From 3d08cd331c1adcf0d917392f7e527b3f00511748 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Fri, 24 May 2024 06:52:22 +0200 Subject: Merging upstream version 6.8. Signed-off-by: Daniel Baumann --- man/man3/malloc_get_state.3 | 115 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 115 insertions(+) create mode 100644 man/man3/malloc_get_state.3 (limited to 'man/man3/malloc_get_state.3') diff --git a/man/man3/malloc_get_state.3 b/man/man3/malloc_get_state.3 new file mode 100644 index 0000000..8a24f85 --- /dev/null +++ b/man/man3/malloc_get_state.3 @@ -0,0 +1,115 @@ +'\" t +.\" Copyright (c) 2012 by Michael Kerrisk +.\" +.\" SPDX-License-Identifier: Linux-man-pages-copyleft +.\" +.TH malloc_get_state 3 2024-05-02 "Linux man-pages (unreleased)" +.SH NAME +malloc_get_state, malloc_set_state \- +record and restore state of malloc implementation +.SH LIBRARY +Standard C library +.RI ( libc ", " \-lc ) +.SH SYNOPSIS +.nf +.B #include +.P +.B void *malloc_get_state(void); +.BI "int malloc_set_state(void *" state ); +.fi +.SH DESCRIPTION +.IR Note : +these functions are removed in glibc 2.25. +.P +The +.BR malloc_get_state () +function records the current state of all +.BR malloc (3) +internal bookkeeping variables +(but not the actual contents of the heap +or the state of +.BR malloc_hook (3) +functions pointers). +The state is recorded in a system-dependent opaque data structure +dynamically allocated via +.BR malloc (3), +and a pointer to that data structure is returned as the function result. +(It is the caller's responsibility to +.BR free (3) +this memory.) +.P +The +.BR malloc_set_state () +function restores the state of all +.BR malloc (3) +internal bookkeeping variables to the values recorded in +the opaque data structure pointed to by +.IR state . +.SH RETURN VALUE +On success, +.BR malloc_get_state () +returns a pointer to a newly allocated opaque data structure. +On error (for example, memory could not be allocated for the data structure), +.BR malloc_get_state () +returns NULL. +.P +On success, +.BR malloc_set_state () +returns 0. +If the implementation detects that +.I state +does not point to a correctly formed data structure, +.\" if(ms->magic != MALLOC_STATE_MAGIC) return -1; +.BR malloc_set_state () +returns \-1. +If the implementation detects that +the version of the data structure referred to by +.I state +is a more recent version than this implementation knows about, +.\" /* Must fail if the major version is too high. */ +.\" if((ms->version & ~0xffl) > (MALLOC_STATE_VERSION & ~0xffl)) return -2; +.BR malloc_set_state () +returns \-2. +.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_get_state (), +.BR malloc_set_state () +T} Thread safety MT-Safe +.TE +.SH STANDARDS +GNU. +.SH NOTES +These functions are useful when using this +.BR malloc (3) +implementation as part of a shared library, +and the heap contents are saved/restored via some other method. +This technique is used by GNU Emacs to implement its "dumping" function. +.P +Hook function pointers are never saved or restored by these +functions, with two exceptions: +if malloc checking (see +.BR mallopt (3)) +was in use when +.BR malloc_get_state () +was called, then +.BR malloc_set_state () +resets malloc checking hooks +.\" i.e., calls __malloc_check_init() +if possible; +.\" i.e., malloc checking is not already in use +.\" and the caller requested malloc checking +if malloc checking was not in use in the recorded state, +but the caller has requested malloc checking, +then the hooks are reset to 0. +.SH SEE ALSO +.BR malloc (3), +.BR mallopt (3) -- cgit v1.2.3