1/*
2    SDL - Simple DirectMedia Layer
3    Copyright (C) 1997-2012 Sam Lantinga
4
5    This library is free software; you can redistribute it and/or
6    modify it under the terms of the GNU Library General Public
7    License as published by the Free Software Foundation; either
8    version 2 of the License, or (at your option) any later version.
9
10    This library is distributed in the hope that it will be useful,
11    but WITHOUT ANY WARRANTY; without even the implied warranty of
12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13    Library General Public License for more details.
14
15    You should have received a copy of the GNU Library General Public
16    License along with this library; if not, write to the Free
17    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
18
19    Sam Lantinga
20    slouken@libsdl.org
21*/
22#include "SDL_config.h"
23
24/*
25    Note: This file hasn't been modified so technically we have to keep the disclaimer :-(
26
27    Copyright:  � Copyright 2002 Apple Computer, Inc. All rights reserved.
28
29    Disclaimer: IMPORTANT:  This Apple software is supplied to you by Apple Computer, Inc.
30            ("Apple") in consideration of your agreement to the following terms, and your
31            use, installation, modification or redistribution of this Apple software
32            constitutes acceptance of these terms.  If you do not agree with these terms,
33            please do not use, install, modify or redistribute this Apple software.
34
35            In consideration of your agreement to abide by the following terms, and subject
36            to these terms, Apple grants you a personal, non-exclusive license, under Apple�s
37            copyrights in this original Apple software (the "Apple Software"), to use,
38            reproduce, modify and redistribute the Apple Software, with or without
39            modifications, in source and/or binary forms; provided that if you redistribute
40            the Apple Software in its entirety and without modifications, you must retain
41            this notice and the following text and disclaimers in all such redistributions of
42            the Apple Software.  Neither the name, trademarks, service marks or logos of
43            Apple Computer, Inc. may be used to endorse or promote products derived from the
44            Apple Software without specific prior written permission from Apple.  Except as
45            expressly stated in this notice, no other rights or licenses, express or implied,
46            are granted by Apple herein, including but not limited to any patent rights that
47            may be infringed by your derivative works or by other works in which the Apple
48            Software may be incorporated.
49
50            The Apple Software is provided by Apple on an "AS IS" basis.  APPLE MAKES NO
51            WARRANTIES, EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION THE IMPLIED
52            WARRANTIES OF NON-INFRINGEMENT, MERCHANTABILITY AND FITNESS FOR A PARTICULAR
53            PURPOSE, REGARDING THE APPLE SOFTWARE OR ITS USE AND OPERATION ALONE OR IN
54            COMBINATION WITH YOUR PRODUCTS.
55
56            IN NO EVENT SHALL APPLE BE LIABLE FOR ANY SPECIAL, INDIRECT, INCIDENTAL OR
57            CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
58            GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
59            ARISING IN ANY WAY OUT OF THE USE, REPRODUCTION, MODIFICATION AND/OR DISTRIBUTION
60            OF THE APPLE SOFTWARE, HOWEVER CAUSED AND WHETHER UNDER THEORY OF CONTRACT, TORT
61            (INCLUDING NEGLIGENCE), STRICT LIABILITY OR OTHERWISE, EVEN IF APPLE HAS BEEN
62            ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
63*/
64/*=============================================================================
65    CAGuard.cp
66
67=============================================================================*/
68
69/*=============================================================================
70    Includes
71  =============================================================================*/
72
73/*
74#include <stdio.h>
75#include <stdlib.h>
76#include <string.h>
77*/
78#include "SDL_stdinc.h"
79
80/*#define NDEBUG 1*/
81/*
82#include <assert.h>
83*/
84#define assert(X)
85
86
87#include "SDLOSXCAGuard.h"
88
89/*#warning      Need a try-based Locker too*/
90/*=============================================================================
91    SDLOSXCAGuard
92  =============================================================================*/
93
94static int SDLOSXCAGuard_Lock(SDLOSXCAGuard *cag)
95{
96    int theAnswer = 0;
97
98    if(pthread_self() != cag->mOwner)
99    {
100        OSStatus theError = pthread_mutex_lock(&cag->mMutex);
101        (void)theError;
102        assert(theError == 0);
103        cag->mOwner = pthread_self();
104        theAnswer = 1;
105    }
106
107    return theAnswer;
108}
109
110static void    SDLOSXCAGuard_Unlock(SDLOSXCAGuard *cag)
111{
112    OSStatus theError;
113    assert(pthread_self() == cag->mOwner);
114
115    cag->mOwner = 0;
116    theError = pthread_mutex_unlock(&cag->mMutex);
117    (void)theError;
118    assert(theError == 0);
119}
120
121static int SDLOSXCAGuard_Try (SDLOSXCAGuard *cag, int *outWasLocked)
122{
123    int theAnswer = 0;
124    *outWasLocked = 0;
125
126    if (pthread_self() == cag->mOwner) {
127        theAnswer = 1;
128        *outWasLocked = 0;
129    } else {
130        OSStatus theError = pthread_mutex_trylock(&cag->mMutex);
131        if (theError == 0) {
132            cag->mOwner = pthread_self();
133            theAnswer = 1;
134            *outWasLocked = 1;
135        }
136    }
137
138    return theAnswer;
139}
140
141static void    SDLOSXCAGuard_Wait(SDLOSXCAGuard *cag)
142{
143    OSStatus theError;
144    assert(pthread_self() == cag->mOwner);
145
146    cag->mOwner = 0;
147
148    theError = pthread_cond_wait(&cag->mCondVar, &cag->mMutex);
149    (void)theError;
150    assert(theError == 0);
151    cag->mOwner = pthread_self();
152}
153
154static void    SDLOSXCAGuard_Notify(SDLOSXCAGuard *cag)
155{
156    OSStatus theError = pthread_cond_signal(&cag->mCondVar);
157    (void)theError;
158    assert(theError == 0);
159}
160
161
162SDLOSXCAGuard *new_SDLOSXCAGuard(void)
163{
164    OSStatus theError;
165    SDLOSXCAGuard *cag = (SDLOSXCAGuard *) SDL_malloc(sizeof (SDLOSXCAGuard));
166    if (cag == NULL)
167        return NULL;
168    SDL_memset(cag, '\0', sizeof (*cag));
169
170    #define SET_SDLOSXCAGUARD_METHOD(m) cag->m = SDLOSXCAGuard_##m
171    SET_SDLOSXCAGUARD_METHOD(Lock);
172    SET_SDLOSXCAGUARD_METHOD(Unlock);
173    SET_SDLOSXCAGUARD_METHOD(Try);
174    SET_SDLOSXCAGUARD_METHOD(Wait);
175    SET_SDLOSXCAGUARD_METHOD(Notify);
176    #undef SET_SDLOSXCAGUARD_METHOD
177
178    theError = pthread_mutex_init(&cag->mMutex, NULL);
179    (void)theError;
180    assert(theError == 0);
181
182    theError = pthread_cond_init(&cag->mCondVar, NULL);
183    (void)theError;
184    assert(theError == 0);
185
186    cag->mOwner = 0;
187    return cag;
188}
189
190void delete_SDLOSXCAGuard(SDLOSXCAGuard *cag)
191{
192    if (cag != NULL)
193    {
194        pthread_mutex_destroy(&cag->mMutex);
195        pthread_cond_destroy(&cag->mCondVar);
196        SDL_free(cag);
197    }
198}
199
200