Update adds a general source for retrieving a monotonic time.
In addition, AE has been updated to utilize the new monotonic
clock for timer processing.
This performance improvement is **not** enabled in a default build due to various H/W compatibility
concerns, see README.md for details. It does however change the default use of gettimeofday with
clock_gettime and somewhat improves performance.
This update provides the following
1. An interface for retrieving a monotonic clock. getMonotonicUs returns a uint64_t (aka monotime)
with the number of micro-seconds from an arbitrary point. No more messing with tv_sec/tv_usec.
Simple routines are provided for measuring elapsed milli-seconds or elapsed micro-seconds (the
most common use case for a monotonic timer). No worries about time moving backwards.
2. High-speed assembler implementation for x86 and ARM. The standard method for retrieving the
monotonic clock is POSIX.1b (1993): clock_gettime(CLOCK_MONOTONIC, timespec*). However, most
modern processors provide a constant speed instruction clock which can be retrieved in a fraction
of the time that it takes to call clock_gettime. For x86, this is provided by the RDTSC
instruction. For ARM, this is provided by the CNTVCT_EL0 instruction. As a compile-time option,
these high-speed timers can be chosen. (Default is POSIX clock_gettime.)
3. Refactor of event loop timers. The timer processing in ae.c has been refactored to use the new
monotonic clock interface. This results in simpler/cleaner logic and improved performance.
This fixes issue #539.
Basically if there is enough free memory the OS may buffer the RDB file
that the slave transfers on disk from the master. The file may
actually be flused on disk at once by the operating system when it gets
closed by Redis, causing the close system call to block for a long time.
This patch is a modified version of one provided by yoav-steinberg of
@garantiadata (the original version was posted in the issue #539
comments), and tries to flush the OS buffers incrementally (every 8 MB
of loaded data).
networking related stuff moved into networking.c
moved more code
more work on layout of source code
SDS instantaneuos memory saving. By Pieter and Salvatore at VMware ;)
cleanly compiling again after the first split, now splitting it in more C files
moving more things around... work in progress
split replication code
splitting more
Sets split
Hash split
replication split
even more splitting
more splitting
minor change
