Decouple `struct lttng_session` from filter code

Use `struct lttng_ctx` directly so that the future event notifier
infrastructure, which will be outside any session, can use it.

Signed-off-by: Francis Deslauriers <francis.deslauriers@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: I84109a0c01636bc5206f43e7abdceee27124c520

diff --git a/include/lttng/ust-events.h b/include/lttng/ust-events.h
index 3fee93c435038acf3150759aa7d5c964bd38e448..66c7390b9e24100c7e0ff84b63bdee14cbc592d6 100644 (file)
--- a/include/lttng/ust-events.h
+++ b/include/lttng/ust-events.h
@@ -471,7 +471,11 @@ struct lttng_bytecode_runtime {
        uint64_t (*filter)(void *filter_data, const char *filter_stack_data);
        int link_failed;
        struct cds_list_head node;      /* list of bytecode runtime in event */
-       struct lttng_session *session;
+       /*
+        * Pointer to a `struct lttng_session`-owned and URCU-protected
+        * pointer.
+        */
+       struct lttng_ctx **pctx;
 };
 
 /*

diff --git a/liblttng-ust/lttng-filter-interpreter.c b/liblttng-ust/lttng-filter-interpreter.c
index 6c42b20f1c790838f69fb6c6e1605a8419283f3a..49daa211e1a59b3e24d59bfa00faceda9de2115b 100644 (file)
--- a/liblttng-ust/lttng-filter-interpreter.c
+++ b/liblttng-ust/lttng-filter-interpreter.c
@@ -370,7 +370,7 @@ static int context_get_index(struct lttng_ctx *ctx,
        return 0;
 }
 
-static int dynamic_get_index(struct lttng_session *session,
+static int dynamic_get_index(struct lttng_ctx *ctx,
                struct bytecode_runtime *runtime,
                uint64_t index, struct estack_entry *stack_top)
 {
@@ -437,9 +437,6 @@ static int dynamic_get_index(struct lttng_session *session,
        case LOAD_ROOT_CONTEXT:
        case LOAD_ROOT_APP_CONTEXT:     /* Fall-through */
        {
-               struct lttng_ctx *ctx;
-
-               ctx = rcu_dereference(session->ctx);
                ret = context_get_index(ctx,
                                &stack_top->u.ptr,
                                gid->ctx_index);
@@ -634,7 +631,7 @@ uint64_t lttng_filter_interpret_bytecode(void *filter_data,
                const char *filter_stack_data)
 {
        struct bytecode_runtime *bytecode = filter_data;
-       struct lttng_session *session = bytecode->p.session;
+       struct lttng_ctx *ctx = rcu_dereference(*bytecode->p.pctx);
        void *pc, *next_pc, *start_pc;
        int ret = -EINVAL;
        uint64_t retval = 0;
@@ -2013,13 +2010,11 @@ uint64_t lttng_filter_interpret_bytecode(void *filter_data,
                {
                        struct load_op *insn = (struct load_op *) pc;
                        struct field_ref *ref = (struct field_ref *) insn->data;
-                       struct lttng_ctx *ctx;
                        struct lttng_ctx_field *ctx_field;
                        struct lttng_ctx_value v;
 
                        dbg_printf("get context ref offset %u type dynamic\n",
                                ref->offset);
-                       ctx = rcu_dereference(session->ctx);
                        ctx_field = &ctx->fields[ref->offset];
                        ctx_field->get_value(ctx_field, &v);
                        estack_push(stack, top, ax, bx, ax_t, bx_t);
@@ -2063,13 +2058,11 @@ uint64_t lttng_filter_interpret_bytecode(void *filter_data,
                {
                        struct load_op *insn = (struct load_op *) pc;
                        struct field_ref *ref = (struct field_ref *) insn->data;
-                       struct lttng_ctx *ctx;
                        struct lttng_ctx_field *ctx_field;
                        struct lttng_ctx_value v;
 
                        dbg_printf("get context ref offset %u type string\n",
                                ref->offset);
-                       ctx = rcu_dereference(session->ctx);
                        ctx_field = &ctx->fields[ref->offset];
                        ctx_field->get_value(ctx_field, &v);
                        estack_push(stack, top, ax, bx, ax_t, bx_t);
@@ -2092,13 +2085,11 @@ uint64_t lttng_filter_interpret_bytecode(void *filter_data,
                {
                        struct load_op *insn = (struct load_op *) pc;
                        struct field_ref *ref = (struct field_ref *) insn->data;
-                       struct lttng_ctx *ctx;
                        struct lttng_ctx_field *ctx_field;
                        struct lttng_ctx_value v;
 
