libsigrok/session.c

561 lines
13 KiB
C

/*
* 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 "sigrok.h"
#include "sigrok-internal.h"
/* demo.c. TODO: Should not be global! */
extern SR_PRIV GIOChannel channels[2];
struct source {
int fd;
int events;
int timeout;
sr_receive_data_callback_t cb;
void *cb_data;
};
/* There can only be one session at a time. */
/* 'session' is not static, it's used elsewhere (via 'extern'). */
struct sr_session *session;
static int num_sources = 0;
static struct source *sources = NULL;
static int source_timeout = -1;
/**
* 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: %s: session malloc failed", __func__);
return NULL; /* TODO: SR_ERR_MALLOC? */
}
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("session: %s: session was NULL", __func__);
return SR_ERR_BUG;
}
g_slist_free(session->devs);
session->devs = NULL;
/* TODO: Error checks needed? */
/* TODO: Loop over protocol decoders and free them. */
g_free(session);
session = NULL;
return SR_OK;
}
/**
* Remove all the devices from the current session. TODO?
*
* 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("session: %s: session was NULL", __func__);
return SR_ERR_BUG;
}
g_slist_free(session->devs);
session->devs = NULL;
return SR_OK;
}
/**
* Add a device to the current session.
*
* @param dev The device to add to the current session. Must not be NULL.
* Also, dev->driver and dev->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(struct sr_dev *dev)
{
int ret;
if (!dev) {
sr_err("session: %s: dev was NULL", __func__);
return SR_ERR_ARG;
}
if (!session) {
sr_err("session: %s: session was NULL", __func__);
return SR_ERR_BUG;
}
/* If dev->driver is NULL, this is a virtual device. */
if (!dev->driver) {
sr_dbg("session: %s: dev->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, dev);
return SR_OK;
}
/* dev->driver is non-NULL (i.e. we have a real device). */
if (!dev->driver->dev_open) {
sr_err("session: %s: dev->driver->dev_open was NULL",
__func__);
return SR_ERR_BUG;
}
if ((ret = dev->driver->dev_open(dev->driver_index)) != SR_OK) {
sr_err("session: %s: dev_open failed (%d)", __func__, ret);
return ret;
}
session->devs = g_slist_append(session->devs, dev);
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("session: %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("session: %s: session was NULL", __func__);
return SR_ERR_BUG;
}
if (!cb) {
sr_err("session: %s: cb was NULL", __func__);
return SR_ERR_ARG;
}
session->datafeed_callbacks =
g_slist_append(session->datafeed_callbacks, cb);
return SR_OK;
}
/**
* TODO.
*/
static int sr_session_run_poll(void)
{
GPollFD *fds, my_gpollfd;
int ret, i;
fds = NULL;
while (session->running) {
/* TODO: Add comment. */
g_free(fds);
/* Construct g_poll()'s array. */
if (!(fds = g_try_malloc(sizeof(GPollFD) * num_sources))) {
sr_err("session: %s: fds malloc failed", __func__);
return SR_ERR_MALLOC;
}
for (i = 0; i < num_sources; i++) {
#ifdef _WIN32
g_io_channel_win32_make_pollfd(&channels[0],
sources[i].events, &my_gpollfd);
#else
my_gpollfd.fd = sources[i].fd;
my_gpollfd.events = sources[i].events;
fds[i] = my_gpollfd;
#endif
}
ret = g_poll(fds, num_sources, source_timeout);
for (i = 0; i < num_sources; i++) {
if (fds[i].revents > 0 || (ret == 0
&& source_timeout == sources[i].timeout)) {
/*
* Invoke the source's callback on an event,
* or if the poll timeout out and this source
* asked for that timeout.
*/
if (!sources[i].cb(fds[i].fd, fds[i].revents,
sources[i].cb_data))
sr_session_source_remove(sources[i].fd);
}
}
}
g_free(fds);
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 *dev;
GSList *l;
int ret;
if (!session) {
sr_err("session: %s: session was NULL; a session must be "
"created first, before starting it.", __func__);
return SR_ERR_BUG;
}
if (!session->devs) {
/* TODO: Actually the case? */
sr_err("session: %s: session->devs was NULL; a session "
"cannot be started without devices.", __func__);
return SR_ERR_BUG;
}
/* TODO: Check driver_index validity? */
sr_info("session: starting");
for (l = session->devs; l; l = l->next) {
dev = l->data;
/* TODO: Check for dev != NULL. */
if ((ret = dev->driver->dev_acquisition_start(
dev->driver_index, dev)) != SR_OK) {
sr_err("session: %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.
*
* TODO: Various error checks etc.
*
* @return SR_OK upon success, SR_ERR_BUG upon errors.
