# ====================================================================
#
#      synch.cdl
#
#      configuration data related to the kernel synchronization primitives
#
# ====================================================================
#####COPYRIGHTBEGIN####
#                                                                          
# -------------------------------------------                              
# The contents of this file are subject to the Red Hat eCos Public License 
# Version 1.1 (the "License"); you may not use this file except in         
# compliance with the License.  You may obtain a copy of the License at    
# http://www.redhat.com/                                                   
#                                                                          
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# the License.                                                             
#                                                                          
# The Original Code is eCos - Embedded Configurable Operating System,      
# released September 30, 1998.                                             
#                                                                          
# The Initial Developer of the Original Code is Red Hat.                   
# Portions created by Red Hat are                                          
# Copyright (C) 1998, 1999, 2000 Red Hat, Inc.                             
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# ====================================================================
######DESCRIPTIONBEGIN####
#
# Author(s):      jskov
# Original data:  nickg
# Contributors:
# Date:           1999-07-05
#
#####DESCRIPTIONEND####
#
# ====================================================================

# NOTE: the requires statement is only valid for the current kernel.
# Priority inheritance is possible in other schedulers as well
# but is not yet implemented.
cdl_option CYGSEM_KERNEL_SYNCH_MUTEX_PRIORITY_INHERITANCE_SIMPLE {
    display       "Simple mutex priority inheritance"
    requires      CYGSEM_KERNEL_SCHED_MLQUEUE
    default_value 1
    description   "
        This option enables a relatively simple implementation of
        mutex priority inheritance. The implementation will only work
        in the mlqueue scheduler, and it does not handle the rare
        case of nested mutexes completely correctly. However it is
        both fast and deterministic. Mutex priority inheritance can
        be disabled if the application does not require it, which
        will reduce both code size and data space."
}

cdl_option CYGSEM_KERNEL_SYNCH_MUTEX_PRIORITY_INHERITANCE_SIMPLE_RELAY {
    display    "Relay enhancement to simple mutex priority inheritance"
    active_if	CYGSEM_KERNEL_SYNCH_MUTEX_PRIORITY_INHERITANCE_SIMPLE
    default_value 1
    description   "
        This option enables an extension to the simple implementation of
        mutex priority inheritance whereby a thread releasing a mutex to a
        waiting thread relays its own priority to the new owner if there
        are still further threads waiting.  This can be viewed as a
        discovered priority ceiling."
}

cdl_option CYGMFN_KERNEL_SYNCH_MBOXT_PUT_CAN_WAIT {
    display       "Message box blocking put support"
    default_value 1
    description   "
        Message boxes can support three different versions of the
        put-message operation. The first is tryput(), which will fail
        if the message box is already full. The other two are the
        ordinary put() function which will block if the message box
        is full, and a timed put() operation which will block for
        upto a certain length of time if the message box is currently
        full. The blocking versions require extra memory in the
        message box data structure and extra code in the other
        message box functions, so they can be disabled if the
        application does not require them. If this option is enabled
        then the system will always provide the blocking put()
        function, and it will also provide the timed put() function
        if thread timers are enabled."
}

cdl_option CYGNUM_KERNEL_SYNCH_MBOX_QUEUE_SIZE {
    display       "Message box queue size"
    flavor        data
    legal_values  1 to 65535
    default_value 10
    description   "
        This configuration option controls the number of messages
        that can be queued in a message box before a non-blocking
        put() operation will fail or a blocking put() operation will
        block. The cost in memory is one pointer per message box for
        each possible message."
}

cdl_option CYGMFN_KERNEL_SYNCH_CONDVAR_TIMED_WAIT {
    display       "Condition variable timed-wait support"
    requires      CYGFUN_KERNEL_THREADS_TIMER
    default_value 1
    description   "
        This option enables the condition variable timed wait
        facility."
}