source: roaraudio/libroar/scheduler.c @ 5697:f3a6f503e20e

//scheduler.c:

/*
 *      Copyright (C) Philipp 'ph3-der-loewe' Schafft - 2012
 *
 *  This file is part of libroar a part of RoarAudio,
 *  a cross-platform sound system for both, home and professional use.
 *  See README for details.
 *
 *  This file is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License version 3
 *  as published by the Free Software Foundation.
 *
 *  libroar is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this software; see the file COPYING.  If not, write to
 *  the Free Software Foundation, 51 Franklin Street, Fifth Floor,
 *  Boston, MA 02110-1301, USA.
 *
 *  NOTE for everyone want's to change something and send patches:
 *  read README and HACKING! There a addition information on
 *  the license of this document you need to read before you send
 *  any patches.
 *
 *  NOTE for uses of non-GPL (LGPL,...) software using libesd, libartsc
 *  or libpulse*:
 *  The libs libroaresd, libroararts and libroarpulse link this lib
 *  and are therefore GPL. Because of this it may be illigal to use
 *  them with any software that uses libesd, libartsc or libpulse*.
 */

#include "libroar.h"

#define INIT_SIZE   8
#define MAX_PROTOS 16

struct protocol {
 const struct roar_keyval * para;
 ssize_t paralen;
 struct roar_dl_lhandle * lhandle;
 const struct roar_dl_proto * impl;
};

struct roar_scheduler {
 size_t refc;
 int flags;
 enum roar_scheduler_strategy strategy;
 struct roar_scheduler_source ** sources;
 size_t sources_len;
 struct roar_vio_select * vios;
 size_t vios_len;
 struct roar_dl_fnreg callback;
 struct protocol protos[MAX_PROTOS];
};

static int __update_cpi_listen_client (struct roar_scheduler * sched, struct roar_scheduler_source * source);

struct roar_scheduler * roar_scheduler_new(int flags, enum roar_scheduler_strategy strategy) {
 struct roar_scheduler * sched = roar_mm_malloc(sizeof(struct roar_scheduler));

 if ( sched == NULL )
  return NULL;

 if ( flags == ROAR_SCHEDULER_FLAG_DEFAULT )
  flags = ROAR_SCHEDULER_FLAG_NONE;

 memset(sched, 0, sizeof(struct roar_scheduler));
 sched->refc = 1;
 sched->flags = flags;
 sched->strategy = strategy;

 sched->sources = roar_mm_malloc(INIT_SIZE*sizeof(struct roar_scheduler_source *));
 if ( sched->sources != NULL ) {
  sched->sources_len = INIT_SIZE;
  memset(sched->sources, 0, INIT_SIZE*sizeof(struct roar_scheduler_source *));
 }

 sched->vios = roar_mm_malloc(sched->sources_len*sizeof(struct roar_vio_select));
 if ( sched->vios != 0 )
  sched->vios_len = sched->sources_len;

 return sched;
}

#define _CHKSCHED(extra) if ( sched == NULL || (extra) ) { roar_err_set(ROAR_ERROR_FAULT); return -1; }

int                     roar_scheduler_ref(struct roar_scheduler * sched) {
 _CHKSCHED(0);

 sched->refc++;

 return 0;
}

int                     roar_scheduler_unref(struct roar_scheduler * sched) {
 size_t i;

 _CHKSCHED(0);

 sched->refc--;

 if (sched->refc)
  return 0;

 for (i = 0; i < sched->sources_len; i++)
  if ( sched->sources[i] != NULL )
   roar_scheduler_source_del(sched, sched->sources[i]);

 if ( sched->vios != NULL )
  roar_mm_free(sched->vios);
 if ( sched->sources != NULL )
  roar_mm_free(sched->sources);
 roar_mm_free(sched);
 return 0;
}

static void __delete_cpi_client(struct roar_scheduler * sched, struct roar_scheduler_source * cur, struct roar_dl_librarypara * para) {
 if ( cur->handle.cpi.impl->unset_proto != NULL )
  cur->handle.cpi.impl->unset_proto(cur->handle.cpi.client, cur->vio, &(cur->handle.cpi.obuffer), &(cur->handle.cpi.userdata), cur->handle.cpi.protopara, cur->handle.cpi.protoparalen, para);

 roar_vio_close(cur->vio);
 cur->vio = NULL;

