From 0c51e8f329cdd907761e34c3e4394200a56c6812 Mon Sep 17 00:00:00 2001 From: Simon Marchi Date: Mon, 2 Dec 2019 16:41:52 -0500 Subject: [PATCH] actions: introduce action group MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit This patch introduces action groups as a new kind of action. When creating a trigger, it is only possible to attach a single action. Action groups allow users to attach more than one action. A group is created using lttng_action_group_create. Actions are added to it using lttng_action_group_add_action. The group can then be used in a trigger, like any other action. The operations required to be implemented by actions (serialize, create_from_buffer, validate) are implemented by executing the operation on all elements. Current limitations are: - To avoid any cycle, it is not possible to add a group inside a group. Signed-off-by: Jonathan Rajotte Signed-off-by: Jérémie Galarneau Signed-off-by: Simon Marchi Change-Id: I2ae6aed21d9a6b45510d37a435773b1bd7d76528 --- include/Makefile.am | 2 + include/lttng/action/action.h | 1 + include/lttng/action/group-internal.h | 29 +++ include/lttng/action/group.h | 61 +++++ include/lttng/lttng.h | 1 + src/common/Makefile.am | 1 + src/common/actions/action.c | 6 + src/common/actions/group.c | 350 ++++++++++++++++++++++++++ src/common/actions/snapshot-session.c | 16 +- 9 files changed, 455 insertions(+), 12 deletions(-) create mode 100644 include/lttng/action/group-internal.h create mode 100644 include/lttng/action/group.h create mode 100644 src/common/actions/group.c diff --git a/include/Makefile.am b/include/Makefile.am index af89a3372..baad620dd 100644 --- a/include/Makefile.am +++ b/include/Makefile.am @@ -121,6 +121,7 @@ lttnginclude_HEADERS = \ lttngactioninclude_HEADERS= \ lttng/action/action.h \ + lttng/action/group.h \ lttng/action/notify.h \ lttng/action/rotate-session.h \ lttng/action/snapshot-session.h \ @@ -147,6 +148,7 @@ noinst_HEADERS = \ lttng/save-internal.h \ lttng/load-internal.h \ lttng/action/action-internal.h \ + lttng/action/group-internal.h \ lttng/action/notify-internal.h \ lttng/action/rotate-session-internal.h \ lttng/action/snapshot-session-internal.h \ diff --git a/include/lttng/action/action.h b/include/lttng/action/action.h index 3cd2460f8..1309f85bd 100644 --- a/include/lttng/action/action.h +++ b/include/lttng/action/action.h @@ -21,6 +21,7 @@ enum lttng_action_type { LTTNG_ACTION_TYPE_STOP_SESSION = 2, LTTNG_ACTION_TYPE_ROTATE_SESSION = 3, LTTNG_ACTION_TYPE_SNAPSHOT_SESSION = 4, + LTTNG_ACTION_TYPE_GROUP = 5, }; enum lttng_action_status { diff --git a/include/lttng/action/group-internal.h b/include/lttng/action/group-internal.h new file mode 100644 index 000000000..cddee55ed --- /dev/null +++ b/include/lttng/action/group-internal.h @@ -0,0 +1,29 @@ +/* + * Copyright (C) 2019 Simon Marchi + * + * SPDX-License-Identifier: LGPL-2.1-only + * + */ + +#ifndef LTTNG_ACTION_GROUP_INTERNAL_H +#define LTTNG_ACTION_GROUP_INTERNAL_H + +#include + +#include + +struct lttng_action; +struct lttng_payload_view; + +/* + * Create an action group from a payload view. + * + * On success, return the number of bytes consumed from `view`, and the created + * group in `*group`. On failure, return -1. + */ +LTTNG_HIDDEN +extern ssize_t lttng_action_group_create_from_payload( + struct lttng_payload_view *view, + struct lttng_action **group); + +#endif /* LTTNG_ACTION_GROUP_INTERNAL_H */ diff --git a/include/lttng/action/group.h b/include/lttng/action/group.h new file mode 100644 index 000000000..af1e73216 --- /dev/null +++ b/include/lttng/action/group.h @@ -0,0 +1,61 @@ +/* + * Copyright (C) 2019 Simon Marchi + * + * SPDX-License-Identifier: LGPL-2.1-only + * + */ + +#ifndef LTTNG_ACTION_GROUP_H +#define LTTNG_ACTION_GROUP_H + +struct lttng_action; +struct lttng_action_group; + +#ifdef __cplusplus +extern "C" { +#endif + +/* + * Create a newly allocated action group object. + * + * Returns a new