banish fd passing. currently a bit ugly but seems to work

diff --git a/lib/speaker-protocol.c b/lib/speaker-protocol.c
index 1c5199aa9ec9c736d3ef7dd50fc785078cbbf06b..ab8b4ee9354d85e9dbb08583a5b06591ee290609 100644 (file)
--- a/lib/speaker-protocol.c
+++ b/lib/speaker-protocol.c
@@ -27,7 +27,8 @@
 #include <sys/socket.h>
 #include <string.h>
 #include <errno.h>
 #include <sys/socket.h>
 #include <string.h>
 #include <errno.h>

-#include <sys/uio.h>
+#include <unistd.h>
+#include <stddef.h>

 
 #include "speaker-protocol.h"
 #include "log.h"
 
 #include "speaker-protocol.h"
 #include "log.h"


@@ -35,85 +36,32 @@
 /** @brief Send a speaker message
  * @param fd File descriptor to send to
  * @param sm Pointer to message
 /** @brief Send a speaker message
  * @param fd File descriptor to send to
  * @param sm Pointer to message

- * @param datafd File descriptoxr to pass with message or -1
- *
- * @p datafd will be the output from some decoder.

  */
  */

-void speaker_send(int fd, const struct speaker_message *sm, int datafd) {
-  struct msghdr m;
-  struct iovec iov;
-  union {
-    struct cmsghdr cmsg;
-    char size[CMSG_SPACE(sizeof (int))];
-  } u;
+void speaker_send(int fd, const struct speaker_message *sm) {

   int ret;
 
   int ret;
 

-  memset(&m, 0, sizeof m);
-  m.msg_iov = &iov;
-  m.msg_iovlen = 1;
-  iov.iov_base = (void *)sm;
-  iov.iov_len = sizeof *sm;
-  if(datafd != -1) {
-    m.msg_control = (void *)&u.cmsg;
-    m.msg_controllen = sizeof u;
-    memset(&u, 0, sizeof u);
-    u.cmsg.cmsg_len = CMSG_LEN(sizeof (int));
-    u.cmsg.cmsg_level = SOL_SOCKET;
-    u.cmsg.cmsg_type = SCM_RIGHTS;
-    *(int *)CMSG_DATA(&u.cmsg) = datafd;
-  }

   do {
   do {

-    ret = sendmsg(fd, &m, 0);
+    ret = write(fd, sm, sizeof *sm);

   } while(ret < 0 && errno == EINTR);
   if(ret < 0)
   } while(ret < 0 && errno == EINTR);
   if(ret < 0)

-    fatal(errno, "sendmsg");
+    fatal(errno, "write");

 }
 
 /** @brief Receive a speaker message
  * @param fd File descriptor to read from
  * @param sm Where to store received message
 }
 
 /** @brief Receive a speaker message
  * @param fd File descriptor to read from
  * @param sm Where to store received message

- * @param datafd Where to store received file descriptor or NULL

  * @return -ve on @c EAGAIN, 0 at EOF, +ve on success
  * @return -ve on @c EAGAIN, 0 at EOF, +ve on success

- *
- * If @p datafd is NULL but a file descriptor is nonetheless received,
- * the process is terminated with an error.

  */
  */

-int speaker_recv(int fd, struct speaker_message *sm, int *datafd) {
-  struct msghdr m;
-  struct iovec iov;
-  union {
-    struct cmsghdr cmsg;
-    char size[CMSG_SPACE(sizeof (int))];
-  } u;
+int speaker_recv(int fd, struct speaker_message *sm) {

   int ret;
 
   int ret;
 

-  memset(&m, 0, sizeof m);
-  m.msg_iov = &iov;
-  m.msg_iovlen = 1;
-  iov.iov_base = (void *)sm;
-  iov.iov_len = sizeof *sm;
-  if(datafd) {
-    m.msg_control = (void *)&u.cmsg;
-    m.msg_controllen = sizeof u;
-    memset(&u, 0, sizeof u);
-    u.cmsg.cmsg_len = CMSG_LEN(sizeof (int));
-    u.cmsg.cmsg_level = SOL_SOCKET;
-    u.cmsg.cmsg_type = SCM_RIGHTS;
-    *datafd = -1;
-  }

   do {
   do {

-    ret = recvmsg(fd, &m, MSG_DONTWAIT);
+    ret = read(fd, sm, sizeof *sm);

