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Diffstat (limited to 'man3/malloc_info.3')
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diff --git a/man3/malloc_info.3 b/man3/malloc_info.3 deleted file mode 100644 index 9df31cf..0000000 --- a/man3/malloc_info.3 +++ /dev/null @@ -1,257 +0,0 @@ -'\" t -.\" Copyright (c) 2012 by Michael Kerrisk <mtk.manpages@gmail.com> -.\" -.\" SPDX-License-Identifier: Linux-man-pages-copyleft -.\" -.TH malloc_info 3 2024-02-26 "Linux man-pages 6.7" -.SH NAME -malloc_info \- export malloc state to a stream -.SH LIBRARY -Standard C library -.RI ( libc ", " \-lc ) -.SH SYNOPSIS -.nf -.B #include <malloc.h> -.P -.BI "int malloc_info(int " options ", FILE *" stream ); -.fi -.SH DESCRIPTION -The -.BR malloc_info () -function exports an XML string that describes the current state -of the memory-allocation -implementation in the caller. -The string is printed on the file stream -.IR stream . -The exported string includes information about all arenas (see -.BR malloc (3)). -.P -As currently implemented, -.I options -must be zero. -.SH RETURN VALUE -On success, -.BR malloc_info () -returns 0. -On failure, it returns \-1, and -.I errno -is set to indicate the error. -.SH ERRORS -.TP -.B EINVAL -.I options -was nonzero. -.SH ATTRIBUTES -For an explanation of the terms used in this section, see -.BR attributes (7). -.TS -allbox; -lbx lb lb -l l l. -Interface Attribute Value -T{ -.na -.nh -.BR malloc_info () -T} Thread safety MT-Safe -.TE -.SH STANDARDS -GNU. -.SH HISTORY -glibc 2.10. -.SH NOTES -The memory-allocation information is provided as an XML string -(rather than a C structure) -because the information may change over time -(according to changes in the underlying implementation). -The output XML string includes a version field. -.P -The -.BR open_memstream (3) -function can be used to send the output of -.BR malloc_info () -directly into a buffer in memory, rather than to a file. -.P -The -.BR malloc_info () -function is designed to address deficiencies in -.BR malloc_stats (3) -and -.BR mallinfo (3). -.SH EXAMPLES -The program below takes up to four command-line arguments, -of which the first three are mandatory. -The first argument specifies the number of threads that -the program should create. -All of the threads, including the main thread, -allocate the number of blocks of memory specified by the second argument. -The third argument controls the size of the blocks to be allocated. -The main thread creates blocks of this size, -the second thread created by the program allocates blocks of twice this size, -the third thread allocates blocks of three times this size, and so on. -.P -The program calls -.BR malloc_info () -twice to display the memory-allocation state. -The first call takes place before any threads -are created or memory allocated. -The second call is performed after all threads have allocated memory. -.P -In the following example, -the command-line arguments specify the creation of one additional thread, -and both the main thread and the additional thread -allocate 10000 blocks of memory. -After the blocks of memory have been allocated, -.BR malloc_info () -shows the state of two allocation arenas. -.P -.in +4n -.EX -.RB "$ " "getconf GNU_LIBC_VERSION" -glibc 2.13 -.RB "$ " "./a.out 1 10000 100" -============ Before allocating blocks ============ -<malloc version="1"> -<heap nr="0"> -<sizes> -</sizes> -<total type="fast" count="0" size="0"/> -<total type="rest" count="0" size="0"/> -<system type="current" size="135168"/> -<system type="max" size="135168"/> -<aspace type="total" size="135168"/> -<aspace type="mprotect" size="135168"/> -</heap> -<total type="fast" count="0" size="0"/> -<total type="rest" count="0" size="0"/> -<system type="current" size="135168"/> -<system type="max" size="135168"/> -<aspace type="total" size="135168"/> -<aspace type="mprotect" size="135168"/> -</malloc> -\& -============ After allocating blocks ============ -<malloc version="1"> -<heap nr="0"> -<sizes> -</sizes> -<total type="fast" count="0" size="0"/> -<total type="rest" count="0" size="0"/> -<system type="current" size="1081344"/> -<system type="max" size="1081344"/> -<aspace type="total" size="1081344"/> -<aspace type="mprotect" size="1081344"/> -</heap> -<heap nr="1"> -<sizes> -</sizes> -<total type="fast" count="0" size="0"/> -<total type="rest" count="0" size="0"/> -<system type="current" size="1032192"/> -<system type="max" size="1032192"/> -<aspace type="total" size="1032192"/> -<aspace type="mprotect" size="1032192"/> -</heap> -<total type="fast" count="0" size="0"/> -<total type="rest" count="0" size="0"/> -<system type="current" size="2113536"/> -<system type="max" size="2113536"/> -<aspace type="total" size="2113536"/> -<aspace type="mprotect" size="2113536"/> -</malloc> -.EE -.in -.SS Program source -.\" SRC BEGIN (malloc_info.c) -.EX -#include <err.h> -#include <errno.h> -#include <malloc.h> -#include <pthread.h> -#include <stdlib.h> -#include <unistd.h> -\& -static size_t blockSize; -static size_t numThreads; -static unsigned int numBlocks; -\& -static void * -thread_func(void *arg) -{ - int tn = (int) arg; -\& - /* The multiplier \[aq](2 + tn)\[aq] ensures that each thread (including - the main thread) allocates a different amount of memory. */ -\& - for (unsigned int j = 0; j < numBlocks; j++) - if (malloc(blockSize * (2 + tn)) == NULL) - err(EXIT_FAILURE, "malloc\-thread"); -\& - sleep(100); /* Sleep until main thread terminates. */ - return NULL; -} -\& -int -main(int argc, char *argv[]) -{ - int sleepTime; - pthread_t *thr; -\& - if (argc < 4) { - fprintf(stderr, - "%s num\-threads num\-blocks block\-size [sleep\-time]\en", - argv[0]); - exit(EXIT_FAILURE); - } -\& - numThreads = atoi(argv[1]); - numBlocks = atoi(argv[2]); - blockSize = atoi(argv[3]); - sleepTime = (argc > 4) ? atoi(argv[4]) : 0; -\& - thr = calloc(numThreads, sizeof(*thr)); - if (thr == NULL) - err(EXIT_FAILURE, "calloc"); -\& - printf("============ Before allocating blocks ============\en"); - malloc_info(0, stdout); -\& - /* Create threads that allocate different amounts of memory. */ -\& - for (size_t tn = 0; tn < numThreads; tn++) { - errno = pthread_create(&thr[tn], NULL, thread_func, - (void *) tn); - if (errno != 0) - err(EXIT_FAILURE, "pthread_create"); -\& - /* If we add a sleep interval after the start\-up of each - thread, the threads likely won\[aq]t contend for malloc - mutexes, and therefore additional arenas won\[aq]t be - allocated (see malloc(3)). */ -\& - if (sleepTime > 0) - sleep(sleepTime); - } -\& - /* The main thread also allocates some memory. */ -\& - for (unsigned int j = 0; j < numBlocks; j++) - if (malloc(blockSize) == NULL) - err(EXIT_FAILURE, "malloc"); -\& - sleep(2); /* Give all threads a chance to - complete allocations. */ -\& - printf("\en============ After allocating blocks ============\en"); - malloc_info(0, stdout); -\& - exit(EXIT_SUCCESS); -} -.EE -.\" SRC END -.SH SEE ALSO -.BR mallinfo (3), -.BR malloc (3), -.BR malloc_stats (3), -.BR mallopt (3), -.BR open_memstream (3) |