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session.c
729 lines (631 loc) · 18.5 KB
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session.c
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/*
* This file is part of the sigrok project.
*
* Copyright (C) 2010-2012 Bert Vermeulen <bert@biot.com>
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <glib.h>
#include "libsigrok.h"
#include "libsigrok-internal.h"
/* Message logging helpers with driver-specific prefix string. */
#define DRIVER_LOG_DOMAIN "session: "
#define sr_log(l, s, args...) sr_log(l, DRIVER_LOG_DOMAIN s, ## args)
#define sr_spew(s, args...) sr_spew(DRIVER_LOG_DOMAIN s, ## args)
#define sr_dbg(s, args...) sr_dbg(DRIVER_LOG_DOMAIN s, ## args)
#define sr_info(s, args...) sr_info(DRIVER_LOG_DOMAIN s, ## args)
#define sr_warn(s, args...) sr_warn(DRIVER_LOG_DOMAIN s, ## args)
#define sr_err(s, args...) sr_err(DRIVER_LOG_DOMAIN s, ## args)
/**
* @file
*
* Creating, using, or destroying libsigrok sessions.
*/
/**
* @defgroup grp_session Session handling
*
* Creating, using, or destroying libsigrok sessions.
*
* @{
*/
struct source {
int timeout;
sr_receive_data_callback_t cb;
void *cb_data;
/* This is used to keep track of the object (fd, pollfd or channel) which is
* being polled and will be used to match the source when removing it again.
*/
gintptr poll_object;
};
/* There can only be one session at a time. */
/* 'session' is not static, it's used elsewhere (via 'extern'). */
struct sr_session *session;
/**
* Create a new session.
*
* @todo Should it use the file-global "session" variable or take an argument?
* The same question applies to all the other session functions.
*
* @return A pointer to the newly allocated session, or NULL upon errors.
*/
SR_API struct sr_session *sr_session_new(void)
{
if (!(session = g_try_malloc0(sizeof(struct sr_session)))) {
sr_err("Session malloc failed.");
return NULL;
}
session->source_timeout = -1;
return session;
}
/**
* Destroy the current session.
*
* This frees up all memory used by the session.
*
* @return SR_OK upon success, SR_ERR_BUG if no session exists.
*/
SR_API int sr_session_destroy(void)
{
if (!session) {
sr_err("%s: session was NULL", __func__);
return SR_ERR_BUG;
}
sr_session_dev_remove_all();
/* TODO: Error checks needed? */
g_free(session);
session = NULL;
return SR_OK;
}
/**
* Close a device instance.
*
* @param sdi The device instance to close. Must not be NULL. Also,
* sdi->driver, sdi->driver->priv, and sdi->priv must not be NULL.
*/
static void sr_dev_close(struct sr_dev_inst *sdi)
{
int ret;
if (!sdi) {
sr_err("Invalid device instance, can't close device.");
return;
}
/* In the drivers sdi->priv is a 'struct dev_context *devc'. */
if (!sdi->priv) {
/*
* Should be sr_err() in theory, but the 'demo' driver has
* NULL for sdi->priv, so we use sr_dbg() until that's fixed.
*/
sr_dbg("Invalid device context, can't close device.");
return;
}
if (!sdi->driver) {
sr_err("Invalid driver, can't close device.");
return;
}
if (!sdi->driver->priv) {
sr_err("Driver not initialized, can't close device.");
return;
}
sr_spew("Closing '%s' device instance %d.", sdi->driver->name,
sdi->index);
if ((ret = sdi->driver->dev_close(sdi)) < 0)
sr_err("Failed to close device instance: %d.", ret);
}
/**
* Remove all the devices from the current session.
*
* The session itself (i.e., the struct sr_session) is not free'd and still
* exists after this function returns.
*
* @return SR_OK upon success, SR_ERR_BUG if no session exists.
*/
SR_API int sr_session_dev_remove_all(void)
{
if (!session) {
sr_err("%s: session was NULL", __func__);
return SR_ERR_BUG;
}
g_slist_free_full(session->devs, (GDestroyNotify)sr_dev_close);
session->devs = NULL;
return SR_OK;
}
/**
* Add a device instance to the current session.