   } while(ret < 0 && errno == EINTR);
   if(ret < 0) {
     if(errno != EAGAIN) fatal(errno, "recvmsg");
     return -1;
   }
   } while(ret < 0 && errno == EINTR);
   if(ret < 0) {
     if(errno != EAGAIN) fatal(errno, "recvmsg");
     return -1;
   }

-  if((size_t)m.msg_controllen >= CMSG_LEN(sizeof (int))) {
-    if(!datafd)
-      fatal(0, "got an unexpected file descriptor from recvmsg");
-    else
-      *datafd = *(int *)CMSG_DATA(&u.cmsg);
-  }

   return ret;
 }
 
   return ret;
 }
 

diff --git a/lib/speaker-protocol.h b/lib/speaker-protocol.h
index 8809f0ff60d6eb086a5ab39b5fca79ab601e4560..b271373a1a129066cc5b4f5f2c54ebc8935eb4ef 100644 (file)
--- a/lib/speaker-protocol.h
+++ b/lib/speaker-protocol.h
@@ -32,7 +32,6 @@ struct speaker_message {
   /** @brief Message type
    *
    * Messges from the main server:
   /** @brief Message type
    *
    * Messges from the main server:

-   * - @ref SM_PREPARE

    * - @ref SM_PLAY
    * - @ref SM_PAUSE
    * - @ref SM_RESUME
    * - @ref SM_PLAY
    * - @ref SM_PAUSE
    * - @ref SM_RESUME


@@ -54,12 +53,6 @@ struct speaker_message {
 };
 
 /* messages from the main DisOrder server */
 };
 
 /* messages from the main DisOrder server */

-/** @brief Prepare track @c id
- *
- * This message will include a file descriptor.  The speaker starts buffering
- * audio data read from this file against the time that it must be played.
- */
-#define SM_PREPARE 0

 
 /** @brief Play track @c id
  *
 
 /** @brief Play track @c id
  *


@@ -96,13 +89,12 @@ struct speaker_message {
  */
 #define SM_PLAYING 131
 
  */
 #define SM_PLAYING 131
 

-void speaker_send(int fd, const struct speaker_message *sm, int datafd);
-/* Send a message.  DATAFD is passed too if not -1.  Does not close DATAFD. */
+void speaker_send(int fd, const struct speaker_message *sm);
+/* Send a message. */

 
 

-int speaker_recv(int fd, struct speaker_message *sm, int *datafd);
-/* Receive a message.  If DATAFD is not null then can receive an FD.  Return 0
- * on EOF, +ve if a message is read, -1 on EAGAIN, terminates on any other
- * error. */
+int speaker_recv(int fd, struct speaker_message *sm);
+/* Receive a message.  Return 0 on EOF, +ve if a message is read, -1 on EAGAIN,
+ * terminates on any other error. */

 
 /** @brief One chunk in a stream */
 struct stream_header {
 
 /** @brief One chunk in a stream */
 struct stream_header {

diff --git a/server/play.c b/server/play.c
index b50e19b7ceccecbb53c42338b51b8102accc08c9..1530fe8a29fd55e0f7f75074dbc579dd7ce3d033 100644 (file)
--- a/server/play.c
+++ b/server/play.c
@@ -36,6 +36,7 @@
 #include <pcre.h>
 #include <ao/ao.h>
 #include <sys/wait.h>
 #include <pcre.h>
 #include <ao/ao.h>
 #include <sys/wait.h>

+#include <sys/un.h>

 
 #include "event.h"
 #include "log.h"
 
 #include "event.h"
 #include "log.h"


@@ -95,7 +96,7 @@ static int speaker_terminated(ev_source attribute((unused)) *ev,
 static int speaker_readable(ev_source *ev, int fd,
                            void attribute((unused)) *u) {
   struct speaker_message sm;
 static int speaker_readable(ev_source *ev, int fd,
                            void attribute((unused)) *u) {
   struct speaker_message sm;