 if ( cur->handle.cpi.obuffer != NULL ) {
  roar_buffer_free(cur->handle.cpi.obuffer);
  cur->handle.cpi.obuffer = NULL;
 }

 if ( cur->handle.cpi.userdata != NULL ) {
  roar_mm_free(cur->handle.cpi.userdata);
  cur->handle.cpi.userdata = NULL;
 }

 roar_scheduler_source_del(sched, cur);
}

static int __flush_cpi_client(struct roar_scheduler * sched, struct roar_scheduler_source * cur, struct roar_dl_librarypara * para) {
 size_t len;
 ssize_t ret;
 void * buf;

 if ( roar_buffer_get_len(cur->handle.cpi.obuffer, &len) == -1 )
  return 0;

 if ( roar_buffer_get_data(cur->handle.cpi.obuffer, &buf) == -1 )
  return 0;

 ret = roar_vio_write(cur->vio, buf, len);

 if ( ret < 1 )
  return -1;

 if ( ret == (ssize_t)len ) {
  if ( roar_buffer_next(&(cur->handle.cpi.obuffer)) == -1 )
   return -1;
 } else {
  if ( roar_buffer_set_offset(cur->handle.cpi.obuffer, ret) == -1 )
   return -1;
 }

 return 0;
}

static int __run_waits(struct roar_scheduler * sched) {
 struct roar_scheduler_source * cur;
 size_t i;
 int ret = -1;

 for (i = 0; ret == -1 && i < sched->sources_len; i++) {
  if ( (cur = sched->sources[i]) == NULL )
   continue;
  switch (cur->type) {
   case ROAR_SCHEDULER_PLUGIN:
     ret = roar_dl_appsched_trigger(cur->lhandle, ROAR_DL_APPSCHED_WAIT);
    break;
   case ROAR_SCHEDULER_PLUGINCONTAINER:
     ret = roar_plugincontainer_appsched_trigger(cur->handle.container, ROAR_DL_APPSCHED_WAIT);
    break;
#ifndef DEBUG
   default: /* noop */ break;
#endif
  }
 }

 return ret;
}

// what to do?:
// 0. get all VIOs.
// 1. get timeout or use internal default.
// 2. run roar_vio_select().
// 3. send all events based on results.
// 4. send UPDATE to all plugins and containers.
int                     roar_scheduler_iterate(struct roar_scheduler * sched) {
 enum roar_scheduler_strategy strategy;
 struct roar_vio_selecttv timeout = {8, 0}; // default: 8 sec. Just a random value.
 struct roar_scheduler_source * cur, * new_client;
 struct roar_dl_librarypara * para;
 struct roar_dl_lhandle * lhandle;
 ssize_t ret;
 size_t i;
 int have_timeout = 0;
 size_t todo = 0, vios = 0;
 int tmp;

 _CHKSCHED(0);

 strategy = sched->strategy;
 if ( strategy == ROAR_SCHEDULER_STRATEGY_DEFAULT )
  strategy = ROAR_SCHEDULER_STRATEGY_SELECTORWAIT;

 if ( sched->vios == NULL || sched->vios_len < sched->sources_len ) {
  if ( sched->vios != NULL ) {
   roar_mm_free(sched->vios);
   sched->vios = NULL;
   sched->vios_len = 0;
  }

  sched->vios = roar_mm_malloc(sched->sources_len*sizeof(struct roar_vio_select));
  if ( sched->vios != NULL )
   sched->vios_len = sched->sources_len;
 }

 // error from roar_mm_malloc() is still set.
 if ( sched->vios == NULL )
  return -1;

 memset(sched->vios, 0, sched->vios_len*sizeof(struct roar_vio_select));
 for (i = 0; i < sched->vios_len; i++)
  sched->vios[i].eventsq = ROAR_VIO_SELECT_NO_RETEST;

 for (i = 0; i < sched->sources_len; i++) {
  if ( (cur = sched->sources[i]) == NULL )
   continue;
  switch (cur->type) {
   case ROAR_SCHEDULER_VIO:
     ROAR_VIO_SELECT_SETVIO(&(sched->vios[i]), cur->vio, cur->handle.eventsq);
     todo++;
     vios++;
    break;
   case ROAR_SCHEDULER_TIMEOUT:
     timeout = cur->handle.timeout;
     have_timeout = 1;
     todo++;
    break;
   case ROAR_SCHEDULER_CPI_LISTEN:
     if ( cur->flags & ROAR_SCHEDULER_FLAG_STUB )
      __update_cpi_listen_client(sched, cur);

