Close stream and channel file descriptors as soon as passed to sessiond
[lttng-ust.git] / libringbuffer / ring_buffer_frontend.c
index 436e4b8c89981e5ebe7b2dffb679b43fbd521c54..d0649f3e36b9e33b0e1b247854fd6a2c000f714a 100644 (file)
 #include <fcntl.h>
 #include <urcu/compiler.h>
 #include <urcu/ref.h>
+#include <helper.h>
 
 #include "smp.h"
 #include <lttng/ringbuffer-config.h>
+#include "vatomic.h"
 #include "backend.h"
 #include "frontend.h"
 #include "shm.h"
@@ -83,26 +85,15 @@ struct switch_offsets {
 
 __thread unsigned int lib_ring_buffer_nesting;
 
+/*
+ * TODO: this is unused. Errors are saved within the ring buffer.
+ * Eventually, allow consumerd to print these errors.
+ */
 static
 void lib_ring_buffer_print_errors(struct channel *chan,
                                  struct lttng_ust_lib_ring_buffer *buf, int cpu,
                                  struct lttng_ust_shm_handle *handle);
 
-/*
- * Must be called under cpu hotplug protection.
- */
-void lib_ring_buffer_free(struct lttng_ust_lib_ring_buffer *buf,
-                         struct lttng_ust_shm_handle *handle)
-{
-       struct channel *chan = shmp(handle, buf->backend.chan);
-
-       lib_ring_buffer_print_errors(chan, buf, buf->backend.cpu, handle);
-       /* buf->commit_hot will be freed by shm teardown */
-       /* buf->commit_cold will be freed by shm teardown */
-
-       lib_ring_buffer_backend_free(&buf->backend);
-}
-
 /**
  * lib_ring_buffer_reset - Reset ring buffer to initial values.
  * @buf: Ring buffer.
@@ -174,10 +165,9 @@ int lib_ring_buffer_create(struct lttng_ust_lib_ring_buffer *buf,
 {
        const struct lttng_ust_lib_ring_buffer_config *config = &chanb->config;
        struct channel *chan = caa_container_of(chanb, struct channel, backend);
-       void *priv = chanb->priv;
-       unsigned int num_subbuf;
+       void *priv = channel_get_private(chan);
        size_t subbuf_header_size;
-       u64 tsc;
+       uint64_t tsc;
        int ret;
 
        /* Test for cpu hotplug */
@@ -207,9 +197,6 @@ int lib_ring_buffer_create(struct lttng_ust_lib_ring_buffer *buf,
                goto free_commit;
        }
 
-       num_subbuf = chan->backend.num_subbuf;
-       //init_waitqueue_head(&buf->read_wait);
-
        /*
         * Write the subbuffer header for first subbuffer so we know the total
         * duration of data gathering.
@@ -235,7 +222,6 @@ free_init:
 free_commit:
        /* commit_hot will be freed by shm teardown */
 free_chanbuf:
-       lib_ring_buffer_backend_free(&buf->backend);
        return ret;
 }
 
