Version 2.4.4
[lttng-modules.git] / lttng-ring-buffer-client.h
index 1a04520c6d83ee6ee9026640c50f59a2374b215e..7055e770734e52a6f339f3c6b78e1c7913f07a1d 100644 (file)
@@ -1,11 +1,23 @@
 /*
  * lttng-ring-buffer-client.h
  *
- * Copyright (C) 2010 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
- *
  * LTTng lib ring buffer client template.
  *
- * Dual LGPL v2.1/GPL v2 license.
+ * Copyright (C) 2010-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; only
+ * version 2.1 of the License.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
 #include <linux/module.h>
 #include "lttng-tracer.h"
 #include "wrapper/ringbuffer/frontend_types.h"
 
+#define LTTNG_COMPACT_EVENT_BITS       5
+#define LTTNG_COMPACT_TSC_BITS         27
+
+static struct lttng_transport lttng_relay_transport;
+
 /*
  * Keep the natural field alignment for _each field_ within this structure if
  * you ever add/remove a field from this header. Packed attribute is not used
@@ -45,13 +62,13 @@ struct packet_header {
                /* Stream packet context */
                uint64_t timestamp_begin;       /* Cycle count at subbuffer start */
                uint64_t timestamp_end;         /* Cycle count at subbuffer end */
-               uint32_t events_discarded;      /*
+               uint64_t content_size;          /* Size of data in subbuffer */
+               uint64_t packet_size;           /* Subbuffer size (include padding) */
+               unsigned long events_discarded; /*
                                                 * Events lost in this subbuffer since
                                                 * the beginning of the trace.
                                                 * (may overflow)
                                                 */
-               uint32_t content_size;          /* Size of data in subbuffer */
-               uint32_t packet_size;           /* Subbuffer size (include padding) */
                uint32_t cpu_id;                /* CPU id associated with stream */
                uint8_t header_end;             /* End of header */
        } ctx;
@@ -71,6 +88,7 @@ size_t ctx_get_size(size_t offset, struct lttng_ctx *ctx)
 
        if (likely(!ctx))
                return 0;
+       offset += lib_ring_buffer_align(offset, ctx->largest_align);
        for (i = 0; i < ctx->nr_fields; i++)
                offset += ctx->fields[i].get_size(offset);
        return offset - orig_offset;
@@ -85,6 +103,7 @@ void ctx_record(struct lib_ring_buffer_ctx *bufctx,
 
        if (likely(!ctx))
                return;
+       lib_ring_buffer_align_ctx(bufctx, ctx->largest_align);
        for (i = 0; i < ctx->nr_fields; i++)
                ctx->fields[i].record(&ctx->fields[i], bufctx, chan);
 }
@@ -120,8 +139,8 @@ unsigned char record_header_size(const struct lib_ring_buffer_config *config,
                if (!(ctx->rflags & (RING_BUFFER_RFLAG_FULL_TSC | LTTNG_RFLAG_EXTENDED))) {
                        offset += sizeof(uint32_t);     /* id and timestamp */
                } else {
-                       /* Minimum space taken by 5-bit id */
-                       offset += sizeof(uint8_t);
+                       /* Minimum space taken by LTTNG_COMPACT_EVENT_BITS id */
+                       offset += (LTTNG_COMPACT_EVENT_BITS + CHAR_BIT - 1) / CHAR_BIT;
                        /* Align extended struct on largest member */
                        offset += lib_ring_buffer_align(offset, lttng_alignof(uint64_t));
                        offset += sizeof(uint32_t);     /* id */
@@ -187,8 +206,14 @@ void lttng_write_event_header(const struct lib_ring_buffer_config *config,
        {
                uint32_t id_time = 0;
 
-               bt_bitfield_write(&id_time, uint32_t, 0, 5, event_id);
-               bt_bitfield_write(&id_time, uint32_t, 5, 27, ctx->tsc);
+               bt_bitfield_write(&id_time, uint32_t,
+                               0,
+                               LTTNG_COMPACT_EVENT_BITS,
+                               event_id);
+               bt_bitfield_write(&id_time, uint32_t,
+                               LTTNG_COMPACT_EVENT_BITS,
+                               LTTNG_COMPACT_TSC_BITS,
+                               ctx->tsc);
                lib_ring_buffer_write(config, ctx, &id_time, sizeof(id_time));
                break;
        }
@@ -229,14 +254,22 @@ void lttng_write_event_header_slow(const struct lib_ring_buffer_config *config,
                if (!(ctx->rflags & (RING_BUFFER_RFLAG_FULL_TSC | LTTNG_RFLAG_EXTENDED))) {
                        uint32_t id_time = 0;
 
