X-Git-Url: http://git.tuebingen.mpg.de/?p=paraslash.git;a=blobdiff_plain;f=afs.c;h=e2e252152cf7c300c9842ae153a5fcbaa1b45271;hp=b5cf9f792e955d8c7df53483a3aeb7ec6970d1a1;hb=368d49f12b32005b9a32abe95c6aee467ae889b0;hpb=df18715e70c9d5c096a536435e5959d0d7d4ba56

diff --git a/afs.c b/afs.c
index b5cf9f79..e2e25215 100644
--- a/afs.c
+++ b/afs.c
@@ -1,45 +1,31 @@
+/*
+ * Copyright (C) 2007-2008 Andre Noll <maan@systemlinux.org>
+ *
+ * Licensed under the GPL v2. For licencing details see COPYING.
+ */
+
+/** \file afs.c Paraslash's audio file selector. */
+
+#include <signal.h>
+#include <fnmatch.h>
+#include "server.cmdline.h"
 #include "para.h"
-#include "afh.h"
 #include "error.h"
+#include "string.h"
+#include "afh.h"
+#include "afs.h"
+#include "server.h"
 #include <dirent.h> /* readdir() */
 #include <sys/mman.h>
 #include <sys/time.h>
-//#include <inttypes.h>
-
 #include "net.h"
-#include "afs.h"
 #include "ipc.h"
-#include "string.h"
 #include "list.h"
 #include "sched.h"
 #include "signal.h"
 #include "fd.h"
 
-/** \file afs.c Paraslash's audio file selector. */
-
-/**
- * Compare two osl objects of string type.
- *
- * \param obj1 Pointer to the first object.
- * \param obj2 Pointer to the second object.
- *
- * In any case, only \p MIN(obj1->size, obj2->size) characters of each string
- * are taken into account.
- *
- * \return It returns an integer less than, equal to, or greater than zero if
- * \a obj1 is found, respectively, to be less than, to match, or be greater than
- * obj2.
- *
- * \sa strcmp(3), strncmp(3), osl_compare_func.
- */
-int string_compare(const struct osl_object *obj1, const struct osl_object *obj2)
-{
-	const char *str1 = (const char *)obj1->data;
-	const char *str2 = (const char *)obj2->data;
-	return strncmp(str1, str2, PARA_MIN(obj1->size, obj2->size));
-}
-
-/** The osl tables used by afs. \sa blob.c */
+/** The osl tables used by afs. \sa blob.c. */
 enum afs_table_num {
 	/** Contains audio file information. See aft.c. */
 	TBLNUM_AUDIO_FILES,
@@ -67,7 +53,15 @@ enum afs_table_num {
 	NUM_AFS_TABLES
 };
 
-static struct table_info afs_tables[NUM_AFS_TABLES];
+static struct afs_table afs_tables[NUM_AFS_TABLES] = {
+	[TBLNUM_AUDIO_FILES] = {.init = aft_init},
+	[TBLNUM_ATTRIBUTES] = {.init = attribute_init},
+	[TBLNUM_SCORES] = {.init = score_init},
+	[TBLNUM_MOODS] = {.init = moods_init},
+	[TBLNUM_LYRICS] = {.init = lyrics_init},
+	[TBLNUM_IMAGES] = {.init = images_init},
+	[TBLNUM_PLAYLIST] = {.init = playlists_init},
+};
 
 struct command_task {
 	/** The file descriptor for the local socket. */
@@ -81,69 +75,50 @@ struct command_task {
 	struct task task;
 };
 
+extern struct misc_meta_data *mmd;
+
+static int server_socket;
+static struct command_task command_task_struct;
+static struct signal_task signal_task_struct;
+
+static enum play_mode current_play_mode;
+static char *current_mop; /* mode or playlist specifier. NULL means dummy mooe */
+
 
 /**
- * A wrapper for strtol(3).
- *
- * \param str The string to be converted to a long integer.
- * \param result The converted value is stored here.
- *
- * \return Positive on success, -E_ATOL on errors.
+ * A random number used to "authenticate" the connection.
  *
- * \sa strtol(3), atoi(3).
+ * para_server picks this number by random before forking the afs process.  The
+ * command handlers write this number together with the id of the shared memory
+ * area containing the query. This way, a malicious local user has to know this
+ * number to be able to cause the afs process to crash by sending fake queries.
  */
-int para_atol(const char *str, long *result)
-{
-	char *endptr;
-	long val;
-	int ret, base = 10;
-
-	errno = 0; /* To distinguish success/failure after call */
-	val = strtol(str, &endptr, base);
-	ret = -E_ATOL;
-	if (errno == ERANGE && (val == LONG_MAX || val == LONG_MIN))
-		goto out; /* overflow */
-	if (errno != 0 && val == 0)
-		goto out; /* other error */
-	if (endptr == str)
-		goto out; /* No digits were found */
-	if (*endptr != '\0')
-		goto out; /* Further characters after number */
-	*result = val;
-	ret = 1;
-out:
-	return ret;
-}
+extern uint32_t afs_socket_cookie;
 
 /**
- * Struct to let para_server call a function specified from child context.
+ * Struct to let command handlers execute a callback in afs context.
+ *
+ * Commands that need to change the state of afs can't change the relevant data
+ * structures directly because commands are executed in a child process, i.e.
+ * they get their own virtual address space.
+ *
+ * This structure is used by \p send_callback_request() (executed from handler
+ * context) in order to let the afs process call the specified function. An
+ * instance of that structure is written to a shared memory area together with
+ * the arguments to the callback function. The identifier of the shared memory
+ * area is written to the command socket.
+ *
+ * The afs process accepts connections on the command socket and reads the
+ * shared memory id, attaches the corresponing area, calls the given handler to
+ * perform the desired action and to optionally compute a result.
  *
- * Commands that need to change the state of para_server can't
- * change the relevant data structures directly because commands
- * are executed in a child process, i.e. they get their own
- * virtual address space. This structure must be used to let
- * para_server (i.e. the parent process) call a function specified
- * by the child (the command handler).
+ * The result and a \p callback_result structure is then written to another
+ * shared memory area. The identifier for that area is written to the handler's
+ * command socket, so that the handler process can read the id, attach the
+ * shared memory area and use the result.
  *
- * \sa fork(2), ipc.c.
+ * \sa struct callback_result.
  */
-struct callback_data {
-	/** The function to be called. */
-	callback_function *handler;
-	/** The sma for the parameters of the callback function. */
-	int query_shmid;
-	/** The size of the query sma. */
-	size_t query_size;
-	/** If the callback produced a result, it is stored in this sma. */
-	int result_shmid;
-	/** The size of the result sma. */
-	size_t result_size;
-	/** The return value of the callback function. */
-	int callback_ret;
-	/** The return value of the callback() procedure. */
-	int sma_ret;
-};
-
 struct callback_query {
 	/** The function to be called. */
 	callback_function *handler;
@@ -151,108 +126,124 @@ struct callback_query {
 	size_t query_size;
 };
 
+/**
+ * Structure embedded in the result of a callback.
+ *
+ * If the callback produced a result, an instance of that structure is embeeded
+ * into the shared memory area holding the result, mainly to let the command
+ * handler know the size of the result.
+ *
+ * \sa struct callback_query.
+ */
 struct callback_result {
 	/** The number of bytes of the result. */
 	size_t result_size;
 };
 