-  int ret = speaker_recv(fd, &sm, 0);
+  int ret = speaker_recv(fd, &sm);

   
   if(ret < 0) return 0;                        /* EAGAIN */
   if(!ret) {                           /* EOF */
   
   if(ret < 0) return 0;                        /* EAGAIN */
   if(!ret) {                           /* EOF */


@@ -169,7 +170,7 @@ void speaker_reload(void) {
 
   memset(&sm, 0, sizeof sm);
   sm.type = SM_RELOAD;
 
   memset(&sm, 0, sizeof sm);
   sm.type = SM_RELOAD;

-  speaker_send(speaker_fd, &sm, -1);
+  speaker_send(speaker_fd, &sm);

 }
 
 /* timeout for play retry */
 }
 
 /* timeout for play retry */


@@ -238,9 +239,9 @@ static int player_finished(ev_source *ev,
   switch(q->state) {
   case playing_unplayed:
   case playing_random:
   switch(q->state) {
   case playing_unplayed:
   case playing_random:

-    /* If this was an SM_PREPARE track then either it failed or we deliberately
-     * stopped it because it was removed from the queue or moved down it.  So
-     * leave it state alone for future use. */
+    /* If this was a pre-prepared track then either it failed or we
+     * deliberately stopped it because it was removed from the queue or moved
+     * down it.  So leave it state alone for future use. */

     break;
   default:
     /* We actually started playing this track. */
     break;
   default:
     /* We actually started playing this track. */


@@ -285,13 +286,18 @@ static int find_player(const struct queue_entry *q) {
 #define START_HARDFAIL 1               /* Track is broken. */
 #define START_SOFTFAIL 2          /* Track OK, system (temporarily?) broken */
 
 #define START_HARDFAIL 1               /* Track is broken. */
 #define START_SOFTFAIL 2          /* Track OK, system (temporarily?) broken */
 

-/* Play or prepare Q */
+/** @brief Play or prepare @p q
+ * @param ev Event loop
+ * @param q Track to play/prepare
+ * @param prepare_only If true, only prepares track
+ * @return @ref START_OK, @ref START_HARDFAIL or @ref START_SOFTFTAIL
+ */

 static int start(ev_source *ev,
                 struct queue_entry *q,
 static int start(ev_source *ev,
                 struct queue_entry *q,

-                int smop) {
+                int prepare_only) {

   int n, lfd;
   const char *p;
   int n, lfd;
   const char *p;

-  int np[2], sp[2];
+  int np[2], sfd;

   struct speaker_message sm;
   char buffer[64];
   int optc;
   struct speaker_message sm;
   char buffer[64];
   int optc;


@@ -302,16 +308,19 @@ static int start(ev_source *ev,
   const char *waitdevice = 0;
   const char *const *optv;
   pid_t pid, npid;
   const char *waitdevice = 0;
   const char *const *optv;
   pid_t pid, npid;

+  struct sockaddr_un addr;
+  uint32_t l;

 
   memset(&sm, 0, sizeof sm);
 
   memset(&sm, 0, sizeof sm);

+  D(("start %s %d", q->id, prepare_only));

   if(find_player_pid(q->id) > 0) {
   if(find_player_pid(q->id) > 0) {

-    if(smop == SM_PREPARE) return START_OK;
-    /* We have already sent an SM_PREPARE for this track so we just need to
-     * tell the speaker process to start actually playing the queued up audio
-     * data */
+    if(prepare_only) return START_OK;
+    /* We have already prepared this track so we just need to tell the speaker
+     * process to start actually playing the queued up audio data */

     strcpy(sm.id, q->id);
     sm.type = SM_PLAY;
     strcpy(sm.id, q->id);
     sm.type = SM_PLAY;

-    speaker_send(speaker_fd, &sm, -1);
+    speaker_send(speaker_fd, &sm);
+    D(("sent SM_PLAY for %s", sm.id));

     return START_OK;
   }
   /* Find the player plugin. */
     return START_OK;
   }
   /* Find the player plugin. */