@@ -409,7 +395,9 @@ static void channel_free(struct channel *chan, struct lttng_ust_shm_handle *hand
  * channel_create - Create channel.
  * @config: ring buffer instance configuration
  * @name: name of the channel
- * @priv: ring buffer client private data
+ * @priv_data: ring buffer client private data area pointer (output)
+ * @priv_data_size: length, in bytes, of the private data area.
+ * @priv_data_init: initialization data for private data.
  * @buf_addr: pointer the the beginning of the preallocated buffer contiguous
  *            address mapping. It is used only by RING_BUFFER_STATIC
  *            configuration. It can be set to NULL for other backends.
@@ -424,14 +412,18 @@ static void channel_free(struct channel *chan, struct lttng_ust_shm_handle *hand
  * Returns NULL on failure.
  */
 struct lttng_ust_shm_handle *channel_create(const struct lttng_ust_lib_ring_buffer_config *config,
-                  const char *name, void *priv, void *buf_addr,
-                  size_t subbuf_size,
+                  const char *name,
+                  void **priv_data,
+                  size_t priv_data_align,
+                  size_t priv_data_size,
+                  void *priv_data_init,
+                  void *buf_addr, size_t subbuf_size,
                   size_t num_subbuf, unsigned int switch_timer_interval,
                   unsigned int read_timer_interval,
-                  int *shm_fd, int *wait_fd, uint64_t *memory_map_size)
+                  int **shm_fd, int **wait_fd, uint64_t **memory_map_size)
 {
        int ret, cpu;
-       size_t shmsize;
+       size_t shmsize, chansize;
        struct channel *chan;
        struct lttng_ust_shm_handle *handle;
        struct shm_object *shmobj;
@@ -457,19 +449,38 @@ struct lttng_ust_shm_handle *channel_create(const struct lttng_ust_lib_ring_buff
                shmsize += sizeof(struct lttng_ust_lib_ring_buffer_shmp) * num_possible_cpus();
        else
                shmsize += sizeof(struct lttng_ust_lib_ring_buffer_shmp);
+       chansize = shmsize;
+       shmsize += offset_align(shmsize, priv_data_align);
+       shmsize += priv_data_size;
 
        shmobj = shm_object_table_append(handle->table, shmsize);
        if (!shmobj)
                goto error_append;
        /* struct channel is at object 0, offset 0 (hardcoded) */
-       set_shmp(handle->chan, zalloc_shm(shmobj, shmsize));
+       set_shmp(handle->chan, zalloc_shm(shmobj, chansize));
        assert(handle->chan._ref.index == 0);
        assert(handle->chan._ref.offset == 0);
        chan = shmp(handle, handle->chan);
        if (!chan)
                goto error_append;
 
-       ret = channel_backend_init(&chan->backend, name, config, priv,
+       /* space for private data */
+       if (priv_data_size) {
+               DECLARE_SHMP(void, priv_data_alloc);
+
+               align_shm(shmobj, priv_data_align);
+               chan->priv_data_offset = shmobj->allocated_len;
+               set_shmp(priv_data_alloc, zalloc_shm(shmobj, priv_data_size));
+               if (!shmp(handle, priv_data_alloc))
+                       goto error_append;
+               *priv_data = channel_get_private(chan);
+               memcpy(*priv_data, priv_data_init, priv_data_size);
+       } else {
+               chan->priv_data_offset = -1;
+               *priv_data = NULL;
+       }
+
+       ret = channel_backend_init(&chan->backend, name, config,
                                   subbuf_size, num_subbuf, handle);
        if (ret)
                goto error_backend_init;
@@ -570,74 +581,37 @@ void channel_release(struct channel *chan, struct lttng_ust_shm_handle *handle,
  * Call "destroy" callback, finalize channels, decrement the channel
  * reference count. Note that when readers have completed data
  * consumption of finalized channels, get_subbuf() will return -ENODATA.
- * They should release their handle at that point.  Returns the private
- * data pointer.
+ * They should release their handle at that point. 
  */
-void *channel_destroy(struct channel *chan, struct lttng_ust_shm_handle *handle,
+void channel_destroy(struct channel *chan, struct lttng_ust_shm_handle *handle,
                int shadow)
 {
-       const struct lttng_ust_lib_ring_buffer_config *config = &chan->backend.config;
-       void *priv;
-       int cpu;
-
        if (shadow) {
                channel_release(chan, handle, shadow);
-               return NULL;
+               return;
        }
 
        channel_unregister_notifiers(chan, handle);
 
-       if (config->alloc == RING_BUFFER_ALLOC_PER_CPU) {
-               for_each_channel_cpu(cpu, chan) {
-                       struct lttng_ust_lib_ring_buffer *buf = shmp(handle, chan->backend.buf[cpu].shmp);
-
-                       if (config->cb.buffer_finalize)
-                               config->cb.buffer_finalize(buf,
-                                                          chan->backend.priv,
-                                                          cpu, handle);
-                       if (buf->backend.allocated)
-                               lib_ring_buffer_switch_slow(buf, SWITCH_FLUSH,
-                                               handle);
-                       /*
-                        * Perform flush before writing to finalized.
-                        */
-                       cmm_smp_wmb();
-                       CMM_ACCESS_ONCE(buf->finalized) = 1;
-                       //wake_up_interruptible(&buf->read_wait);
-               }
-       } else {
-               struct lttng_ust_lib_ring_buffer *buf = shmp(handle, chan->backend.buf[0].shmp);
+       /*
+        * Note: the consumer takes care of finalizing and switching the
+        * buffers.
+        */
 