     if ( !(cur->flags & ROAR_SCHEDULER_FLAG_STUB) ) {
      ROAR_VIO_SELECT_SETVIO(&(sched->vios[i]), cur->vio, ROAR_VIO_SELECT_READ);
      todo++;
      vios++;
     }
    break;
   case ROAR_SCHEDULER_CPI_CLIENT:
     if ( cur->flags & ROAR_SCHEDULER_FLAG_STUB )
      __update_cpi_listen_client(sched, cur);

     if ( !(cur->flags & ROAR_SCHEDULER_FLAG_STUB) ) {
      tmp = 0;

      if ( cur->handle.cpi.impl->status != NULL ) {
       if ( cur->lhandle != NULL )
        roar_dl_context_restore(cur->lhandle);

       para = roar_dl_getpara(cur->lhandle);
       if ( cur->handle.cpi.impl->status(cur->handle.cpi.client, cur->vio, &(cur->handle.cpi.obuffer), &(cur->handle.cpi.userdata), cur->handle.cpi.protopara, cur->handle.cpi.protoparalen, para) & ROAR_DL_PROTO_STATUS_RX_READY )
        tmp |= ROAR_VIO_SELECT_READ;
       if ( para != NULL )
        roar_dl_para_unref(para);

       if ( cur->lhandle != NULL )
        roar_dl_context_store(cur->lhandle);
      } else {
       tmp |= ROAR_VIO_SELECT_READ;
      }

      if ( sched->sources[i]->handle.cpi.obuffer != NULL )
       tmp |= ROAR_VIO_SELECT_WRITE;

      ROAR_VIO_SELECT_SETVIO(&(sched->vios[i]), sched->sources[i]->vio, tmp);
      todo++;
      vios++;
     }
    break;
   case ROAR_SCHEDULER_PLUGIN:
   case ROAR_SCHEDULER_PLUGINCONTAINER:
     todo++;
    break;
#ifndef DEBUG
   default: /* noop */ break;
#endif
  }
 }

 if (!todo) {
  roar_err_set(ROAR_ERROR_NOENT);
  return 0;
 }

 if ( strategy == ROAR_SCHEDULER_STRATEGY_WAITORSELECT || strategy == ROAR_SCHEDULER_STRATEGY_WAIT ) {
  ret = __run_waits(sched);
  if ( ret == 0 || strategy == ROAR_SCHEDULER_STRATEGY_WAIT )
   ret = 1;
 } else {
  ret = -1;
 }

 if ( ret == -1 && !(strategy == ROAR_SCHEDULER_STRATEGY_SELECTORWAIT && vios == 0) ) {
  ret = roar_vio_select(sched->vios, sched->vios_len, &timeout, NULL);
 }

 if ( ret < 0 && strategy == ROAR_SCHEDULER_STRATEGY_SELECTORWAIT ) {
  ret = __run_waits(sched);
  if ( ret == 0 )
   ret = 1;

  if ( ret == -1 && vios == 0 )
   ret = roar_vio_select(sched->vios, sched->vios_len, &timeout, NULL);
 }

 if ( ret == -1 )
  return -1;
 if ( ret == 0 && !have_timeout )
  return 1;

 for (i = 0; i < sched->sources_len; i++) {
  if ( (cur = sched->sources[i]) == NULL )
   continue;
  switch (cur->type) {
   case ROAR_SCHEDULER_VIO:
     if ( sched->vios[i].eventsa )
      if ( cur->cb != NULL )
       cur->cb(sched->sources[i], sched->sources[i]->userdata, sched->vios[i].eventsa);
    break;
   case ROAR_SCHEDULER_TIMEOUT:
     if ( ret == 0 )
      if ( cur->cb != NULL )
       cur->cb(sched->sources[i], sched->sources[i]->userdata, 0);
    break;
   case ROAR_SCHEDULER_PLUGIN:
     roar_dl_appsched_trigger(cur->lhandle, ROAR_DL_APPSCHED_UPDATE);
    break;
   case ROAR_SCHEDULER_PLUGINCONTAINER:
     roar_plugincontainer_appsched_trigger(cur->handle.container, ROAR_DL_APPSCHED_UPDATE);
    break;
   case ROAR_SCHEDULER_CPI_LISTEN:
     if ( !sched->vios[i].eventsa )
      continue;