*/
SR_API int sr_session_run(void)
{
if (!session) {
sr_err("session: %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("session: %s: session->devs was NULL; a session "
"cannot be run without devices.", __func__);
return SR_ERR_BUG;
}
sr_info("session: running");
session->running = TRUE;
/* Do we have real sources? */
if (num_sources == 1 && sources[0].fd == -1) {
/* Dummy source, freewheel over it. */
while (session->running)
sources[0].cb(-1, 0, sources[0].cb_data);
} else {
/* Real sources, use g_poll() main loop. */
sr_session_run_poll();
}
return SR_OK;
}
/**
* Halt the current session.
*
* This requests the current session be stopped as soon as possible, for
* example on receiving an SR_DF_END packet.
*
* @return SR_OK upon success, SR_ERR_BUG if no session exists.
*/
SR_API int sr_session_halt(void)
{
if (!session) {
sr_err("session: %s: session was NULL", __func__);
return SR_ERR_BUG;
}
sr_info("session: halting");
session->running = FALSE;
return SR_OK;
}
/**
* 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 *dev;
GSList *l;
if (!session) {
sr_err("session: %s: session was NULL", __func__);
return SR_ERR_BUG;
}
sr_info("session: stopping");
session->running = FALSE;
for (l = session->devs; l; l = l->next) {
dev = l->data;
/* Check for dev != NULL. */
if (dev->driver) {
if (dev->driver->dev_acquisition_stop)
dev->driver->dev_acquisition_stop(dev->driver_index, dev);
if (dev->driver->cleanup)
dev->driver->cleanup();
}
}
return SR_OK;
}
/**
* Debug helper.
*
* @param packet The packet to show debugging information for.
*/
static void datafeed_dump(struct sr_datafeed_packet *packet)
{
struct sr_datafeed_logic *logic;
switch (packet->type) {
case SR_DF_HEADER:
sr_dbg("bus: received SR_DF_HEADER");
break;
case SR_DF_TRIGGER:
sr_dbg("bus: received SR_DF_TRIGGER");
break;
case SR_DF_LOGIC:
logic = packet->payload;
/* TODO: Check for logic != NULL. */
sr_dbg("bus: received SR_DF_LOGIC %" PRIu64 " bytes", logic->length);
break;
case SR_DF_END:
sr_dbg("bus: received SR_DF_END");
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 dev TODO.
* @param packet The datafeed packet to send to the session bus.
*
* @return SR_OK upon success, SR_ERR_ARG upon invalid arguments.
*/
SR_PRIV int sr_session_send(struct sr_dev *dev,
struct sr_datafeed_packet *packet)
{
GSList *l;
sr_datafeed_callback_t cb;
if (!dev) {
sr_err("session: %s: dev was NULL", __func__);
return SR_ERR_ARG;
}
if (!packet) {
sr_err("session: %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;
/* TODO: Check for cb != NULL. */
cb(dev, packet);
}
return SR_OK;
}
/**
* TODO.
*
* TODO: More error checks etc.
*
* @param fd TODO.
* @param events TODO.
* @param timeout TODO.
* @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)
{
struct source *new_sources, *s;
if (!cb) {
sr_err("session: %s: cb was NULL", __func__);
return SR_ERR_ARG;
}
/* Note: cb_data can be NULL, that's not a bug. */
new_sources = g_try_malloc0(sizeof(struct source) * (num_sources + 1));
if (!new_sources) {
sr_err("session: %s: new_sources malloc failed", __func__);
return SR_ERR_MALLOC;
}
if (sources) {
memcpy(new_sources, sources,
sizeof(struct source) * num_sources);
g_free(sources);
}
s = &new_sources[num_sources++];
s->fd = fd;
s->events = events;
s->timeout = timeout;
s->cb = cb;
s->cb_data = cb_data;
sources = new_sources;
if (timeout != source_timeout && timeout > 0
&& (source_timeout == -1 || timeout < source_timeout))
source_timeout = timeout;
return SR_OK;
}
/**
* Remove the source belonging to the specified file descriptor.
*
* TODO: More error checks.
*
* @param fd TODO.
*
* @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)
{
struct source *new_sources;
int old, new;
if (!sources) {
sr_err("session: %s: sources was NULL", __func__);
return SR_ERR_BUG;
}
/* TODO: Check if 'fd' valid. */
new_sources = g_try_malloc0(sizeof(struct source) * num_sources);
if (!new_sources) {
sr_err("session: %s: new_sources malloc failed", __func__);
return SR_ERR_MALLOC;
}
for (old = 0, new = 0; old < num_sources; old++) {
if (sources[old].fd != fd)
memcpy(&new_sources[new++], &sources[old],
sizeof(struct source));
}
if (old != new) {
g_free(sources);
sources = new_sources;
num_sources--;
} else {
/* Target fd was not found. */
g_free(new_sources);
}
return SR_OK;
}