/*
- * Copyright (C) 2006-2009 Andre Noll <maan@systemlinux.org>
+ * Copyright (C) 2006-2014 Andre Noll <maan@systemlinux.org>
*
* Licensed under the GPL v2. For licencing details see COPYING.
*/
-/**
- * \file grab_client.c Functions for grabbing the stream at any position
- * in a filter chain.
- *
- * \sa filter_chain filter_chain_info filter.
- */
+/** \file grab_client.c Functions for grabbing the audio stream. */
#include <regex.h>
#include <sys/types.h>
-#include <dirent.h>
-#include <stdbool.h>
#include "para.h"
#include "list.h"
#include "string.h"
#include "fd.h"
-/** Grab clients that are not yet attached any btr node. */
-static struct list_head inactive_grab_client_list;
+/**
+ * How to handle blocking writes for the grab client fds.
+ */
+enum grab_mode {
+ /** Ignore the data and do not write. */
+ GM_SLOPPY,
+ /** Write anyway (default). */
+ GM_AGGRESSIVE,
+ /** Close fd if write would block. */
+ GM_PEDANTIC,
+};
+
+/** Flags specified as arguments to the grab command. */
+enum grab_flags {
+ /** Stop grabbing if audio file changes. */
+ GF_ONE_SHOT = 1,
+};
-/** Grab clients that are attached to a btr node. */
-static struct list_head active_grab_client_list;
+/** Describes one active grab client. */
+struct grab_client {
+ /* The value of the -p option. */
+ char *parent;
+ /* The value of the -n option. */
+ char *name;
+ /** The file descriptor to send the grabbed stream to. */
+ int fd;
+ /** See \ref grab_mode. */
+ enum grab_mode mode;
+ /** Flags given at the command line. */
+ enum grab_flags flags;
+ /** The point of the grab client's node in the buffer tree. */
+ struct btr_node *btrn;
+ /* The task of this grab client. */
+ struct task task;
+ /** Belongs to either the active or the inactive list. */
+ struct list_head node;
+};
+
+/* Grab clients that are attached to a btr node. */
+static INITIALIZED_LIST_HEAD(active_grab_client_list);
+/* Grab clients that are not currently attached any btr node. */
+static INITIALIZED_LIST_HEAD(inactive_grab_client_list);
static int gc_write(struct grab_client *gc, char *buf, size_t len)
{
if (gc->mode == GM_SLOPPY)
return len;
}
- ret = write_nonblock(gc->fd, buf, len, 0);
+ ret = xwrite(gc->fd, buf, len);
if (ret < 0)
goto err;
if (ret > 0)
if (ret == 0)
return;
- if (ret < 0) {
- s->timeout.tv_sec = 0;
- s->timeout.tv_usec = 0;
- return;
- }
+ if (ret < 0)
+ sched_min_delay(s);
para_fd_set(gc->fd, &s->wfds, &s->max_fileno);
}
* We need this forward declaration as post_select() needs
* activate_grab_client and vice versa.
*/
-static void gc_post_select(struct sched *s, struct task *t);
+static int gc_post_select(struct sched *s, struct task *t);
/**
* Move a grab client to the active list and start it.
*
* \param gc The grab client to activate.
- *
*/
-static void activate_grab_client(struct grab_client *gc)
+static void gc_activate(struct grab_client *gc, struct sched *s)
{
struct btr_node *root = audiod_get_btr_root(), *parent;
+ char *name = gc->name? gc->name : "grab";
if (!root)
return;
parent = btr_search_node(gc->parent, root);
if (!parent)
return;
- PARA_INFO_LOG("activating %p (fd %d)\n", gc, gc->fd);
+ PARA_INFO_LOG("activating fd %d\n", gc->fd);
list_move(&gc->node, &active_grab_client_list);
- gc->btrn = btr_new_node("grab", parent, NULL, NULL);
- if (!gc->task.pre_select) {
- gc->task.pre_select = gc_pre_select;
- gc->task.post_select = gc_post_select;
- sprintf(gc->task.status, "grab");
- register_task(&gc->task);
- }
+ gc->btrn = btr_new_node(&(struct btr_node_description)
+ EMBRACE(.name = name, .parent = parent));
+ gc->task.pre_select = gc_pre_select;
+ gc->task.post_select = gc_post_select;
+ snprintf(gc->task.status, sizeof(gc->task.status) - 1, "%s", name);
+ gc->task.status[sizeof(gc->task.status) - 1] = '\0';
+ gc->task.error = 0;
+ register_task(s, &gc->task);
}
/**
* Activate inactive grab clients if possible.
*
+ * \param s Needed to schedule the grab client task.