@@ -320,7 +329,7 @@ static int start(ev_source *ev,
     return START_HARDFAIL;
   q->type = play_get_type(q->pl);
   /* Can't prepare non-raw tracks. */
     return START_HARDFAIL;
   q->type = play_get_type(q->pl);
   /* Can't prepare non-raw tracks. */

-  if(smop == SM_PREPARE
+  if(prepare_only

      && (q->type & DISORDER_PLAYER_TYPEMASK) != DISORDER_PLAYER_RAW)
     return START_OK;
   /* Call the prefork function. */
      && (q->type & DISORDER_PLAYER_TYPEMASK) != DISORDER_PLAYER_RAW)
     return START_OK;
   /* Call the prefork function. */


@@ -365,52 +374,62 @@ static int start(ev_source *ev,
     xclose(lfd);                       /* tidy up */
     setpgid(0, 0);
     if((q->type & DISORDER_PLAYER_TYPEMASK) == DISORDER_PLAYER_RAW) {
     xclose(lfd);                       /* tidy up */
     setpgid(0, 0);
     if((q->type & DISORDER_PLAYER_TYPEMASK) == DISORDER_PLAYER_RAW) {

-      /* "Raw" format players need special treatment:
-       * 1) their output needs to go via the disorder-normalize process
-       * 2) the output of that needs to be passed to the disorder-speaker
-       *    process.
+      /* "Raw" format players always have their output send down a pipe
+       * to the disorder-normalize process.  This will connect to the
+       * speaker process to actually play the audio data.

        */
       /* np will be the pipe to disorder-normalize */
       if(socketpair(PF_UNIX, SOCK_STREAM, 0, np) < 0)
        fatal(errno, "error calling socketpair");
       xshutdown(np[0], SHUT_WR);       /* normalize reads from np[0] */
       xshutdown(np[1], SHUT_RD);       /* decoder writes to np[1] */
        */
       /* np will be the pipe to disorder-normalize */
       if(socketpair(PF_UNIX, SOCK_STREAM, 0, np) < 0)
        fatal(errno, "error calling socketpair");
       xshutdown(np[0], SHUT_WR);       /* normalize reads from np[0] */
       xshutdown(np[1], SHUT_RD);       /* decoder writes to np[1] */

-      /* sp will be the pipe to disorder-speaker */
-      sm.type = smop;
-      if(socketpair(PF_UNIX, SOCK_STREAM, 0, sp) < 0)
-       fatal(errno, "error calling socketpair");
-      xshutdown(sp[0], SHUT_WR);       /* speaker reads from sp[0] */
-      xshutdown(sp[1], SHUT_RD);       /* normalize writes to sp[1] */

       /* Start disorder-normalize */
       if(!(npid = xfork())) {
        if(!xfork()) {
       /* Start disorder-normalize */
       if(!(npid = xfork())) {
        if(!xfork()) {

+         /* Connect to the speaker process */
+         memset(&addr, 0, sizeof addr);
+         addr.sun_family = AF_UNIX;
+         snprintf(addr.sun_path, sizeof addr.sun_path,
+                  "%s/speaker", config->home);
+         sfd = xsocket(PF_UNIX, SOCK_STREAM, 0);
+         if(connect(sfd, &addr, sizeof addr) < 0)
+           fatal(errno, "connecting to %s", addr.sun_path);
+         l = strlen(q->id);
+         if(write(sfd, &l, sizeof l) < 0
+            || write(sfd, q->id, l) < 0)
+           fatal(errno, "writing to %s", addr.sun_path);
+         /* Await the ack */
+         read(sfd, &l, 1);
+         /* Plumbing */

          xdup2(np[0], 0);
          xdup2(np[0], 0);

-         xdup2(sp[1], 1);
+         xdup2(sfd, 1);

          xclose(np[0]);
          xclose(np[1]);
          xclose(np[0]);
          xclose(np[1]);

