Crate jemalloc_sys

Rust bindings to the jemalloc C library.

jemalloc is a general purpose memory allocation, its documentation can be found here:

• API documentation
• Wiki (design documents, presentations, profiling, debugging, tuning, …)

jemalloc exposes both a standard and a non-standard API.

Standard API

The standard API includes: the malloc, calloc, realloc, and free, which conform to to ISO/IEC 9899:1990 (“ISO C90”), posix_memalign which conforms to conforms to POSIX.1-2016, and aligned_alloc.

Note that these standard leave some details as implementation defined. This docs document this behavior for jemalloc, but keep in mind that other standard-conforming implementations of these functions in other allocators might behave slightly different.

Non-Standard API

The non-standard API includes: mallocx, rallocx, xallocx, sallocx, dallocx, sdallocx, and nallocx. These functions all have a flags argument that can be used to specify options. Use bitwise or | to specify one or more of the following: MALLOCX_LG_ALIGN, MALLOCX_ALIGN, MALLOCX_ZERO, MALLOCX_TCACHE, MALLOCX_TCACHE_NONE, and MALLOCX_ARENA.

Environment variables

The MALLOC_CONF environment variable affects the execution of the allocation functions.

For the documentation of the MALLCTL namespace visit the jemalloc documenation.

Structs

• extent_hooks_s
  Extent lifetime management functions.

Constants

• MALLOCX_TCACHE_NONE
  Do not use a thread-specific cache (tcache).
• MALLOCX_ZERO
  Initialize newly allocated memory to contain zero bytes.

Statics

• NO_BG_THREAD_TARGETS
  jemalloc’s background_thread support is known not to work on these targets:
• NO_UNPREFIXED_MALLOC_TARGETS
  targets that don’t support unprefixed malloc
• UNSUPPORTED_TARGETS
  jemalloc is known not to work on these targets:
• UNTESTED_TARGETS
  jemalloc-sys is not tested on these targets in CI:
• malloc_conf
  Compile-time string of configuration options.
• malloc_message
  Allows overriding the function which emits the text strings forming the errors and warnings if for some reason the STDERR_FILENO file descriptor is not suitable for this.

Functions

• MALLOCX_ALIGN
  Align the memory allocation to start at an address that is a multiple of align, where a is a power of two.
• MALLOCX_ARENA
  Use the arena specified by the index a.
• MALLOCX_LG_ALIGN
  Align the memory allocation to start at an address that is a multiple of 1 << la.
• MALLOCX_TCACHE
  Use the thread-specific cache (tcache) specified by the identifier tc.
• aligned_alloc^⚠
  Allocates size bytes of memory at an address which is a multiple of alignment.
• calloc^⚠
  Allocates zero-initialized space for an array of number objects, each of whose size is size.
• dallocx^⚠
  Deallocates previously-allocated memory region referenced by ptr.
• free^⚠
  Deallocates previously-allocated memory region referenced by ptr.
• mallctl^⚠
  General interface for introspecting the memory allocator, as well as setting modifiable parameters and triggering actions.
• mallctlbymib^⚠
  Like mallctl but taking a mib as input instead of a name.
• mallctlnametomib^⚠
  Translates a name to a “Management Information Base” (MIB) that can be passed repeatedly to mallctlbymib.
• malloc^⚠
  Allocates size bytes of uninitialized memory.
• malloc_stats_print^⚠
  Writes summary statistics via the write_cb callback function pointer and cbopaque data passed to write_cb, or malloc_message if write_cb is null.
• malloc_usable_size^⚠
  Returns the real size of the previously-allocated memory region referenced by ptr.
• mallocx^⚠
  Allocates at least size bytes of memory according to flags.
• nallocx^⚠
  Returns the real size of the allocation that would result from a mallocx function call with the same arguments.
• posix_memalign^⚠
  Allocates size bytes of memory at an address which is a multiple of alignment and is placed in *ptr.
• rallocx^⚠
  Resizes the previously-allocated memory region referenced by ptr to be at least size bytes.
• realloc^⚠
  Resizes the previously-allocated memory region referenced by ptr to size bytes.
• sallocx^⚠
  Returns the real size of the previously-allocated memory region referenced by ptr.
• sdallocx^⚠
  Deallocates previously-allocated memory region referenced by ptr with size hint.
• xallocx^⚠
  Resizes the previously-allocated memory region referenced by ptr in place to be at least size bytes, returning the real size of the allocation.

Type Definitions

• extent_alloc_t
  Extent allocation function.
• extent_commit_t
  Extent commit function.
• extent_dalloc_t
  Extent deallocation function.
• extent_decommit_t
  Extent decommit function.
• extent_destroy_t
  Extent destruction function.
• extent_hooks_t
  Extent lifetime management functions.
• extent_merge_t
  Extent merge function.
• extent_purge_t
  Extent purge function.
• extent_split_t
  Extent split function.