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#pragma once

#  Ticket Lock
# 
#  Ticket locks are fair spinlocks that order acccess on a first-in,
#  first-out basis. The lock is composed of a head counter and a tail
#  counter. The head counter indicates the ticket number of the current
#  lock owner. The tail counter indicates the last issued ticket number.
#  To acquire the lock, the acquiring thread atomically increments the
#  tail counter to assign itself a ticket number. It then waits until

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/*
 * atomic memory interlock latency benchmark (public domain)
 * author: Michael Clark <michaeljclark@mac.com>
 * c++ -pthread -O2 atomic_latency.cc -o atomic_latency
 */

#include <cstdio>
#include <thread>
#include <atomic>
#include <chrono>

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/*
 * PLEASE LICENSE 11/2020, John Smith <john.smith@example.com>
 *
 * All rights to this work are granted for all purposes, with exception of
 * author's implied right of copyright to defend the free use of this work.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES

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// See LICENSE for license details.

#include <vector>
#include <atomic>
#include <thread>
#include <mutex>
#include <memory>
#include <functional>
#include <condition_variable>

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/*
 * ftkitty - program that outputs text using kitty image protocol
 *
 * meet `ftkitty`, a tiny example emitting graphics to the terminal
 * using #FreeType, #HarfBuzz, and the #kitty graphics protocol.
 * this is possible with ImageMagick and icat, but ftkitty is smaller
 * and mostly it's just an experiment with terminal protocols.
 *
 * g++ -O2 examples/ftkitty.cc $(pkg-config --libs freetype2 --libs harfbuzz
 *      --cflags freetype2 --cflags harfbuzz) -o build/ftkitty

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commit ac3c81578e760af11732da8f925b87ba7b1f70be
Author: Michael Clark <michaeljclark@mac.com>
Date:   Tue Feb 25 10:45:10 2020 +1300

    Perform 2D rectangle intersection test and return topology classes

diff --git a/src/geometry.h b/src/geometry.h
new file mode 100644
index 000000000000..1b5d890c2f58
--- /dev/null

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--- linux-4.19-rc8.orig/arch/riscv/kernel/setup.c	2018-10-15 18:20:24.000000000 +1300
+++ linux-4.19-rc8/arch/riscv/kernel/setup.c	2018-10-19 00:25:54.571772704 +1300
@@ -227,7 +227,9 @@
 	setup_bootmem();
 	paging_init();
 	unflatten_device_tree();
+#ifdef CONFIG_SWIOTLB
 	swiotlb_init(1);
+#endif
 

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#include <stdio.h>
#include <stdlib.h>
#include <stdatomic.h>
#include <limits.h>
#include <pthread.h>

/*
 * Intel® 64 and IA-32 Architectures Software Developer’s Manual
 *
 * Volume 3A - 8.1.1 Guaranteed Atomic Operations

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NOTE: - indicates RVC accesible register

register usage histogram (gcc 7.0.1 20170321 experimental) -Os newlib
~~~~~~~~~~~~~~~~~~~~~~~~
    1. a5         15.12% [1711277823] ---------------------------------------
    2. a2         13.64% [1543505068] -----------------------------------
    3. a7         10.38% [1174405192] ==========================
    4. a4          8.95% [1012926250] -----------------------
    5. a6          7.77% [878706830] ====================
    6. t4          5.30% [599785556] =============

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u     : { [31:12],                            [11:7] } -> { simm[31:12],                                  rd[4:0] }
uj    : { [31:12],                            [11:7] } -> { simm[20|10:1|11|19:12],                       rd[4:0] }
i     : { [31:20],          [19:15],          [11:7] } -> { simm[11:0],                rs1[4:0],          rd[4:0] }
i_sh5 : { [24:20],          [19:15],          [11:7] } -> { imm[4:0],                  rs1[4:0],          rd[4:0] }
i_sh6 : { [25:20],          [19:15],          [11:7] } -> { imm[5:0],                  rs1[4:0],          rd[4:0] }
i_sh7 : { [26:20],          [19:15],          [11:7] } -> { imm[6:0],                  rs1[4:0],          rd[4:0] }
i_csr : { [31:20],          [19:15],          [11:7] } -> { imm[11:0],                 rs1[4:0],          rd[4:0] }
s     : {          [24:20], [19:15],          [11:7] } -> { simm[11:5],     rs2[4:0],  rs1[4:0],        simm[4:0] }
sb    : {          [24:20], [19:15],          [11:7] } -> { simm[12|10:5],  rs2[4:0],  rs1[4:0],