-         xclose(sp[0]);
-         xclose(sp[1]);
+         xclose(sfd);
+         /* Ask the speaker to actually start playing the track; we do it here
+          * so it's definitely after ack. */
+         if(!prepare_only) {
+           strcpy(sm.id, q->id);
+           sm.type = SM_PLAY;
+           speaker_send(speaker_fd, &sm);
+           D(("sent SM_PLAY for %s", sm.id));
+         }

          execlp("disorder-normalize", "disorder-normalize", (char *)0);
          fatal(errno, "executing disorder-normalize");
          execlp("disorder-normalize", "disorder-normalize", (char *)0);
          fatal(errno, "executing disorder-normalize");

+         /* end of the innermost fork */

        }
        _exit(0);
        }
        _exit(0);

-      } else {
-       int w;
-
-       while(waitpid(npid, &w, 0) < 0 && errno == EINTR)
-         ;
+       /* end of the middle fork */

       }
       }

-      /* Send the speaker process the file descriptor to read from */
-      strcpy(sm.id, q->id);
-      speaker_send(speaker_fd, &sm, sp[0]);
+      /* Wait for the middle fork to finish */
+      while(waitpid(npid, &n, 0) < 0 && errno == EINTR)
+       ;

       /* Pass the file descriptor to the driver in an environment
        * variable. */
       snprintf(buffer, sizeof buffer, "DISORDER_RAW_FD=%d", np[1]);
       if(putenv(buffer) < 0)
        fatal(errno, "error calling putenv");
       /* Close all the FDs we don't need */
       /* Pass the file descriptor to the driver in an environment
        * variable. */
       snprintf(buffer, sizeof buffer, "DISORDER_RAW_FD=%d", np[1]);
       if(putenv(buffer) < 0)
        fatal(errno, "error calling putenv");
       /* Close all the FDs we don't need */

-      xclose(sp[0]);
-      xclose(sp[1]);

       xclose(np[0]);
     }
     if(waitdevice) {
       xclose(np[0]);
     }
     if(waitdevice) {


@@ -466,7 +485,7 @@ int prepare(ev_source *ev,
   q->type = play_get_type(q->pl);
   if((q->type & DISORDER_PLAYER_TYPEMASK) != DISORDER_PLAYER_RAW)
     return 0;                          /* Not a raw player */
   q->type = play_get_type(q->pl);
   if((q->type & DISORDER_PLAYER_TYPEMASK) != DISORDER_PLAYER_RAW)
     return 0;                          /* Not a raw player */

-  return start(ev, q, SM_PREPARE);     /* Prepare it */
+  return start(ev, q, 1/*prepare_only*/); /* Prepare it */

 }
 
 void abandon(ev_source attribute((unused)) *ev,
 }
 
 void abandon(ev_source attribute((unused)) *ev,


@@ -484,7 +503,7 @@ void abandon(ev_source attribute((unused)) *ev,
   memset(&sm, 0, sizeof sm);
   sm.type = SM_CANCEL;
   strcpy(sm.id, q->id);
   memset(&sm, 0, sizeof sm);
   sm.type = SM_CANCEL;
   strcpy(sm.id, q->id);

-  speaker_send(speaker_fd, &sm, -1);
+  speaker_send(speaker_fd, &sm);

 }
 
 int add_random_track(void) {
 }
 
 int add_random_track(void) {


@@ -542,7 +561,7 @@ void play(ev_source *ev) {
     return;
   D(("taken %p (%s) from queue", (void *)q, q->track));
   /* Try to start playing. */
     return;
   D(("taken %p (%s) from queue", (void *)q, q->track));
   /* Try to start playing. */

-  switch(start(ev, q, SM_PLAY)) {
+  switch(start(ev, q, 0/*!prepare_only*/)) {

   case START_HARDFAIL:
     if(q == qhead.next) {
       queue_remove(q, 0);              /* Abandon this track. */
   case START_HARDFAIL:
     if(q == qhead.next) {
       queue_remove(q, 0);              /* Abandon this track. */


@@ -645,7 +664,7 @@ void scratch(const char *who, const char *id) {
       memset(&sm, 0, sizeof sm);
       sm.type = SM_CANCEL;
       strcpy(sm.id, playing->id);
       memset(&sm, 0, sizeof sm);
       sm.type = SM_CANCEL;
       strcpy(sm.id, playing->id);