+ *
* This is called from audiod.c when the current audio file changes. It loops
* over all inactive grab clients and checks each grab client's configuration
* to determine if the client in question wishes to grab the new stream. If
* yes, this grab client is moved from the inactive to the active grab client list.
+ *
+ * This function also garbage collects all grab clients whose tasks have been
+ * unscheduled.
*/
-void activate_grab_clients(void)
+void activate_grab_clients(struct sched *s)
{
struct grab_client *gc, *tmp;
list_for_each_entry_safe(gc, tmp, &inactive_grab_client_list, node) {
- if (gc->task.error == -E_TASK_UNREGISTERED) {
+ if (gc->fd < 0) {
list_del(&gc->node);
free(gc);
continue;
}
- activate_grab_client(gc);
+ gc_activate(gc, s);
}
}
-static void add_inactive_gc(struct grab_client *gc)
-{
- PARA_INFO_LOG("adding grab client %p (fd %d) to inactive list\n",
- gc, gc->fd);
- para_list_add(&gc->node, &inactive_grab_client_list);
-}
-
static int gc_close(struct grab_client *gc, int err)
{
- btr_remove_node(gc->btrn);
- btr_free_node(gc->btrn);
- gc->btrn = NULL;
+ btr_remove_node(&gc->btrn);
PARA_INFO_LOG("closing gc: %s\n", para_strerror(-err));
list_move(&gc->node, &inactive_grab_client_list);
if (err == -E_GC_WRITE || (gc->flags & GF_ONE_SHOT)) {
+ /*
+ * We must not free the gc structure here as it contains ->task
+ * which is still used because this function is called from
+ * post_select().
+ */
close(gc->fd);
+ gc->fd = -1;
free(gc->parent);
+ free(gc->name);
return 1;
}
- activate_grab_client(gc);
return 0;
}
-static void gc_post_select(__a_unused struct sched *s, struct task *t)
+static int gc_post_select(__a_unused struct sched *s, struct task *t)
{
struct grab_client *gc = container_of(t, struct grab_client, task);
struct btr_node *btrn = gc->btrn;
size_t sz;
char *buf;
- t->error = 0;
ret = btr_node_status(btrn, 0, BTR_NT_LEAF);
if (ret == 0)
- return;
+ return 0;
if (ret < 0)
goto err;
sz = btr_next_buffer(btrn, &buf);
goto err;
if (ret > 0)
btr_consume(btrn, ret);
- return;
+ return 0;
err:
- t->error = gc_close(gc, ret)? ret : 0;
+ gc_close(gc, ret);
+ return ret;
}
-static int check_gc_args(int argc, char **argv, struct grab_client *gc)
+static int gc_check_args(int argc, char **argv, struct grab_client *gc)
{
int i;
gc->parent = para_strdup(arg + 3);
continue;
}
+ if (!strncmp(arg, "-n=", 3)) {
+ gc->name = para_strdup(arg + 3);
+ continue;
+ }
return -E_GC_SYNTAX;
}
if (i != argc)
* \param fd The file descriptor of the client.
* \param argc Argument count.
* \param argv Argument vector.
+ * \param s The scheduler to register the grab client task to.
*
* If the command line options given by \a argc and \a argv are valid.
* allocate a struct grab_client and initialize it with this valid
- * configuration. Moreover, add the new grab client to the inactive list.
+ * configuration.
*
- * \return Standard.
+ * If the new grab client can be added to an existing buffer tree, activate it.
+ * Otherwise, add it to the inactive list for later activation.
*
- * \sa grab_client, inactive_grab_client_list, activate_grab_client,
- * filter_node::callbacks.
+ * \return Standard.
*/
-int grab_client_new(int fd, int argc, char **argv)
+int grab_client_new(int fd, int argc, char **argv, struct sched *s)
{
int ret;
struct grab_client *gc = para_calloc(sizeof(struct grab_client));
- ret = check_gc_args(argc, argv, gc);
+ ret = gc_check_args(argc, argv, gc);
if (ret < 0)
goto err_out;
gc->fd = fd;
- add_inactive_gc(gc);
- activate_grab_client(gc);
+ para_list_add(&gc->node, &inactive_grab_client_list);
+ gc_activate(gc, s);
return 1;
err_out:
free(gc);
return ret;
}
-
-/**
- * Initialize the grabbing subsystem.
- *
- * This has to be called once during startup before any other function from
- * grab_client.c may be used. It initializes \a inactive_grab_client_list.
- */
-void init_grabbing(void)
-{
- PARA_INFO_LOG("grab init\n");
- INIT_LIST_HEAD(&inactive_grab_client_list);
- INIT_LIST_HEAD(&active_grab_client_list);
-}
projects / paraslash.git / blobdiff