                        dbg_printf("get context ref offset %u type s64\n",
                                ref->offset);
-                       ctx = rcu_dereference(session->ctx);
                        ctx_field = &ctx->fields[ref->offset];
                        ctx_field->get_value(ctx_field, &v);
                        estack_push(stack, top, ax, bx, ax_t, bx_t);
@@ -2113,13 +2104,11 @@ uint64_t lttng_filter_interpret_bytecode(void *filter_data,
                {
                        struct load_op *insn = (struct load_op *) pc;
                        struct field_ref *ref = (struct field_ref *) insn->data;
-                       struct lttng_ctx *ctx;
                        struct lttng_ctx_field *ctx_field;
                        struct lttng_ctx_value v;
 
                        dbg_printf("get context ref offset %u type double\n",
                                ref->offset);
-                       ctx = rcu_dereference(session->ctx);
                        ctx_field = &ctx->fields[ref->offset];
                        ctx_field->get_value(ctx_field, &v);
                        estack_push(stack, top, ax, bx, ax_t, bx_t);
@@ -2205,7 +2194,7 @@ uint64_t lttng_filter_interpret_bytecode(void *filter_data,
                        struct get_index_u16 *index = (struct get_index_u16 *) insn->data;
 
                        dbg_printf("op get index u16\n");
-                       ret = dynamic_get_index(session, bytecode, index->index, estack_ax(stack, top));
+                       ret = dynamic_get_index(ctx, bytecode, index->index, estack_ax(stack, top));
                        if (ret)
                                goto end;
                        estack_ax_v = estack_ax(stack, top)->u.v;
@@ -2220,7 +2209,7 @@ uint64_t lttng_filter_interpret_bytecode(void *filter_data,
                        struct get_index_u64 *index = (struct get_index_u64 *) insn->data;
 
                        dbg_printf("op get index u64\n");
-                       ret = dynamic_get_index(session, bytecode, index->index, estack_ax(stack, top));
+                       ret = dynamic_get_index(ctx, bytecode, index->index, estack_ax(stack, top));
                        if (ret)
                                goto end;
                        estack_ax_v = estack_ax(stack, top)->u.v;

diff --git a/liblttng-ust/lttng-filter-specialize.c b/liblttng-ust/lttng-filter-specialize.c
index ba46a103a253ae5b045660c1780a053e61eb344e..0a19896b43038fa11dc4120e1f469998bc40b3a0 100644 (file)
--- a/liblttng-ust/lttng-filter-specialize.c
+++ b/liblttng-ust/lttng-filter-specialize.c
@@ -507,7 +507,7 @@ static int specialize_load_object(const struct lttng_event_field *field,
        return 0;
 }
 
-static int specialize_context_lookup(struct lttng_session *session,
+static int specialize_context_lookup(struct lttng_ctx *ctx,
                struct bytecode_runtime *runtime,
                struct load_op *insn,
                struct vstack_load *load)
@@ -518,11 +518,11 @@ static int specialize_context_lookup(struct lttng_session *session,
        struct filter_get_index_data gid;
        ssize_t data_offset;
 
-       idx = specialize_context_lookup_name(session->ctx, runtime, insn);
+       idx = specialize_context_lookup_name(ctx, runtime, insn);
        if (idx < 0) {
                return -ENOENT;
        }
-       ctx_field = &session->ctx->fields[idx];
+       ctx_field = &ctx->fields[idx];
        field = &ctx_field->event_field;
        ret = specialize_load_object(field, load, true);
        if (ret)
@@ -541,7 +541,7 @@ static int specialize_context_lookup(struct lttng_session *session,
        return 0;
 }
 
-static int specialize_app_context_lookup(struct lttng_session *session,
+static int specialize_app_context_lookup(struct lttng_ctx **pctx,
                struct bytecode_runtime *runtime,
                struct load_op *insn,
                struct vstack_load *load)
@@ -564,19 +564,18 @@ static int specialize_app_context_lookup(struct lttng_session *session,
        }
        strcpy(name, "$app.");
        strcat(name, orig_name);
-       idx = lttng_get_context_index(session->ctx, name);
+       idx = lttng_get_context_index(*pctx, name);
        if (idx < 0) {
                assert(lttng_context_is_app(name));
                ret = lttng_ust_add_app_context_to_ctx_rcu(name,
-                               &session->ctx);
+                               pctx);
                if (ret)
                        return ret;
-               idx = lttng_get_context_index(session->ctx,
-                       name);
+               idx = lttng_get_context_index(*pctx, name);
                if (idx < 0)
                        return -ENOENT;
        }
-       ctx_field = &session->ctx->fields[idx];
+       ctx_field = &(*pctx)->fields[idx];
        field = &ctx_field->event_field;
        ret = specialize_load_object(field, load, true);
        if (ret)
@@ -685,7 +684,7 @@ int lttng_filter_specialize_bytecode(struct lttng_event *event,
        int ret = -EINVAL;
        struct vstack _stack;
        struct vstack *stack = &_stack;
-       struct lttng_session *session = bytecode->p.session;
+       struct lttng_ctx **pctx = bytecode->p.pctx;
 
        vstack_init(stack);
 