     if ( cur->flags & ROAR_SCHEDULER_FLAG_STUB )
      continue;

     if ( cur->cb != NULL )
      cur->cb(sched->sources[i], sched->sources[i]->userdata, sched->vios[i].eventsa);

     new_client = roar_mm_malloc(sizeof(struct roar_scheduler_source));
     if ( new_client == NULL )
      continue;
     memcpy(new_client, cur, sizeof(struct roar_scheduler_source));
     new_client->type = ROAR_SCHEDULER_CPI_CLIENT;
     new_client->flags = ROAR_SCHEDULER_FLAG_FREE;
     new_client->vio   = roar_mm_malloc(sizeof(struct roar_vio_calls));

     if ( new_client->vio == NULL ) {
      roar_mm_free(new_client);
      continue;
     }

     if ( roar_vio_accept(new_client->vio, cur->vio) == -1 ) {
      roar_mm_free(new_client->vio);
      roar_mm_free(new_client);
      continue;
     }

     new_client->vio->flags |= ROAR_VIO_FLAGS_FREESELF;

     if ( roar_scheduler_source_add(sched, new_client) == -1 ) {
      roar_vio_close(new_client->vio);
      roar_mm_free(new_client);
     }
     roar_vio_unref(new_client->vio);

     if ( new_client->cb != NULL )
      new_client->cb(new_client, new_client->userdata, 0);

     if ( cur->handle.cpi.impl->set_proto != NULL ) {
      lhandle = new_client->lhandle;
      para = roar_dl_getpara(lhandle);

      if ( lhandle != NULL )
       roar_dl_context_restore(lhandle);
      new_client->handle.cpi.impl->set_proto(new_client->handle.cpi.client, new_client->vio, &(new_client->handle.cpi.obuffer), &(new_client->handle.cpi.userdata), new_client->handle.cpi.protopara, new_client->handle.cpi.protoparalen, para);
      if ( lhandle != NULL )
       roar_dl_context_store(lhandle);

      if ( para != NULL )
       roar_dl_para_unref(para);
     }
    break;
   case ROAR_SCHEDULER_CPI_CLIENT:
     if ( !sched->vios[i].eventsa )
      continue;

     if ( cur->flags & ROAR_SCHEDULER_FLAG_STUB )
      continue;

     if ( cur->cb != NULL )
      cur->cb(sched->sources[i], sched->sources[i]->userdata, sched->vios[i].eventsa);

     lhandle = cur->lhandle;
     para = roar_dl_getpara(lhandle);
     tmp = 0;

     if ( sched->vios[i].eventsa & ROAR_VIO_SELECT_WRITE ) {
      if ( cur->handle.cpi.impl->flush != NULL ) {
       if ( lhandle != NULL )
        roar_dl_context_restore(lhandle);

       cur->handle.cpi.impl->flush(cur->handle.cpi.client, cur->vio, &(cur->handle.cpi.obuffer), &(cur->handle.cpi.userdata), cur->handle.cpi.protopara, cur->handle.cpi.protoparalen, para);

       if ( lhandle != NULL )
        roar_dl_context_store(lhandle);
      } else {
        tmp = __flush_cpi_client(sched, cur, para);
      }

      if ( tmp == 0 && cur->handle.cpi.obuffer == NULL && cur->handle.cpi.impl->flushed != NULL ) {
       if ( lhandle != NULL )
        roar_dl_context_restore(lhandle);

       cur->handle.cpi.impl->flushed(cur->handle.cpi.client, cur->vio, &(cur->handle.cpi.obuffer), &(cur->handle.cpi.userdata), cur->handle.cpi.protopara, cur->handle.cpi.protoparalen, para);

       if ( lhandle != NULL )
        roar_dl_context_store(lhandle);
      }
     }

     if ( sched->vios[i].eventsa & ROAR_VIO_SELECT_READ ) {
      if ( cur->handle.cpi.impl->handle != NULL ) {
       if ( lhandle != NULL )
        roar_dl_context_restore(lhandle);

       if ( cur->handle.cpi.impl->handle(cur->handle.cpi.client, cur->vio, &(cur->handle.cpi.obuffer), &(cur->handle.cpi.userdata), cur->handle.cpi.protopara, cur->handle.cpi.protoparalen, para) == -1 ) {
        tmp = -1;
       }

       if ( lhandle != NULL )
        roar_dl_context_store(lhandle);
      }
     }

     if ( tmp == -1 ) {
      if ( lhandle != NULL )
       roar_dl_context_restore(lhandle);
      __delete_cpi_client(sched, cur, para);
      if ( lhandle != NULL )
       roar_dl_context_store(lhandle);
     }

     if ( para != NULL )
      roar_dl_para_unref(para);
    break;
#ifndef DEBUG
   default: /* noop */ break;
#endif
  }
 }

 return 1;
}

int                     roar_scheduler_run(struct roar_scheduler * sched) {
 int ret;