-static struct callback_data *shm_callback_data;
-static int callback_mutex;
-static int child_mutex;
-static int result_mutex;
-
 /**
- * Ask the parent process to call a given function.
+ * Ask the afs process to call a given function.
  *
  * \param f The function to be called.
  * \param query Pointer to arbitrary data for the callback.
- * \param result Callback result will be stored here.
+ * \param result_handler Called for each shm area sent by the callback.
+ * \param private_result_data Passed verbatim to \a result_handler.
  *
- * This function creates a shared memory area, copies the buffer pointed to by
- * \a buf to that area and notifies the parent process that  \a f should be
- * called ASAP. It provides proper locking via semaphores to protect against
- * concurent access to the shared memory area and against concurrent access by
- * another child process that asks to call the same function.
+ * This function creates a socket for communication with the afs process and a
+ * shared memory area (sma) to which the buffer pointed to by \a query is
+ * copied.  It then notifies the afs process that the callback function \a f
+ * should be executed by sending the shared memory identifier (shmid) to the
+ * socket.
+
+ * If the callback produces a result, it sends any number of shared memory
+ * identifiers back via the socket. For each such identifier received, \a
+ * result_handler is called. The contents of the sma identified by the received
+ * shmid are passed to that function as an osl object. The private_result_data
+ * pointer is passed as the second argument to \a result_handler.
  *
- * \return Negative, if the shared memory area could not be set up. The return
- * value of the callback function otherwise.
+ * \return Negative, on errors, the return value of the callback function
+ * otherwise.
  *
- * \sa shm_new(), shm_attach(), shm_detach(), mutex_lock(), mutex_unlock(),
- * shm_destroy(), struct callback_data, send_option_arg_callback_request(),
- * send_standard_callback_request().
+ * \sa send_option_arg_callback_request(), send_standard_callback_request().
  */
 int send_callback_request(callback_function *f, struct osl_object *query,
-		struct osl_object *result)
+		callback_result_handler *result_handler,
+		void *private_result_data)
 {
-	struct callback_data cbd = {.handler = f};
-	int ret;
-	void *query_sma;
+	struct callback_query *cq;
+	int num_results = 0, ret, fd = -1, query_shmid, result_shmid;
+	void *query_shm, *result_shm;
+	char buf[sizeof(afs_socket_cookie) + sizeof(int)];
+	size_t query_shm_size = sizeof(*cq);
 
-	assert(query->data && query->size);
-	ret = shm_new(query->size);
+	if (query)
+		query_shm_size += query->size;
+	ret = shm_new(query_shm_size);
 	if (ret < 0)
 		return ret;
-	cbd.query_shmid = ret;
-	cbd.query_size = query->size;
-	ret = shm_attach(cbd.query_shmid, ATTACH_RW, &query_sma);
+	query_shmid = ret;
+	ret = shm_attach(query_shmid, ATTACH_RW, &query_shm);
 	if (ret < 0)
 		goto out;
-	memcpy(query_sma, query->data, query->size);
-	ret = shm_detach(query_sma);
+	cq = query_shm;
+	cq->handler = f;
+	cq->query_size = query_shm_size - sizeof(*cq);
+
+	if (query)
+		memcpy(query_shm + sizeof(*cq), query->data, query->size);
+	ret = shm_detach(query_shm);
 	if (ret < 0)
 		goto out;
-	/* prevent other children from interacting */
-	mutex_lock(child_mutex);
-	/* prevent parent from messing with shm_callback_data. */
-	mutex_lock(callback_mutex);
-	/* all three mutexes are locked, set parameters for callback */
-	*shm_callback_data = cbd;
-	/* unblock parent */
-	mutex_unlock(callback_mutex);
-	kill(getppid(), SIGUSR1); /* wake up parent */
-	/*
-	 * At this time only the parent can run. It will execute our callback
-	 * and unlock the result_mutex when ready to indicate that the child
-	 * may use the result. So let's sleep on this mutex.
-	 */
-	mutex_lock(result_mutex);
-	/* No need to aquire the callback mutex again */
-	ret = shm_callback_data->sma_ret;
-	if (ret < 0) /* sma problem, callback might not have been executed */
-		goto unlock_child_mutex;
-	if (shm_callback_data->result_shmid >= 0) { /* parent provided a result */
-		void *sma;
-		ret = shm_attach(shm_callback_data->result_shmid, ATTACH_RO,
-			&sma);
+
+	*(uint32_t *) buf = afs_socket_cookie;
+	*(int *) (buf + sizeof(afs_socket_cookie)) = query_shmid;
+
+	ret = create_remote_socket(conf.afs_socket_arg);
+	if (ret < 0)
+		goto out;
+	fd = ret;
+	ret = send_bin_buffer(fd, buf, sizeof(buf));
+	if (ret < 0)
+		goto out;
+	for (;;) {
+		ret = recv_bin_buffer(fd, buf, sizeof(int));
+		if (ret <= 0)
+			goto out;
+		if (ret != sizeof(int)) {
+			ret = -E_AFS_SHORT_READ;
+			goto out;
+		}
+		ret = *(int *) buf;
+		if (ret <= 0)
+			goto out;
+		result_shmid = ret;
+		ret = shm_attach(result_shmid, ATTACH_RO, &result_shm);
 		if (ret >= 0) {
-			if (result) { /* copy result */
-				result->size = shm_callback_data->result_size;
-				result->data = para_malloc(result->size);
-				memcpy(result->data, sma, result->size);
-				ret = shm_detach(sma);
-				if (ret < 0)
+			struct callback_result *cr = result_shm;
+			struct osl_object result;
+			num_results++;
+			result.size = cr->result_size;
+			result.data = result_shm + sizeof(*cr);
+			if (result.size) {
+				assert(result_handler);
+				ret = result_handler(&result, private_result_data);
+				if (shm_detach(result_shm) < 0)
 					PARA_ERROR_LOG("can not detach result\n");
-			} else
-				PARA_WARNING_LOG("no result pointer\n");
+			}
 		} else
 			PARA_ERROR_LOG("attach result failed: %d\n", ret);
-		if (shm_destroy(shm_callback_data->result_shmid) < 0)
+		if (shm_destroy(result_shmid) < 0)
 			PARA_ERROR_LOG("destroy result failed\n");
-	} else { /* no result from callback */
-		if (result) {
-			PARA_WARNING_LOG("callback has no result\n");
-			result->data = NULL;
-			result->size = 0;
-		}
+		if (ret < 0)
+			break;
 	}
-	ret = shm_callback_data->callback_ret;
-unlock_child_mutex:
-	/* give other children a chance */
-	mutex_unlock(child_mutex);
 out:
-	if (shm_destroy(cbd.query_shmid) < 0)
+	if (shm_destroy(query_shmid) < 0)
 		PARA_ERROR_LOG("%s\n", "shm destroy error");
-	PARA_DEBUG_LOG("callback_ret: %d\n", ret);
+	if (fd >= 0)
+		close(fd);
+	if (ret >= 0)
+		ret = num_results;
+//	PARA_DEBUG_LOG("callback_ret: %d\n", ret);
 	return ret;
 }
 
