        struct lttng_event *event = ctx->priv;
@@ -205,12 +224,16 @@ size_t record_header_size(const struct lttng_ust_lib_ring_buffer_config *config,
        }
        if (lttng_ctx) {
                /* 2.8+ probe ABI. */
-               offset += ctx_get_size(offset, lttng_ctx->chan_ctx, APP_CTX_ENABLED);
-               offset += ctx_get_size(offset, lttng_ctx->event_ctx, APP_CTX_ENABLED);
+               offset += ctx_get_aligned_size(offset, lttng_ctx->chan_ctx,
+                               client_ctx->packet_context_len);
+               offset += ctx_get_aligned_size(offset, lttng_ctx->event_ctx,
+                               client_ctx->event_context_len);
        } else {
                /* Pre 2.8 probe ABI. */
-               offset += ctx_get_size(offset, lttng_chan->ctx, APP_CTX_DISABLED);
-               offset += ctx_get_size(offset, event->ctx, APP_CTX_DISABLED);
+               offset += ctx_get_aligned_size(offset, lttng_chan->ctx,
+                               client_ctx->packet_context_len);
+               offset += ctx_get_aligned_size(offset, event->ctx,
+                               client_ctx->event_context_len);
        }
        *pre_header_padding = padding;
        return offset - orig_offset;
@@ -379,10 +402,11 @@ static
 size_t client_record_header_size(const struct lttng_ust_lib_ring_buffer_config *config,
                                 struct channel *chan, size_t offset,
                                 size_t *pre_header_padding,
-                                struct lttng_ust_lib_ring_buffer_ctx *ctx)
+                                struct lttng_ust_lib_ring_buffer_ctx *ctx,
+                                void *client_ctx)
 {
        return record_header_size(config, chan, offset,
-                                 pre_header_padding, ctx);
+                                 pre_header_padding, ctx, client_ctx);
 }
 
 /**
@@ -694,8 +718,27 @@ int lttng_event_reserve(struct lttng_ust_lib_ring_buffer_ctx *ctx,
                      uint32_t event_id)
 {
        struct lttng_channel *lttng_chan = channel_get_private(ctx->chan);
+       struct lttng_event *event = ctx->priv;
+       struct lttng_stack_ctx *lttng_ctx = ctx->priv2;
+       struct lttng_client_ctx client_ctx;
        int ret, cpu;
 
+       /* Compute internal size of context structures. */
+
+       if (lttng_ctx) {
+               /* 2.8+ probe ABI. */
+               ctx_get_struct_size(lttng_ctx->chan_ctx, &client_ctx.packet_context_len,
+                               APP_CTX_ENABLED);
+               ctx_get_struct_size(lttng_ctx->event_ctx, &client_ctx.event_context_len,
+                               APP_CTX_ENABLED);
+       } else {
+               /* Pre 2.8 probe ABI. */
+               ctx_get_struct_size(lttng_chan->ctx, &client_ctx.packet_context_len,
+                               APP_CTX_DISABLED);
+               ctx_get_struct_size(event->ctx, &client_ctx.event_context_len,
+                               APP_CTX_DISABLED);
+       }
+
        cpu = lib_ring_buffer_get_cpu(&client_config);
        if (cpu < 0)
                return -EPERM;
@@ -714,7 +757,7 @@ int lttng_event_reserve(struct lttng_ust_lib_ring_buffer_ctx *ctx,
                WARN_ON_ONCE(1);
        }
 
-       ret = lib_ring_buffer_reserve(&client_config, ctx);
+       ret = lib_ring_buffer_reserve(&client_config, ctx, &client_ctx);
        if (caa_unlikely(ret))
                goto put;
        if (caa_likely(ctx->ctx_len