Decouple `struct lttng_event` from filter code

The filter infrastructure will be used by event notifiers and decoupling
this will allow for massive code reuse.

Of all `struct lttng_event`'s fields, filter code needs:
  1. The `const struct lttng_event_desc *desc` field,
  2. The `struct cds_list_head bytecode_runtime_head` list.

These fields are used to do the tracepoint field relocation
(`apply_field_reloc()` and `specialize_event_payload_lookup()`).

Given that only these two fields are needed, we can pass them directly
to these functions.

Signed-off-by: Francis Deslauriers <francis.deslauriers@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: I25cb6fba5ba3cb74dbc4ee9f1fa1026171a6599a

diff --git a/liblttng-ust/lttng-events.c b/liblttng-ust/lttng-events.c
index 0c684df2f3f6759d9930c2317926dce2853ae7a9..02e6704e4f2fd8464841a6c20567149bf1a6701b 100644 (file)
--- a/liblttng-ust/lttng-events.c
+++ b/liblttng-ust/lttng-events.c
@@ -977,7 +977,10 @@ int lttng_event_enabler_ref_events(struct lttng_event_enabler *event_enabler)
                /*
                 * Link filter bytecodes if not linked yet.
                 */
-               lttng_event_enabler_link_bytecode(event, event_enabler);
+               lttng_enabler_link_bytecode(event->desc,
+                       &session->ctx,
+                       &event->bytecode_runtime_head,
+                       lttng_event_enabler_as_enabler(event_enabler));
 
                /* TODO: merge event context. */
        }

diff --git a/liblttng-ust/lttng-filter-specialize.c b/liblttng-ust/lttng-filter-specialize.c
index d4f8a957f51ff191f348121008a8cc3c9800ceb5..b7ab6158cb4f8cbff6001095a927f1f16eeb9a7d 100644 (file)
--- a/liblttng-ust/lttng-filter-specialize.c
+++ b/liblttng-ust/lttng-filter-specialize.c
@@ -599,14 +599,13 @@ end:
        return ret;
 }
 
-static int specialize_event_payload_lookup(struct lttng_event *event,
+static int specialize_payload_lookup(const struct lttng_event_desc *event_desc,
                struct bytecode_runtime *runtime,
                struct load_op *insn,
                struct vstack_load *load)
 {
        const char *name;
        uint16_t offset;
-       const struct lttng_event_desc *desc = event->desc;
        unsigned int i, nr_fields;
        bool found = false;
        uint32_t field_offset = 0;
@@ -615,11 +614,11 @@ static int specialize_event_payload_lookup(struct lttng_event *event,
        struct filter_get_index_data gid;
        ssize_t data_offset;
 
-       nr_fields = desc->nr_fields;
+       nr_fields = event_desc->nr_fields;
        offset = ((struct get_symbol *) insn->data)->offset;
        name = runtime->p.bc->bc.data + runtime->p.bc->bc.reloc_offset + offset;
        for (i = 0; i < nr_fields; i++) {
-               field = &desc->fields[i];
+               field = &event_desc->fields[i];
                if (field->u.ext.nofilter) {
                        continue;
                }
@@ -678,7 +677,7 @@ end:
        return ret;
 }
 
-int lttng_filter_specialize_bytecode(struct lttng_event *event,
+int lttng_filter_specialize_bytecode(const struct lttng_event_desc *event_desc,
                struct bytecode_runtime *bytecode)
 {
        void *pc, *next_pc, *start_pc;
@@ -1428,7 +1427,7 @@ int lttng_filter_specialize_bytecode(struct lttng_event *event,
                                break;
                        case LOAD_ROOT_PAYLOAD:
                                /* Lookup event payload field. */
-                               ret = specialize_event_payload_lookup(event,
+                               ret = specialize_payload_lookup(event_desc,
                                        bytecode, insn,
                                        &vstack_ax(stack)->load);
                                if (ret)

diff --git a/liblttng-ust/lttng-filter.c b/liblttng-ust/lttng-filter.c
index e9774b489acfe4672270cbd1ff952827f9292558..5ee12d26e8fb9fa08c91c437652b7b31d2d46a57 100644 (file)
--- a/liblttng-ust/lttng-filter.c
+++ b/liblttng-ust/lttng-filter.c
@@ -188,14 +188,13 @@ const char *print_op(enum filter_op op)
 }
 
 static
-int apply_field_reloc(struct lttng_event *event,
+int apply_field_reloc(const struct lttng_event_desc *event_desc,
                struct bytecode_runtime *runtime,
                uint32_t runtime_len,
                uint32_t reloc_offset,
                const char *field_name,
                enum filter_op filter_op)
 {
-       const struct lttng_event_desc *desc;
        const struct lttng_event_field *fields, *field = NULL;
        unsigned int nr_fields, i;
        struct load_op *op;
@@ -204,13 +203,12 @@ int apply_field_reloc(struct lttng_event *event,
        dbg_printf("Apply field reloc: %u %s\n", reloc_offset, field_name);
 
