2 * Copyright (C) 2006-2010 Andre Noll <maan@systemlinux.org>
4 * Licensed under the GPL v2. For licencing details see COPYING.
7 /** \file grab_client.c Functions for grabbing the audio stream. */
10 #include <sys/types.h>
18 #include "buffer_tree.h"
20 #include "grab_client.h"
27 * How to handle blocking writes for the grab client fds.
30 /** Ignore the data and do not write. */
32 /** Write anyway (default). */
34 /** Close fd if write would block. */
38 /** Flags specified as arguments to the grab command. */
40 /** Stop grabbing if audio file changes. */
44 /** Describes one active grab client. */
46 /* The value of the -p option. */
48 /* The value of the -n option. */
50 /** The file descriptor to send the grabbed stream to. */
52 /** See \ref grab_mode. */
54 /** Flags given at the command line. */
55 enum grab_flags flags
;
56 /** The point of the grab client's node in the buffer tree. */
57 struct btr_node
*btrn
;
58 /* The task of this grab client. */
60 /** Belongs to either the active or the inactive list. */
61 struct list_head node
;
64 /* Grab clients that are attached to a btr node. */
65 INITIALIZED_LIST_HEAD(active_grab_client_list
);
66 /* Grab clients that are not currently attached any btr node. */
67 INITIALIZED_LIST_HEAD(inactive_grab_client_list
);
69 static int gc_write(struct grab_client
*gc
, char *buf
, size_t len
)
71 int ret
= write_ok(gc
->fd
);
75 if (ret
== 0) { /* fd not ready */
76 if (gc
->mode
== GM_PEDANTIC
)
78 if (gc
->mode
== GM_SLOPPY
)
81 ret
= write_nonblock(gc
->fd
, buf
, len
);
87 if (gc
->mode
== GM_PEDANTIC
)
89 if (gc
->mode
== GM_SLOPPY
)
97 static void gc_pre_select(struct sched
*s
, struct task
*t
)
99 struct grab_client
*gc
= container_of(t
, struct grab_client
, task
);
100 int ret
= btr_node_status(gc
->btrn
, 0, BTR_NT_LEAF
);
105 s
->timeout
.tv_sec
= 0;
106 s
->timeout
.tv_usec
= 0;
109 para_fd_set(gc
->fd
, &s
->wfds
, &s
->max_fileno
);
113 * We need this forward declaration as post_select() needs
114 * activate_grab_client and vice versa.
116 static void gc_post_select(struct sched
*s
, struct task
*t
);
119 * Move a grab client to the active list and start it.
121 * \param gc The grab client to activate.
123 static void gc_activate(struct grab_client
*gc
)
125 struct btr_node
*root
= audiod_get_btr_root(), *parent
;
126 char *name
= gc
->name
? gc
->name
: "grab";
130 parent
= btr_search_node(gc
->parent
, root
);
133 PARA_INFO_LOG("activating fd %d\n", gc
->fd
);
134 list_move(&gc
->node
, &active_grab_client_list
);
135 gc
->btrn
= btr_new_node(&(struct btr_node_description
)
136 EMBRACE(.name
= name
, .parent
= parent
));
137 if (!gc
->task
.pre_select
) {
138 gc
->task
.pre_select
= gc_pre_select
;
139 gc
->task
.post_select
= gc_post_select
;
140 snprintf(gc
->task
.status
, sizeof(gc
->task
.status
) - 1, "%s", name
);
141 gc
->task
.status
[sizeof(gc
->task
.status
) - 1] = '\0';
142 register_task(&gc
->task
);
147 * Activate inactive grab clients if possible.
149 * This is called from audiod.c when the current audio file changes. It loops
150 * over all inactive grab clients and checks each grab client's configuration
151 * to determine if the client in question wishes to grab the new stream. If
152 * yes, this grab client is moved from the inactive to the active grab client list.
154 * This function also garbage collects all grab clients whose tasks have been
157 void activate_grab_clients(void)
159 struct grab_client
*gc
, *tmp
;
161 list_for_each_entry_safe(gc
, tmp
, &inactive_grab_client_list
, node
) {
162 if (gc
->task
.error
== -E_TASK_UNREGISTERED
) {
171 static int gc_close(struct grab_client
*gc
, int err
)
173 btr_remove_node(gc
->btrn
);
174 btr_free_node(gc
->btrn
);
176 PARA_INFO_LOG("closing gc: %s\n", para_strerror(-err
));
177 list_move(&gc
->node
, &inactive_grab_client_list
);
178 if (err
== -E_GC_WRITE
|| (gc
->flags
& GF_ONE_SHOT
)) {
180 * We must not free the gc structure here as it contains ->task
181 * which is still used because this function is called from
193 static void gc_post_select(__a_unused
struct sched
*s
, struct task
*t
)
195 struct grab_client
*gc
= container_of(t
, struct grab_client
, task
);
196 struct btr_node
*btrn
= gc
->btrn
;
202 ret
= btr_node_status(btrn
, 0, BTR_NT_LEAF
);
207 sz
= btr_next_buffer(btrn
, &buf
);
209 ret
= gc_write(gc
, buf
, sz
);
213 btr_consume(btrn
, ret
);
216 t
->error
= gc_close(gc
, ret
)? ret
: 0;
219 static int gc_check_args(int argc
, char **argv
, struct grab_client
*gc
)
223 for (i
= 1; i
< argc
; i
++) {
224 const char *arg
= argv
[i
];
227 if (!strcmp(arg
, "--")) {
231 if (!strncmp(arg
, "-m", 2)) {
236 gc
->mode
= GM_SLOPPY
;
239 gc
->mode
= GM_AGGRESSIVE
;
242 gc
->mode
= GM_PEDANTIC
;
248 if (!strcmp(arg
, "-o")) {
249 gc
->flags
|= GF_ONE_SHOT
;
252 if (!strncmp(arg
, "-p=", 3)) {
253 gc
->parent
= para_strdup(arg
+ 3);
256 if (!strncmp(arg
, "-n=", 3)) {
257 gc
->name
= para_strdup(arg
+ 3);
268 * Check the command line options and allocate a grab_client structure.
270 * \param fd The file descriptor of the client.
271 * \param argc Argument count.
272 * \param argv Argument vector.
274 * If the command line options given by \a argc and \a argv are valid.
275 * allocate a struct grab_client and initialize it with this valid
278 * If the new grab client can be added to an existing buffer tree, activate it.
279 * Otherwise, add it to the inactive list for later activation.
283 int grab_client_new(int fd
, int argc
, char **argv
)
286 struct grab_client
*gc
= para_calloc(sizeof(struct grab_client
));
288 ret
= gc_check_args(argc
, argv
, gc
);
292 para_list_add(&gc
->node
, &inactive_grab_client_list
);