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31 .\" Japanese Version Copyright (c) 2013 Akihiro MOTOKI
32 .\" all rights reserved.
33 .\" Translated 2013-07-22, Akihiro MOTOKI <amotoki@gmail.com>
34 .\" Updated 2013-07-31, Akihiro MOTOKI <amotoki@gmail.com>
36 .TH MALLOC_INFO 3 2013\-04\-19 GNU "Linux Programmer's Manual"
38 malloc_info \- malloc の状態をストリームに出力する
41 \fB#include <malloc.h>\fP
43 \fBint malloc_info(int \fP\fIoptions\fP\fB, FILE *\fP\fIfp\fP\fB);\fP
46 \fBmalloc_info\fP() 関数は、 呼び出し元のメモリ割り当て実装の現在の状態を表す XML 文字列を出力する。 文字列は、 ファイルストリーム
47 \fIfp\fP に出力される。 出力された文字列には、 全ての割り当て領域の情報が含まれる (\fBmalloc\fP(3) 参照)。
49 現在の実装では、 \fIoptions\fP は 0 でなければならない。
51 \fBmalloc_info\fP() は、成功すると 0 を返す。 エラーの場合、\-1 を返し、 \fIerrno\fP にエラーの原因を示す値を設定する。
55 \fIoptions\fP が 0 でなかった。
57 \fBmalloc_info\fP() は glibc バージョン 2.10 で追加された。
61 メモリ割り当て情報は (C の構造体ではなく) XML 文字列として提供される。 これは、 この情報は時間をたつと (内部で使用している実装によって)
62 変わる可能性があるからである。 出力される XML 文字列にはバージョンフィールドが付いている。
64 \fBopen_memstream\fP(3) 関数を使うと、 \fBmalloc_info\fP() の出力を、
65 ファイルではなくメモリ内のバッファに直接送ることができる。
67 \fBmalloc_info\fP() 関数は、 \fBmalloc_stats\fP(3) と \fBmallinfo\fP(3) の不備を解決するために設定された。
69 The program below takes up to four command\-line arguments, of which the
70 first three are mandatory. The first argument specifies the number of
71 threads that the program should create. All of the threads, including the
72 main thread, allocate the number of blocks of memory specified by the second
73 argument. The third argument controls the size of the blocks to be
74 allocated. The main thread creates blocks of this size, the second thread
75 created by the program allocates blocks of twice this size, the third thread
76 allocates blocks of three times this size, and so on.
78 The program calls \fBmalloc_info\fP() twice to display the memory\-allocation
79 state. The first call takes place before any threads are created or memory
80 allocated. The second call is performed after all threads have allocated
83 In the following example, the command\-line arguments specify the creation of
84 one additional thread, and both the main thread and the additional thread
85 allocate 10000 blocks of memory. After the blocks of memory have been
86 allocated, \fBmalloc_info\fP() shows the state of two allocation arenas.
90 $ \fBgetconf GNU_LIBC_VERSION\fP
92 $ \fB./a.out 1 10000 100\fP
93 ============ Before allocating blocks ============
98 <total type="fast" count="0" size="0"/>
99 <total type="rest" count="0" size="0"/>
100 <system type="current" size="135168"/>
101 <system type="max" size="135168"/>
102 <aspace type="total" size="135168"/>
103 <aspace type="mprotect" size="135168"/>
105 <total type="fast" count="0" size="0"/>
106 <total type="rest" count="0" size="0"/>
107 <system type="current" size="135168"/>
108 <system type="max" size="135168"/>
109 <aspace type="total" size="135168"/>
110 <aspace type="mprotect" size="135168"/>
113 ============ After allocating blocks ============
118 <total type="fast" count="0" size="0"/>
119 <total type="rest" count="0" size="0"/>
120 <system type="current" size="1081344"/>
121 <system type="max" size="1081344"/>
122 <aspace type="total" size="1081344"/>
123 <aspace type="mprotect" size="1081344"/>
128 <total type="fast" count="0" size="0"/>
129 <total type="rest" count="0" size="0"/>
130 <system type="current" size="1032192"/>
131 <system type="max" size="1032192"/>
132 <aspace type="total" size="1032192"/>
133 <aspace type="mprotect" size="1032192"/>
135 <total type="fast" count="0" size="0"/>
136 <total type="rest" count="0" size="0"/>
137 <system type="current" size="2113536"/>
138 <system type="max" size="2113536"/>
139 <aspace type="total" size="2113536"/>
140 <aspace type="mprotect" size="2113536"/>
153 static size_t blockSize;
154 static int numThreads, numBlocks;
156 #define errExit(msg) do { perror(msg); exit(EXIT_FAILURE); \e
160 thread_func(void *arg)
165 /* The multiplier \(aq(2 + tn)\(aq ensures that each thread (including
166 the main thread) allocates a different amount of memory */
168 for (j = 0; j < numBlocks; j++)
169 if (malloc(blockSize * (2 + tn)) == NULL)
170 errExit("malloc\-thread");
172 sleep(100); /* Sleep until main thread terminates */
177 main(int argc, char *argv[])
179 int j, tn, sleepTime;
184 "%s num\-threads num\-blocks block\-size [sleep\-time]\en",
189 numThreads = atoi(argv[1]);
190 numBlocks = atoi(argv[2]);
191 blockSize = atoi(argv[3]);
192 sleepTime = (argc > 4) ? atoi(argv[4]) : 0;
194 thr = calloc(numThreads, sizeof(pthread_t));
198 printf("============ Before allocating blocks ============\en");
199 malloc_info(0, stdout);
201 /* Create threads that allocate different amounts of memory */
203 for (tn = 0; tn < numThreads; tn++) {
204 errno = pthread_create(&thr[tn], NULL, thread_func,
207 errExit("pthread_create");
209 /* If we add a sleep interval after the start\-up of each
210 thread, the threads likely won\(aqt contend for malloc
211 mutexes, and therefore additional arenas won\(aqt be
212 allocated (see malloc(3)). */
218 /* The main thread also allocates some memory */
220 for (j = 0; j < numBlocks; j++)
221 if (malloc(blockSize) == NULL)
224 sleep(2); /* Give all threads a chance to
225 complete allocations */
227 printf("\en============ After allocating blocks ============\en");
228 malloc_info(0, stdout);
234 \fBmallinfo\fP(3), \fBmalloc\fP(3), \fBmalloc_stats\fP(3), \fBmallopt\fP(3),
235 \fBopen_memstream\fP(3)
237 この man ページは Linux \fIman\-pages\fP プロジェクトのリリース 3.53 の一部
238 である。プロジェクトの説明とバグ報告に関する情報は
239 http://www.kernel.org/doc/man\-pages/ に書かれている。