*
* @param sdi The device instance to add to the current session. Must not
* be NULL. Also, sdi->driver and sdi->driver->dev_open must
* not be NULL.
*
* @return SR_OK upon success, SR_ERR_ARG upon invalid arguments.
*/
SR_API int sr_session_dev_add(const struct sr_dev_inst *sdi)
{
int ret;
if (!sdi) {
sr_err("%s: sdi was NULL", __func__);
return SR_ERR_ARG;
}
if (!session) {
sr_err("%s: session was NULL", __func__);
return SR_ERR_BUG;
}
/* If sdi->driver is NULL, this is a virtual device. */
if (!sdi->driver) {
sr_dbg("%s: sdi->driver was NULL, this seems to be "
"a virtual device; continuing", __func__);
/* Just add the device, don't run dev_open(). */
session->devs = g_slist_append(session->devs, (gpointer)sdi);
return SR_OK;
}
/* sdi->driver is non-NULL (i.e. we have a real device). */
if (!sdi->driver->dev_open) {
sr_err("%s: sdi->driver->dev_open was NULL", __func__);
return SR_ERR_BUG;
}
if ((ret = sdi->driver->dev_open((struct sr_dev_inst *)sdi)) != SR_OK) {
sr_err("%s: dev_open failed (%d)", __func__, ret);
return ret;
}
session->devs = g_slist_append(session->devs, (gpointer)sdi);
return SR_OK;
}
/**
* Remove all datafeed callbacks in the current session.
*
* @return SR_OK upon success, SR_ERR_BUG if no session exists.
*/
SR_API int sr_session_datafeed_callback_remove_all(void)
{
if (!session) {
sr_err("%s: session was NULL", __func__);
return SR_ERR_BUG;
}
g_slist_free(session->datafeed_callbacks);
session->datafeed_callbacks = NULL;
return SR_OK;
}
/**
* Add a datafeed callback to the current session.
*
* @param cb Function to call when a chunk of data is received.
* Must not be NULL.
*
* @return SR_OK upon success, SR_ERR_BUG if no session exists.
*/
SR_API int sr_session_datafeed_callback_add(sr_datafeed_callback_t cb)
{
if (!session) {
sr_err("%s: session was NULL", __func__);
return SR_ERR_BUG;
}
if (!cb) {
sr_err("%s: cb was NULL", __func__);
return SR_ERR_ARG;
}
session->datafeed_callbacks =
g_slist_append(session->datafeed_callbacks, cb);
return SR_OK;
}
static int sr_session_run_poll(void)
{
unsigned int i;
int ret;
while (session->num_sources > 0) {
ret = g_poll(session->pollfds, session->num_sources,
session->source_timeout);
for (i = 0; i < session->num_sources; i++) {
if (session->pollfds[i].revents > 0 || (ret == 0
&& session->source_timeout == session->sources[i].timeout)) {
/*
* Invoke the source's callback on an event,
* or if the poll timed out and this source
* asked for that timeout.
*/
if (!session->sources[i].cb(session->pollfds[i].fd,
session->pollfds[i].revents,
session->sources[i].cb_data))
sr_session_source_remove(session->sources[i].poll_object);
}
}
}
return SR_OK;
}
/**
* Start a session.
*
* There can only be one session at a time.
*
* @return SR_OK upon success, SR_ERR upon errors.
*/
SR_API int sr_session_start(void)
{
struct sr_dev_inst *sdi;
GSList *l;
int ret;
if (!session) {
sr_err("%s: session was NULL; a session must be "
"created before starting it.", __func__);
return SR_ERR_BUG;
}
if (!session->devs) {
sr_err("%s: session->devs was NULL; a session "
"cannot be started without devices.", __func__);
return SR_ERR_BUG;
}
sr_info("Starting.");
ret = SR_OK;
for (l = session->devs; l; l = l->next) {
sdi = l->data;
if ((ret = sdi->driver->dev_acquisition_start(sdi, sdi)) != SR_OK) {
sr_err("%s: could not start an acquisition "
"(%d)", __func__, ret);
break;
}
}
/* TODO: What if there are multiple devices? Which return code? */
return ret;
}
/**
* Run the session.