        /* Lookup event by name */
-       desc = event->desc;
-       if (!desc)
+       if (!event_desc)
                return -EINVAL;
-       fields = desc->fields;
+       fields = event_desc->fields;
        if (!fields)
                return -EINVAL;
-       nr_fields = desc->nr_fields;
+       nr_fields = event_desc->nr_fields;
        for (i = 0; i < nr_fields; i++) {
                if (fields[i].u.ext.nofilter) {
                        continue;
@@ -291,8 +289,7 @@ int apply_field_reloc(struct lttng_event *event,
 }
 
 static
-int apply_context_reloc(struct lttng_event *event,
-               struct bytecode_runtime *runtime,
+int apply_context_reloc(struct bytecode_runtime *runtime,
                uint32_t runtime_len,
                uint32_t reloc_offset,
                const char *context_name,
@@ -370,7 +367,7 @@ int apply_context_reloc(struct lttng_event *event,
 }
 
 static
-int apply_reloc(struct lttng_event *event,
+int apply_reloc(const struct lttng_event_desc *event_desc,
                struct bytecode_runtime *runtime,
                uint32_t runtime_len,
                uint32_t reloc_offset,
@@ -387,10 +384,10 @@ int apply_reloc(struct lttng_event *event,
        op = (struct load_op *) &runtime->code[reloc_offset];
        switch (op->op) {
        case FILTER_OP_LOAD_FIELD_REF:
-               return apply_field_reloc(event, runtime, runtime_len,
+               return apply_field_reloc(event_desc, runtime, runtime_len,
                        reloc_offset, name, op->op);
        case FILTER_OP_GET_CONTEXT_REF:
-               return apply_context_reloc(event, runtime, runtime_len,
+               return apply_context_reloc(runtime, runtime_len,
                        reloc_offset, name, op->op);
        case FILTER_OP_GET_SYMBOL:
        case FILTER_OP_GET_SYMBOL_FIELD:
@@ -408,12 +405,11 @@ int apply_reloc(struct lttng_event *event,
 
 static
 int bytecode_is_linked(struct lttng_ust_filter_bytecode_node *filter_bytecode,
-               struct lttng_event *event)
+               struct cds_list_head *bytecode_runtime_head)
 {
        struct lttng_bytecode_runtime *bc_runtime;
 
-       cds_list_for_each_entry(bc_runtime,
-                       &event->bytecode_runtime_head, node) {
+       cds_list_for_each_entry(bc_runtime, bytecode_runtime_head, node) {
                if (bc_runtime->bc == filter_bytecode)
                        return 1;
        }
@@ -425,7 +421,8 @@ int bytecode_is_linked(struct lttng_ust_filter_bytecode_node *filter_bytecode,
  * bytecode runtime.
  */
 static
-int _lttng_filter_event_link_bytecode(struct lttng_event *event,
+int _lttng_filter_link_bytecode(const struct lttng_event_desc *event_desc,
+               struct lttng_ctx **ctx,
                struct lttng_ust_filter_bytecode_node *filter_bytecode,
                struct cds_list_head *insert_loc)
 {
@@ -436,7 +433,7 @@ int _lttng_filter_event_link_bytecode(struct lttng_event *event,
        if (!filter_bytecode)
                return 0;
        /* Bytecode already linked */
-       if (bytecode_is_linked(filter_bytecode, event))
+       if (bytecode_is_linked(filter_bytecode, insert_loc))
                return 0;
 
        dbg_printf("Linking...\n");
@@ -449,7 +446,7 @@ int _lttng_filter_event_link_bytecode(struct lttng_event *event,
                goto alloc_error;
        }
        runtime->p.bc = filter_bytecode;
-       runtime->p.pctx = &event->chan->session->ctx;
+       runtime->p.pctx = ctx;
        runtime->len = filter_bytecode->bc.reloc_offset;
        /* copy original bytecode */
        memcpy(runtime->code, filter_bytecode->bc.data, runtime->len);
@@ -465,7 +462,7 @@ int _lttng_filter_event_link_bytecode(struct lttng_event *event,
                const char *name =
                        (const char *) &filter_bytecode->bc.data[offset + sizeof(uint16_t)];
 