 _CHKSCHED(0);

 while ((ret = roar_scheduler_iterate(sched)) > 0);

 return ret;
}

static int __cpi_callback(enum roar_dl_fnreg_action action, int fn, int subtype, const void * object, size_t objectlen, int version, int options, void * userdata, struct roar_dl_lhandle * lhandle) {
 const struct roar_dl_proto * impl = object;
 struct roar_scheduler * sched = userdata;
 struct roar_dl_librarypara * para;
 size_t i;

 (void)fn, (void)subtype, (void)version, (void)options;

 if ( sched == NULL ) {
  roar_err_set(ROAR_ERROR_FAULT);
  return -1;
 }

 if ( objectlen != ROAR_DL_PROTO_SIZE ) {
  ROAR_WARN("__cpi_callback(*): Library %p tries to register protocol with bad object length.", lhandle);
  roar_err_set(ROAR_ERROR_BADLIB);
  return -1;
 }

 switch (action)  {
  case ROAR_DL_FNREG:
    for (i = 0; i < MAX_PROTOS; i++) {
     if ( sched->protos[i].impl == NULL ) {
      memset(&(sched->protos[i]), 0, sizeof(sched->protos[i]));
      sched->protos[i].para = NULL;
      sched->protos[i].paralen = -1;
      sched->protos[i].lhandle = lhandle;
      sched->protos[i].impl = impl;
      return 0;
     }
    }
   break;
  case ROAR_DL_FNUNREG:
    for (i = 0; i < sched->sources_len; i++) {
     if ( sched->sources[i] == NULL )
      continue;
     if ( sched->sources[i]->type != ROAR_SCHEDULER_CPI_LISTEN && sched->sources[i]->type != ROAR_SCHEDULER_CPI_CLIENT )
      continue;
     if ( sched->sources[i]->handle.cpi.proto != impl->proto )
      continue;

     para = roar_dl_getpara(lhandle);

     if ( lhandle != NULL )
      roar_dl_context_restore(lhandle);
     __delete_cpi_client(sched, sched->sources[i], para);
     if ( lhandle != NULL )
      roar_dl_context_store(lhandle);

     if ( para != NULL )
      roar_dl_para_unref(para);
    }

    for (i = 0; i < MAX_PROTOS; i++) {
     if ( sched->protos[i].impl != NULL && sched->protos[i].lhandle == lhandle ) {
      memset(&(sched->protos[i]), 0, sizeof(sched->protos[i]));
      sched->protos[i].impl = NULL;
     }
    }
    return 0;
   break;
 }

 roar_err_set(ROAR_ERROR_NOSPC);
 return -1;
}

static int __update_cpi_service (struct roar_scheduler * sched, struct roar_scheduler_source * source, int del) {
 if ( del ) {
  roar_err_set(ROAR_ERROR_NOTSUP);
  return -1;
 }

 sched->callback.fn = ROAR_DL_FN_PROTO;
 sched->callback.subtype = ROAR_DL_PROTO_SUBTYPE;
 sched->callback.version = ROAR_DL_PROTO_VERSION;
 sched->callback.callback = __cpi_callback;
 sched->callback.userdata = sched;

 ROAR_DL_RFNREG(ROAR_DL_HANDLE_LIBROAR, sched->callback);

 return -1;
}

static int __update_cpi_listen_client (struct roar_scheduler * sched, struct roar_scheduler_source * source) {
 size_t i;