-      speaker_send(speaker_fd, &sm, -1);
+      speaker_send(speaker_fd, &sm);

       D(("sending SM_CANCEL for %s", playing->id));
     }
     /* put a scratch track onto the front of the queue (but don't
       D(("sending SM_CANCEL for %s", playing->id));
     }
     /* put a scratch track onto the front of the queue (but don't


@@ -713,7 +732,7 @@ int pause_playing(const char *who) {
   case DISORDER_PLAYER_RAW:
     memset(&sm, 0, sizeof sm);
     sm.type = SM_PAUSE;
   case DISORDER_PLAYER_RAW:
     memset(&sm, 0, sizeof sm);
     sm.type = SM_PAUSE;

-    speaker_send(speaker_fd, &sm, -1);
+    speaker_send(speaker_fd, &sm);

     break;
   }
   if(who) info("paused by %s", who);
     break;
   }
   if(who) info("paused by %s", who);


@@ -744,7 +763,7 @@ void resume_playing(const char *who) {
   case DISORDER_PLAYER_RAW:
     memset(&sm, 0, sizeof sm);
     sm.type = SM_RESUME;
   case DISORDER_PLAYER_RAW:
     memset(&sm, 0, sizeof sm);
     sm.type = SM_RESUME;

-    speaker_send(speaker_fd, &sm, -1);
+    speaker_send(speaker_fd, &sm);

     break;
   }
   if(who) info("resumed by %s", who);
     break;
   }
   if(who) info("resumed by %s", who);

diff --git a/server/speaker.c b/server/speaker.c
index 70d21625c23dab914c13533bbb5f43c4b899051b..11916c15a9b524a66120cf93ddac21ad38682f1e 100644 (file)
--- a/server/speaker.c
+++ b/server/speaker.c
@@ -66,6 +66,7 @@
 #include <time.h>
 #include <fcntl.h>
 #include <poll.h>
 #include <time.h>
 #include <fcntl.h>
 #include <poll.h>

+#include <sys/un.h>

 
 #include "configuration.h"
 #include "syscalls.h"
 
 #include "configuration.h"
 #include "syscalls.h"


@@ -91,6 +92,9 @@ struct pollfd fds[NFDS];
 /** @brief Next free slot in @ref fds */
 int fdno;
 
 /** @brief Next free slot in @ref fds */
 int fdno;
 

+/** @brief Listen socket */
+static int listenfd;
+

 static time_t last_report;              /* when we last reported */
 static int paused;                      /* pause status */
 
 static time_t last_report;              /* when we last reported */
 static int paused;                      /* pause status */
 


@@ -179,15 +183,6 @@ static void destroy(struct track *t) {
   free(t);
 }
 
   free(t);
 }
 

-/** @brief Notice a new connection */
-static void acquire(struct track *t, int fd) {
-  D(("acquire %s %d", t->id, fd));
-  if(t->fd != -1)
-    xclose(t->fd);
-  t->fd = fd;
-  nonblock(fd);
-}
-

 /** @brief Read data into a sample buffer
  * @param t Pointer to track
  * @return 0 on success, -1 on EOF
 /** @brief Read data into a sample buffer
  * @param t Pointer to track
  * @return 0 on success, -1 on EOF


@@ -249,7 +244,7 @@ void abandon(void) {
   memset(&sm, 0, sizeof sm);
   sm.type = SM_FINISHED;
   strcpy(sm.id, playing->id);
   memset(&sm, 0, sizeof sm);
   sm.type = SM_FINISHED;
   strcpy(sm.id, playing->id);

-  speaker_send(1, &sm, 0);
+  speaker_send(1, &sm);

   removetrack(playing->id);
   destroy(playing);
   playing = 0;
   removetrack(playing->id);
   destroy(playing);
   playing = 0;


@@ -350,7 +345,7 @@ static void report(void) {
     sm.type = paused ? SM_PAUSED : SM_PLAYING;
     strcpy(sm.id, playing->id);
     sm.data = playing->played / config->sample_format.rate;
     sm.type = paused ? SM_PAUSED : SM_PLAYING;
     strcpy(sm.id, playing->id);
     sm.data = playing->played / config->sample_format.rate;

