/* * This file is part of the libsigrok project. * * Copyright (C) 2010-2012 Bert Vermeulen * * 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 . */ #include #include #include #include #include #include "libsigrok.h" #include "libsigrok-internal.h" #define LOG_PREFIX "session" /** * @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; }; struct datafeed_callback { sr_datafeed_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; /** * 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. * * @retval NULL Error. * @retval other A pointer to the newly allocated session. */ 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; session->running = FALSE; session->abort_session = FALSE; g_mutex_init(&session->stop_mutex); return session; } /** * Destroy the current session. * This frees up all memory used by the session. * * @retval SR_OK Success. * @retval SR_ERR_BUG 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_mutex_clear(&session->stop_mutex); g_free(session); session = NULL; return SR_OK; } /** * 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. * * @retval SR_OK Success. * @retval SR_ERR_BUG 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(session->devs); 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. * * @retval SR_OK Success. * @retval SR_ERR_ARG Invalid argument. * @retval SR_ERR_BUG No session exists. */ 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; } session->devs = g_slist_append(session->devs, (gpointer)sdi); if (session->running) { /* Adding a device to a running session. Start acquisition * on that device now. */ if ((ret = sdi->driver->dev_acquisition_start(sdi, (void *)sdi)) != SR_OK) sr_err("Failed to start acquisition of device in " "running session: %d", ret); } return SR_OK; } /** * List all device instances attached to the current session. * * @param devlist A pointer where the device instance list will be * stored on return. If no devices are in the session, * this will be NULL. Each element in the list points * to a struct sr_dev_inst *. * The list must be freed by the caller, but not the * elements pointed to. * * @retval SR_OK Success. * @retval SR_ERR Invalid argument. */ SR_API int sr_session_dev_list(GSList **devlist) { *devlist = NULL; if (!session) return SR_ERR; *devlist = g_slist_copy(session->devs); return SR_OK; } /** * Remove all datafeed callbacks in the current session. * * @retval SR_OK Success. * @retval SR_ERR_BUG 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_full(session->datafeed_callbacks, g_free); 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. * @param cb_data Opaque pointer passed in by the caller. * * @retval SR_OK Success. * @retval SR_ERR_BUG No session exists. */ SR_API int sr_session_datafeed_callback_add(sr_datafeed_callback_t cb, void *cb_data) { struct datafeed_callback *cb_struct; 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; } if (!(cb_struct = g_try_malloc0(sizeof(struct datafeed_callback)))) return SR_ERR_MALLOC; cb_struct->cb = cb; cb_struct->cb_data = cb_data; session->datafeed_callbacks = g_slist_append(session->datafeed_callbacks, cb_struct); return SR_OK; } /** * Call every device in the session's callback. * * For sessions not driven by select loops such as sr_session_run(), * but driven by another scheduler, this can be used to poll the devices * from within that scheduler. * * @param block If TRUE, this call will wait for any of the session's * sources to fire an event on the file descriptors, or * any of their timeouts to activate. In other words, this * can be used as a select loop. * If FALSE, all sources have their callback run, regardless * of file descriptor or timeout status. * * @retval SR_OK Success. * @retval SR_ERR Error occured. */ static int sr_session_iteration(gboolean block) { unsigned int i; int ret; ret = g_poll(session->pollfds, session->num_sources, block ? session->source_timeout : 0); 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); } /* * We want to take as little time as possible to stop * the session if we have been told to do so. Therefore, * we check the flag after processing every source, not * just once per main event loop. */ g_mutex_lock(&session->stop_mutex); if (session->abort_session) { sr_session_stop_sync(); /* But once is enough. */ session->abort_session = FALSE; } g_mutex_unlock(&session->stop_mutex); } return SR_OK; } /** * Start a session. * * There can only be one session at a time. * * @retval SR_OK Success. * @retval SR_ERR Error occured. */ 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 " "(%s)", __func__, sr_strerror(ret)); break; } } /* TODO: What if there are multiple devices? Which return code? */ return ret; } /** * Run the session. * * @retval SR_OK Success. * @retval SR_ERR_BUG Error occured. */ 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; } session->running = TRUE; 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. */ while (session->num_sources) sr_session_iteration(TRUE); } return SR_OK; } /** * Stop the current session. * * The current session is stopped immediately, with all acquisition sessions * being stopped and hardware drivers cleaned up. * * This must be called from within the session thread, to prevent freeing * resources that the session thread will try to use. * * @retval SR_OK Success. * @retval SR_ERR_BUG No session exists. * * @private */ SR_PRIV int sr_session_stop_sync(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); } } 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. * * If the session is run in a separate thread, this function will not block * until the session is finished executing. It is the caller's responsibility * to wait for the session thread to return before assuming that the session is * completely decommissioned. * * @retval SR_OK Success. * @retval SR_ERR_BUG No session exists. */ SR_API int sr_session_stop(void) { if (!session) { sr_err("%s: session was NULL", __func__); return SR_ERR_BUG; } g_mutex_lock(&session->stop_mutex); session->abort_session = TRUE; g_mutex_unlock(&session->stop_mutex); 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. * * @retval SR_OK Success. * @retval SR_ERR_ARG Invalid argument. * * @private */ SR_PRIV int sr_session_send(const struct sr_dev_inst *sdi, const struct sr_datafeed_packet *packet) { GSList *l; struct datafeed_callback *cb_struct; 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_struct = l->data; cb_struct->cb(sdi, packet, cb_struct->cb_data); } return SR_OK; } /** * Add an event source for a file descriptor. * * @param pollfd The GPollFD. * @param[in] 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. * * @retval SR_OK Success. * @retval SR_ERR_ARG Invalid argument. * @retval SR_ERR_MALLOC Memory allocation error. */ 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. * * @retval SR_OK Success. * @retval SR_ERR_ARG Invalid argument. * @retval SR_ERR_MALLOC Memory allocation error. */ 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. * * @retval SR_OK Success. * @retval SR_ERR_ARG Invalid argument. * @retval SR_ERR_MALLOC Memory allocation error. */ 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. * * @retval SR_OK Success. * @retval SR_ERR_ARG Invalid argument. * @retval SR_ERR_MALLOC Memory allocation error. */ 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 poll_object The channel for which the source should be removed. * * @retval SR_OK Success * @retval SR_ERR_ARG Invalid arguments * @retval SR_ERR_MALLOC Memory allocation error * @retval SR_ERR_BUG Internal error */ 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. * * @retval SR_OK Success * @retval SR_ERR_ARG Invalid argument * @retval SR_ERR_MALLOC Memory allocation error. * @retval SR_ERR_BUG Internal error. */ 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. * * @retval SR_OK Success. * @retval SR_ERR_ARG Invalid argument. * @retval SR_ERR_MALLOC Memory allocation error. * @return SR_ERR_BUG Internal error. */ SR_API int sr_session_source_remove_channel(GIOChannel *channel) { return _sr_session_source_remove((gintptr)channel); } /** @} */