@@ -263,7 +254,8 @@ out:
  * \param argc Argument count.
  * \param argv Standard argument vector.
  * \param f The callback function.
- * \param result The result of the query is stored here.
+ * \param result_handler See \ref send_callback_request.
+ * \param private_result_data See \ref send_callback_request.
  *
  * Some commands have a couple of options that are parsed in child context for
  * syntactic correctness and are stored in a special options structure for that
@@ -273,8 +265,9 @@ out:
  * \sa send_standard_callback_request(), send_callback_request().
  */
 int send_option_arg_callback_request(struct osl_object *options,
-		int argc, const char **argv, callback_function *f,
-		struct osl_object *result)
+		int argc,  char * const * const argv, callback_function *f,
+		callback_result_handler *result_handler,
+		void *private_result_data)
 {
 	char *p;
 	int i, ret;
@@ -292,7 +285,8 @@ int send_option_arg_callback_request(struct osl_object *options,
 		strcpy(p, argv[i]); /* OK */
 		p += strlen(argv[i]) + 1;
 	}
-	ret = send_callback_request(f, &query, result);
+	ret = send_callback_request(f, &query, result_handler,
+		private_result_data);
 	free(query.data);
 	return ret;
 }
@@ -303,7 +297,8 @@ int send_option_arg_callback_request(struct osl_object *options,
  * \param argc The same meaning as in send_option_arg_callback_request().
  * \param argv The same meaning as in send_option_arg_callback_request().
  * \param f The same meaning as in send_option_arg_callback_request().
- * \param result The same meaning as in send_option_arg_callback_request().
+ * \param result_handler See \ref send_callback_request.
+ * \param private_result_data See \ref send_callback_request.
  *
  * This is similar to send_option_arg_callback_request(), but no options buffer
  * is passed to the parent process.
@@ -311,266 +306,568 @@ int send_option_arg_callback_request(struct osl_object *options,
  * \return The return value of the underlying call to
  * send_option_arg_callback_request().
  */
-int send_standard_callback_request(int argc, const char **argv,
-		callback_function *f, struct osl_object *result)
+int send_standard_callback_request(int argc,  char * const * const argv,
+		callback_function *f, callback_result_handler *result_handler,
+		void *private_result_data)
+{
+	return send_option_arg_callback_request(NULL, argc, argv, f, result_handler,
+		private_result_data);
+}
+
+static int action_if_pattern_matches(struct osl_row *row, void *data)
+{
+	struct pattern_match_data *pmd = data;
+	struct osl_object name_obj;
+	const char *p, *name;
+	int ret = osl_get_object(pmd->table, row, pmd->match_col_num, &name_obj);
+	const char *pattern_txt = (const char *)pmd->patterns.data;
+
+	if (ret < 0)
+		return ret;
+	name = (char *)name_obj.data;
+	if ((!name || !*name) && (pmd->pm_flags & PM_SKIP_EMPTY_NAME))
+		return 1;
+	if (!pmd->patterns.size && (pmd->pm_flags & PM_NO_PATTERN_MATCHES_EVERYTHING))
+		return pmd->action(pmd->table, row, name, pmd->data);
+	for (p = pattern_txt; p < pattern_txt + pmd->patterns.size;
+			p += strlen(p) + 1) {
+		ret = fnmatch(p, name, pmd->fnmatch_flags);
+		if (ret == FNM_NOMATCH)
+			continue;
+		if (ret)
+			return -E_FNMATCH;
+		return pmd->action(pmd->table, row, name, pmd->data);
+	}
+	return 1;
+}
+
+/**
+ * Execute the given function for each matching row.
+ *
+ * \param pmd Describes what to match and how.
+ *
+ * \return The return value of the underlying call to osl_rbtree_loop()
+ * or osl_rbtree_loop_reverse().
+ */
+int for_each_matching_row(struct pattern_match_data *pmd)
 {
-	return send_option_arg_callback_request(NULL, argc, argv, f, result);
+	if (pmd->pm_flags & PM_REVERSE_LOOP)
+		return osl_rbtree_loop_reverse(pmd->table, pmd->loop_col_num, pmd,
+			action_if_pattern_matches);
+	return osl_rbtree_loop(pmd->table, pmd->loop_col_num, pmd,
+			action_if_pattern_matches);
+}
+
+/**
+ * Compare two osl objects of string type.
+ *
+ * \param obj1 Pointer to the first object.
+ * \param obj2 Pointer to the second object.
+ *
+ * In any case, only \p MIN(obj1->size, obj2->size) characters of each string
+ * are taken into account.
+ *
+ * \return It returns an integer less than, equal to, or greater than zero if
+ * \a obj1 is found, respectively, to be less than, to match, or be greater than
+ * obj2.
+ *
+ * \sa strcmp(3), strncmp(3), osl_compare_func.
+ */
+int string_compare(const struct osl_object *obj1, const struct osl_object *obj2)
+{
+	const char *str1 = (const char *)obj1->data;
+	const char *str2 = (const char *)obj2->data;
+	return strncmp(str1, str2, PARA_MIN(obj1->size, obj2->size));
 }
 
 /*
- * write input from fd to dynamically allocated char array,
- * but maximal max_size byte. Return size.
+ * write input from fd to dynamically allocated buffer,
+ * but maximal max_size byte.
  */
-static int fd2buf(int fd, char **buf, int max_size)
+static int fd2buf(int fd, unsigned max_size, struct osl_object *obj)
 {
 	const size_t chunk_size = 1024;
-	size_t size = 2048;
-	char *p;
+	size_t size = 2048, received = 0;
 	int ret;
+	char *buf = para_malloc(size);
 
-	*buf = para_malloc(size * sizeof(char));
-	p = *buf;
-	while ((ret = read(fd, p, chunk_size)) > 0) {
-		p += ret;
-		if ((p - *buf) + chunk_size >= size) {
-			char *tmp;
-
+	for (;;) {
+		ret = recv_bin_buffer(fd, buf + received, chunk_size);
+		if (ret <= 0)
+			break;
+		received += ret;
+		if (received + chunk_size >= size) {
 			size *= 2;
-			if (size > max_size) {
-				ret = -E_INPUT_TOO_LARGE;
-				goto out;
-			}
-			tmp = para_realloc(*buf, size);
-			p = (p - *buf) + tmp;
-			*buf = tmp;
+			ret = -E_INPUT_TOO_LARGE;
+			if (size > max_size)
+				break;
+			buf = para_realloc(buf, size);
 		}
 	}
-	if (ret < 0) {
-		ret = -E_READ;
-		goto out;
-	}
-	ret = p - *buf;
-out:
-	if (ret < 0 && *buf)
-		free(*buf);
+	obj->data = buf;
+	obj->size = received;
+	if (ret < 0)
+		free(buf);
 	return ret;
 }
 
 /**
- * Read from stdin, and send the result to the parent process.
+ * Read data from a file descriptor, and send it to the afs process.
  *
+ * \param fd File descriptor to read data from.
  * \param arg_obj Pointer to the arguments to \a f.
  * \param f The callback function.
  * \param max_len Don't read more than that many bytes from stdin.
- * \param result The result of the query is stored here.
+ * \param result_handler See \ref send_callback_request.
+ * \param private_result_data See \ref send_callback_request.
  *
  * This function is used by commands that wish to let para_server store
  * arbitrary data specified by the user (for instance the add_blob family of
- * commands). First, at most \a max_len bytes are read from stdin, the result
+ * commands). First, at most \a max_len bytes are read from \a fd, the result
  * is concatenated with the buffer given by \a arg_obj, and the combined buffer
- * is made available to the parent process via shared memory.
+ * is made available to the afs process via the callback method. See \ref
+ * send_callback_request for details.
  *
  * \return Negative on errors, the return value of the underlying call to
  * send_callback_request() otherwise.
  */
-int stdin_command(struct osl_object *arg_obj, callback_function *f,
-		unsigned max_len, struct osl_object *result)
+int stdin_command(int fd, struct osl_object *arg_obj, callback_function *f,
+		unsigned max_len, callback_result_handler *result_handler,
+		void *private_result_data)
 {
-	char *stdin_buf;
-	size_t stdin_len;
-	struct osl_object query;
-	int ret = fd2buf(STDIN_FILENO, &stdin_buf, max_len);
+	struct osl_object query, stdin_obj;
+	int ret;
 
+	ret = send_buffer(fd, AWAITING_DATA_MSG);
+	if (ret < 0)
+		return ret;
+	ret = fd2buf(fd, max_len, &stdin_obj);
 	if (ret < 0)
 		return ret;
-	stdin_len = ret;
-	query.size = arg_obj->size + stdin_len;
+	query.size = arg_obj->size + stdin_obj.size;
 	query.data = para_malloc(query.size);
 	memcpy(query.data, arg_obj->data, arg_obj->size);
-	memcpy((char *)query.data + arg_obj->size, stdin_buf, stdin_len);
-	free(stdin_buf);
-	ret = send_callback_request(f, &query, result);
+	memcpy((char *)query.data + arg_obj->size, stdin_obj.data, stdin_obj.size);
+	free(stdin_obj.data);
+	ret = send_callback_request(f, &query, result_handler, private_result_data);
 	free(query.data);
 	return ret;
 }
 