-    speaker_send(1, &sm, 0);
+    speaker_send(1, &sm);

   }
   time(&last_report);
 }
   }
   time(&last_report);
 }


@@ -400,7 +395,7 @@ static int playable(void) {
 static void mainloop(void) {
   struct track *t;
   struct speaker_message sm;
 static void mainloop(void) {
   struct track *t;
   struct speaker_message sm;

-  int n, fd, stdin_slot, timeout;
+  int n, fd, stdin_slot, timeout, listen_slot;

 
   while(getppid() != 1) {
     fdno = 0;
 
   while(getppid() != 1) {
     fdno = 0;


@@ -409,9 +404,14 @@ static void mainloop(void) {
     timeout = 1000;
     /* Always ready for commands from the main server. */
     stdin_slot = addfd(0, POLLIN);
     timeout = 1000;
     /* Always ready for commands from the main server. */
     stdin_slot = addfd(0, POLLIN);

+    /* Also always ready for inbound connections */
+    listen_slot = addfd(listenfd, POLLIN);

     /* Try to read sample data for the currently playing track if there is
      * buffer space. */
     /* Try to read sample data for the currently playing track if there is
      * buffer space. */

-    if(playing && !playing->eof && playing->used < (sizeof playing->buffer))
+    if(playing
+       && playing->fd >= 0
+       && !playing->eof
+       && playing->used < (sizeof playing->buffer))

       playing->slot = addfd(playing->fd, POLLIN);
     else if(playing)
       playing->slot = -1;
       playing->slot = addfd(playing->fd, POLLIN);
     else if(playing)
       playing->slot = -1;


@@ -432,7 +432,9 @@ static void mainloop(void) {
      * nothing important can't be monitored. */
     for(t = tracks; t; t = t->next)
       if(t != playing) {
      * nothing important can't be monitored. */
     for(t = tracks; t; t = t->next)
       if(t != playing) {

-        if(!t->eof && t->used < sizeof t->buffer) {
+        if(t->fd >= 0
+           && !t->eof
+           && t->used < sizeof t->buffer) {

           t->slot = addfd(t->fd,  POLLIN | POLLHUP);
         } else
           t->slot = -1;
           t->slot = addfd(t->fd,  POLLIN | POLLHUP);
         } else
           t->slot = -1;


@@ -459,25 +461,54 @@ static void mainloop(void) {
         play(3 * FRAMES);
       }
     }
         play(3 * FRAMES);
       }
     }

+    /* Perhaps a connection has arrived */
+    if(fds[listen_slot].revents & POLLIN) {
+      struct sockaddr_un addr;
+      socklen_t addrlen = sizeof addr;
+      uint32_t l;
+      char id[24];
+
+      if((fd = accept(listenfd, &addr, &addrlen)) >= 0) {
+        if(read(fd, &l, sizeof l) < 4) {
+          error(errno, "reading length from inbound connection");
+          xclose(fd);
+        } else if(l >= sizeof id) {
+          error(0, "id length too long");
+          xclose(fd);
+        } else if(read(fd, id, l) < (ssize_t)l) {
+          error(errno, "reading id from inbound connection");
+          xclose(fd);
+        } else {
+          id[l] = 0;
+          D(("id %s fd %d", id, fd));
+          t = findtrack(id, 1/*create*/);
+          write(fd, "", 1);             /* write an ack */
+          if(t->fd != -1) {
+            error(0, "got a connection for a track that already has one");
+            xclose(fd);
+          } else {
+            nonblock(fd);
+            t->fd = fd;               /* yay */
+          }
+        }
+      } else
+        error(errno, "accept");
+    }

     /* Perhaps we have a command to process */
     if(fds[stdin_slot].revents & POLLIN) {
       /* There might (in theory) be several commands queued up, but in general
        * this won't be the case, so we don't bother looping around to pick them
        * all up. */ 
     /* Perhaps we have a command to process */
     if(fds[stdin_slot].revents & POLLIN) {
       /* There might (in theory) be several commands queued up, but in general
        * this won't be the case, so we don't bother looping around to pick them
        * all up. */ 