-               if (config->cb.buffer_finalize)
-                       config->cb.buffer_finalize(buf, chan->backend.priv, -1, handle);
-               if (buf->backend.allocated)
-                       lib_ring_buffer_switch_slow(buf, SWITCH_FLUSH,
-                                               handle);
-               /*
-                * Perform flush before writing to finalized.
-                */
-               cmm_smp_wmb();
-               CMM_ACCESS_ONCE(buf->finalized) = 1;
-               //wake_up_interruptible(&buf->read_wait);
-       }
-       CMM_ACCESS_ONCE(chan->finalized) = 1;
-       //wake_up_interruptible(&chan->hp_wait);
-       //wake_up_interruptible(&chan->read_wait);
        /*
         * sessiond/consumer are keeping a reference on the shm file
         * descriptor directly. No need to refcount.
         */
-       priv = chan->backend.priv;
        channel_release(chan, handle, shadow);
-       return priv;
+       return;
 }
 
 struct lttng_ust_lib_ring_buffer *channel_get_ring_buffer(
                                        const struct lttng_ust_lib_ring_buffer_config *config,
                                        struct channel *chan, int cpu,
                                        struct lttng_ust_shm_handle *handle,
-                                       int *shm_fd, int *wait_fd,
-                                       uint64_t *memory_map_size)
+                                       int **shm_fd, int **wait_fd,
+                                       uint64_t **memory_map_size)
 {
        struct shm_ref *ref;
 
@@ -951,7 +925,7 @@ void lib_ring_buffer_print_subbuffer_errors(struct lttng_ust_lib_ring_buffer *bu
        commit_count_sb = v_read(config, &shmp_index(handle, buf->commit_cold, cons_idx)->cc_sb);
 
        if (subbuf_offset(commit_count, chan) != 0)
-               ERRMSG("ring buffer %s, cpu %d: "
+               DBG("ring buffer %s, cpu %d: "
                       "commit count in subbuffer %lu,\n"
                       "expecting multiples of %lu bytes\n"
                       "  [ %lu bytes committed, %lu bytes reader-visible ]\n",
@@ -959,7 +933,7 @@ void lib_ring_buffer_print_subbuffer_errors(struct lttng_ust_lib_ring_buffer *bu
                       chan->backend.subbuf_size,
                       commit_count, commit_count_sb);
 
-       ERRMSG("ring buffer: %s, cpu %d: %lu bytes committed\n",
+       DBG("ring buffer: %s, cpu %d: %lu bytes committed\n",
               chan->backend.name, cpu, commit_count);
 }
 
@@ -972,12 +946,6 @@ void lib_ring_buffer_print_buffer_errors(struct lttng_ust_lib_ring_buffer *buf,
        const struct lttng_ust_lib_ring_buffer_config *config = &chan->backend.config;
        unsigned long write_offset, cons_offset;
 
-       /*
-        * Can be called in the error path of allocation when
-        * trans_channel_data is not yet set.
-        */
-       if (!chan)
-               return;
        /*
         * No need to order commit_count, write_offset and cons_offset reads
         * because we execute at teardown when no more writer nor reader
@@ -986,7 +954,7 @@ void lib_ring_buffer_print_buffer_errors(struct lttng_ust_lib_ring_buffer *buf,
        write_offset = v_read(config, &buf->offset);
        cons_offset = uatomic_read(&buf->consumed);
        if (write_offset != cons_offset)
-               ERRMSG("ring buffer %s, cpu %d: "
+               DBG("ring buffer %s, cpu %d: "
                       "non-consumed data\n"
                       "  [ %lu bytes written, %lu bytes read ]\n",
                       chan->backend.name, cpu, write_offset, cons_offset);
@@ -1006,9 +974,9 @@ void lib_ring_buffer_print_errors(struct channel *chan,
                                  struct lttng_ust_shm_handle *handle)
 {
        const struct lttng_ust_lib_ring_buffer_config *config = &chan->backend.config;
-       void *priv = chan->backend.priv;
+       void *priv = channel_get_private(chan);
 