+static int pass_afd(int fd, char *buf, size_t size)
+{
+	struct msghdr msg = {.msg_iov = NULL};
+	struct cmsghdr *cmsg;
+	char control[255];
+	int ret;
+	struct iovec iov;
+
+	iov.iov_base = buf;
+	iov.iov_len  = size;
+
+	msg.msg_iov = &iov;
+	msg.msg_iovlen = 1;
+
+	msg.msg_control = control;
+	msg.msg_controllen = sizeof(control);
+
+	cmsg = CMSG_FIRSTHDR(&msg);
+	cmsg->cmsg_level = SOL_SOCKET;
+	cmsg->cmsg_type = SCM_RIGHTS;
+	cmsg->cmsg_len = CMSG_LEN(sizeof(int));
+	*(int *)CMSG_DATA(cmsg) = fd;
+
+	/* Sum of the length of all control messages in the buffer */
+	msg.msg_controllen = cmsg->cmsg_len;
+	PARA_DEBUG_LOG("passing %zu bytes and fd %d\n", size, fd);
+	ret = sendmsg(server_socket, &msg, 0);
+	if (ret < 0) {
+		ret = -ERRNO_TO_PARA_ERROR(errno);
+		return ret;
+	}
+	return 1;
+}
+
 /**
  * Open the audio file with highest score.
  *
- * \param afd Audio file data is returned here.
+ * This stores all information for streaming the "best" audio file in a shared
+ * memory area. The id of that area and an open file descriptor for the next
+ * audio file are passed to the server process.
  *
- * This stores all information for streaming the "best" audio file
- * in the \a afd structure.
+ * \return Standard.
  *
- * \return Positive on success, negative on errors.
- *
- * \sa close_audio_file(), open_and_update_audio_file().
+ * \sa open_and_update_audio_file().
  */
-int open_next_audio_file(struct audio_file_data *afd)
+static int open_next_audio_file(void)
 {
 	struct osl_row *aft_row;
+	struct audio_file_data afd;
+	int ret, shmid;
+	char buf[8];
+	long score;
+again:
+	PARA_NOTICE_LOG("getting next audio file\n");
+	ret = score_get_best(&aft_row, &score);
+	if (ret < 0) {
+		PARA_ERROR_LOG("%s\n", para_strerror(-ret));
+		goto no_admissible_files;
+	}
+	ret = open_and_update_audio_file(aft_row, score, &afd);
+	if (ret < 0) {
+		PARA_ERROR_LOG("%s\n", para_strerror(-ret));
+		ret = score_delete(aft_row);
+		if (ret < 0) {
+			PARA_ERROR_LOG("%s\n", para_strerror(-ret));
+			goto no_admissible_files;
+		}
+		goto again;
+	}
+	shmid = ret;
+	if (!write_ok(server_socket)) {
+		ret = -E_AFS_SOCKET;
+		goto destroy;
+	}
+	*(uint32_t *)buf = NEXT_AUDIO_FILE;
+	*(uint32_t *)(buf + 4) = (uint32_t)shmid;
+	ret = pass_afd(afd.fd, buf, 8);
+	close(afd.fd);
+	if (ret >= 0)
+		return ret;
+destroy:
+	shm_destroy(shmid);
+	return ret;
+no_admissible_files:
+	*(uint32_t *)buf = NO_ADMISSIBLE_FILES;
+	*(uint32_t *)(buf + 4) = (uint32_t)0;
+	return send_bin_buffer(server_socket, buf, 8);
+}
+
+/* Never fails if arg == NULL */
+static int activate_mood_or_playlist(char *arg, int *num_admissible)
+{
+	enum play_mode mode;
 	int ret;
-	for (;;) {
-		ret = score_get_best(&aft_row, &afd->score);
+
+	if (!arg) {
+		ret = change_current_mood(NULL); /* always successful */
+		mode = PLAY_MODE_MOOD;
+	} else {
+		if (!strncmp(arg, "p/", 2)) {
+			ret = playlist_open(arg + 2);
+			mode = PLAY_MODE_PLAYLIST;
+		} else if (!strncmp(arg, "m/", 2)) {
+			ret = change_current_mood(arg + 2);
+			mode = PLAY_MODE_MOOD;
+		} else
+			return -E_AFS_SYNTAX;
 		if (ret < 0)
 			return ret;
-		ret = open_and_update_audio_file(aft_row, afd);
-		if (ret >= 0)
-			return ret;
 	}
+	if (num_admissible)
+		*num_admissible = ret;
+	current_play_mode = mode;
+	if (arg != current_mop) {
+		free(current_mop);
+		if (arg) {
+			current_mop = para_strdup(arg);
+			mmd_lock();
+			strncpy(mmd->afs_mode_string, arg,
+				sizeof(mmd->afs_mode_string));
+			mmd->afs_mode_string[sizeof(mmd->afs_mode_string) - 1] = '\0';
+			mmd_unlock();
+		} else {
+			mmd_lock();
+			strcpy(mmd->afs_mode_string, "dummy");
+			mmd_unlock();
+			current_mop = NULL;
+		}
+	}
+	return 1;
+}
+
+static void com_select_callback(int fd, const struct osl_object *query)
+{
+	struct para_buffer pb = {
+		.max_size = SHMMAX,
+		.private_data = &fd,
+		.max_size_handler = pass_buffer_as_shm
+	};
+	char *arg = query->data;
+	int num_admissible, ret, ret2;
+
+	ret = clear_score_table();
+	if (ret < 0) {
+		ret2 = para_printf(&pb, "%s\n", para_strerror(-ret));
+		goto out;
+	}
+	if (current_play_mode == PLAY_MODE_MOOD)
+		close_current_mood();
+	else
+		playlist_close();
+	ret = activate_mood_or_playlist(arg, &num_admissible);
+	if (ret < 0) {
+		ret2 = para_printf(&pb, "%s\nswitching back to %s\n",
+			para_strerror(-ret), current_mop?
+			current_mop : "dummy");
+		ret = activate_mood_or_playlist(current_mop, &num_admissible);
+		if (ret < 0) {
+			if (ret2 >= 0)
+				ret2 = para_printf(&pb, "failed, switching to dummy\n");
+			activate_mood_or_playlist(NULL, &num_admissible);
+		}
+	} else
+		ret2 = para_printf(&pb, "activated %s (%d admissible files)\n", current_mop?
+			current_mop : "dummy mood", num_admissible);
+out:
+	if (ret2 >= 0 && pb.offset)
+		pass_buffer_as_shm(pb.buf, pb.offset, &fd);
+	free(pb.buf);
 }
 
 /**
- * Free all resources which were allocated by open_next_audio_file().
+ * Result handler for sending data to the para_client process.
  *
- * \param afd The structure previously filled in by open_next_audio_file().
+ * \param result The data to be sent.
+ * \param fd_ptr Pointer to the file descriptor.
  *
- * \return The return value of the underlying call to para_munmap().
+ * \return The return value of the underlying call to send_bin_buffer().
  *
- * \sa open_next_audio_file().
+ * \sa \ref callback_result_handler.
  */
-int close_audio_file(struct audio_file_data *afd)
+int send_result(struct osl_object *result, void *fd_ptr)
 {
-	free(afd->afhi.chunk_table);
-	return para_munmap(afd->map.data, afd->map.size);
+	int fd = *(int *)fd_ptr;
+	if (!result->size)
+		return 1;
+	return send_bin_buffer(fd, result->data, result->size);
 }
 
-#if 0
-static void play_loop(enum play_mode current_play_mode)
+int com_select(int fd, int argc, char * const * const argv)
 {
-	int i, ret;
-	struct audio_file_data afd;
+	struct osl_object query;
 
-	afd.current_play_mode = current_play_mode;
-	for (i = 0; i < 0; i++) {
-		ret = open_next_audio_file(&afd);
-		if (ret < 0) {
-			PARA_ERROR_LOG("failed to open next audio file: %d\n", ret);
-			return;
-		}
-		PARA_NOTICE_LOG("next audio file: %s, score: %li\n", afd.path, afd.score);
-		sleep(1);
-		close_audio_file(&afd);
-	}
+	if (argc != 2)
+		return -E_AFS_SYNTAX;
+	query.data = argv[1];
+	query.size = strlen(argv[1]) + 1;
+	return send_callback_request(com_select_callback, &query,
+		&send_result, &fd);
 }
-#endif
 