-               ret = apply_reloc(event, runtime, runtime->len, reloc_offset, name);
+               ret = apply_reloc(event_desc, runtime, runtime->len, reloc_offset, name);
                if (ret) {
                        goto link_error;
                }
@@ -477,7 +474,7 @@ int _lttng_filter_event_link_bytecode(struct lttng_event *event,
                goto link_error;
        }
        /* Specialize bytecode */
-       ret = lttng_filter_specialize_bytecode(event, runtime);
+       ret = lttng_filter_specialize_bytecode(event_desc, runtime);
        if (ret) {
                goto link_error;
        }
@@ -507,25 +504,25 @@ void lttng_filter_sync_state(struct lttng_bytecode_runtime *runtime)
 }
 
 /*
- * Link bytecode for all enablers referenced by an event.
+ * Link all bytecodes of the enabler referenced in the provided bytecode list.
  */
-void lttng_event_enabler_link_bytecode(struct lttng_event *event,
-               struct lttng_event_enabler *event_enabler)
+void lttng_enabler_link_bytecode(const struct lttng_event_desc *event_desc,
+               struct lttng_ctx **ctx,
+               struct cds_list_head *bytecode_runtime_head,
+               struct lttng_enabler *enabler)
 {
        struct lttng_ust_filter_bytecode_node *bc;
        struct lttng_bytecode_runtime *runtime;
-       struct lttng_enabler *base_enabler = lttng_event_enabler_as_enabler(event_enabler);
 
-       /* Can only be called for events with desc attached */
-       assert(event->desc);
+       assert(event_desc);
 
        /* Link each bytecode. */
-       cds_list_for_each_entry(bc, &base_enabler->filter_bytecode_head, node) {
+       cds_list_for_each_entry(bc, &enabler->filter_bytecode_head, node) {
                int found = 0, ret;
                struct cds_list_head *insert_loc;
 
                cds_list_for_each_entry(runtime,
-                               &event->bytecode_runtime_head, node) {
+                               bytecode_runtime_head, node) {
                        if (runtime->bc == bc) {
                                found = 1;
                                break;
@@ -541,19 +538,20 @@ void lttng_event_enabler_link_bytecode(struct lttng_event *event,
                 * insert the new bytecode right after it.
                 */
                cds_list_for_each_entry_reverse(runtime,
-                               &event->bytecode_runtime_head, node) {
+                               bytecode_runtime_head, node) {
                        if (runtime->bc->bc.seqnum <= bc->bc.seqnum) {
                                /* insert here */
                                insert_loc = &runtime->node;
                                goto add_within;
                        }
                }
+
                /* Add to head to list */
-               insert_loc = &event->bytecode_runtime_head;
+               insert_loc = bytecode_runtime_head;
        add_within:
                dbg_printf("linking bytecode\n");
-               ret = _lttng_filter_event_link_bytecode(event, bc,
-                               insert_loc);
+               ret = _lttng_filter_link_bytecode(event_desc, ctx, bc,
+                       insert_loc);
                if (ret) {
                        dbg_printf("[lttng filter] warning: cannot link event bytecode\n");
                }

diff --git a/liblttng-ust/lttng-filter.h b/liblttng-ust/lttng-filter.h
index cc15c1546fa469ae1f32871d8a74092662f990bf..f8e112932e3bebac723d77c69bc36351771d365c 100644 (file)
--- a/liblttng-ust/lttng-filter.h
+++ b/liblttng-ust/lttng-filter.h
@@ -291,7 +291,7 @@ struct estack {
 const char *print_op(enum filter_op op);
 
 int lttng_filter_validate_bytecode(struct bytecode_runtime *bytecode);
-int lttng_filter_specialize_bytecode(struct lttng_event *event,
+int lttng_filter_specialize_bytecode(const struct lttng_event_desc *event_desc,
                struct bytecode_runtime *bytecode);
 
 uint64_t lttng_filter_false(void *filter_data,

diff --git a/liblttng-ust/ust-events-internal.h b/liblttng-ust/ust-events-internal.h
index dbd998e8f6088ffde61e01f54469c61ee9312cbc..649fd21133f1ce7e197e91883945ad1484dd7806 100644 (file)
--- a/liblttng-ust/ust-events-internal.h
+++ b/liblttng-ust/ust-events-internal.h
@@ -136,7 +136,9 @@ int lttng_event_enabler_attach_exclusion(struct lttng_event_enabler *enabler,
  * each is linked to the provided event.
  */
 LTTNG_HIDDEN
-void lttng_event_enabler_link_bytecode(struct lttng_event *event,
-               struct lttng_event_enabler *enabler);
+void lttng_enabler_link_bytecode(const struct lttng_event_desc *event_desc,
+               struct lttng_ctx **ctx,
+               struct cds_list_head *bytecode_runtime_head,
+               struct lttng_enabler *enabler);
 
 #endif /* _LTTNG_UST_EVENTS_INTERNAL_H */