action group on success, NULL on failure. This action group + * must be destroyed using lttng_action_group_destroy(). + */ +extern struct lttng_action *lttng_action_group_create(void); + +/* + * Add an action to an lttng_action object of type LTTNG_ACTION_GROUP. + * + * The action group acquires a reference to the action. The action can be + * safely destroyed after calling this function. An action must not be + * modified after adding it to a group. + * + * Adding an action group to an action group is not supported. + */ +extern enum lttng_action_status lttng_action_group_add_action( + struct lttng_action *group, struct lttng_action *action); + +/* + * Get the number of actions in an action group. + */ +extern enum lttng_action_status lttng_action_group_get_count( + const struct lttng_action *group, unsigned int *count); + +/* + * Get an action from the action group at a given index. + * + * Note that the group maintains the ownership of the returned action. + * It must not be destroyed by the user, nor should it be held beyond + * the lifetime of the action group. + * + * Returns an action, or NULL on error. + */ +extern const struct lttng_action *lttng_action_group_get_at_index( + const struct lttng_action *group, + unsigned int index); + +#ifdef __cplusplus +} +#endif + +#endif /* LTTNG_ACTION_GROUP_H */ diff --git a/include/lttng/lttng.h b/include/lttng/lttng.h index f22fad553..6746d7bbf 100644 --- a/include/lttng/lttng.h +++ b/include/lttng/lttng.h @@ -17,6 +17,7 @@ /* Include every LTTng ABI/API available. */ #include +#include #include #include #include diff --git a/src/common/Makefile.am b/src/common/Makefile.am index f8a207534..32b28c82f 100644 --- a/src/common/Makefile.am +++ b/src/common/Makefile.am @@ -28,6 +28,7 @@ EXTRA_DIST = mi-lttng-4.0.xsd libcommon_la_SOURCES = \ actions/action.c \ + actions/group.c \ actions/notify.c \ actions/rotate-session.c \ actions/snapshot-session.c \ diff --git a/src/common/actions/action.c b/src/common/actions/action.c index 1a541ce46..a0347a34c 100644 --- a/src/common/actions/action.c +++ b/src/common/actions/action.c @@ -8,6 +8,7 @@ #include #include #include +#include #include #include #include @@ -19,6 +20,8 @@ static const char *lttng_action_type_string(enum lttng_action_type action_type) switch (action_type) { case LTTNG_ACTION_TYPE_UNKNOWN: return "UNKNOWN"; + case LTTNG_ACTION_TYPE_GROUP: + return "GROUP"; case LTTNG_ACTION_TYPE_NOTIFY: return "NOTIFY"; case LTTNG_ACTION_TYPE_ROTATE_SESSION: @@ -176,6 +179,9 @@ ssize_t lttng_action_create_from_payload(struct lttng_payload_view *view, create_from_payload_cb = lttng_action_stop_session_create_from_payload; break; + case LTTNG_ACTION_TYPE_GROUP: + create_from_payload_cb = lttng_action_group_create_from_payload; + break; default: ERR("Failed to create action from payload, unhandled action type: action-type=%u (%s)", action_comm->action_type, diff --git a/src/common/actions/group.c b/src/common/actions/group.c new file mode 100644 index 000000000..5931eb38b --- /dev/null +++ b/src/common/actions/group.c @@ -0,0 +1,350 @@ +/* + * Copyright (C) 2019 Simon Marchi + * + * SPDX-License-Identifier: LGPL-2.1-only + * + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define IS_GROUP_ACTION(action) \ + (lttng_action_get_type_const(action) == LTTNG_ACTION_TYPE_GROUP) + +struct lttng_action_group { + struct lttng_action parent; + + /* The array owns the action elements. */ + struct lttng_dynamic_pointer_array actions; +}; + +struct lttng_action_group_comm { + uint32_t action_count; + + /* + * Variable data: each element serialized sequentially. + */ + char data[]; +} LTTNG_PACKED; + +static void destroy_lttng_action_group_element(void *ptr) +{ + struct lttng_action *element = (struct lttng_action *) ptr; + + lttng_action_destroy(element); +} + +static struct lttng_action_group *action_group_from_action( + const struct lttng_action *action) +{ + assert(action); + + return