X-Git-Url: http://git.liburcu.org/?a=blobdiff_plain;f=liblttng-ust%2Fevent-notifier-notification.c;fp=liblttng-ust%2Fevent-notifier-notification.c;h=0000000000000000000000000000000000000000;hb=9d4c8b2d907edb9ebc9bfde55602598e7ba0832e;hp=b3e2c94f1bd7a2d7180ad64256bcb325ea393e85;hpb=6ba6fd60507f8e045bdc4f1be14e9d99c6a15f7f;p=lttng-ust.git diff --git a/liblttng-ust/event-notifier-notification.c b/liblttng-ust/event-notifier-notification.c deleted file mode 100644 index b3e2c94f..00000000 --- a/liblttng-ust/event-notifier-notification.c +++ /dev/null @@ -1,401 +0,0 @@ -/* - * SPDX-License-Identifier: LGPL-2.1-only - * - * Copyright (C) 2020 Francis Deslauriers - */ - -#define _LGPL_SOURCE - -#include -#include -#include - -#include -#include -#include - -#include "lttng-tracer-core.h" -#include "ust-events-internal.h" -#include "../libmsgpack/msgpack.h" -#include "lttng-bytecode.h" -#include "ust-share.h" - -/* - * We want this write to be atomic AND non-blocking, meaning that we - * want to write either everything OR nothing. - * According to `pipe(7)`, writes that are less than `PIPE_BUF` bytes must be - * atomic, so we bound the capture buffer size to the `PIPE_BUF` minus the size - * of the notification struct we are sending alongside the capture buffer. - */ -#define CAPTURE_BUFFER_SIZE \ - (PIPE_BUF - sizeof(struct lttng_ust_abi_event_notifier_notification) - 1) - -struct lttng_event_notifier_notification { - int notification_fd; - uint64_t event_notifier_token; - uint8_t capture_buf[CAPTURE_BUFFER_SIZE]; - struct lttng_msgpack_writer writer; - bool has_captures; -}; - -static -void capture_enum(struct lttng_msgpack_writer *writer, - struct lttng_interpreter_output *output) -{ - lttng_msgpack_begin_map(writer, 2); - lttng_msgpack_write_str(writer, "type"); - lttng_msgpack_write_str(writer, "enum"); - - lttng_msgpack_write_str(writer, "value"); - - switch (output->type) { - case LTTNG_INTERPRETER_TYPE_SIGNED_ENUM: - lttng_msgpack_write_signed_integer(writer, output->u.s); - break; - case LTTNG_INTERPRETER_TYPE_UNSIGNED_ENUM: - lttng_msgpack_write_signed_integer(writer, output->u.u); - break; - default: - abort(); - } - - lttng_msgpack_end_map(writer); -} - -static -int64_t capture_sequence_element_signed(uint8_t *ptr, - const struct lttng_ust_type_integer *integer_type) -{ - int64_t value; - unsigned int size = integer_type->size; - bool byte_order_reversed = integer_type->reverse_byte_order; - - switch (size) { - case 8: - value = *ptr; - break; - case 16: - { - int16_t tmp; - tmp = *(int16_t *) ptr; - if (byte_order_reversed) - tmp = bswap_16(tmp); - - value = tmp; - break; - } - case 32: - { - int32_t tmp; - tmp = *(int32_t *) ptr; - if (byte_order_reversed) - tmp = bswap_32(tmp); - - value = tmp; - break; - } - case 64: - { - int64_t tmp; - tmp = *(int64_t *) ptr; - if (byte_order_reversed) - tmp = bswap_64(tmp); - - value = tmp; - break; - } - default: - abort(); - } - - return value; -} - -static -uint64_t capture_sequence_element_unsigned(uint8_t *ptr, - const struct lttng_ust_type_integer *integer_type) -{ - uint64_t value; - unsigned int size = integer_type->size; - bool byte_order_reversed = integer_type->reverse_byte_order; - - switch (size) { - case 8: - value = *ptr; - break; - case 16: - { - uint16_t tmp; - tmp = *(uint16_t *) ptr; - if (byte_order_reversed) - tmp = bswap_16(tmp); - - value = tmp; - break; - } - case 32: - { - uint32_t tmp; - tmp = *(uint32_t *) ptr; - if (byte_order_reversed) - tmp = bswap_32(tmp); - - value = tmp; - break; - } - case 64: - { - uint64_t tmp; - tmp = *(uint64_t *) ptr; - if (byte_order_reversed) - tmp = bswap_64(tmp); - - value = tmp; - break; - } - default: - abort(); - } - - return value; -} - -static -void capture_sequence(struct lttng_msgpack_writer *writer, - struct lttng_interpreter_output *output) -{ - const struct lttng_ust_type_integer *integer_type; - const struct lttng_ust_type_common *nested_type; - uint8_t *ptr; - bool signedness; - int i; - - lttng_msgpack_begin_array(writer, output->u.sequence.nr_elem); - - ptr = (uint8_t *) output->u.sequence.ptr; - nested_type = output->u.sequence.nested_type; - switch (nested_type->type) { - case lttng_ust_type_integer: - integer_type = lttng_ust_get_type_integer(nested_type); - break; - case lttng_ust_type_enum: - /* Treat enumeration as an integer. */ - integer_type = lttng_ust_get_type_integer(lttng_ust_get_type_enum(nested_type)->container_type); - break; - default: - /* Capture of array of non-integer are not supported. */ - abort(); - } - signedness = integer_type->signedness; - for (i = 0; i < output->u.sequence.nr_elem; i++) { - if (signedness) { - lttng_msgpack_write_signed_integer(writer, - capture_sequence_element_signed(ptr, integer_type)); - } else { - lttng_msgpack_write_unsigned_integer(writer, - capture_sequence_element_unsigned(ptr, integer_type)); - } - - /* - * We assume that alignment is smaller or equal to the size. - * This currently holds true but if it changes in the future, - * we will want to change the pointer arithmetics below to - * take into account that the next element might be further - * away. - */ - assert(integer_type->alignment <= integer_type->size); - - /* Size is in number of bits. */ - ptr += (integer_type->size / CHAR_BIT) ; - } - - lttng_msgpack_end_array(writer); -} - -static -void notification_init(struct lttng_event_notifier_notification *notif, - struct lttng_ust_event_notifier *event_notifier) -{ - struct lttng_msgpack_writer *writer = ¬if->writer; - - notif->event_notifier_token = event_notifier->priv->parent.user_token; - notif->notification_fd = event_notifier->priv->group->notification_fd; - notif->has_captures = false; - - if (event_notifier->priv->num_captures > 0) { - lttng_msgpack_writer_init(writer, notif->capture_buf, - CAPTURE_BUFFER_SIZE); - - lttng_msgpack_begin_array(writer, event_notifier->priv->num_captures); - notif->has_captures = true; - } -} - -static -void notification_append_capture( - struct lttng_event_notifier_notification *notif, - struct lttng_interpreter_output *output) -{ - struct lttng_msgpack_writer *writer = ¬if->writer; - - switch (output->type) { - case LTTNG_INTERPRETER_TYPE_S64: - lttng_msgpack_write_signed_integer(writer, output->u.s); - break; - case LTTNG_INTERPRETER_TYPE_U64: - lttng_msgpack_write_unsigned_integer(writer, output->u.u); - break; - case LTTNG_INTERPRETER_TYPE_DOUBLE: - lttng_msgpack_write_double(writer, output->u.d); - break; - case LTTNG_INTERPRETER_TYPE_STRING: - lttng_msgpack_write_str(writer, output->u.str.str); - break; - case LTTNG_INTERPRETER_TYPE_SEQUENCE: - capture_sequence(writer, output); - break; - case LTTNG_INTERPRETER_TYPE_SIGNED_ENUM: - case LTTNG_INTERPRETER_TYPE_UNSIGNED_ENUM: - capture_enum(writer, output); - break; - default: - abort(); - } -} - -static -void notification_append_empty_capture( - struct lttng_event_notifier_notification *notif) -{ - lttng_msgpack_write_nil(¬if->writer); -} - -static void record_error(struct lttng_ust_event_notifier *event_notifier) -{ - struct lttng_event_notifier_group *event_notifier_group = - event_notifier->priv->group; - struct lttng_counter *error_counter; - size_t dimension_index[1]; - int ret; - - error_counter = CMM_LOAD_SHARED(event_notifier_group->error_counter); - /* - * load-acquire paired with store-release orders creation of the - * error counter and setting error_counter_len before the - * error_counter is used. - * Currently a full memory barrier is used, which could be - * turned into acquire-release barriers. - */ - cmm_smp_mb(); - /* This group may not have an error counter attached to it. */ - if (!error_counter) - return; - - dimension_index[0] = event_notifier->priv->error_counter_index; - ret = event_notifier_group->error_counter->ops->counter_add( - error_counter->counter, dimension_index, 1); - if (ret) - WARN_ON_ONCE(1); -} - -static -void notification_send(struct lttng_event_notifier_notification *notif, - struct lttng_ust_event_notifier *event_notifier) -{ - ssize_t ret; - size_t content_len; - int iovec_count = 1; - struct lttng_ust_abi_event_notifier_notification ust_notif = {0}; - struct iovec iov[2]; - - assert(notif); - - ust_notif.token = event_notifier->priv->parent.user_token; - - /* - * Prepare sending the notification from multiple buffers using an - * array of `struct iovec`. The first buffer of the vector is - * notification structure itself and is always present. - */ - iov[0].iov_base = &ust_notif; - iov[0].iov_len = sizeof(ust_notif); - - if (notif->has_captures) { - /* - * If captures were requested, the second buffer of the array - * is the capture buffer. - */ - assert(notif->writer.buffer); - content_len = notif->writer.write_pos - notif->writer.buffer; - - assert(content_len > 0 && content_len <= CAPTURE_BUFFER_SIZE); - - iov[1].iov_base = notif->capture_buf; - iov[1].iov_len = content_len; - - iovec_count++; - } else { - content_len = 0; - } - - /* - * Update the capture buffer size so that receiver of the buffer will - * know how much to expect. - */ - ust_notif.capture_buf_size = content_len; - - /* Send all the buffers. */ - ret = ust_patient_writev(notif->notification_fd, iov, iovec_count); - if (ret == -1) { - if (errno == EAGAIN) { - record_error(event_notifier); - DBG("Cannot send event_notifier notification without blocking: %s", - strerror(errno)); - } else { - DBG("Error to sending event notifier notification: %s", - strerror(errno)); - abort(); - } - } -} - -void lttng_event_notifier_notification_send( - struct lttng_ust_event_notifier *event_notifier, - const char *stack_data, - struct lttng_ust_notification_ctx *notif_ctx) -{ - /* - * This function is called from the probe, we must do dynamic - * allocation in this context. - */ - struct lttng_event_notifier_notification notif = {0}; - - notification_init(¬if, event_notifier); - - if (caa_unlikely(notif_ctx->eval_capture)) { - struct lttng_ust_bytecode_runtime *capture_bc_runtime; - - /* - * Iterate over all the capture bytecodes. If the interpreter - * functions returns successfully, append the value of the - * `output` parameter to the capture buffer. If the interpreter - * fails, append an empty capture to the buffer. - */ - cds_list_for_each_entry_rcu(capture_bc_runtime, - &event_notifier->priv->capture_bytecode_runtime_head, node) { - struct lttng_interpreter_output output; - - if (capture_bc_runtime->interpreter_func(capture_bc_runtime, - stack_data, &output) == LTTNG_UST_BYTECODE_INTERPRETER_OK) - notification_append_capture(¬if, &output); - else - notification_append_empty_capture(¬if); - } - } - - /* - * Send the notification (including the capture buffer) to the - * sessiond. - */ - notification_send(¬if, event_notifier); -}