-      n = speaker_recv(0, &sm, &fd);
+      n = speaker_recv(0, &sm);
+      /* TODO */

       if(n > 0)
        switch(sm.type) {
       if(n > 0)
        switch(sm.type) {

-       case SM_PREPARE:
-          D(("SM_PREPARE %s %d", sm.id, fd));
-         if(fd == -1) fatal(0, "got SM_PREPARE but no file descriptor");
-         t = findtrack(sm.id, 1);
-          acquire(t, fd);
-         break;

        case SM_PLAY:
        case SM_PLAY:

-          D(("SM_PLAY %s %d", sm.id, fd));

           if(playing) fatal(0, "got SM_PLAY but already playing something");
          t = findtrack(sm.id, 1);
           if(playing) fatal(0, "got SM_PLAY but already playing something");
          t = findtrack(sm.id, 1);

-          if(fd != -1) acquire(t, fd);
+          D(("SM_PLAY %s fd %d", t->id, t->fd));
+          if(t->fd == -1)
+            error(0, "cannot play track because no connection arrived");

           playing = t;
           /* We attempt to play straight away rather than going round the loop.
            * play() is clever enough to perform any activation that is
           playing = t;
           /* We attempt to play straight away rather than going round the loop.
            * play() is clever enough to perform any activation that is


@@ -507,7 +538,7 @@ static void mainloop(void) {
            if(t == playing) {
               sm.type = SM_FINISHED;
               strcpy(sm.id, playing->id);
            if(t == playing) {
               sm.type = SM_FINISHED;
               strcpy(sm.id, playing->id);

-              speaker_send(1, &sm, 0);
+              speaker_send(1, &sm);

              playing = 0;
             }
            destroy(t);
              playing = 0;
             }
            destroy(t);


@@ -526,7 +557,9 @@ static void mainloop(void) {
     }
     /* Read in any buffered data */
     for(t = tracks; t; t = t->next)
     }
     /* Read in any buffered data */
     for(t = tracks; t; t = t->next)

-      if(t->slot != -1 && (fds[t->slot].revents & (POLLIN | POLLHUP)))
+      if(t->fd != -1
+         && t->slot != -1
+         && (fds[t->slot].revents & (POLLIN | POLLHUP)))

          fill(t);
     /* Maybe we finished playing a track somewhere in the above */
     maybe_finished();
          fill(t);
     /* Maybe we finished playing a track somewhere in the above */
     maybe_finished();


@@ -542,6 +575,8 @@ static void mainloop(void) {
 
 int main(int argc, char **argv) {
   int n;
 
 int main(int argc, char **argv) {
   int n;

+  struct sockaddr_un addr;
+  static const int one = 1;

 
   set_progname(argv);
   if(!setlocale(LC_CTYPE, "")) fatal(errno, "error calling setlocale");
 
   set_progname(argv);
   if(!setlocale(LC_CTYPE, "")) fatal(errno, "error calling setlocale");


@@ -582,6 +617,20 @@ int main(int argc, char **argv) {
   backend = backends[n];
   /* backend-specific initialization */
   backend->init();
   backend = backends[n];
   /* backend-specific initialization */
   backend->init();

+  /* set up the listen socket */
+  listenfd = xsocket(PF_UNIX, SOCK_STREAM, 0);
+  memset(&addr, 0, sizeof addr);
+  addr.sun_family = AF_UNIX;
+  snprintf(addr.sun_path, sizeof addr.sun_path, "%s/speaker",
+           config->home);
+  if(unlink(addr.sun_path) < 0 && errno != ENOENT)
+    error(errno, "removing %s", addr.sun_path);
+  xsetsockopt(listenfd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof one);
+  if(bind(listenfd, &addr, sizeof addr) < 0)
+    fatal(errno, "error binding socket to %s", addr.sun_path);
+  xlisten(listenfd, 128);
+  nonblock(listenfd);
+  info("listening on %s", addr.sun_path);

   mainloop();
   info("stopped (parent terminated)");
   exit(0);
   mainloop();
   info("stopped (parent terminated)");
   exit(0);