-
-static enum play_mode init_admissible_files(void)
+static void init_admissible_files(char *arg)
 {
-	int ret;
-	char *given_mood, *given_playlist;
-
-	given_mood = "mood_that_was_given_at_the_command_line";
-	given_playlist = "given_playlist";
-
-	if (given_mood) {
-		ret = mood_open(given_mood);
-		if (ret >= 0) {
-			if (given_playlist)
-				PARA_WARNING_LOG("ignoring playlist %s\n",
-					given_playlist);
-			return PLAY_MODE_MOOD;
-		}
-	}
-	if (given_playlist) {
-		ret = playlist_open(given_playlist);
-		if (ret >= 0)
-			return PLAY_MODE_PLAYLIST;
-	}
-	ret = mood_open(NULL); /* open first available mood */
-	if (ret >= 0)
-		return PLAY_MODE_MOOD;
-	mood_open(""); /* open dummy mood, always successful */
-	return PLAY_MODE_MOOD;
+	if (activate_mood_or_playlist(arg, NULL) < 0)
+		activate_mood_or_playlist(NULL, NULL); /* always successful */
 }
 
 static int setup_command_socket_or_die(void)
 {
-	int ret;
-	char *socket_name = "/tmp/afs_command_socket";
+	int ret, socket_fd;
+	char *socket_name = conf.afs_socket_arg;
 	struct sockaddr_un unix_addr;
 
 	unlink(socket_name);
 	ret = create_local_socket(socket_name, &unix_addr,
 		S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IWOTH);
-	if (ret < 0)
+	if (ret < 0) {
+		PARA_EMERG_LOG("%s: %s\n", para_strerror(-ret), socket_name);
 		exit(EXIT_FAILURE);
-	if (listen(ret , 5) < 0) {
-		PARA_EMERG_LOG("%s", "can not listen on socket\n");
+	}
+	socket_fd = ret;
+	if (listen(socket_fd , 5) < 0) {
+		PARA_EMERG_LOG("can not listen on socket\n");
 		exit(EXIT_FAILURE);
 	}
-	PARA_INFO_LOG("listening on command socket %s (fd %d)\n", socket_name,
-		ret);
-	return ret;
+	ret = mark_fd_nonblocking(socket_fd);
+	if (ret < 0) {
+		close(socket_fd);
+		return ret;
+	}
+	PARA_INFO_LOG("listening on socket %s (fd %d)\n", socket_name,
+		socket_fd);
+	return socket_fd;
 }
 
-static int server_socket;
+static void close_afs_tables(void)
+{
+	int i;
+	PARA_NOTICE_LOG("closing afs_tables\n");
+	for (i = 0; i < NUM_AFS_TABLES; i++)
+		afs_tables[i].close();
+}
 
-void loop(void)
+static char *database_dir;
+
+static void get_database_dir(void)
 {
-	for (;;)
-		sleep(1);
+	if (!database_dir) {
+		if (conf.afs_database_dir_given)
+			database_dir = para_strdup(conf.afs_database_dir_arg);
+		else {
+			char *home = para_homedir();
+			database_dir = make_message(
+				"%s/.paraslash/afs_database", home);
+			free(home);
+		}
+	}
+	PARA_INFO_LOG("afs_database dir %s\n", database_dir);
+}
+
+static int make_database_dir(void)
+{
+	int ret;
+
+	get_database_dir();
+	ret = para_mkdir(database_dir, 0777);
+	if (ret >= 0 || is_errno(-ret, EEXIST))
+		return 1;
+	return ret;
 }
 
-static void afs_shutdown(enum osl_close_flags flags)
+static int open_afs_tables(void)
 {
-	PARA_NOTICE_LOG("cleaning up\n");
-	score_shutdown(flags);
-	attribute_shutdown(flags);
-	mood_close();
-	playlist_close();
-	moods_shutdown(flags);
-	playlists_shutdown(flags);
-	lyrics_shutdown(flags);
-	images_shutdown(flags);
-	aft_shutdown(flags);
+	int i, ret;
+
+	get_database_dir();
+	PARA_NOTICE_LOG("opening %u osl tables in %s\n", NUM_AFS_TABLES,
+		database_dir);
+	for (i = 0; i < NUM_AFS_TABLES; i++) {
+		ret = afs_tables[i].open(database_dir);
+		if (ret >= 0)
+			continue;
+		PARA_ERROR_LOG("%s init: %s\n", afs_tables[i].name,
+			para_strerror(-ret));
+		break;
+	}
+	if (ret >= 0)
+		return ret;
+	while (i)
+		afs_tables[--i].close();
+	return ret;
 }
 
 static void signal_pre_select(struct sched *s, struct task *t)
 {
-	struct signal_task *st = t->private_data;
-	t->ret = 1;
+	struct signal_task *st = container_of(t, struct signal_task, task);
 	para_fd_set(st->fd, &s->rfds, &s->max_fileno);
 }
 
 static void signal_post_select(struct sched *s, struct task *t)
 {
-	struct signal_task *st = t->private_data;
-	t->ret = 1;
+	struct signal_task *st = container_of(t, struct signal_task, task);
+	if (getppid() == 1) {
+		t->error = -E_AFS_PARENT_DIED;
+		return;
+	}
 	if (!FD_ISSET(st->fd, &s->rfds))
 		return;
 	st->signum = para_next_signal();
-	PARA_NOTICE_LOG("caught signal %d\n", st->signum);
-	t->ret = 1;
-	if (st->signum == SIGUSR1)
-		return; /* ignore SIGUSR1 */
-	afs_shutdown(OSL_MARK_CLEAN);
-	t->ret = -E_SIGNAL_CAUGHT;
+	if (st->signum == SIGHUP) {
+		close_afs_tables();
+		t->error = open_afs_tables();
+		if (t->error < 0)
+			return;
+		init_admissible_files(current_mop);
+		return;
+	}
+	sched_shutdown();
+	t->error = -E_AFS_SIGNAL;
 }
 
 static void register_signal_task(void)
 {
-	static struct signal_task signal_task_struct;
 	struct signal_task *st = &signal_task_struct;
+
+	if (signal(SIGPIPE, SIG_IGN) == SIG_ERR) {
+		PARA_EMERG_LOG("failed to ignore SIGPIPE\n");
+		exit(EXIT_FAILURE);
+	}
+	if (signal(SIGUSR1, SIG_IGN) == SIG_ERR) {
+		PARA_EMERG_LOG("failed to ignore SIGUSR1\n");
+		exit(EXIT_FAILURE);
+	}
 	st->fd = para_signal_init();
 	PARA_INFO_LOG("signal pipe: fd %d\n", st->fd);
 	para_install_sighandler(SIGINT);
 	para_install_sighandler(SIGTERM);
-	para_install_sighandler(SIGPIPE);
+	para_install_sighandler(SIGHUP);
 
 	st->task.pre_select = signal_pre_select;
 	st->task.post_select = signal_post_select;
-	st->task.private_data = st;
 	sprintf(st->task.status, "signal task");
 	register_task(&st->task);
 }
 
+static struct list_head afs_client_list;
+
+/** Describes on connected afs client. */
+struct afs_client {
+	/** Position in the afs client list. */
+	struct list_head node;
+	/** The socket file descriptor for this client. */
+	int fd;
+	/** The time the client connected. */
+	struct timeval connect_time;
+};
+
 static void command_pre_select(struct sched *s, struct task *t)
 {
-	struct command_task *ct = t->private_data;
-	t->ret = 1;
+	struct command_task *ct = container_of(t, struct command_task, task);
+	struct afs_client *client;
+
+	para_fd_set(server_socket, &s->rfds, &s->max_fileno);
 	para_fd_set(ct->fd, &s->rfds, &s->max_fileno);
+	list_for_each_entry(client, &afs_client_list, node)
+		para_fd_set(client->fd, &s->rfds, &s->max_fileno);
+}
+
+/**
+ * Send data as shared memory to a file descriptor.
+ *
+ * \param buf The buffer holding the data to be sent.
+ * \param size The size of \a buf.
+ * \param fd_ptr A pointer to the file descriptor.
+ *
+ * This function is used as the \a max_size handler in a \ref para_buffer
+ * structure. If used this way, it is called by \ref para_printf() whenever
+ * the buffer passed to para_printf() is about to exceed its maximal size.
+ *
+ * This function creates a shared memory area large enough to hold
+ * the content given by \a buf and \a size and sends the identifier
+ * of this area to the file descriptor given by \a fd_ptr.
+ *
+ * \return Zero if \a buf is \p NULL or \a size is zero. Negative on errors,
+ * and positive on success.
+ */
+int pass_buffer_as_shm(char *buf, size_t size, void *fd_ptr)
+{
+	int ret, shmid, fd = *(int *)fd_ptr;
+	void *shm;
+	struct callback_result *cr;
+
+	if (!buf || !size)
+		return 0;
+	ret = shm_new(size + sizeof(struct callback_result));
+	if (ret < 0)
+		return ret;
+	shmid = ret;
+	ret = shm_attach(shmid, ATTACH_RW, &shm);
+	if (ret < 0)
+		goto err;
+	cr = shm;
+	cr->result_size = size;
+	memcpy(shm + sizeof(*cr), buf, size);
+	ret = shm_detach(shm);
+	if (ret < 0)
+		goto err;
+	ret = send_bin_buffer(fd, (char *)&shmid, sizeof(int));
+	if (ret >= 0)
+		return ret;
+err:
+	if (shm_destroy(shmid) < 0)
+		PARA_ERROR_LOG("destroy result failed\n");
+	return ret;
 }
 
