This is one of the few POSIX APIs that was missing. It lets you choose a monotonic clock for your condition variables. This might improve perf on some platforms. It might also grant more flexibility with NTP configs. I know Qt is one project that believes it needs this. To introduce this, I needed to change some the *NSYNC APIs, to support passing a clock param. There's also new benchmarks, demonstrating Cosmopolitan's supremacy over many libc implementations when it comes to mutex performance. Cygwin has an alarmingly bad pthread_mutex_t implementation. It is so bad that they would have been significantly better off if they'd used naive spinlocks. |
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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