 ROAR_DBG("__update_cpi_listen_client(sched=%p, source=%p): proto=%i, impl=%p", sched, source, source->handle.cpi.proto, source->handle.cpi.impl);

 if ( source->handle.cpi.proto < 1 && source->handle.cpi.impl != NULL )
  source->handle.cpi.proto = source->handle.cpi.impl->proto;

 if ( source->handle.cpi.proto > 0 && source->handle.cpi.impl == NULL ) {
  for (i = 0; i < MAX_PROTOS; i++) {
   if ( sched->protos[i].impl == NULL )
    continue;
   ROAR_DBG("__update_cpi_listen_client(sched=%p, source=%p): proto=%i<->%i", sched, source, sched->protos[i].impl->proto, source->handle.cpi.proto);
   if ( sched->protos[i].impl->proto != source->handle.cpi.proto )
    continue;
   source->handle.cpi.impl = sched->protos[i].impl;
   break;
  }
 }

 if ( source->handle.cpi.proto > 0 ) {
  source->flags |= ROAR_SCHEDULER_FLAG_STUB;
  if ( source->handle.cpi.impl == NULL )
   return 0;
  source->flags -= ROAR_SCHEDULER_FLAG_STUB;
  return 0;
 }

 roar_err_set(ROAR_ERROR_INVAL);
 return -1;
}

int                     roar_scheduler_source_add(struct roar_scheduler * sched,
                                                  struct roar_scheduler_source * source) {
 size_t i;
 struct roar_scheduler_source ** next = NULL;
 int err;
 
 _CHKSCHED(source == NULL);

 ROAR_DBG("roar_scheduler_source_add(sched=%p, source=%p): proto=%i, impl=%p", sched, source, source->handle.cpi.proto, source->handle.cpi.impl);

 for (i = 0; i < sched->sources_len; i++) {
  if ( sched->sources[i] != NULL )
   continue;
  next = &(sched->sources[i]);
  break;
 }

 if ( next == NULL ) {
  // TODO: re-allocate some space here.
  roar_err_set(ROAR_ERROR_NOSPC);
  return -1;
 }

 if ( source->flags == ROAR_SCHEDULER_FLAG_DEFAULT )
  source->flags = ROAR_SCHEDULER_FLAG_NONE;

 switch (source->type) {
  case ROAR_SCHEDULER_CPI_LISTEN:
  case ROAR_SCHEDULER_CPI_CLIENT:
    if ( __update_cpi_listen_client(sched, source) == -1 )
     return -1;
   break;
  case ROAR_SCHEDULER_CPI_SERVICE:
    if ( __update_cpi_service(sched, source, 0) == -1 )
     return -1;
   break;
#ifndef DEBUG
   default: /* noop */ break;
#endif
 }

 if ( source->lhandle != NULL )
  if ( roar_dl_ref(source->lhandle) == -1 )
   return -1;

 if ( source->vio != NULL ) {
  if ( roar_vio_ref(source->vio) == -1 ) {
   err = roar_error;
   if ( source->lhandle != NULL )
    roar_dl_unref(source->lhandle);
   roar_err_set(err);
   return -1;
  }
 }

 if ( source->type == ROAR_SCHEDULER_PLUGINCONTAINER ) {
  if ( roar_plugincontainer_ref(source->handle.container) == -1 ) {
   err = roar_error;
   if ( source->lhandle != NULL )
    roar_dl_unref(source->lhandle);
   if ( source->vio != NULL )
    roar_vio_unref(source->vio);
   roar_err_set(err);
   return -1;
  }
 }

 *next = source;

 return 0;
}

int                     roar_scheduler_source_del(struct roar_scheduler * sched,
                                                  struct roar_scheduler_source * source) {
 size_t i;
 struct roar_scheduler_source ** next = NULL;

 _CHKSCHED(source == NULL);

 for (i = 0; i < sched->sources_len; i++) {
  if ( sched->sources[i] != source )
   continue;
  next = &(sched->sources[i]);
  break;
 }

 if ( next == NULL ) {
  roar_err_set(ROAR_ERROR_NOENT);
  return -1;
 }

 switch (source->type) {
  case ROAR_SCHEDULER_PLUGINCONTAINER:
    roar_plugincontainer_ref(source->handle.container);
   break;
  case ROAR_SCHEDULER_CPI_SERVICE:
    if ( __update_cpi_service(sched, source, 1) == -1 )
     return -1;
   break;
#ifndef DEBUG
   default: /* noop */ break;
#endif
 }

 if ( source->lhandle != NULL )
  roar_dl_unref(source->lhandle);
 if ( source->vio != NULL )
  roar_vio_unref(source->vio);

 if ( source->flags & ROAR_SCHEDULER_FLAG_FREE )
  roar_mm_free(source);

 *next = NULL;
 return 0;
}

//ll