*
* @return SR_OK upon success, SR_ERR_BUG upon errors.
*/
SR_API int sr_session_run(void)
{
if (!session) {
sr_err("%s: session was NULL; a session must be "
"created first, before running it.", __func__);
return SR_ERR_BUG;
}
if (!session->devs) {
/* TODO: Actually the case? */
sr_err("%s: session->devs was NULL; a session "
"cannot be run without devices.", __func__);
return SR_ERR_BUG;
}
sr_info("Running.");
/* Do we have real sources? */
if (session->num_sources == 1 && session->pollfds[0].fd == -1) {
/* Dummy source, freewheel over it. */
while (session->num_sources)
session->sources[0].cb(-1, 0, session->sources[0].cb_data);
} else {
/* Real sources, use g_poll() main loop. */
sr_session_run_poll();
}
return SR_OK;
}
/**
* Halt the current session.
*
* This function is deprecated and should not be used in new code, use
* sr_session_stop() instead. The behaviour of this function is identical to
* sr_session_stop().
*
* @return SR_OK upon success, SR_ERR_BUG if no session exists.
*/
SR_API int sr_session_halt(void)
{
return sr_session_stop();
}
/**
* Stop the current session.
*
* The current session is stopped immediately, with all acquisition sessions
* being stopped and hardware drivers cleaned up.
*
* @return SR_OK upon success, SR_ERR_BUG if no session exists.
*/
SR_API int sr_session_stop(void)
{
struct sr_dev_inst *sdi;
GSList *l;
if (!session) {
sr_err("%s: session was NULL", __func__);
return SR_ERR_BUG;
}
sr_info("Stopping.");
for (l = session->devs; l; l = l->next) {
sdi = l->data;
if (sdi->driver) {
if (sdi->driver->dev_acquisition_stop)
sdi->driver->dev_acquisition_stop(sdi, sdi);
}
}
/*
* Some sources may not be necessarily associated with a device.
* Those sources may still be present even after stopping all devices.
* We need to make sure all sources are removed, or we risk running the
* session in an infinite loop.
*/
while (session->num_sources)
sr_session_source_remove(session->sources[0].poll_object);
return SR_OK;
}
/**
* Debug helper.
*
* @param packet The packet to show debugging information for.
*/
static void datafeed_dump(const struct sr_datafeed_packet *packet)
{
const struct sr_datafeed_logic *logic;
const struct sr_datafeed_analog *analog;
switch (packet->type) {
case SR_DF_HEADER:
sr_dbg("bus: Received SR_DF_HEADER packet.");
break;
case SR_DF_TRIGGER:
sr_dbg("bus: Received SR_DF_TRIGGER packet.");
break;
case SR_DF_META:
sr_dbg("bus: Received SR_DF_META packet.");
break;
case SR_DF_LOGIC:
logic = packet->payload;
sr_dbg("bus: Received SR_DF_LOGIC packet (%" PRIu64 " bytes).",
logic->length);
break;
case SR_DF_ANALOG:
analog = packet->payload;
sr_dbg("bus: Received SR_DF_ANALOG packet (%d samples).",
analog->num_samples);
break;
case SR_DF_END:
sr_dbg("bus: Received SR_DF_END packet.");
break;
case SR_DF_FRAME_BEGIN:
sr_dbg("bus: Received SR_DF_FRAME_BEGIN packet.");
break;
case SR_DF_FRAME_END:
sr_dbg("bus: Received SR_DF_FRAME_END packet.");
break;
default:
sr_dbg("bus: Received unknown packet type: %d.", packet->type);
break;
}
}
/**
* Send a packet to whatever is listening on the datafeed bus.
*
* Hardware drivers use this to send a data packet to the frontend.
*
* @param sdi TODO.
