1 /*
2 Copyright (c) 2000, 2013, Oracle and/or its affiliates
3 Copyright (c) 2009, 2014, SkySQL Ab
4
5 This program is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by
7 the Free Software Foundation; version 2 of the License.
8
9 This program is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 GNU General Public License for more details.
13
14 You should have received a copy of the GNU General Public License
15 along with this program; if not, write to the Free Software
16 Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1335 USA */
17
18 #include "mysys_priv.h"
19 #include "mysys_err.h"
20 #include <m_string.h>
21
22 struct my_memory_header
23 {
24 PSI_thread *m_owner;
25 size_t m_size;
26 PSI_memory_key m_key;
27 };
28 typedef struct my_memory_header my_memory_header;
29 #define HEADER_SIZE 24
30
31 #define USER_TO_HEADER(P) ((my_memory_header*)((char *)(P) - HEADER_SIZE))
32 #define HEADER_TO_USER(P) ((char*)(P) + HEADER_SIZE)
33
34 /**
35 Inform application that memory usage has changed
36
37 @param size Size of memory segment allocated or freed
38 @param flag 1 if thread specific (allocated by MY_THREAD_SPECIFIC),
39 0 if system specific.
40
41 The type os size is long long, to be able to handle negative numbers to
42 decrement the memory usage
43
44 @return 0 - ok
45 1 - failure, abort the allocation
46 */
dummy(long long size,my_bool is_thread_specific)47 static void dummy(long long size __attribute__((unused)),
48 my_bool is_thread_specific __attribute__((unused)))
49 {}
50
51 static MALLOC_SIZE_CB update_malloc_size= dummy;
52
set_malloc_size_cb(MALLOC_SIZE_CB func)53 void set_malloc_size_cb(MALLOC_SIZE_CB func)
54 {
55 update_malloc_size= func ? func : dummy;
56 }
57
58
59 /**
60 Allocate a sized block of memory.
61
62 @param size The size of the memory block in bytes.
63 @param flags Failure action modifiers (bitmasks).
64
65 @return A pointer to the allocated memory block, or NULL on failure.
66 */
my_malloc(PSI_memory_key key,size_t size,myf my_flags)67 void *my_malloc(PSI_memory_key key, size_t size, myf my_flags)
68 {
69 my_memory_header *mh;
70 void *point;
71 DBUG_ENTER("my_malloc");
72 DBUG_PRINT("my",("size: %zu flags: %lu", size, my_flags));
73 compile_time_assert(sizeof(my_memory_header) <= HEADER_SIZE);
74
75 if (!(my_flags & (MY_WME | MY_FAE)))
76 my_flags|= my_global_flags;
77
78 /* Safety */
79 if (!size)
80 size=1;
81 if (size > SIZE_T_MAX - 1024L*1024L*16L) /* Wrong call */
82 DBUG_RETURN(0);
83
84 /* We have to align size as we store MY_THREAD_SPECIFIC flag in the LSB */
85 size= ALIGN_SIZE(size);
86
87 if (DBUG_EVALUATE_IF("simulate_out_of_memory", 1, 0))
88 mh= NULL;
89 else
90 mh= (my_memory_header*) sf_malloc(size + HEADER_SIZE, my_flags);
91
92 if (mh == NULL)
93 {
94 my_errno=errno;
95 if (my_flags & MY_FAE)
96 error_handler_hook=fatal_error_handler_hook;
97 if (my_flags & (MY_FAE+MY_WME))
98 my_error(EE_OUTOFMEMORY, MYF(ME_BELL+ME_ERROR_LOG+ME_FATAL),size);
99 if (my_flags & MY_FAE)
100 abort();
101 point= NULL;
102 }
103 else
104 {
105 int flag= MY_TEST(my_flags & MY_THREAD_SPECIFIC);
106 mh->m_size= size | flag;
107 mh->m_key= PSI_CALL_memory_alloc(key, size, & mh->m_owner);
108 update_malloc_size(size + HEADER_SIZE, flag);
109 point= HEADER_TO_USER(mh);
110 if (my_flags & MY_ZEROFILL)
111 bzero(point, size);
112 else
113 TRASH_ALLOC(point, size);
114 }
115 DBUG_PRINT("exit",("ptr: %p", point));
116 DBUG_RETURN(point);
117 }
118
119
120 /**
121 @brief wrapper around realloc()
122
123 @param old_point pointer to currently allocated area
124 @param size new size requested, must be >0
