f7780de24b
Cosmopolitan now supports mremap(), which is only supported on Linux and NetBSD. First, it allows memory mappings to be relocated without copying them; this can dramatically speed up data structures like std::vector if the array size grows larger than 256kb. The mremap() system call is also 10x faster than munmap() when shrinking large memory mappings. There's now two functions, getpagesize() and getgransize() which help to write portable code that uses mmap(MAP_FIXED). Alternative sysconf() may be called with our new _SC_GRANSIZE. The madvise() system call now has a better wrapper with improved documentation. |
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| .. | ||
| calls | ||
| consts | ||
| dos2errno | ||
| errfuns | ||
| BUILD.mk | ||
| consts.sh | ||
| describeos.greg.c | ||
| dos2errno.sh | ||
| errfun.S | ||
| errfun2.c | ||
| errfuns.h | ||
| errfuns.sh | ||
| errno.c | ||
| gen.sh | ||
| hostos.S | ||
| macros.internal.h | ||
| README.md | ||
| restorert.S | ||
| strace.greg.c | ||
| syscall2.S | ||
| syscall3.S | ||
| syscall4.S | ||
| syscalls.sh | ||
| syscon.S | ||
| syscount.S | ||
| syslib.S | ||
| sysret.c | ||
| systemfive.S | ||
| sysv.c | ||
SYNOPSIS
System Five Import Libraries
OVERVIEW
Bell System Five is the umbrella term we use to describe Linux, FreeBSD, OpenBSD, and Mac OS X which all have nearly-identical application binary interfaces that stood the test of time, having definitions nearly the same as those of AT&T back in the 1980's.
Cosmopolitan aims to help you build apps that can endure over the course of decades, just like these systems have: without needing to lift a finger for maintenance churn, broken builds, broken hearts.
The challenge to System V binary compatibility basically boils down to numbers. All these systems agree on what services are provided, but tend to grant them wildly different numbers.
We address this by putting all the numbers in a couple big shell scripts, ask the GNU Assembler to encode them into binaries using an efficient LEB128 encoding, unpacked by _init(), and ref'd via extern const. It gives us good debuggability, and any costs are gained back by fewer branches in wrapper functions.z