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author | dan miller | 2007-10-20 02:49:29 +0000 |
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committer | dan miller | 2007-10-20 02:49:29 +0000 |
commit | e36d23a85ebff914d74bb541558c2b6082b78edb (patch) | |
tree | 54b58fdf162e78af64055282a6035c8d2443389d /libraries/sqlite/unix/sqlite-3.5.1/src/mem1.c | |
parent | * Fixed an issue whereby avatar chat distances were being calculated against ... (diff) | |
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sqlite source (unix build) added to libraries
Diffstat (limited to '')
-rw-r--r-- | libraries/sqlite/unix/sqlite-3.5.1/src/mem1.c | 229 |
1 files changed, 229 insertions, 0 deletions
diff --git a/libraries/sqlite/unix/sqlite-3.5.1/src/mem1.c b/libraries/sqlite/unix/sqlite-3.5.1/src/mem1.c new file mode 100644 index 0000000..1e9fcfa --- /dev/null +++ b/libraries/sqlite/unix/sqlite-3.5.1/src/mem1.c | |||
@@ -0,0 +1,229 @@ | |||
1 | /* | ||
2 | ** 2007 August 14 | ||
3 | ** | ||
4 | ** The author disclaims copyright to this source code. In place of | ||
5 | ** a legal notice, here is a blessing: | ||
6 | ** | ||
7 | ** May you do good and not evil. | ||
8 | ** May you find forgiveness for yourself and forgive others. | ||
9 | ** May you share freely, never taking more than you give. | ||
10 | ** | ||
11 | ************************************************************************* | ||
12 | ** This file contains the C functions that implement a memory | ||
13 | ** allocation subsystem for use by SQLite. | ||
14 | ** | ||
15 | ** $Id: mem1.c,v 1.10 2007/09/02 17:50:35 drh Exp $ | ||
16 | */ | ||
17 | |||
18 | /* | ||
19 | ** This version of the memory allocator is the default. It is | ||
20 | ** used when no other memory allocator is specified using compile-time | ||
21 | ** macros. | ||
22 | */ | ||
23 | #if !defined(SQLITE_MEMDEBUG) && !defined(SQLITE_OMIT_MEMORY_ALLOCATION) | ||
24 | |||
25 | /* | ||
26 | ** We will eventually construct multiple memory allocation subsystems | ||
27 | ** suitable for use in various contexts: | ||
28 | ** | ||
29 | ** * Normal multi-threaded builds | ||
30 | ** * Normal single-threaded builds | ||
31 | ** * Debugging builds | ||
32 | ** | ||
33 | ** This initial version is suitable for use in normal multi-threaded | ||
34 | ** builds. We envision that alternative versions will be stored in | ||
35 | ** separate source files. #ifdefs will be used to select the code from | ||
36 | ** one of the various memN.c source files for use in any given build. | ||
37 | */ | ||
38 | #include "sqliteInt.h" | ||
39 | |||
40 | /* | ||
41 | ** All of the static variables used by this module are collected | ||
42 | ** into a single structure named "mem". This is to keep the | ||
43 | ** static variables organized and to reduce namespace pollution | ||
44 | ** when this module is combined with other in the amalgamation. | ||
45 | */ | ||
46 | static struct { | ||
47 | /* | ||
48 | ** The alarm callback and its arguments. The mem.mutex lock will | ||
49 | ** be held while the callback is running. Recursive calls into | ||
50 | ** the memory subsystem are allowed, but no new callbacks will be | ||
51 | ** issued. The alarmBusy variable is set to prevent recursive | ||
52 | ** callbacks. | ||
53 | */ | ||
54 | sqlite3_int64 alarmThreshold; | ||
55 | void (*alarmCallback)(void*, sqlite3_int64,int); | ||
56 | void *alarmArg; | ||
57 | int alarmBusy; | ||
58 | |||
59 | /* | ||
60 | ** Mutex to control access to the memory allocation subsystem. | ||
61 | */ | ||
62 | sqlite3_mutex *mutex; | ||
63 | |||
64 | /* | ||
65 | ** Current allocation and high-water mark. | ||
66 | */ | ||
67 | sqlite3_int64 nowUsed; | ||
68 | sqlite3_int64 mxUsed; | ||
69 | |||
70 | |||
71 | } mem; | ||
72 | |||
73 | /* | ||
74 | ** Enter the mutex mem.mutex. Allocate it if it is not already allocated. | ||
75 | */ | ||
76 | static void enterMem(void){ | ||
77 | if( mem.mutex==0 ){ | ||
78 | mem.mutex = sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_MEM); | ||
79 | } | ||
80 | sqlite3_mutex_enter(mem.mutex); | ||
81 | } | ||
82 | |||
83 | /* | ||
84 | ** Return the amount of memory currently checked out. | ||
85 | */ | ||
