server-skynet-source-3rd-je.../include/jemalloc/internal/jemalloc_internal_defs.h.in
gnzlbg 08260a6b94 Add experimental API: smallocx_return_t smallocx(size, flags)
---

Motivation:

This new experimental memory-allocaction API returns a pointer to
the allocation as well as the usable size of the allocated memory
region.

The `s` in `smallocx` stands for `sized`-`mallocx`, attempting to
convey that this API returns the size of the allocated memory region.

It should allow C++ P0901r0 [0] and Rust Alloc::alloc_excess to make
use of it.

The main purpose of these APIs is to improve telemetry. It is more accurate
to register `smallocx(size, flags)` than `smallocx(nallocx(size), flags)`,
for example. The latter will always line up perfectly with the existing
size classes, causing a loss of telemetry information about the internal
fragmentation induced by potentially poor size-classes choices.

Instrumenting `nallocx` does not help much since user code can cache its
result and use it repeatedly.

---

Implementation:

The implementation adds a new `usize` option to `static_opts_s` and an `usize`
variable to `dynamic_opts_s`. These are then used to cache the result of
`sz_index2size` and similar functions in the code paths in which they are
unconditionally invoked. In the code-paths in which these functions are not
unconditionally invoked, `smallocx` calls, as opposed to `mallocx`, these
functions explicitly.

---

[0]: http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0901r0.html
2018-10-17 07:12:28 -07:00