@@ -1412,7 +1411,7 @@ int lttng_filter_specialize_bytecode(struct lttng_event *event,
                                goto end;
                        case LOAD_ROOT_CONTEXT:
                                /* Lookup context field. */
-                               ret = specialize_context_lookup(session,
+                               ret = specialize_context_lookup(*pctx,
                                        bytecode, insn,
                                        &vstack_ax(stack)->load);
                                if (ret)
@@ -1420,7 +1419,7 @@ int lttng_filter_specialize_bytecode(struct lttng_event *event,
                                break;
                        case LOAD_ROOT_APP_CONTEXT:
                                /* Lookup app context field. */
-                               ret = specialize_app_context_lookup(session,
+                               ret = specialize_app_context_lookup(pctx,
                                        bytecode, insn,
                                        &vstack_ax(stack)->load);
                                if (ret)

diff --git a/liblttng-ust/lttng-filter.c b/liblttng-ust/lttng-filter.c
index bbc212892342f988041b025577de506eeaf0e029..7dbe6f26e85c38667e872b7da94064ea06c94555 100644 (file)
--- a/liblttng-ust/lttng-filter.c
+++ b/liblttng-ust/lttng-filter.c
@@ -300,22 +300,21 @@ int apply_context_reloc(struct lttng_event *event,
        struct load_op *op;
        struct lttng_ctx_field *ctx_field;
        int idx;
-       struct lttng_session *session = runtime->p.session;
+       struct lttng_ctx *ctx = *runtime->p.pctx;
 
        dbg_printf("Apply context reloc: %u %s\n", reloc_offset, context_name);
 
        /* Get context index */
-       idx = lttng_get_context_index(session->ctx, context_name);
+       idx = lttng_get_context_index(ctx, context_name);
        if (idx < 0) {
                if (lttng_context_is_app(context_name)) {
                        int ret;
 
                        ret = lttng_ust_add_app_context_to_ctx_rcu(context_name,
-                                       &session->ctx);
+                                       &ctx);
                        if (ret)
                                return ret;
-                       idx = lttng_get_context_index(session->ctx,
-                               context_name);
+                       idx = lttng_get_context_index(ctx, context_name);
                        if (idx < 0)
                                return -ENOENT;
                } else {
@@ -327,7 +326,7 @@ int apply_context_reloc(struct lttng_event *event,
                return -EINVAL;
 
        /* Get context return type */
-       ctx_field = &session->ctx->fields[idx];
+       ctx_field = &ctx->fields[idx];
        op = (struct load_op *) &runtime->code[reloc_offset];
 
        switch (filter_op) {
@@ -449,7 +448,7 @@ int _lttng_filter_event_link_bytecode(struct lttng_event *event,
                goto alloc_error;
        }
        runtime->p.bc = filter_bytecode;
-       runtime->p.session = event->chan->session;
+       runtime->p.pctx = &event->chan->session->ctx;
        runtime->len = filter_bytecode->bc.reloc_offset;
        /* copy original bytecode */
        memcpy(runtime->code, filter_bytecode->bc.data, runtime->len);
@@ -569,13 +568,19 @@ int lttng_filter_enabler_attach_bytecode(struct lttng_enabler *enabler,
        return 0;
 }
 
-void lttng_free_event_filter_runtime(struct lttng_event *event)
+static
+void free_filter_runtime(struct cds_list_head *bytecode_runtime_head)
 {
        struct bytecode_runtime *runtime, *tmp;
 
-       cds_list_for_each_entry_safe(runtime, tmp,
-                       &event->bytecode_runtime_head, p.node) {
+       cds_list_for_each_entry_safe(runtime, tmp, bytecode_runtime_head,
+                       p.node) {
                free(runtime->data);
                free(runtime);
        }
 }
+
+void lttng_free_event_filter_runtime(struct lttng_event *event)
+{
+       free_filter_runtime(&event->bytecode_runtime_head);
+}