third_party/npapi/npspy/extern/nspr/pratom.h

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /*
   3  * The contents of this file are subject to the Mozilla Public
   4  * License Version 1.1 (the "License"); you may not use this file
   5  * except in compliance with the License. You may obtain a copy of
   6  * the License at http://www.mozilla.org/MPL/
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   8  * Software distributed under the License is distributed on an "AS
   9  * IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
  10  * implied. See the License for the specific language governing
  11  * rights and limitations under the License.
  12  *
  13  * The Original Code is the Netscape Portable Runtime (NSPR).
  14  *
  15  * The Initial Developer of the Original Code is Netscape
  16  * Communications Corporation.  Portions created by Netscape are
  17  * Copyright (C) 1998-2000 Netscape Communications Corporation.  All
  18  * Rights Reserved.
  19  *
  20  * Contributor(s):
  21  *
  22  * Alternatively, the contents of this file may be used under the
  23  * terms of the GNU General Public License Version 2 or later (the
  24  * "GPL"), in which case the provisions of the GPL are applicable
  25  * instead of those above.  If you wish to allow use of your
  26  * version of this file only under the terms of the GPL and not to
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  28  * indicate your decision by deleting the provisions above and
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  30  * the GPL.  If you do not delete the provisions above, a recipient
  31  * may use your version of this file under either the MPL or the
  32  * GPL.
  33  */
  34
  35 /* GLOBAL FUNCTIONS:
  36 ** DESCRIPTION:
  37 **     PR Atomic operations
  38 */
  39
  40 #ifndef pratom_h___
  41 #define pratom_h___
  42
  43 #include "prtypes.h"
  44 #include "prlock.h"
  45
  46 PR_BEGIN_EXTERN_C
  47
  48 /*
  49 ** FUNCTION: PR_AtomicIncrement
  50 ** DESCRIPTION:
  51 **    Atomically increment a 32 bit value.
  52 ** INPUTS:
  53 **    val:  a pointer to the value to increment
  54 ** RETURN:
  55 **    the returned value is the result of the increment
  56 */
  57 NSPR_API(PRInt32)       PR_AtomicIncrement(PRInt32 *val);
  58
  59 /*
  60 ** FUNCTION: PR_AtomicDecrement
  61 ** DESCRIPTION:
  62 **    Atomically decrement a 32 bit value.
  63 ** INPUTS:
  64 **    val:  a pointer to the value to decrement
  65 ** RETURN:
  66 **    the returned value is the result of the decrement
  67 */
  68 NSPR_API(PRInt32)       PR_AtomicDecrement(PRInt32 *val);
  69
  70 /*
  71 ** FUNCTION: PR_AtomicSet
  72 ** DESCRIPTION:
  73 **    Atomically set a 32 bit value.
  74 ** INPUTS:
  75 **    val: A pointer to a 32 bit value to be set
  76 **    newval: The newvalue to assign to val
  77 ** RETURN:
  78 **    Returns the prior value
  79 */
  80 NSPR_API(PRInt32) PR_AtomicSet(PRInt32 *val, PRInt32 newval);
  81
  82 /*
  83 ** FUNCTION: PR_AtomicAdd
  84 ** DESCRIPTION:
  85 **    Atomically add a 32 bit value.
  86 ** INPUTS:
  87 **    ptr:  a pointer to the value to increment
  88 **        val:  value to be added
  89 ** RETURN:
  90 **    the returned value is the result of the addition
  91 */
  92 NSPR_API(PRInt32)       PR_AtomicAdd(PRInt32 *ptr, PRInt32 val);
  93
  94 /*
  95 ** LIFO linked-list (stack)
  96 */
  97 typedef struct PRStackElemStr PRStackElem;
  98
  99 struct PRStackElemStr {
 100     PRStackElem *prstk_elem_next;       /* next pointer MUST be at offset 0;
 101                                                                           assembly language code relies on this */
 102 };
 103
 104 typedef struct PRStackStr PRStack;
 105
 106 /*
 107 ** FUNCTION: PR_CreateStack
 108 ** DESCRIPTION:
 109 **    Create a stack, a LIFO linked list
 110 ** INPUTS:
 111 **    stack_name:  a pointer to string containing the name of the stack
 112 ** RETURN:
 113 **    A pointer to the created stack, if successful, else NULL.
 114 */
 115 NSPR_API(PRStack *)     PR_CreateStack(const char *stack_name);
 116
 117 /*
 118 ** FUNCTION: PR_StackPush
 119 ** DESCRIPTION:
 120 **    Push an element on the top of the stack
 121 ** INPUTS:
 122 **    stack:            pointer to the stack
 123 **    stack_elem:       pointer to the stack element
 124 ** RETURN:
 125 **    None
 126 */
 127 NSPR_API(void)                  PR_StackPush(PRStack *stack, PRStackElem *stack_elem);
 128
 129 /*
 130 ** FUNCTION: PR_StackPop
 131 ** DESCRIPTION:
 132 **    Remove the element on the top of the stack
 133 ** INPUTS:
 134 **    stack:            pointer to the stack
 135 ** RETURN:
 136 **    A pointer to the stack element removed from the top of the stack,
 137 **        if non-empty,
 138 **    else NULL
 139 */
 140 NSPR_API(PRStackElem *) PR_StackPop(PRStack *stack);
 141
 142 /*
 143 ** FUNCTION: PR_DestroyStack
 144 ** DESCRIPTION:
 145 **    Destroy the stack
 146 ** INPUTS:
 147 **    stack:            pointer to the stack
 148 ** RETURN:
 149 **    PR_SUCCESS - if successfully deleted
 150 **        PR_FAILURE - if the stack is not empty
 151 **                                      PR_GetError will return
 152 **                                              PR_INVALID_STATE_ERROR - stack is not empty
 153 */
 154 NSPR_API(PRStatus)              PR_DestroyStack(PRStack *stack);
 155
 156 PR_END_EXTERN_C
 157
 158 #endif /* pratom_h___ */