376 lines
11 KiB
C

#ifndef JEMALLOC_INTERNAL_DEFS_H_
#define JEMALLOC_INTERNAL_DEFS_H_
/*
* If JEMALLOC_PREFIX is defined via --with-jemalloc-prefix, it will cause all
* public APIs to be prefixed. This makes it possible, with some care, to use
* multiple allocators simultaneously.
*/
#undef JEMALLOC_PREFIX
#undef JEMALLOC_CPREFIX
/*
* Define overrides for non-standard allocator-related functions if they are
* present on the system.
*/
#undef JEMALLOC_OVERRIDE___LIBC_CALLOC
#undef JEMALLOC_OVERRIDE___LIBC_FREE
#undef JEMALLOC_OVERRIDE___LIBC_MALLOC
#undef JEMALLOC_OVERRIDE___LIBC_MEMALIGN
#undef JEMALLOC_OVERRIDE___LIBC_REALLOC
#undef JEMALLOC_OVERRIDE___LIBC_VALLOC
#undef JEMALLOC_OVERRIDE___POSIX_MEMALIGN
/*
* JEMALLOC_PRIVATE_NAMESPACE is used as a prefix for all library-private APIs.
* For shared libraries, symbol visibility mechanisms prevent these symbols
* from being exported, but for static libraries, naming collisions are a real
* possibility.
*/
#undef JEMALLOC_PRIVATE_NAMESPACE
/*
* Hyper-threaded CPUs may need a special instruction inside spin loops in
* order to yield to another virtual CPU.
*/
#undef CPU_SPINWAIT
/* 1 if CPU_SPINWAIT is defined, 0 otherwise. */
#undef HAVE_CPU_SPINWAIT
/*
* Number of significant bits in virtual addresses. This may be less than the
* total number of bits in a pointer, e.g. on x64, for which the uppermost 16
* bits are the same as bit 47.
*/
#undef LG_VADDR
/* Defined if C11 atomics are available. */
#undef JEMALLOC_C11_ATOMICS
/* Defined if GCC __atomic atomics are available. */
#undef JEMALLOC_GCC_ATOMIC_ATOMICS
/* Defined if GCC __sync atomics are available. */
#undef JEMALLOC_GCC_SYNC_ATOMICS
/*
* Defined if __sync_add_and_fetch(uint32_t *, uint32_t) and
* __sync_sub_and_fetch(uint32_t *, uint32_t) are available, despite
* __GCC_HAVE_SYNC_COMPARE_AND_SWAP_4 not being defined (which means the
* functions are defined in libgcc instead of being inlines).
*/
#undef JE_FORCE_SYNC_COMPARE_AND_SWAP_4
/*
* Defined if __sync_add_and_fetch(uint64_t *, uint64_t) and
* __sync_sub_and_fetch(uint64_t *, uint64_t) are available, despite
* __GCC_HAVE_SYNC_COMPARE_AND_SWAP_8 not being defined (which means the
* functions are defined in libgcc instead of being inlines).
*/
#undef JE_FORCE_SYNC_COMPARE_AND_SWAP_8
/*
* Defined if __builtin_clz() and __builtin_clzl() are available.
*/
#undef JEMALLOC_HAVE_BUILTIN_CLZ
/*
* Defined if os_unfair_lock_*() functions are available, as provided by Darwin.
*/
#undef JEMALLOC_OS_UNFAIR_LOCK
/*
* Defined if OSSpin*() functions are available, as provided by Darwin, and
* documented in the spinlock(3) manual page.
*/
#undef JEMALLOC_OSSPIN
/* Defined if syscall(2) is usable. */
#undef JEMALLOC_USE_SYSCALL
/*
* Defined if secure_getenv(3) is available.
*/
#undef JEMALLOC_HAVE_SECURE_GETENV
/*
* Defined if issetugid(2) is available.
*/
#undef JEMALLOC_HAVE_ISSETUGID
/* Defined if pthread_atfork(3) is available. */
#undef JEMALLOC_HAVE_PTHREAD_ATFORK
/* Defined if pthread_setname_np(3) is available. */
#undef JEMALLOC_HAVE_PTHREAD_SETNAME_NP
/*
* Defined if clock_gettime(CLOCK_MONOTONIC_COARSE, ...) is available.
*/
#undef JEMALLOC_HAVE_CLOCK_MONOTONIC_COARSE
/*
* Defined if clock_gettime(CLOCK_MONOTONIC, ...) is available.
*/
#undef JEMALLOC_HAVE_CLOCK_MONOTONIC
/*
* Defined if mach_absolute_time() is available.
*/
#undef JEMALLOC_HAVE_MACH_ABSOLUTE_TIME
/*
* Defined if _malloc_thread_cleanup() exists. At least in the case of
* FreeBSD, pthread_key_create() allocates, which if used during malloc
* bootstrapping will cause recursion into the pthreads library. Therefore, if
* _malloc_thread_cleanup() exists, use it as the basis for thread cleanup in
* malloc_tsd.
*/
#undef JEMALLOC_MALLOC_THREAD_CLEANUP
/*
* Defined if threaded initialization is known to be safe on this platform.
* Among other things, it must be possible to initialize a mutex without
* triggering allocation in order for threaded allocation to be safe.
*/
#undef JEMALLOC_THREADED_INIT
/*
* Defined if the pthreads implementation defines
* _pthread_mutex_init_calloc_cb(), in which case the function is used in order
* to avoid recursive allocation during mutex initialization.
*/
#undef JEMALLOC_MUTEX_INIT_CB
/* Non-empty if the tls_model attribute is supported. */
#undef JEMALLOC_TLS_MODEL
/*
* JEMALLOC_DEBUG enables assertions and other sanity checks, and disables
* inline functions.
*/
#undef JEMALLOC_DEBUG
/* JEMALLOC_STATS enables statistics calculation. */
#undef JEMALLOC_STATS
/* JEMALLOC_EXPERIMENTAL_SMALLOCX_API enables experimental smallocx API. */
#undef JEMALLOC_EXPERIMENTAL_SMALLOCX_API
/* JEMALLOC_PROF enables allocation profiling. */
#undef JEMALLOC_PROF
/* Use libunwind for profile backtracing if defined. */
#undef JEMALLOC_PROF_LIBUNWIND
/* Use libgcc for profile backtracing if defined. */
#undef JEMALLOC_PROF_LIBGCC
/* Use gcc intrinsics for profile backtracing if defined. */
#undef JEMALLOC_PROF_GCC
/*
* JEMALLOC_DSS enables use of sbrk(2) to allocate extents from the data storage
* segment (DSS).
*/
#undef JEMALLOC_DSS
/* Support memory filling (junk/zero). */
#undef JEMALLOC_FILL
/* Support utrace(2)-based tracing. */
#undef JEMALLOC_UTRACE
/* Support optional abort() on OOM. */
#undef JEMALLOC_XMALLOC
