ring buffer context: cpu number becomes an output of reserve

[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 4fbfc709a19d9e8f834384aef54c0cbe3bbad2bb..4e2b86a2d6c7ccbef220ed50e0fc1d4730dff0fb 100644 (file)
--- a/liblttng-ust/lttng-ring-buffer-client.h
+++ b/liblttng-ust/lttng-ring-buffer-client.h
@@ -10,6 +10,7 @@
 #include <stdint.h>
 
 #include <ust-events-internal.h>
+#include <lttng/urcu/pointer.h>
 #include "ust-bitfield.h"
 #include "ust-compat.h"
 #include "clock.h"
@@ -62,6 +63,8 @@ struct packet_header {
 struct lttng_client_ctx {
        size_t packet_context_len;
        size_t event_context_len;
+       struct lttng_ust_ctx *chan_ctx;
+       struct lttng_ust_ctx *event_ctx;
 };
 
 static inline uint64_t lib_ring_buffer_clock_read(struct lttng_ust_lib_ring_buffer_channel *chan)
@@ -173,7 +176,6 @@ size_t record_header_size(const struct lttng_ust_lib_ring_buffer_config *config,
                                 struct lttng_client_ctx *client_ctx)
 {
        struct lttng_ust_channel_buffer *lttng_chan = channel_get_private(chan);
-       struct lttng_ust_stack_ctx *lttng_ctx = ctx->priv;
        size_t orig_offset = offset;
        size_t padding;
 
@@ -212,9 +214,9 @@ size_t record_header_size(const struct lttng_ust_lib_ring_buffer_config *config,
                padding = 0;
                WARN_ON_ONCE(1);
        }
-       offset += ctx_get_aligned_size(offset, lttng_ctx->chan_ctx,
+       offset += ctx_get_aligned_size(offset, client_ctx->chan_ctx,
                        client_ctx->packet_context_len);
-       offset += ctx_get_aligned_size(offset, lttng_ctx->event_ctx,
+       offset += ctx_get_aligned_size(offset, client_ctx->event_ctx,
                        client_ctx->event_context_len);
        *pre_header_padding = padding;
        return offset - orig_offset;
@@ -226,6 +228,7 @@ size_t record_header_size(const struct lttng_ust_lib_ring_buffer_config *config,
 static
 void lttng_write_event_header_slow(const struct lttng_ust_lib_ring_buffer_config *config,
                                 struct lttng_ust_lib_ring_buffer_ctx *ctx,
+                                struct lttng_client_ctx *client_ctx,
                                 uint32_t event_id);
 
 /*
@@ -240,10 +243,10 @@ void lttng_write_event_header_slow(const struct lttng_ust_lib_ring_buffer_config
 static __inline__
 void lttng_write_event_header(const struct lttng_ust_lib_ring_buffer_config *config,
                            struct lttng_ust_lib_ring_buffer_ctx *ctx,
+                           struct lttng_client_ctx *client_ctx,
                            uint32_t event_id)
 {
        struct lttng_ust_channel_buffer *lttng_chan = channel_get_private(ctx->chan);
-       struct lttng_ust_stack_ctx *lttng_ctx = ctx->priv;
 
        if (caa_unlikely(ctx->rflags))
                goto slow_path;
@@ -278,23 +281,23 @@ void lttng_write_event_header(const struct lttng_ust_lib_ring_buffer_config *con
                WARN_ON_ONCE(1);
        }
 
-       ctx_record(ctx, lttng_chan, lttng_ctx->chan_ctx, APP_CTX_ENABLED);
-       ctx_record(ctx, lttng_chan, lttng_ctx->event_ctx, APP_CTX_ENABLED);
+       ctx_record(ctx, lttng_chan, client_ctx->chan_ctx, APP_CTX_ENABLED);
+       ctx_record(ctx, lttng_chan, client_ctx->event_ctx, APP_CTX_ENABLED);
        lib_ring_buffer_align_ctx(ctx, ctx->largest_align);
 
        return;
 
 slow_path:
-       lttng_write_event_header_slow(config, ctx, event_id);
+       lttng_write_event_header_slow(config, ctx, client_ctx, event_id);
 }
 
 static
 void lttng_write_event_header_slow(const struct lttng_ust_lib_ring_buffer_config *config,
                                 struct lttng_ust_lib_ring_buffer_ctx *ctx,
+                                struct lttng_client_ctx *client_ctx,
                                 uint32_t event_id)
 {
        struct lttng_ust_channel_buffer *lttng_chan = channel_get_private(ctx->chan);
-       struct lttng_ust_stack_ctx *lttng_ctx = ctx->priv;
 
        switch (lttng_chan->priv->header_type) {
        case 1: /* compact */
@@ -351,8 +354,8 @@ void lttng_write_event_header_slow(const struct lttng_ust_lib_ring_buffer_config
        default:
                WARN_ON_ONCE(1);
        }
-       ctx_record(ctx, lttng_chan, lttng_ctx->chan_ctx, APP_CTX_ENABLED);
-       ctx_record(ctx, lttng_chan, lttng_ctx->event_ctx, APP_CTX_ENABLED);
+       ctx_record(ctx, lttng_chan, client_ctx->chan_ctx, APP_CTX_ENABLED);
+       ctx_record(ctx, lttng_chan, client_ctx->event_ctx, APP_CTX_ENABLED);
        lib_ring_buffer_align_ctx(ctx, ctx->largest_align);
 }
 