container_of(action, struct lttng_action_group, parent); +} + +static const struct lttng_action_group *action_group_from_action_const( + const struct lttng_action *action) +{ + assert(action); + + return container_of(action, struct lttng_action_group, parent); +} + +static bool lttng_action_group_validate(struct lttng_action *action) +{ + unsigned int i, count; + struct lttng_action_group *action_group; + bool valid; + + assert(IS_GROUP_ACTION(action)); + + action_group = action_group_from_action(action); + + count = lttng_dynamic_pointer_array_get_count(&action_group->actions); + + for (i = 0; i < count; i++) { + struct lttng_action *child = + lttng_dynamic_pointer_array_get_pointer( + &action_group->actions, i); + + assert(child); + + if (!lttng_action_validate(child)) { + valid = false; + goto end; + } + } + + valid = true; + +end: + return valid; +} + +static bool lttng_action_group_is_equal( + const struct lttng_action *_a, const struct lttng_action *_b) +{ + bool is_equal = false; + unsigned int i; + unsigned int a_count, b_count; + + if (lttng_action_group_get_count(_a, &a_count) != + LTTNG_ACTION_STATUS_OK) { + goto end; + } + + if (lttng_action_group_get_count(_b, &b_count) != + LTTNG_ACTION_STATUS_OK) { + goto end; + } + + if (a_count != b_count) { + goto end; + } + + for (i = 0; i < a_count; i++) { + const struct lttng_action *child_a = + lttng_action_group_get_at_index(_a, i); + const struct lttng_action *child_b = + lttng_action_group_get_at_index(_b, i); + + assert(child_a); + assert(child_b); + + if (!lttng_action_is_equal(child_a, child_b)) { + goto end; + } + } + + is_equal = true; +end: + return is_equal; +} + +static int lttng_action_group_serialize( + struct lttng_action *action, struct lttng_payload *payload) +{ + struct lttng_action_group *action_group; + struct lttng_action_group_comm comm; + int ret; + unsigned int i, count; + + assert(action); + assert(payload); + assert(IS_GROUP_ACTION(action)); + + action_group = action_group_from_action(action); + + DBG("Serializing action group"); + + count = lttng_dynamic_pointer_array_get_count(&action_group->actions); + + comm.action_count = count; + + ret = lttng_dynamic_buffer_append( + &payload->buffer, &comm, sizeof(comm)); + if (ret) { + ret = -1; + goto end; + } + + for (i = 0; i < count; i++) { + struct lttng_action *child = + lttng_dynamic_pointer_array_get_pointer( + &action_group->actions, i); + + assert(child); + + ret = lttng_action_serialize(child, payload); + if (ret) { + goto end; + } + } + + ret = 0; + +end: + return ret; +} + +static void lttng_action_group_destroy(struct lttng_action *action) +{ + struct lttng_action_group *action_group; + + if (!action) { + goto end; + } + + action_group = action_group_from_action(action); + lttng_dynamic_pointer_array_reset(&action_group->actions); + free(action_group); + +end: + return; +} + +ssize_t lttng_action_group_create_from_payload( + struct lttng_payload_view *view, + struct lttng_action **p_action) +{ + ssize_t consumed_len; + const struct lttng_action_group_comm *comm; + struct lttng_action *group; + struct lttng_action *child_action = NULL; + enum lttng_action_status status; + size_t i; + + group = lttng_action_group_create(); + if (!group) { + consumed_len = -1; + goto end; + } + + comm = (typeof(comm)) view->buffer.data; + + consumed_len = sizeof(struct lttng_action_group_comm); + + for (i = 0; i < comm->action_count; i++) { + ssize_t consumed_len_child; + struct lttng_payload_view child_view = + lttng_payload_view_from_view(view, consumed_len, + view->buffer.size - consumed_len); + + consumed_len_child = lttng_action_create_from_payload( + &child_view, &child_action); + if (consumed_len_child < 0) { + consumed_len = -1; + goto end; + } + + status = lttng_action_group_add_action(group, child_action); + if (status != LTTNG_ACTION_STATUS_OK) { + consumed_len = -1; + goto end; + } + + /* Transfer ownership to the action group. */ + lttng_action_put(child_action); + child_action = NULL; + + consumed_len += consumed_len_child; + } + + *p_action = group; + group = NULL; + +end: + lttng_action_group_destroy(group); + return consumed_len; +} + +struct lttng_action *lttng_action_group_create(void) +{ + struct lttng_action_group *action_group; + struct lttng_action *action; + + action_group = zmalloc(sizeof(struct lttng_action_group)); + if (!action_group) { + action = NULL; + goto end; + } + + action = &action_group->parent; + + lttng_action_init(action, LTTNG_ACTION_TYPE_GROUP, + lttng_action_group_validate, + lttng_action_group_serialize, + lttng_action_group_is_equal, + lttng_action_group_destroy); + + lttng_dynamic_pointer_array_init(&action_group->actions, + destroy_lttng_action_group_element); + +end: + return action; +} + +enum lttng_action_status lttng_action_group_add_action( + struct lttng_action *group, struct lttng_action *action) +{ + struct lttng_action_group *action_group; + enum lttng_action_status status; + int ret; + + if (!group || !IS_GROUP_ACTION(action) || !action) { + status = LTTNG_ACTION_STATUS_INVALID; + goto end; + } + + /* + * Don't allow adding groups in groups for now, since we're afraid of + * cycles. + */ + if (IS_GROUP_ACTION(action)) { + status = LTTNG_ACTION_STATUS_INVALID; + goto end; + } + + action_group = action_group_from_action(group); + + ret = lttng_dynamic_pointer_array_add_pointer(&action_group->actions, + action); + if (ret < 0) { + status = LTTNG_ACTION_STATUS_ERROR; + goto end; + } + + /* Take ownership of the object. */ + lttng_action_get(action); + status = LTTNG_ACTION_STATUS_OK; +end: + return status; +} + +enum lttng_action_status lttng_action_group_get_count( + const struct lttng_action *group, unsigned int *count) +{ + const struct lttng_action_group *action_group; + enum lttng_action_status status = LTTNG_ACTION_STATUS_OK; + + if (!group || !IS_GROUP_ACTION(group)) { + status = LTTNG_ACTION_STATUS_INVALID; + *count = 0; + goto end; + } + + action_group = action_group_from_action_const(group); + *count = lttng_dynamic_pointer_array_get_count(&action_group->actions); +end: + return status; +} + +const struct lttng_action *lttng_action_group_get_at_index( + const struct lttng_action *group, unsigned int index) +{ + unsigned int count; + const struct lttng_action_group *action_group; + const struct lttng_action * action = NULL; + + if (lttng_action_group_get_count(group, &count) != + LTTNG_ACTION_STATUS_OK) { + goto end; + } + + if (index >= count) { + goto end; + } + + action_group = action_group_from_action_const(group); + action = lttng_dynamic_pointer_array_get_pointer(&action_group->actions, + index); +end: + return action; +} diff --git a/src/common/actions/snapshot-session.c b/src/common/actions/snapshot-session.c index 9e8e43577..058179633 100644 --- a/src/common/actions/snapshot-session.c +++ b/src/common/actions/snapshot-session.c @@ -124,16 +124,9 @@ end: return is_equal; } -static size_t serialize_strlen(const char *s) +static size_t serialize_strlen(const char *str) { - - size_t len = 0; - - if (s) { - len = strlen(s) + 1; - } - - return len; + return str ? strlen(str) + 1 : 0; } static int lttng_action_snapshot_session_serialize( @@ -258,7 +251,7 @@ ssize_t lttng_action_snapshot_session_create_from_payload( comm->snapshot_output_len); if (!snapshot_output_buffer_view.buffer.data) { - fprintf(stderr, "Failed to create buffer view for snapshot output.\n"); + ERR("Failed to create buffer view for snapshot output."); goto error; } @@ -267,8 +260,7 @@ ssize_t lttng_action_snapshot_session_create_from_payload( &snapshot_output_buffer_view, &snapshot_output); if (snapshot_output_consumed_len != comm->snapshot_output_len) { - fprintf(stderr, - "Failed to deserialize snapshot output object: " + ERR("Failed to deserialize snapshot output object: " "consumed-len: %zd, expected-len: %" PRIu32, snapshot_output_consumed_len, comm->snapshot_output_len); -- 2.34.1