1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
|
/*****************************************************************************\
* Copyright (c) Athena Dev Teams - Licensed under GNU GPL *
* For more information, see LICENCE in the main folder *
* *
* <H1>Entry Reusage System</H1> *
* *
* There are several root entry managers, each with a different entry size. *
* Each manager will keep track of how many instances have been 'created'. *
* They will only automatically destroy themselves after the last instance *
* is destroyed. *
* *
* Entries can be allocated from the managers. *
* If it has reusable entries (freed entry), it uses one. *
* So no assumption should be made about the data of the entry. *
* Entries should be freed in the manager they where allocated from. *
* Failure to do so can lead to unexpected behaviours. *
* *
* <H2>Advantages:</H2> *
* - The same manager is used for entries of the same size. *
* So entries freed in one instance of the manager can be used by other *
* instances of the manager. *
* - Much less memory allocation/deallocation - program will be faster. *
* - Avoids memory fragmentaion - program will run better for longer. *
* *
* <H2>Disavantages:</H2> *
* - Unused entries are almost inevitable - memory being wasted. *
* - A manager will only auto-destroy when all of its instances are *
* destroyed so memory will usually only be recovered near the end. *
* - Always wastes space for entries smaller than a pointer. *
* *
* WARNING: The system is not thread-safe at the moment. *
* *
* HISTORY: *
* 0.1 - Initial version *
* *
* @version 0.1 - Initial version *
* @author Flavio @ Amazon Project *
* @encoding US-ASCII *
\*****************************************************************************/
#ifndef _COMMON_ERS_H_
#define _COMMON_ERS_H_
#include "../common/cbasetypes.h"
/*****************************************************************************\
* (1) All public parts of the Entry Reusage System. *
* DISABLE_ERS - Define to disable this system. *
* ERS_ALIGNED - Alignment of the entries in the blocks. *
* ERS - Entry manager. *
* ers_new - Allocate an instance of an entry manager. *
* ers_report - Print a report about the current state. *
* ers_final - Clears the remainder of the manangers. *
\*****************************************************************************/
/**
* Define this to disable the Entry Reusage System.
* All code except the typedef of ERInterface will be disabled.
* To allow a smooth transition,
*/
//#define DISABLE_ERS
/**
* Entries are aligned to ERS_ALIGNED bytes in the blocks of entries.
* By default it aligns to one byte, using the "natural order" of the entries.
* This should NEVER be set to zero or less.
* If greater than one, some memory can be wasted. This should never be needed
* but is here just in case some aligment issues arise.
*/
#ifndef ERS_ALIGNED
# define ERS_ALIGNED 1
#endif /* not ERS_ALIGN_ENTRY */
enum ERSOptions {
ERS_OPT_NONE = 0x0,
ERS_OPT_CLEAR = 0x1,/* silently clears any entries left in the manager upon destruction */
ERS_OPT_WAIT = 0x2,/* wait for entries to come in order to list! */
ERS_OPT_FREE_NAME = 0x4,/* name is dynamic memory, and should be freed */
ERS_OPT_CLEAN = 0x8,/* clears used memory upon ers_free so that its all new to be reused on the next alloc */
ERS_OPT_FLEX_CHUNK = 0x10,/* signs that it should look for its own cache given it'll have a dynamic chunk size, so that it doesn't affect the other ERS it'd otherwise be sharing */
/* Compound, is used to determine whether it should be looking for a cache of matching options */
ERS_CACHE_OPTIONS = ERS_OPT_CLEAN|ERS_OPT_FLEX_CHUNK,
};
/**
* Public interface of the entry manager.
* @param alloc Allocate an entry from this manager
* @param free Free an entry allocated from this manager
* @param entry_size Return the size of the entries of this manager
* @param destroy Destroy this instance of the manager
*/
typedef struct eri {
/**
* Allocate an entry from this entry manager.
* If there are reusable entries available, it reuses one instead.
* @param self Interface of the entry manager
* @return An entry
*/
void *(*alloc)(struct eri *self);
/**
* Free an entry allocated from this manager.
* WARNING: Does not check if the entry was allocated by this manager.
* Freeing such an entry can lead to unexpected behaviour.
* @param self Interface of the entry manager
* @param entry Entry to be freed
*/
void (*free)(struct eri *self, void *entry);
/**
* Return the size of the entries allocated from this manager.
* @param self Interface of the entry manager
* @return Size of the entries of this manager in bytes
*/
size_t (*entry_size)(struct eri *self);
/**
* Destroy this instance of the manager.
* The manager is actually only destroyed when all the instances are destroyed.
* When destroying the manager a warning is shown if the manager has
* missing/extra entries.
* @param self Interface of the entry manager
*/
void (*destroy)(struct eri *self);
/* */
void (*chunk_size) (struct eri *self, unsigned int new_size);
} *ERS;
#ifdef DISABLE_ERS
// Use memory manager to allocate/free and disable other interface functions
# define ers_alloc(obj,type) (type *)aMalloc(sizeof(type))
# define ers_free(obj,entry) aFree(entry)
# define ers_entry_size(obj) (size_t)0
# define ers_destroy(obj)
# define ers_chunk_size(obj,size)
// Disable the public functions
# define ers_new(size,name,options) NULL
# define ers_report()
# define ers_final()
#else /* not DISABLE_ERS */
// These defines should be used to allow the code to keep working whenever
// the system is disabled
# define ers_alloc(obj,type) ((type *)(obj)->alloc(obj))
# define ers_free(obj,entry) ((obj)->free((obj),(entry)))
# define ers_entry_size(obj) ((obj)->entry_size(obj))
# define ers_destroy(obj) ((obj)->destroy(obj))
# define ers_chunk_size(obj,size) ((obj)->chunk_size((obj),(size)))
/**
* Get a new instance of the manager that handles the specified entry size.
* Size has to greater than 0.
* If the specified size is smaller than a pointer, the size of a pointer is
* used instead.
* It's also aligned to ERS_ALIGNED bytes, so the smallest multiple of
* ERS_ALIGNED that is greater or equal to size is what's actually used.
* @param The requested size of the entry in bytes
* @return Interface of the object
*/
ERS ers_new(uint32 size, char *name, enum ERSOptions options);
/**
* Print a report about the current state of the Entry Reusage System.
* Shows information about the global system and each entry manager.
* The number of entries are checked and a warning is shown if extra reusable
* entries are found.
* The extra entries are included in the count of reusable entries.
*/
void ers_report(void);
/**
* Clears the remainder of the manangers
**/
void ers_final(void);
#endif /* DISABLE_ERS / not DISABLE_ERS */
#endif /* _COMMON_ERS_H_ */
|