 /*
@@ -580,492 +877,323 @@ static void command_pre_select(struct sched *s, struct task *t)
  */
 static int call_callback(int fd, int query_shmid)
 {
-	void *query_shm, *result_shm;
+	void *query_shm;
 	struct callback_query *cq;
-	struct callback_result *cr;
-	struct osl_object query, result = {.data = NULL};
-	int result_shmid = -1, ret, ret2;
+	struct osl_object query;
+	int ret;
 
-	ret = shm_attach(query_shmid, ATTACH_RO, &query_shm);
+	ret = shm_attach(query_shmid, ATTACH_RW, &query_shm);
 	if (ret < 0)
-		goto out;
+		return ret;
 	cq = query_shm;
 	query.data = (char *)query_shm + sizeof(*cq);
 	query.size = cq->query_size;
-	ret = cq->handler(&query, &result);
-	ret2 = shm_detach(query_shm);
-	if (ret2 < 0 && ret >= 0)
-		ret = ret2;
-	if (ret < 0)
-		goto out;
-	ret = 0;
-	if (!result.data || !result.size)
-		goto out;
-	ret = shm_new(result.size + sizeof(struct callback_result));
-	if (ret < 0)
-		goto out;
-	result_shmid = ret;
-	ret = shm_attach(result_shmid, ATTACH_RW, &result_shm);
-	if (ret < 0)
-		goto out;
-	cr = result_shm;
-	cr->result_size = result.size;
-	memcpy(result_shm + sizeof(*cr), result.data, result.size);
-	ret = shm_detach(result_shm);
-	if (ret < 0)
-		goto out;
-	ret = result_shmid;
-out:
-	free(result.data);
-	ret2 = send_bin_buffer(fd, (char *)ret, sizeof(int));
-	if (ret < 0 || ret2 < 0) {
-		if (result_shmid >= 0)
-			if (shm_destroy(result_shmid) < 0)
-				PARA_ERROR_LOG("destroy result failed\n");
-		if (ret >= 0)
-			ret = ret2;
+	cq->handler(fd, &query);
+	return 1;
+}
+
+static int execute_server_command(void)
+{
+	char buf[8];
+	int ret = recv_bin_buffer(server_socket, buf, sizeof(buf) - 1);
+
+	if (ret <= 0) {
+		if (!ret)
+			ret = -ERRNO_TO_PARA_ERROR(ECONNRESET);
+		goto err;
 	}
+	buf[ret] = '\0';
+	PARA_DEBUG_LOG("received: %s\n", buf);
+	ret = -E_BAD_CMD;
+	if (strcmp(buf, "new"))
+		goto err;
+	ret = open_next_audio_file();
+err:
 	return ret;
 }
 
-static void command_post_select(struct sched *s, struct task *t)
+static void execute_afs_command(int fd, uint32_t expected_cookie)
 {
-	struct command_task *ct = t->private_data;
-	struct sockaddr_un unix_addr;
-	char buf[sizeof(uint32_t) + sizeof(int)];
 	uint32_t cookie;
-	int query_shmid, fd;
+	int query_shmid;
+	char buf[sizeof(cookie) + sizeof(query_shmid)];
+	int ret = recv_bin_buffer(fd, buf, sizeof(buf));
 
-	t->ret = 1;
-	if (!FD_ISSET(ct->fd, &s->rfds))
-		return;
-	t->ret = para_accept(ct->fd, &unix_addr, sizeof(unix_addr));
-	if (t->ret < 0)
+	if (ret < 0)
+		goto err;
+	if (ret != sizeof(buf)) {
+		PARA_NOTICE_LOG("short read (%d bytes, expected %lu)\n",
+			ret, (long unsigned) sizeof(buf));
 		return;
-	/*
-	 * The following errors may be caused by a malicious local user. So do
-	 * not return an error in this case as this would terminate  para_afs
-	 * and para_server.
-	 */
-	fd = t->ret;
-	t->ret = recv_bin_buffer(ct->fd, buf, sizeof(buf));
-	if (t->ret < 0) {
-		PARA_NOTICE_LOG("%s\n", PARA_STRERROR(-t->ret));
-		t->ret = 1;
-		goto out;
-	}
-	if (t->ret != sizeof(buf)) {
-		PARA_NOTICE_LOG("short read (%d bytes, expected %d)\n",
-			t->ret, sizeof(buf));
-		t->ret = 1;
-		goto out;
 	}
 	cookie = *(uint32_t *)buf;
-	if (cookie != ct->cookie) {
+	if (cookie != expected_cookie) {
 		PARA_NOTICE_LOG("received invalid cookie(got %u, expected %u)\n",
-			(unsigned)cookie, (unsigned)ct->cookie);
-		t->ret = 1;
-		goto out;
+			(unsigned)cookie, (unsigned)expected_cookie);
+		return;
 	}
 	query_shmid = *(int *)(buf + sizeof(cookie));
 	if (query_shmid < 0) {
 		PARA_WARNING_LOG("received invalid query shmid %d)\n",
 			query_shmid);
-		t->ret = 1;
-		goto out;
+		return;
 	}
-	t->ret = call_callback(fd, query_shmid);
-	if (t->ret < 0) {
-		PARA_NOTICE_LOG("%s\n", PARA_STRERROR(-t->ret));
-		t->ret = 1;
-		goto out;
+	ret = call_callback(fd, query_shmid);
+	if (ret >= 0)
+		return;
+err:
+	PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
+}
+
+/** Shutdown connection if query has not arrived until this many seconds. */
+#define AFS_CLIENT_TIMEOUT 3
+
+static void command_post_select(struct sched *s, struct task *t)
+{
+	struct command_task *ct = container_of(t, struct command_task, task);
+	struct sockaddr_un unix_addr;
+	struct afs_client *client, *tmp;
+	int fd, ret;
+
+	if (FD_ISSET(server_socket, &s->rfds)) {
+		ret = execute_server_command();
+		if (ret < 0) {
+			PARA_EMERG_LOG("%s\n", para_strerror(-ret));
+			sched_shutdown();
+			return;
+		}
 	}
-out:
-	close(fd);
+
+	/* Check the list of connected clients. */
+	list_for_each_entry_safe(client, tmp, &afs_client_list, node) {
+		if (FD_ISSET(client->fd, &s->rfds))
+			execute_afs_command(client->fd, ct->cookie);
+		else { /* prevent bogus connection flooding */
+			struct timeval diff;
+			tv_diff(now, &client->connect_time, &diff);
+			if (diff.tv_sec < AFS_CLIENT_TIMEOUT)
+				continue;
+			PARA_WARNING_LOG("connection timeout\n");
+		}
+		close(client->fd);
+		list_del(&client->node);
+		free(client);
+	}
+	/* Accept connections on the local socket. */
+	if (!FD_ISSET(ct->fd, &s->rfds))
+		return;
+	ret = para_accept(ct->fd, &unix_addr, sizeof(unix_addr));
+	if (ret < 0) {
+		PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
+		return;
+	}
+	fd = ret;
+	ret = mark_fd_nonblocking(fd);
+	if (ret < 0) {
+		PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
+		close(fd);
+		return;
+	}
+	client = para_malloc(sizeof(*client));
+	client->fd = fd;
+	client->connect_time = *now;
+	para_list_add(&client->node, &afs_client_list);
 }
 
 static void register_command_task(uint32_t cookie)
 {
-	static struct command_task command_task_struct;
 	struct command_task *ct = &command_task_struct;
 	ct->fd = setup_command_socket_or_die();
 	ct->cookie = cookie;
 
 	ct->task.pre_select = command_pre_select;
 	ct->task.post_select = command_post_select;
-	ct->task.private_data = ct;
 	sprintf(ct->task.status, "command task");
 	register_task(&ct->task);
 }
 