@@ -694,19 +697,20 @@ int lttng_event_reserve(struct lttng_ust_lib_ring_buffer_ctx *ctx,
 {
        struct lttng_ust_channel_buffer *lttng_chan = channel_get_private(ctx->chan);
        struct lttng_ust_stack_ctx *lttng_ctx = ctx->priv;
+       struct lttng_ust_event_recorder *event_recorder = lttng_ctx->event_recorder;
        struct lttng_client_ctx client_ctx;
-       int ret, cpu;
+       int ret;
 
+       client_ctx.chan_ctx = lttng_ust_rcu_dereference(lttng_chan->priv->ctx);
+       client_ctx.event_ctx = lttng_ust_rcu_dereference(event_recorder->priv->ctx);
        /* Compute internal size of context structures. */
-       ctx_get_struct_size(lttng_ctx->chan_ctx, &client_ctx.packet_context_len,
+       ctx_get_struct_size(client_ctx.chan_ctx, &client_ctx.packet_context_len,
                        APP_CTX_ENABLED);
-       ctx_get_struct_size(lttng_ctx->event_ctx, &client_ctx.event_context_len,
+       ctx_get_struct_size(client_ctx.event_ctx, &client_ctx.event_context_len,
                        APP_CTX_ENABLED);
 
-       cpu = lib_ring_buffer_get_cpu(&client_config);
-       if (cpu < 0)
+       if (lib_ring_buffer_nesting_inc(&client_config) < 0)
                return -EPERM;
-       ctx->cpu = cpu;
 
        switch (lttng_chan->priv->header_type) {
        case 1: /* compact */
@@ -729,10 +733,10 @@ int lttng_event_reserve(struct lttng_ust_lib_ring_buffer_ctx *ctx,
                ret = -EPERM;
                goto put;
        }
-       lttng_write_event_header(&client_config, ctx, event_id);
+       lttng_write_event_header(&client_config, ctx, &client_ctx, event_id);
        return 0;
 put:
-       lib_ring_buffer_put_cpu(&client_config);
+       lib_ring_buffer_nesting_dec(&client_config);
        return ret;
 }
 
@@ -740,7 +744,7 @@ static
 void lttng_event_commit(struct lttng_ust_lib_ring_buffer_ctx *ctx)
 {
        lib_ring_buffer_commit(&client_config, ctx);
-       lib_ring_buffer_put_cpu(&client_config);
+       lib_ring_buffer_nesting_dec(&client_config);
 }
 
 static
@@ -757,6 +761,13 @@ void lttng_event_strcpy(struct lttng_ust_lib_ring_buffer_ctx *ctx, const char *s
        lib_ring_buffer_strcpy(&client_config, ctx, src, len, '#');
 }
 
+static
+void lttng_event_pstrcpy_pad(struct lttng_ust_lib_ring_buffer_ctx *ctx,
+                    const char *src, size_t len)
+{
+       lib_ring_buffer_pstrcpy(&client_config, ctx, src, len, '\0');
+}
+
 #if 0
 static
 wait_queue_head_t *lttng_get_reader_wait_queue(struct lttng_ust_lib_ring_buffer_channel *chan)
@@ -806,8 +817,8 @@ int lttng_flush_buffer(struct lttng_ust_lib_ring_buffer_channel *chan,
 static struct lttng_transport lttng_relay_transport = {
        .name = "relay-" RING_BUFFER_MODE_TEMPLATE_STRING "-mmap",
        .ops = {
-               .struct_size = sizeof(struct lttng_ust_channel_ops),
-               .priv = __LTTNG_COMPOUND_LITERAL(struct lttng_ust_channel_ops_private, {
+               .struct_size = sizeof(struct lttng_ust_channel_buffer_ops),
+               .priv = __LTTNG_COMPOUND_LITERAL(struct lttng_ust_channel_buffer_ops_private, {
                        .pub = &lttng_relay_transport.ops,
                        .channel_create = _channel_create,
                        .channel_destroy = lttng_channel_destroy,
@@ -820,6 +831,7 @@ static struct lttng_transport lttng_relay_transport = {
                .event_commit = lttng_event_commit,
                .event_write = lttng_event_write,
                .event_strcpy = lttng_event_strcpy,
+               .event_pstrcpy_pad = lttng_event_pstrcpy_pad,
        },
        .client_config = &client_config,
 };