125 @param my_flags flags
126
127 @note if size==0 realloc() may return NULL; my_realloc() treats this as an
128 error which is not the intention of realloc()
129 */
my_realloc(PSI_memory_key key,void * old_point,size_t size,myf my_flags)130 void *my_realloc(PSI_memory_key key, void *old_point, size_t size, myf my_flags)
131 {
132 my_memory_header *old_mh, *mh;
133 void *point;
134 size_t old_size;
135 my_bool old_flags;
136 DBUG_ENTER("my_realloc");
137 DBUG_PRINT("my",("ptr: %p size: %zu flags: %lu", old_point, size, my_flags));
138
139 DBUG_ASSERT(size > 0);
140 if (!old_point && (my_flags & MY_ALLOW_ZERO_PTR))
141 DBUG_RETURN(my_malloc(key, size, my_flags));
142
143 old_mh= USER_TO_HEADER(old_point);
144 old_size= old_mh->m_size & ~1;
145 old_flags= old_mh->m_size & 1;
146
147 DBUG_ASSERT(old_mh->m_key == key || old_mh->m_key == PSI_NOT_INSTRUMENTED);
148 DBUG_ASSERT(old_flags == MY_TEST(my_flags & MY_THREAD_SPECIFIC));
149
150 size= ALIGN_SIZE(size);
151 mh= sf_realloc(old_mh, size + HEADER_SIZE, my_flags);
152
153 if (mh == NULL)
154 {
155 if (size < old_size)
156 DBUG_RETURN(old_point);
157 my_errno=errno;
158 if (my_flags & MY_FREE_ON_ERROR)
159 {
160 /* my_free will take care of size accounting */
161 my_free(old_point);
162 old_point= 0;
163 }
164 if (my_flags & (MY_FAE+MY_WME))
165 my_error(EE_OUTOFMEMORY, MYF(ME_BELL + ME_FATAL), size);
166 point= NULL;
167 }
168 else
169 {
170 mh->m_size= size | old_flags;
171 mh->m_key= PSI_CALL_memory_realloc(key, old_size, size, & mh->m_owner);
172 update_malloc_size((longlong)size - (longlong)old_size, old_flags);
173 point= HEADER_TO_USER(mh);
174 }
175
176 DBUG_PRINT("exit",("ptr: %p", point));
177 DBUG_RETURN(point);
178 }
179
180
181 /**
182 Free memory allocated with my_malloc.
183
184 @param ptr Pointer to the memory allocated by my_malloc.
185 */
my_free(void * ptr)186 void my_free(void *ptr)
187 {
188 my_memory_header *mh;
189 size_t old_size;
190 my_bool old_flags;
191 DBUG_ENTER("my_free");
192 DBUG_PRINT("my",("ptr: %p", ptr));
193
194 if (ptr == NULL)
195 DBUG_VOID_RETURN;
196
197 mh= USER_TO_HEADER(ptr);
198 old_size= mh->m_size & ~1;
199 old_flags= mh->m_size & 1;
200 PSI_CALL_memory_free(mh->m_key, old_size, mh->m_owner);
201
202 update_malloc_size(- (longlong) old_size - HEADER_SIZE, old_flags);
203
204 #ifndef SAFEMALLOC
205 /*
206 Trash memory if not safemalloc. We don't have to do this if safemalloc
207 is used as safemalloc will also do trashing
208 */
209 TRASH_FREE(ptr, old_size);
210 #endif
211 sf_free(mh);
212 DBUG_VOID_RETURN;
213 }
214
215
my_memdup(PSI_memory_key key,const void * from,size_t length,myf my_flags)216 void *my_memdup(PSI_memory_key key, const void *from, size_t length, myf my_flags)
217 {
218 void *ptr;
219 DBUG_ENTER("my_memdup");
220
221 if ((ptr= my_malloc(key, length,my_flags)) != 0)
222 memcpy(ptr, from, length);
223 DBUG_RETURN(ptr);
224 }
225
226
my_strdup(PSI_memory_key key,const char * from,myf my_flags)227 char *my_strdup(PSI_memory_key key, const char *from, myf my_flags)
228 {
229 char *ptr;
230 size_t length= strlen(from)+1;
231 DBUG_ENTER("my_strdup");
232
233 if ((ptr= (char*) my_malloc(key, length, my_flags)))
234 memcpy(ptr, from, length);
235 DBUG_RETURN(ptr);
236 }
237
238
my_strndup(PSI_memory_key key,const char * from,size_t length,myf my_flags)239 char *my_strndup(PSI_memory_key key, const char *from, size_t length, myf my_flags)
240 {
241 char *ptr;
242 DBUG_ENTER("my_strndup");
243
244 if ((ptr= (char*) my_malloc(key, length+1, my_flags)))
245 {
246 memcpy(ptr, from, length);
247 ptr[length]= 0;
248 }
249 DBUG_RETURN(ptr);
250 }
251
252