libcilkrts/runtime/signal_node.h

   1 /* signal_node.h                  -*-C++-*-
   2  *
   3  *************************************************************************
   4  *
   5  *  Copyright (C) 2009-2016, Intel Corporation
   6  *  All rights reserved.
   7  *
   8  *  Redistribution and use in source and binary forms, with or without
   9  *  modification, are permitted provided that the following conditions
  10  *  are met:
  11  *
  12  *    * Redistributions of source code must retain the above copyright
  13  *      notice, this list of conditions and the following disclaimer.
  14  *    * Redistributions in binary form must reproduce the above copyright
  15  *      notice, this list of conditions and the following disclaimer in
  16  *      the documentation and/or other materials provided with the
  17  *      distribution.
  18  *    * Neither the name of Intel Corporation nor the names of its
  19  *      contributors may be used to endorse or promote products derived
  20  *      from this software without specific prior written permission.
  21  *
  22  *  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  23  *  "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  24  *  LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  25  *  A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  26  *  HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
  27  *  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
  28  *  BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
  29  *  OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
  30  *  AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  31  *  LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY
  32  *  WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  33  *  POSSIBILITY OF SUCH DAMAGE.
  34  *
  35  *  *********************************************************************
  36  *
  37  *  PLEASE NOTE: This file is a downstream copy of a file mainitained in
  38  *  a repository at cilkplus.org. Changes made to this file that are not
  39  *  submitted through the contribution process detailed at
  40  *  http://www.cilkplus.org/submit-cilk-contribution will be lost the next
  41  *  time that a new version is released. Changes only submitted to the
  42  *  GNU compiler collection or posted to the git repository at
  43  *  https://bitbucket.org/intelcilkruntime/intel-cilk-runtime.git are
  44  *  not tracked.
  45  *
  46  *  We welcome your contributions to this open source project. Thank you
  47  *  for your assistance in helping us improve Cilk Plus.
  48  **************************************************************************/
  49
  50 /**
  51  * @file signal_node.h
  52  *
  53  * @brief Signal nodes allow coordinated waking and sleeping of the runtime
  54  * without hammering on a single location in memory.
  55  *
  56  * The workers are logically arranged in a binary tree and propagate messages
  57  * leaf-ward.  User workers notify the root about waking and sleeping, so only
  58  * that one node need share a cache line with a user worker.
  59  */
  60
  61 #ifndef INCLUDED_SIGNAL_NODE_DOT_H
  62 #define INCLUDED_SIGNAL_NODE_DOT_H
  63
  64 #include "rts-common.h"
  65 #include <cilk/common.h>
  66
  67 __CILKRTS_BEGIN_EXTERN_C
  68
  69 /** Opaque type. */
  70 typedef struct signal_node_t signal_node_t;
  71
  72 /**
  73  * Allocate and initialize a signal_node_t
  74  *
  75  * @return The initialized signal_node_t
  76  */
  77 COMMON_SYSDEP
  78 signal_node_t *signal_node_create(void);
  79
  80 /**
  81  * Free any resources and deallocate a signal_node_t
  82  *
  83  * @param node The node to be deallocated.
  84  */
  85 COMMON_SYSDEP void signal_node_destroy(signal_node_t *node);
  86
  87 /**
  88  * Test whether the node thinks the worker should go to sleep
  89  *
  90  * @param node The node to be tested.
  91  *
  92  * @return 1 If the worker should go to sleep
  93  * @return 0 If the worker should not go to sleep
  94  */
  95 COMMON_SYSDEP
  96 unsigned int signal_node_should_wait(signal_node_t *node);
  97
  98 /**
  99  * Specify whether the worker should go to sleep
 100  *
 101  * @param node The node to be set.
 102  * @param msg The value to be set.  Valid values are:
 103  * - 0 - the worker should go to sleep
 104  * - 1 - the worker should stay active
 105  */
 106 COMMON_SYSDEP
 107 void signal_node_msg(signal_node_t *node, unsigned int msg);
 108
 109
 110 /**
 111  * Wait for the node to be set
 112  *
 113  * @param node The node to wait on
 114  */
 115 COMMON_SYSDEP
 116 void signal_node_wait(signal_node_t *node);
 117
 118 __CILKRTS_END_EXTERN_C
 119
 120 #endif // ! defined(INCLUDED_SIGNAL_NODE_DOT_H)