-       ERRMSG("ring buffer %s, cpu %d: %lu records written, "
+       DBG("ring buffer %s, cpu %d: %lu records written, "
                          "%lu records overrun\n",
                          chan->backend.name, cpu,
                          v_read(config, &buf->records_count),
@@ -1017,7 +985,7 @@ void lib_ring_buffer_print_errors(struct channel *chan,
        if (v_read(config, &buf->records_lost_full)
            || v_read(config, &buf->records_lost_wrap)
            || v_read(config, &buf->records_lost_big))
-               ERRMSG("ring buffer %s, cpu %d: records were lost. Caused by:\n"
+               DBG("ring buffer %s, cpu %d: records were lost. Caused by:\n"
                       "  [ %lu buffer full, %lu nest buffer wrap-around, "
                       "%lu event too big ]\n",
                       chan->backend.name, cpu,
@@ -1037,7 +1005,7 @@ static
 void lib_ring_buffer_switch_old_start(struct lttng_ust_lib_ring_buffer *buf,
                                      struct channel *chan,
                                      struct switch_offsets *offsets,
-                                     u64 tsc,
+                                     uint64_t tsc,
                                      struct lttng_ust_shm_handle *handle)
 {
        const struct lttng_ust_lib_ring_buffer_config *config = &chan->backend.config;
@@ -1075,7 +1043,7 @@ static
 void lib_ring_buffer_switch_old_end(struct lttng_ust_lib_ring_buffer *buf,
                                    struct channel *chan,
                                    struct switch_offsets *offsets,
-                                   u64 tsc,
+                                   uint64_t tsc,
                                    struct lttng_ust_shm_handle *handle)
 {
        const struct lttng_ust_lib_ring_buffer_config *config = &chan->backend.config;
@@ -1112,7 +1080,7 @@ static
 void lib_ring_buffer_switch_new_start(struct lttng_ust_lib_ring_buffer *buf,
                                      struct channel *chan,
                                      struct switch_offsets *offsets,
-                                     u64 tsc,
+                                     uint64_t tsc,
                                      struct lttng_ust_shm_handle *handle)
 {
        const struct lttng_ust_lib_ring_buffer_config *config = &chan->backend.config;
@@ -1148,7 +1116,7 @@ static
 void lib_ring_buffer_switch_new_end(struct lttng_ust_lib_ring_buffer *buf,
                                    struct channel *chan,
                                    struct switch_offsets *offsets,
-                                   u64 tsc,
+                                   uint64_t tsc,
                                    struct lttng_ust_shm_handle *handle)
 {
        const struct lttng_ust_lib_ring_buffer_config *config = &chan->backend.config;
@@ -1184,7 +1152,7 @@ int lib_ring_buffer_try_switch_slow(enum switch_mode mode,
                                    struct lttng_ust_lib_ring_buffer *buf,
                                    struct channel *chan,
                                    struct switch_offsets *offsets,
-                                   u64 *tsc)
+                                   uint64_t *tsc)
 {
        const struct lttng_ust_lib_ring_buffer_config *config = &chan->backend.config;
        unsigned long off;
@@ -1249,7 +1217,7 @@ void lib_ring_buffer_switch_slow(struct lttng_ust_lib_ring_buffer *buf, enum swi
        const struct lttng_ust_lib_ring_buffer_config *config = &chan->backend.config;
        struct switch_offsets offsets;
        unsigned long oldidx;
-       u64 tsc;
+       uint64_t tsc;
 
        offsets.size = 0;
 
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