86 | sqlite3_int64 sqlite3_memory_used(void){ | ||
87 | sqlite3_int64 n; | ||
88 | enterMem(); | ||
89 | n = mem.nowUsed; | ||
90 | sqlite3_mutex_leave(mem.mutex); | ||
91 | return n; | ||
92 | } | ||
93 | |||
94 | /* | ||
95 | ** Return the maximum amount of memory that has ever been | ||
96 | ** checked out since either the beginning of this process | ||
97 | ** or since the most recent reset. | ||
98 | */ | ||
99 | sqlite3_int64 sqlite3_memory_highwater(int resetFlag){ | ||
100 | sqlite3_int64 n; | ||
101 | enterMem(); | ||
102 | n = mem.mxUsed; | ||
103 | if( resetFlag ){ | ||
104 | mem.mxUsed = mem.nowUsed; | ||
105 | } | ||
106 | sqlite3_mutex_leave(mem.mutex); | ||
107 | return n; | ||
108 | } | ||
109 | |||
110 | /* | ||
111 | ** Change the alarm callback | ||
112 | */ | ||
113 | int sqlite3_memory_alarm( | ||
114 | void(*xCallback)(void *pArg, sqlite3_int64 used,int N), | ||
115 | void *pArg, | ||
116 | sqlite3_int64 iThreshold | ||
117 | ){ | ||
118 | enterMem(); | ||
119 | mem.alarmCallback = xCallback; | ||
120 | mem.alarmArg = pArg; | ||
121 | mem.alarmThreshold = iThreshold; | ||
122 | sqlite3_mutex_leave(mem.mutex); | ||
123 | return SQLITE_OK; | ||
124 | } | ||
125 | |||
126 | /* | ||
127 | ** Trigger the alarm | ||
128 | */ | ||
129 | static void sqlite3MemsysAlarm(int nByte){ | ||
130 | void (*xCallback)(void*,sqlite3_int64,int); | ||
131 | sqlite3_int64 nowUsed; | ||
132 | void *pArg; | ||
133 | if( mem.alarmCallback==0 || mem.alarmBusy ) return; | ||
134 | mem.alarmBusy = 1; | ||
135 | xCallback = mem.alarmCallback; | ||
136 | nowUsed = mem.nowUsed; | ||
137 | pArg = mem.alarmArg; | ||
138 | sqlite3_mutex_leave(mem.mutex); | ||
139 | xCallback(pArg, nowUsed, nByte); | ||
140 | sqlite3_mutex_enter(mem.mutex); | ||
141 | mem.alarmBusy = 0; | ||
142 | } | ||
143 | |||
144 | /* | ||
145 | ** Allocate nBytes of memory | ||
146 | */ | ||
147 | void *sqlite3_malloc(int nBytes){ | ||
148 | sqlite3_int64 *p = 0; | ||
149 | if( nBytes>0 ){ | ||
150 | enterMem(); | ||
151 | if( mem.alarmCallback!=0 && mem.nowUsed+nBytes>=mem.alarmThreshold ){ | ||
152 | sqlite3MemsysAlarm(nBytes); | ||
153 | } | ||
154 | p = malloc(nBytes+8); | ||
155 | if( p==0 ){ | ||
156 | sqlite3MemsysAlarm(nBytes); | ||
157 | p = malloc(nBytes+8); | ||
158 | } | ||
159 | if( p ){ | ||
160 | p[0] = nBytes; | ||
161 | p++; | ||
162 | mem.nowUsed += nBytes; | ||
163 | if( mem.nowUsed>mem.mxUsed ){ | ||
164 | mem.mxUsed = mem.nowUsed; | ||
165 | } | ||
166 | } | ||
167 | sqlite3_mutex_leave(mem.mutex); | ||
168 | } | ||
169 | return (void*)p; | ||
170 | } | ||
171 | |||
172 | /* | ||
173 | ** Free memory. | ||
174 | */ | ||
175 | void sqlite3_free(void *pPrior){ | ||
176 | sqlite3_int64 *p; | ||
177 | int nByte; | ||
178 | if( pPrior==0 ){ | ||
179 | return; | ||
180 | } | ||
181 | assert( mem.mutex!=0 ); | ||
182 | p = pPrior; | ||
183 | p--; | ||
184 | nByte = (int)*p; | ||
185 | sqlite3_mutex_enter(mem.mutex); | ||
186 | mem.nowUsed -= nByte; | ||
187 | free(p); | ||
188 | sqlite3_mutex_leave(mem.mutex); | ||
189 | } | ||
190 | |||
191 | /* | ||
192 | ** Change the size of an existing memory allocation | ||
193 | */ | ||
194 | void *sqlite3_realloc(void *pPrior, int nBytes){ | ||
195 | int nOld; | ||
196 | sqlite3_int64 *p; | ||
197 | if( pPrior==0 ){ | ||
198 | return sqlite3_malloc(nBytes); | ||
199 | } | ||
200 | if( nBytes<=0 ){ | ||
201 | sqlite3_free(pPrior); | ||
202 | return 0; | ||
203 | } | ||
204 | p = pPrior; | ||
205 | p--; | ||
206 | nOld = (int)p[0]; | ||
207 | assert( mem.mutex!=0 ); | ||
208 | sqlite3_mutex_enter(mem.mutex); | ||
209 | if( mem.nowUsed+nBytes-nOld>=mem.alarmThreshold ){ | ||
210 | sqlite3MemsysAlarm(nBytes-nOld); | ||
211 | } | ||
212 | p = realloc(p, nBytes+8); | ||
213 | if( p==0 ){ | ||
214 | sqlite3MemsysAlarm(nBytes); | ||
215 | p = realloc(p, nBytes+8); | ||
216 | } | ||
217 | if( p ){ | ||
218 | p[0] = nBytes; | ||
219 | p++; | ||
220 | mem.nowUsed += nBytes-nOld; | ||
221 | if( mem.nowUsed>mem.mxUsed ){ | ||
222 | mem.mxUsed = mem.nowUsed; | ||
223 | } | ||
224 | } | ||
225 | sqlite3_mutex_leave(mem.mutex); | ||
226 | return (void*)p; | ||
227 | } | ||
228 | |||
229 | #endif /* !SQLITE_MEMDEBUG && !SQLITE_OMIT_MEMORY_ALLOCATION */ | ||