-void register_tasks(uint32_t cookie)
-{
-	register_signal_task();
-	register_command_task(cookie);
-}
-
-__noreturn int afs_init(uint32_t cookie, int socket_fd)
+/**
+ * Initialize the audio file selector process.
+ *
+ * \param cookie The value used for "authentication".
+ * \param socket_fd File descriptor used for communication with the server.
+ */
+__noreturn void afs_init(uint32_t cookie, int socket_fd)
 {
-	int ret;
-//	void *shm_area;
-	enum play_mode current_play_mode;
 	struct sched s;
+	int i, ret;
 
+	register_signal_task();
+	INIT_LIST_HEAD(&afs_client_list);
+	for (i = 0; i < NUM_AFS_TABLES; i++)
+		afs_tables[i].init(&afs_tables[i]);
+	ret = open_afs_tables();
+	if (ret < 0)
+		goto out;
 	server_socket = socket_fd;
+	ret = mark_fd_nonblocking(server_socket);
+	if (ret < 0)
+		goto out_close;
 	PARA_INFO_LOG("server_socket: %d, afs_socket_cookie: %u\n",
 		server_socket, (unsigned) cookie);
-
-	ret = attribute_init(&afs_tables[TBLNUM_ATTRIBUTES]);
-	if (ret < 0)
-		goto attribute_init_error;
-	ret = moods_init(&afs_tables[TBLNUM_MOODS]);
-	if (ret < 0)
-		goto moods_init_error;
-	ret = playlists_init(&afs_tables[TBLNUM_PLAYLIST]);
-	if (ret < 0)
-		goto playlists_init_error;
-	ret = lyrics_init(&afs_tables[TBLNUM_LYRICS]);
-	if (ret < 0)
-		goto lyrics_init_error;
-	ret = images_init(&afs_tables[TBLNUM_IMAGES]);
-	if (ret < 0)
-		goto images_init_error;
-	ret = score_init(&afs_tables[TBLNUM_SCORES]);
-	if (ret < 0)
-		goto score_init_error;
-	ret = aft_init(&afs_tables[TBLNUM_AUDIO_FILES]);
-	if (ret < 0)
-		goto aft_init_error;
-
-	current_play_mode = init_admissible_files();
-	register_tasks(cookie);
+	init_admissible_files(conf.afs_initial_mode_arg);
+	register_command_task(cookie);
 	s.default_timeout.tv_sec = 0;
-	s.default_timeout.tv_usec = 99 * 1000;
-	sched(&s);
-
-#if 0
-	ret = shm_new(sizeof(struct callback_data));
-	if (ret < 0)
-		return ret;
-	shmid = ret;
-	ret = shm_attach(shmid, ATTACH_RW, &shm_area);
-	if (ret < 0)
-		return ret;
-	shm_callback_data = shm_area;
-	ret = mutex_new();
-	if (ret < 0)
-		return ret;
-	callback_mutex = ret;
-	ret = mutex_new();
-	if (ret < 0)
-		return ret;
-	child_mutex = ret;
-	ret = mutex_new();
+	s.default_timeout.tv_usec = 999 * 1000;
+	ret = schedule(&s);
+out_close:
+	close_afs_tables();
+out:
 	if (ret < 0)
-		return ret;
-	result_mutex = ret;
-	mutex_lock(result_mutex);
-#endif 
-aft_init_error:
-	score_shutdown(OSL_MARK_CLEAN);
-score_init_error:
-	images_shutdown(OSL_MARK_CLEAN);
-images_init_error:
-	lyrics_shutdown(OSL_MARK_CLEAN);
-lyrics_init_error:
-	playlists_shutdown(OSL_MARK_CLEAN);
-playlists_init_error:
-	moods_shutdown(OSL_MARK_CLEAN);
-moods_init_error:
-	attribute_shutdown(OSL_MARK_CLEAN);
-attribute_init_error:
+		PARA_EMERG_LOG("%s\n", para_strerror(-ret));
 	exit(EXIT_FAILURE);
 }
 
-static int create_all_tables(void)
+static void create_tables_callback(int fd, const struct osl_object *query)
 {
+	uint32_t table_mask = *(uint32_t *)query->data;
 	int i, ret;
+	char *buf;
 
+	close_afs_tables();
 	for (i = 0; i < NUM_AFS_TABLES; i++) {
-		struct table_info *ti = afs_tables + i;
+		struct afs_table *t = &afs_tables[i];
 
-		if (ti->flags & TBLFLAG_SKIP_CREATE)
+		if (!(table_mask & (1 << i)))
 			continue;
-		ret = osl_create_table(ti->desc);
+		if (!t->create)
+			continue;
+		ret = t->create(database_dir);
 		if (ret < 0)
-			return ret;
+			goto out;
 	}
-	return 1;
+	ret = open_afs_tables();
+out:
+	if (ret >= 0)
+		buf = make_message("successfully created afs table(s)\n");
+	else
+		buf = make_message("%s\n", para_strerror(-ret));
+	pass_buffer_as_shm(buf, strlen(buf), &fd);
+	free(buf);
 }
 
-/* TODO load tables after init */
-static int com_init(__a_unused int fd, int argc, const char **argv)
+int com_init(int fd, int argc, char * const * const argv)
 {
 	int i, j, ret;
-	if (argc == 1)
-		return create_all_tables();
-	for (i = 1; i < argc; i++) {
-		for (j = 0; j < NUM_AFS_TABLES; j++) {
-			struct table_info *ti = afs_tables + j;
+	uint32_t table_mask = (1 << (NUM_AFS_TABLES + 1)) - 1;
+	struct osl_object query = {.data = &table_mask,
+		.size = sizeof(table_mask)};
 
-			if (ti->flags & TBLFLAG_SKIP_CREATE)
-				continue;
-			if (strcmp(argv[i], ti->desc->name))
-				continue;
-			PARA_NOTICE_LOG("creating table %s\n", argv[i]);
-			ret = osl_create_table(ti->desc);
-			if (ret < 0)
-				return ret;
-			break;
+	ret = make_database_dir();
+	if (ret < 0)
+		return ret;
+	if (argc != 1) {
+		table_mask = 0;
+		for (i = 1; i < argc; i++) {
+			for (j = 0; j < NUM_AFS_TABLES; j++) {
+				struct afs_table *t = &afs_tables[j];
+
+				if (strcmp(argv[i], t->name))
+					continue;
+				table_mask |= (1 << j);
+				break;
+			}
+			if (j == NUM_AFS_TABLES)
+				return -E_BAD_TABLE_NAME;
 		}
-		if (j == NUM_AFS_TABLES)
-			return -E_BAD_TABLE_NAME;
 	}
-	return 1;
+	ret = send_callback_request(create_tables_callback, &query, NULL, NULL);
+	if (ret < 0)
+		return send_va_buffer(fd, "%s\n", para_strerror(-ret));
+	return ret;
 }
 
