[lttng-tools.git] / src / common / payload.h

/*
 * Copyright (C) 2020 Jérémie Galarneau <jeremie.galarneau@efficios.com>
 *
 * SPDX-License-Identifier: LGPL-2.1-only
 *
 */

#ifndef LTTNG_PAYLOAD_H
#define LTTNG_PAYLOAD_H

#include <common/dynamic-buffer.h>
#include <common/dynamic-array.h>
#include <common/fd-handle.h>

/*
 * An lttng_payload encompasses the 'data' (bytes) and any passed file
 * descriptors as part of a message between liblttng-ctl and the session
 * daemon.
 */
struct lttng_payload {
	struct lttng_dynamic_buffer buffer;
	/* private */
	struct lttng_dynamic_pointer_array _fd_handles;
};

/*
 * Initialize a payload. This performs no allocation and is meant
 * to be used instead of zero-ing the payload structure.
 */
LTTNG_HIDDEN
void lttng_payload_init(struct lttng_payload *payload);

/* Copy a payload. */
LTTNG_HIDDEN
int lttng_payload_copy(const struct lttng_payload *src_payload,
		struct lttng_payload *dst_payload);

/* Release any memory and references held by the payload. */
LTTNG_HIDDEN
void lttng_payload_reset(struct lttng_payload *payload);

/*
 * Empty the contents of a payload, releasing all references held.
 * This should be used to put a payload in a re-usable state.
 *
 * lttng_payload_reset must still be called on an lttng_payload to
 * free all allocated memory.
 */
LTTNG_HIDDEN
void lttng_payload_clear(struct lttng_payload *payload);

/**
 * Add an fd to the payload.
 * The payload acquires a reference to the fd_handle.
 *
 * @payload	Payload instance
 * @fd_handle	File descriptor handle to add to the payload
 *
 * Returns 0 on success, -1 on allocation error.
 */
LTTNG_HIDDEN
int lttng_payload_push_fd_handle(struct lttng_payload *payload,
		struct fd_handle *fd_handle);

#endif /* LTTNG_PAYLOAD_H */
Commit	Line	Data
c0a66c84 JG	1	/*
	2	* Copyright (C) 2020 Jérémie Galarneau <jeremie.galarneau@efficios.com>
	3	*
	4	* SPDX-License-Identifier: LGPL-2.1-only
	5	*
	6	*/
	7
	8	#ifndef LTTNG_PAYLOAD_H
	9	#define LTTNG_PAYLOAD_H
	10
	11	#include <common/dynamic-buffer.h>
	12	#include <common/dynamic-array.h>
fe489250	13	#include <common/fd-handle.h>
c0a66c84 JG	14
	15	/*
	16	* An lttng_payload encompasses the 'data' (bytes) and any passed file
	17	* descriptors as part of a message between liblttng-ctl and the session
	18	* daemon.
	19	*/
	20	struct lttng_payload {
	21	struct lttng_dynamic_buffer buffer;
	22	/* private */
fe489250	23	struct lttng_dynamic_pointer_array _fd_handles;
c0a66c84 JG	24	};
	25
	26	/*
	27	* Initialize a payload. This performs no allocation and is meant
de837173	28	* to be used instead of zero-ing the payload structure.
c0a66c84 JG	29	*/
	30	LTTNG_HIDDEN
	31	void lttng_payload_init(struct lttng_payload *payload);
	32
e368fb43 JG	33	/* Copy a payload. */
	34	LTTNG_HIDDEN
	35	int lttng_payload_copy(const struct lttng_payload *src_payload,
	36	struct lttng_payload *dst_payload);
	37
fe489250	38	/* Release any memory and references held by the payload. */
c0a66c84 JG	39	LTTNG_HIDDEN
	40	void lttng_payload_reset(struct lttng_payload *payload);
	41
fe489250 JG	42	/*
	43	* Empty the contents of a payload, releasing all references held.
	44	* This should be used to put a payload in a re-usable state.
	45	*
	46	* lttng_payload_reset must still be called on an lttng_payload to
	47	* free all allocated memory.
	48	*/
	49	LTTNG_HIDDEN
	50	void lttng_payload_clear(struct lttng_payload *payload);
	51
c0a66c84 JG	52	/**
c0a66c84 JG	53	* Add an fd to the payload.
fe489250	54	* The payload acquires a reference to the fd_handle.
c0a66c84 JG	55	*
c0a66c84 JG	56	* @payload Payload instance
fe489250	57	* @fd_handle File descriptor handle to add to the payload
c0a66c84 JG	58	*
	59	* Returns 0 on success, -1 on allocation error.
	60	*/
	61	LTTNG_HIDDEN
fe489250 JG	62	int lttng_payload_push_fd_handle(struct lttng_payload *payload,
fe489250 JG	63	struct fd_handle *fd_handle);
c0a66c84 JG	64
c0a66c84 JG	65	#endif /* LTTNG_PAYLOAD_H */