-                       bt_bitfield_write(&id_time, uint32_t, 0, 5, event_id);
-                       bt_bitfield_write(&id_time, uint32_t, 5, 27, ctx->tsc);
+                       bt_bitfield_write(&id_time, uint32_t,
+                                       0,
+                                       LTTNG_COMPACT_EVENT_BITS,
+                                       event_id);
+                       bt_bitfield_write(&id_time, uint32_t,
+                                       LTTNG_COMPACT_EVENT_BITS,
+                                       LTTNG_COMPACT_TSC_BITS, ctx->tsc);
                        lib_ring_buffer_write(config, ctx, &id_time, sizeof(id_time));
                } else {
                        uint8_t id = 0;
                        uint64_t timestamp = ctx->tsc;
 
-                       bt_bitfield_write(&id, uint8_t, 0, 5, 31);
+                       bt_bitfield_write(&id, uint8_t,
+                                       0,
+                                       LTTNG_COMPACT_EVENT_BITS,
+                                       31);
                        lib_ring_buffer_write(config, ctx, &id, sizeof(id));
                        /* Align extended struct on largest member */
                        lib_ring_buffer_align_ctx(ctx, lttng_alignof(uint64_t));
@@ -320,9 +353,9 @@ static void client_buffer_begin(struct lib_ring_buffer *buf, u64 tsc,
        header->stream_id = lttng_chan->id;
        header->ctx.timestamp_begin = tsc;
        header->ctx.timestamp_end = 0;
+       header->ctx.content_size = ~0ULL; /* for debugging */
+       header->ctx.packet_size = ~0ULL;
        header->ctx.events_discarded = 0;
-       header->ctx.content_size = 0xFFFFFFFF; /* for debugging */
-       header->ctx.packet_size = 0xFFFFFFFF;
        header->ctx.cpu_id = buf->backend.cpu;
 }
 
@@ -341,8 +374,10 @@ static void client_buffer_end(struct lib_ring_buffer *buf, u64 tsc,
        unsigned long records_lost = 0;
 
        header->ctx.timestamp_end = tsc;
-       header->ctx.content_size = data_size * CHAR_BIT;        /* in bits */
-       header->ctx.packet_size = PAGE_ALIGN(data_size) * CHAR_BIT; /* in bits */
+       header->ctx.content_size =
+               (uint64_t) data_size * CHAR_BIT;                /* in bits */
+       header->ctx.packet_size =
+               (uint64_t) PAGE_ALIGN(data_size) * CHAR_BIT;    /* in bits */
        records_lost += lib_ring_buffer_get_records_lost_full(&client_config, buf);
        records_lost += lib_ring_buffer_get_records_lost_wrap(&client_config, buf);
        records_lost += lib_ring_buffer_get_records_lost_big(&client_config, buf);
@@ -359,6 +394,82 @@ static void client_buffer_finalize(struct lib_ring_buffer *buf, void *priv, int
 {
 }
 
+static struct packet_header *client_packet_header(
+               const struct lib_ring_buffer_config *config,
+               struct lib_ring_buffer *buf)
+{
+       return lib_ring_buffer_read_offset_address(&buf->backend, 0);
+}
+
+static int client_timestamp_begin(const struct lib_ring_buffer_config *config,
+               struct lib_ring_buffer *buf,
+               uint64_t *timestamp_begin)
+{
+       struct packet_header *header = client_packet_header(config, buf);
+       *timestamp_begin = header->ctx.timestamp_begin;
+
+       return 0;
+}
+
+static int client_timestamp_end(const struct lib_ring_buffer_config *config,
+                       struct lib_ring_buffer *buf,
+                       uint64_t *timestamp_end)
+{
+       struct packet_header *header = client_packet_header(config, buf);
+       *timestamp_end = header->ctx.timestamp_end;
+
+       return 0;
+}
+
+static int client_events_discarded(const struct lib_ring_buffer_config *config,
+                       struct lib_ring_buffer *buf,
+                       uint64_t *events_discarded)
+{
+       struct packet_header *header = client_packet_header(config, buf);
+       *events_discarded = header->ctx.events_discarded;
+
+       return 0;
+}
+
+static int client_content_size(const struct lib_ring_buffer_config *config,
+                       struct lib_ring_buffer *buf,
+                       uint64_t *content_size)
+{
+       struct packet_header *header = client_packet_header(config, buf);
+       *content_size = header->ctx.content_size;
+
+       return 0;
+}
+
+static int client_packet_size(const struct lib_ring_buffer_config *config,
+                       struct lib_ring_buffer *buf,
+                       uint64_t *packet_size)
+{
+       struct packet_header *header = client_packet_header(config, buf);
+       *packet_size = header->ctx.packet_size;
+
+       return 0;
+}
+
+static int client_stream_id(const struct lib_ring_buffer_config *config,
+                       struct lib_ring_buffer *buf,
+                       uint64_t *stream_id)
+{
+       struct packet_header *header = client_packet_header(config, buf);
+       *stream_id = header->stream_id;
+
+       return 0;
+}
+
+static int client_current_timestamp(const struct lib_ring_buffer_config *config,
+               struct lib_ring_buffer *bufb,
+               uint64_t *ts)
+{
+       *ts = config->cb.ring_buffer_clock_read(bufb->backend.chan);
+
+       return 0;
+}
+
 static const struct lib_ring_buffer_config client_config = {
        .cb.ring_buffer_clock_read = client_ring_buffer_clock_read,
        .cb.record_header_size = client_record_header_size,
@@ -368,7 +479,7 @@ static const struct lib_ring_buffer_config client_config = {
        .cb.buffer_create = client_buffer_create,
        .cb.buffer_finalize = client_buffer_finalize,
 