-/** Describes a command of para_server. */
-struct command {
-	/** The name of the command. */
-	const char *name;
-	/** The handler function. */
-	int (*handler)(int fd, int argc, const char **argv);
-};
-
-static struct command afs_cmds[] = {
-{
-	.name = "add",
-	.handler = com_add,
-},
-{
-	.name = "addlyr",
-	.handler = com_addlyr,
-},
-{
-	.name = "addimg",
-	.handler = com_addimg,
-},
-{
-	.name = "addmood",
-	.handler = com_addmood,
-},
-{
-	.name = "addpl",
-	.handler = com_addpl,
-},
-{
-	.name = "catlyr",
-	.handler = com_catlyr,
-},
-{
-	.name = "catimg",
-	.handler = com_catimg,
-},
-{
-	.name = "mvimg",
-	.handler = com_mvimg,
-},
-{
-	.name = "mvlyr",
-	.handler = com_mvlyr,
-},
-{
-	.name = "mvmood",
-	.handler = com_mvmood,
-},
-{
-	.name = "mvpl",
-	.handler = com_mvpl,
-},
-{
-	.name = "catmood",
-	.handler = com_catmood,
-},
-{
-	.name = "catpl",
-	.handler = com_catpl,
-},
-{
-	.name = "rmatt",
-	.handler = com_rmatt,
-},
-{
-	.name = "init",
-	.handler = com_init,
-},
-{
-	.name = "lsatt",
-	.handler = com_lsatt,
-},
-{
-	.name = "ls",
-	.handler = com_afs_ls,
-},
-{
-	.name = "lslyr",
-	.handler = com_lslyr,
-},
-{
-	.name = "lsimg",
-	.handler = com_lsimg,
-},
-{
-	.name = "lsmood",
-	.handler = com_lsmood,
-},
-{
-	.name = "lspl",
-	.handler = com_lspl,
-},
-{
-	.name = "setatt",
-	.handler = com_setatt,
-},
-{
-	.name = "addatt",
-	.handler = com_addatt,
-},
-{
-	.name = "rm",
-	.handler = com_afs_rm,
-},
-{
-	.name = "rmlyr",
-	.handler = com_rmlyr,
-},
-{
-	.name = "rmimg",
-	.handler = com_rmimg,
-},
-{
-	.name = "rmmood",
-	.handler = com_rmmood,
-},
-{
-	.name = "rmpl",
-	.handler = com_rmpl,
-},
-{
-	.name = "touch",
-	.handler = com_touch,
-},
-{
-	.name = NULL,
-}
+/**
+ * Flags for the check command.
+ *
+ * \sa com_check().
+ */
+enum com_check_flags {
+	/** Check the audio file table. */
+	CHECK_AFT = 1,
+	/** Check the mood table. */
+	CHECK_MOODS = 2,
+	/** Check the playlist table. */
+	CHECK_PLAYLISTS = 4
 };
 
-#if 0
-static void call_callback(void)
+int com_check(int fd, int argc, char * const * const argv)
 {
-	struct osl_object query, result = {.data = NULL};
-	int ret, ret2;
+	unsigned flags = 0;
+	int i, ret;
 
-	shm_callback_data->result_shmid = -1; /* no result */
-	ret = shm_attach(shm_callback_data->query_shmid, ATTACH_RW,
-		&query.data);
-	if (ret < 0)
-		goto out;
-	query.size = shm_callback_data->query_size;
-	shm_callback_data->callback_ret = shm_callback_data->handler(&query,
-		&result);
-	if (result.data && result.size) {
-		void *sma;
-		ret = shm_new(result.size);
+	for (i = 1; i < argc; i++) {
+		const char *arg = argv[i];
+		if (arg[0] != '-')
+			break;
+		if (!strcmp(arg, "--")) {
+			i++;
+			break;
+		}
+		if (!strcmp(arg, "-a")) {
+			flags |= CHECK_AFT;
+			continue;
+		}
+		if (!strcmp(arg, "-p")) {
+			flags |= CHECK_PLAYLISTS;
+			continue;
+		}
+		if (!strcmp(arg, "-m")) {
+			flags |= CHECK_MOODS;
+			continue;
+		}
+		return -E_AFS_SYNTAX;
+	}
+	if (i < argc)
+		return -E_AFS_SYNTAX;
+	if (!flags)
+		flags = ~0U;
+	if (flags & CHECK_AFT) {
+		ret = send_callback_request(aft_check_callback, NULL, send_result, &fd);
 		if (ret < 0)
-			goto detach_query;
-		shm_callback_data->result_shmid = ret;
-		shm_callback_data->result_size = result.size;
-		ret = shm_attach(shm_callback_data->result_shmid, ATTACH_RW, &sma);
+			return ret;
+	}
+	if (flags & CHECK_PLAYLISTS) {
+		ret = send_callback_request(playlist_check_callback, NULL, send_result, &fd);
 		if (ret < 0)
-			goto destroy_result;
-		memcpy(sma, result.data, result.size);
-		ret = shm_detach(sma);
-		if (ret < 0) {
-			PARA_ERROR_LOG("detach result failed\n");
-			goto destroy_result;
-		}
+			return ret;
 	}
-	ret = 1;
-	goto detach_query;
-destroy_result:
-	if (shm_destroy(shm_callback_data->result_shmid) < 0)
-		PARA_ERROR_LOG("destroy result failed\n");
-	shm_callback_data->result_shmid = -1;
-detach_query:
-	free(result.data);
-	ret2 = shm_detach(query.data);
-	if (ret2 < 0) {
-		PARA_ERROR_LOG("detach query failed\n");
-		if (ret >= 0)
-			ret = ret2;
+	if (flags & CHECK_MOODS) {
+		ret = send_callback_request(mood_check_callback, NULL, send_result, &fd);
+		if (ret < 0)
+			return ret;
 	}
-out:
-	if (ret < 0)
-		PARA_ERROR_LOG("sma error %d\n", ret);
-	shm_callback_data->sma_ret = ret;
-	shm_callback_data->handler = NULL;
-	mutex_unlock(result_mutex); /* wake up child */
+	return 1;
 }
 
-static int got_sigchld;
-static void server_loop(int child_pid)
+void afs_event(enum afs_events event, struct para_buffer *pb,
+		void *data)
 {
-//	int status;
-
-	PARA_DEBUG_LOG("server pid: %d, child pid: %d\n",
-		getpid(), child_pid);
-	for (;;)  {
-		mutex_lock(callback_mutex);
-		if (shm_callback_data->handler)
-			call_callback();
-		mutex_unlock(callback_mutex);
-		usleep(100);
-		if (!got_sigchld)
+	int i, ret;
+
+	for (i = 0; i < NUM_AFS_TABLES; i++) {
+		struct afs_table *t = &afs_tables[i];
+		if (!t->event_handler)
 			continue;
-		mutex_destroy(result_mutex);
-		mutex_destroy(callback_mutex);
-		mutex_destroy(child_mutex);
-		afs_shutdown(OSL_MARK_CLEAN);
-		exit(EXIT_SUCCESS);
+		ret = t->event_handler(event, pb, data);
+		if (ret < 0)
+			PARA_CRIT_LOG("%s\n", para_strerror(-ret));
 	}
 }
 
-int main(int argc, const char **argv)
+int images_event_handler(__a_unused enum afs_events event,
+	__a_unused  struct para_buffer *pb, __a_unused void *data)
 {
-	int i, ret = -E_AFS_SYNTAX;
-
-	signal(SIGUSR1, dummy);
-	signal(SIGCHLD, sigchld_handler);
-	if (argc < 2)
-		goto out;
-	ret = setup();
-//	ret = afs_init();
-	if (ret < 0) {
-		PARA_EMERG_LOG("afs_init returned %d\n", ret);
-		exit(EXIT_FAILURE);
-	}
-	ret = fork();
-	if (ret < 0) {
-		ret = -E_FORK;
-		goto out;
-	}
-	if (ret)
-		server_loop(ret);
-	for (i = 0; cmd[i].name; i++) {
-		if (strcmp(cmd[i].name, argv[1]))
-			continue;
-		ret = cmd[i].handler(1, argc - 1 , argv + 1);
-		goto out;
+	return 1;
+}
 
-	}
-	PARA_ERROR_LOG("unknown command: %s\n", argv[1]);
-	ret = -1;
-out:
-	if (ret < 0)
-		PARA_ERROR_LOG("error %d\n", ret);
-	else
-		PARA_DEBUG_LOG("%s", "success\n");
-	afs_shutdown(0);
-	return ret < 0? EXIT_FAILURE : EXIT_SUCCESS;
+int lyrics_event_handler(__a_unused enum afs_events event,
+	__a_unused struct para_buffer *pb, __a_unused void *data)
+{
+	return 1;
 }
-#endif