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/ 7 * 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 27 * allow others to use your version of this file under the MPL, 28 * indicate your decision by deleting the provisions above and 29 * replace them with the notice and other provisions required by 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___ */ 159