-       .tsc_bits = 32,
+       .tsc_bits = LTTNG_COMPACT_TSC_BITS,
        .alloc = RING_BUFFER_ALLOC_PER_CPU,
        .sync = RING_BUFFER_SYNC_PER_CPU,
        .mode = RING_BUFFER_MODE_TEMPLATE,
@@ -379,6 +490,18 @@ static const struct lib_ring_buffer_config client_config = {
        .wakeup = RING_BUFFER_WAKEUP_BY_TIMER,
 };
 
+static
+void release_priv_ops(void *priv_ops)
+{
+       module_put(THIS_MODULE);
+}
+
+static
+void lttng_channel_destroy(struct channel *chan)
+{
+       channel_destroy(chan);
+}
+
 static
 struct channel *_channel_create(const char *name,
                                struct lttng_channel *lttng_chan, void *buf_addr,
@@ -386,15 +509,28 @@ struct channel *_channel_create(const char *name,
                                unsigned int switch_timer_interval,
                                unsigned int read_timer_interval)
 {
-       return channel_create(&client_config, name, lttng_chan, buf_addr,
+       struct channel *chan;
+
+       chan = channel_create(&client_config, name, lttng_chan, buf_addr,
                              subbuf_size, num_subbuf, switch_timer_interval,
                              read_timer_interval);
-}
+       if (chan) {
+               /*
+                * Ensure this module is not unloaded before we finish
+                * using lttng_relay_transport.ops.
+                */
+               if (!try_module_get(THIS_MODULE)) {
+                       printk(KERN_WARNING "LTT : Can't lock transport module.\n");
+                       goto error;
+               }
+               chan->backend.priv_ops = &lttng_relay_transport.ops;
+               chan->backend.release_priv_ops = release_priv_ops;
+       }
+       return chan;
 
-static
-void lttng_channel_destroy(struct channel *chan)
-{
-       channel_destroy(chan);
+error:
+       lttng_channel_destroy(chan);
+       return NULL;
 }
 
 static
@@ -484,7 +620,7 @@ static
 void lttng_event_write_from_user(struct lib_ring_buffer_ctx *ctx,
                               const void __user *src, size_t len)
 {
-       lib_ring_buffer_copy_from_user(&client_config, ctx, src, len);
+       lib_ring_buffer_copy_from_user_inatomic(&client_config, ctx, src, len);
 }
 
 static
@@ -494,6 +630,21 @@ void lttng_event_memset(struct lib_ring_buffer_ctx *ctx,
        lib_ring_buffer_memset(&client_config, ctx, c, len);
 }
 
+static
+void lttng_event_strcpy(struct lib_ring_buffer_ctx *ctx, const char *src,
+               size_t len)
+{
+       lib_ring_buffer_strcpy(&client_config, ctx, src, len, '#');
+}
+
+static
+void lttng_event_strcpy_from_user(struct lib_ring_buffer_ctx *ctx,
+               const char __user *src, size_t len)
+{
+       lib_ring_buffer_strcpy_from_user_inatomic(&client_config, ctx, src,
+                       len, '#');
+}
+
 static
 wait_queue_head_t *lttng_get_writer_buf_wait_queue(struct channel *chan, int cpu)
 {
@@ -535,11 +686,20 @@ static struct lttng_transport lttng_relay_transport = {
                .event_write = lttng_event_write,
                .event_write_from_user = lttng_event_write_from_user,
                .event_memset = lttng_event_memset,
+               .event_strcpy = lttng_event_strcpy,
+               .event_strcpy_from_user = lttng_event_strcpy_from_user,
                .packet_avail_size = NULL,      /* Would be racy anyway */
                .get_writer_buf_wait_queue = lttng_get_writer_buf_wait_queue,
                .get_hp_wait_queue = lttng_get_hp_wait_queue,
                .is_finalized = lttng_is_finalized,
                .is_disabled = lttng_is_disabled,
+               .timestamp_begin = client_timestamp_begin,
+               .timestamp_end = client_timestamp_end,
+               .events_discarded = client_events_discarded,
+               .content_size = client_content_size,
+               .packet_size = client_packet_size,
+               .stream_id = client_stream_id,
+               .current_timestamp = client_current_timestamp,
        },
 };
 
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