* @param packet The datafeed packet to send to the session bus.
*
* @return SR_OK upon success, SR_ERR_ARG upon invalid arguments.
*
* @private
*/
SR_PRIV int sr_session_send(const struct sr_dev_inst *sdi,
const struct sr_datafeed_packet *packet)
{
GSList *l;
sr_datafeed_callback_t cb;
if (!sdi) {
sr_err("%s: sdi was NULL", __func__);
return SR_ERR_ARG;
}
if (!packet) {
sr_err("%s: packet was NULL", __func__);
return SR_ERR_ARG;
}
for (l = session->datafeed_callbacks; l; l = l->next) {
if (sr_log_loglevel_get() >= SR_LOG_DBG)
datafeed_dump(packet);
cb = l->data;
cb(sdi, packet);
}
return SR_OK;
}
/**
* Add an event source for a file descriptor.
*
* @param pollfd The GPollFD.
* @param timeout Max time to wait before the callback is called, ignored if 0.
* @param cb Callback function to add. Must not be NULL.
* @param cb_data Data for the callback function. Can be NULL.
* @param poll_object TODO.
*
* @return SR_OK upon success, SR_ERR_ARG upon invalid arguments, or
* SR_ERR_MALLOC upon memory allocation errors.
*/
static int _sr_session_source_add(GPollFD *pollfd, int timeout,
sr_receive_data_callback_t cb, void *cb_data, gintptr poll_object)
{
struct source *new_sources, *s;
GPollFD *new_pollfds;
if (!cb) {
sr_err("%s: cb was NULL", __func__);
return SR_ERR_ARG;
}
/* Note: cb_data can be NULL, that's not a bug. */
new_pollfds = g_try_realloc(session->pollfds,
sizeof(GPollFD) * (session->num_sources + 1));
if (!new_pollfds) {
sr_err("%s: new_pollfds malloc failed", __func__);
return SR_ERR_MALLOC;
}
new_sources = g_try_realloc(session->sources, sizeof(struct source) *
(session->num_sources + 1));
if (!new_sources) {
sr_err("%s: new_sources malloc failed", __func__);
return SR_ERR_MALLOC;
}
new_pollfds[session->num_sources] = *pollfd;
s = &new_sources[session->num_sources++];
s->timeout = timeout;
s->cb = cb;
s->cb_data = cb_data;
s->poll_object = poll_object;
session->pollfds = new_pollfds;
session->sources = new_sources;
if (timeout != session->source_timeout && timeout > 0
&& (session->source_timeout == -1 || timeout < session->source_timeout))
session->source_timeout = timeout;
return SR_OK;
}
/**
* Add an event source for a file descriptor.
*
* @param fd The file descriptor.
* @param events Events to check for.
* @param timeout Max time to wait before the callback is called, ignored if 0.
* @param cb Callback function to add. Must not be NULL.
* @param cb_data Data for the callback function. Can be NULL.
*
* @return SR_OK upon success, SR_ERR_ARG upon invalid arguments, or
* SR_ERR_MALLOC upon memory allocation errors.
*/
SR_API int sr_session_source_add(int fd, int events, int timeout,
sr_receive_data_callback_t cb, void *cb_data)
{
GPollFD p;
p.fd = fd;
p.events = events;
return _sr_session_source_add(&p, timeout, cb, cb_data, (gintptr)fd);
}
/**
* Add an event source for a GPollFD.
*
* @param pollfd The GPollFD.
* @param timeout Max time to wait before the callback is called, ignored if 0.
* @param cb Callback function to add. Must not be NULL.
* @param cb_data Data for the callback function. Can be NULL.
*
* @return SR_OK upon success, SR_ERR_ARG upon invalid arguments, or
* SR_ERR_MALLOC upon memory allocation errors.
*/
SR_API int sr_session_source_add_pollfd(GPollFD *pollfd, int timeout,
sr_receive_data_callback_t cb, void *cb_data)
{
return _sr_session_source_add(pollfd, timeout, cb,
cb_data, (gintptr)pollfd);
}
/**
* Add an event source for a GIOChannel.