/* Support lazy locking (avoid locking unless a second thread is launched). */
#undef JEMALLOC_LAZY_LOCK
/*
* Minimum allocation alignment is 2^LG_QUANTUM bytes (ignoring tiny size
* classes).
*/
#undef LG_QUANTUM
/* One page is 2^LG_PAGE bytes. */
#undef LG_PAGE
/*
* One huge page is 2^LG_HUGEPAGE bytes. Note that this is defined even if the
* system does not explicitly support huge pages; system calls that require
* explicit huge page support are separately configured.
*/
#undef LG_HUGEPAGE
/*
* If defined, adjacent virtual memory mappings with identical attributes
* automatically coalesce, and they fragment when changes are made to subranges.
* This is the normal order of things for mmap()/munmap(), but on Windows
* VirtualAlloc()/VirtualFree() operations must be precisely matched, i.e.
* mappings do *not* coalesce/fragment.
*/
#undef JEMALLOC_MAPS_COALESCE
/*
* If defined, retain memory for later reuse by default rather than using e.g.
* munmap() to unmap freed extents. This is enabled on 64-bit Linux because
* common sequences of mmap()/munmap() calls will cause virtual memory map
* holes.
*/
#undef JEMALLOC_RETAIN
/* TLS is used to map arenas and magazine caches to threads. */
#undef JEMALLOC_TLS
/*
* Used to mark unreachable code to quiet "end of non-void" compiler warnings.
* Don't use this directly; instead use unreachable() from util.h
*/
#undef JEMALLOC_INTERNAL_UNREACHABLE
/*
* ffs*() functions to use for bitmapping. Don't use these directly; instead,
* use ffs_*() from util.h.
*/
#undef JEMALLOC_INTERNAL_FFSLL
#undef JEMALLOC_INTERNAL_FFSL
#undef JEMALLOC_INTERNAL_FFS
/*
* If defined, explicitly attempt to more uniformly distribute large allocation
* pointer alignments across all cache indices.
*/
#undef JEMALLOC_CACHE_OBLIVIOUS
/*
* If defined, enable logging facilities. We make this a configure option to
* avoid taking extra branches everywhere.
*/
#undef JEMALLOC_LOG
/*
* If defined, use readlinkat() (instead of readlink()) to follow
* /etc/malloc_conf.
*/
#undef JEMALLOC_READLINKAT
/*
* Darwin (OS X) uses zones to work around Mach-O symbol override shortcomings.
*/
#undef JEMALLOC_ZONE
/*
* Methods for determining whether the OS overcommits.
* JEMALLOC_PROC_SYS_VM_OVERCOMMIT_MEMORY: Linux's
* /proc/sys/vm.overcommit_memory file.
* JEMALLOC_SYSCTL_VM_OVERCOMMIT: FreeBSD's vm.overcommit sysctl.
*/
#undef JEMALLOC_SYSCTL_VM_OVERCOMMIT
#undef JEMALLOC_PROC_SYS_VM_OVERCOMMIT_MEMORY
/* Defined if madvise(2) is available. */
#undef JEMALLOC_HAVE_MADVISE
/*
* Defined if transparent huge pages are supported via the MADV_[NO]HUGEPAGE
* arguments to madvise(2).
*/
#undef JEMALLOC_HAVE_MADVISE_HUGE
/*
* Methods for purging unused pages differ between operating systems.
*
* madvise(..., MADV_FREE) : This marks pages as being unused, such that they
* will be discarded rather than swapped out.
* madvise(..., MADV_DONTNEED) : If JEMALLOC_PURGE_MADVISE_DONTNEED_ZEROS is
* defined, this immediately discards pages,
* such that new pages will be demand-zeroed if
* the address region is later touched;
* otherwise this behaves similarly to
* MADV_FREE, though typically with higher
* system overhead.
*/
#undef JEMALLOC_PURGE_MADVISE_FREE
#undef JEMALLOC_PURGE_MADVISE_DONTNEED
#undef JEMALLOC_PURGE_MADVISE_DONTNEED_ZEROS
/* Defined if madvise(2) is available but MADV_FREE is not (x86 Linux only). */
#undef JEMALLOC_DEFINE_MADVISE_FREE
/*
* Defined if MADV_DO[NT]DUMP is supported as an argument to madvise.
*/
#undef JEMALLOC_MADVISE_DONTDUMP
/*
* Defined if transparent huge pages (THPs) are supported via the
* MADV_[NO]HUGEPAGE arguments to madvise(2), and THP support is enabled.
*/
#undef JEMALLOC_THP
/* Define if operating system has alloca.h header. */
#undef JEMALLOC_HAS_ALLOCA_H
/* C99 restrict keyword supported. */
#undef JEMALLOC_HAS_RESTRICT
/* For use by hash code. */
#undef JEMALLOC_BIG_ENDIAN
/* sizeof(int) == 2^LG_SIZEOF_INT. */
#undef LG_SIZEOF_INT
/* sizeof(long) == 2^LG_SIZEOF_LONG. */
#undef LG_SIZEOF_LONG
/* sizeof(long long) == 2^LG_SIZEOF_LONG_LONG. */
#undef LG_SIZEOF_LONG_LONG
/* sizeof(intmax_t) == 2^LG_SIZEOF_INTMAX_T. */
#undef LG_SIZEOF_INTMAX_T
/* glibc malloc hooks (__malloc_hook, __realloc_hook, __free_hook). */
#undef JEMALLOC_GLIBC_MALLOC_HOOK
/* glibc memalign hook. */
#undef JEMALLOC_GLIBC_MEMALIGN_HOOK
/* pthread support */
#undef JEMALLOC_HAVE_PTHREAD
/* dlsym() support */
#undef JEMALLOC_HAVE_DLSYM
/* Adaptive mutex support in pthreads. */
#undef JEMALLOC_HAVE_PTHREAD_MUTEX_ADAPTIVE_NP
/* GNU specific sched_getcpu support */
#undef JEMALLOC_HAVE_SCHED_GETCPU
/* GNU specific sched_setaffinity support */
#undef JEMALLOC_HAVE_SCHED_SETAFFINITY
/*
* If defined, all the features necessary for background threads are present.
*/
#undef JEMALLOC_BACKGROUND_THREAD
/*
* If defined, jemalloc symbols are not exported (doesn't work when
* JEMALLOC_PREFIX is not defined).
*/
#undef JEMALLOC_EXPORT
/* config.malloc_conf options string. */
#undef JEMALLOC_CONFIG_MALLOC_CONF
/* If defined, jemalloc takes the malloc/free/etc. symbol names. */
#undef JEMALLOC_IS_MALLOC
/*
* Defined if strerror_r returns char * if _GNU_SOURCE is defined.
*/
#undef JEMALLOC_STRERROR_R_RETURNS_CHAR_WITH_GNU_SOURCE
#endif /* JEMALLOC_INTERNAL_DEFS_H_ */