aprell’s gists

aprell / atomic.h

Created June 18, 2012 10:59

Atomic read/write

	#ifndef ATOMIC_H
	#define ATOMIC_H

	// Adapted from http://golubenco.org/2007/06/14/atomic-operations

	/**
	* @brief Atomic type
	*/

	typedef int atomic_t;

aprell / pingpong.c

Created July 4, 2012 09:50

RCCE: measuring round-trip latency between two cores

	#include <stdio.h>
	#include <stdlib.h>
	#include <unistd.h>
	#include <RCCE.h>
	#include "timer.h"

	#define PRINT(...) { printf(__VA_ARGS__); fflush(stdout); }
	#define CORE(i) if (RCCE_ue() == (i))

	#define MSG_SIZE 32

aprell / pingpong-all.c

Created July 4, 2012 10:08

RCCE: measuring round-trip latency between one core and all the other cores

	#include <stdio.h>
	#include <stdlib.h>
	#include <unistd.h>
	#include <RCCE.h>
	#include "timer.h"

	#define PRINT(...) { printf(__VA_ARGS__); fflush(stdout); }
	#define CORE(i) if (RCCE_ue() == (i))

	#define MSG_SIZE 32

aprell / variadic_macro.h

Created September 6, 2012 17:33

Variadic macro

	#define vm(args...) \
	do { \
	/* Check if argument list is empty */ \
	if (#args[0] == '\0') { \
	printf("Argument list is empty\n"); \
	} else { \
	printf("Argument list is \"%s\"\n", #args); \
	} \
	} while (0)

aprell / va_nargs.c

Last active August 8, 2024 02:04

Counting arguments in variadic macros

	// RUN: cc -Wall -Wextra %s && ./a.out

	#include <assert.h>

	#if defined(__GNUC__) \|\| defined(__clang__)
	// Supports 0-10 arguments
	#define VA_NARGS_IMPL(_0, _1, _2, _3, _4, _5, _6, _7, _8, _9, _10, N, ...) N
	// ## deletes preceding comma if _VA_ARGS__ is empty (GCC, Clang)
	#define VA_NARGS(...) VA_NARGS_IMPL(_, ## __VA_ARGS__, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0)
	#else

aprell / async.c

Created September 14, 2012 16:31

Asynchronous function call / task support macros

	#include <stdio.h>
	#include <stdlib.h>
	#include <stdbool.h>
	#include <string.h>
	#include "async.h"

	typedef struct {
	void *fn; // pointer to piece of code
	unsigned char data[128]; // data environment
	} Task;

aprell / overload.c

Created September 18, 2012 11:58

Simple function overloading in C

	#include <stdio.h>

	/* Count variadic macro arguments (1-10 arguments, extend as needed)
	*/
	#define VA_NARGS_IMPL(_1, _2, _3, _4, _5, _6, _7, _8, _9, _10, N, ...) N
	#define VA_NARGS(...) VA_NARGS_IMPL(__VA_ARGS__, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1)

	/* Simple name mangling of function sum based on arity
	*/
	#define __sum_impl2(n, ...) __sum_impl__ ## n(__VA_ARGS__)

aprell / overload.h.in

Created September 18, 2012 12:08

Simple function overloading in C (extended)

	#ifndef OVERLOAD__FN__H
	#define OVERLOAD__FN__H

	#ifndef VA_NARGS
	/* Count variadic macro arguments (1-10 arguments, extend as needed)
	*/
	#define VA_NARGS_IMPL(_1, _2, _3, _4, _5, _6, _7, _8, _9, _10, N, ...) N
	#define VA_NARGS(...) VA_NARGS_IMPL(__VA_ARGS__, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1)
	#endif

aprell / named_params.c

Created September 30, 2012 17:56

Named parameters and default argument values in C

	#include <stdio.h>
	#include <stdlib.h>

	struct rectangle {
	double x1, x2, y1, y2;
	};

	double area(struct rectangle r)
	{
	return (r.x2 - r.x1) * (r.y2 - r.y1);

aprell / protected.c

Created October 2, 2012 14:16

Protected blocks in C

	#include <stdio.h>
	#include <stdlib.h>
	#include <assert.h>

	// Make sure that before is executed before a dependent block or statement
	// and after is executed afterwards
	#define PROTECTED(before, after) \
	for (int __i = ((before), 0); !__i; (after), __i++)

	int main(void)

Andreas Prell aprell