*
* @param channel The GIOChannel.
* @param events Events to poll on.
* @param timeout Max time to wait before the callback is called, ignored if 0.
* @param cb Callback function to add. Must not be NULL.
* @param cb_data Data for the callback function. Can be NULL.
*
* @return SR_OK upon success, SR_ERR_ARG upon invalid arguments, or
* SR_ERR_MALLOC upon memory allocation errors.
*/
SR_API int sr_session_source_add_channel(GIOChannel *channel, int events,
int timeout, sr_receive_data_callback_t cb, void *cb_data)
{
GPollFD p;
#ifdef _WIN32
g_io_channel_win32_make_pollfd(channel, events, &p);
#else
p.fd = g_io_channel_unix_get_fd(channel);
p.events = events;
#endif
return _sr_session_source_add(&p, timeout, cb, cb_data, (gintptr)channel);
}
/**
* Remove the source belonging to the specified channel.
*
* @todo Add more error checks and logging.
*
* @param channel The channel for which the source should be removed.
*
* @return SR_OK upon success, SR_ERR_ARG upon invalid arguments, or
* SR_ERR_MALLOC upon memory allocation errors, SR_ERR_BUG upon
* internal errors.
*/
static int _sr_session_source_remove(gintptr poll_object)
{
struct source *new_sources;
GPollFD *new_pollfds;
unsigned int old;
if (!session->sources || !session->num_sources) {
sr_err("%s: sources was NULL", __func__);
return SR_ERR_BUG;
}
for (old = 0; old < session->num_sources; old++) {
if (session->sources[old].poll_object == poll_object)
break;
}
/* fd not found, nothing to do */
if (old == session->num_sources)
return SR_OK;
session->num_sources -= 1;
if (old != session->num_sources) {
memmove(&session->pollfds[old], &session->pollfds[old+1],
(session->num_sources - old) * sizeof(GPollFD));
memmove(&session->sources[old], &session->sources[old+1],
(session->num_sources - old) * sizeof(struct source));
}
new_pollfds = g_try_realloc(session->pollfds, sizeof(GPollFD) * session->num_sources);
if (!new_pollfds && session->num_sources > 0) {
sr_err("%s: new_pollfds malloc failed", __func__);
return SR_ERR_MALLOC;
}
new_sources = g_try_realloc(session->sources, sizeof(struct source) * session->num_sources);
if (!new_sources && session->num_sources > 0) {
sr_err("%s: new_sources malloc failed", __func__);
return SR_ERR_MALLOC;
}
session->pollfds = new_pollfds;
session->sources = new_sources;
return SR_OK;
}
/**
* Remove the source belonging to the specified file descriptor.
*
* @param fd The file descriptor for which the source should be removed.
*
* @return SR_OK upon success, SR_ERR_ARG upon invalid arguments, or
* SR_ERR_MALLOC upon memory allocation errors, SR_ERR_BUG upon
* internal errors.
*/
SR_API int sr_session_source_remove(int fd)
{
return _sr_session_source_remove((gintptr)fd);
}
/**
* Remove the source belonging to the specified poll descriptor.
*
* @param pollfd The poll descriptor for which the source should be removed.
*
* @return SR_OK upon success, SR_ERR_ARG upon invalid arguments, or
* SR_ERR_MALLOC upon memory allocation errors, SR_ERR_BUG upon
* internal errors.
*/
SR_API int sr_session_source_remove_pollfd(GPollFD *pollfd)
{
return _sr_session_source_remove((gintptr)pollfd);
}
/**
* Remove the source belonging to the specified channel.
*
* @param channel The channel for which the source should be removed.
*
* @return SR_OK upon success, SR_ERR_ARG upon invalid arguments, or
* SR_ERR_MALLOC upon memory allocation errors, SR_ERR_BUG upon
* internal errors.
*/
SR_API int sr_session_source_remove_channel(GIOChannel *channel)
{
return _sr_session_source_remove((gintptr)channel);
}
/** @} */