first commit

.github/workflows/test.yml

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+name: test
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+    branches: [main]
+
+jobs:
+  build:
+    name: Test Suite
+    runs-on: ubuntu-latest
+    timeout-minutes: 5
+    steps:
+      - uses: actions/checkout@v4
+      - name: Install Dependencies
+        run: sudo apt-get update; sudo apt-get install --no-install-recommends clang make
+      - name: Run Tests
+        run: ./test.sh

.gitignore

@@ -1,52 +1,2 @@
-# Prerequisites
-*.d
-
-# Object files
-*.o
-*.ko
-*.obj
-*.elf
-
-# Linker output
-*.ilk
-*.map
-*.exp
-
-# Precompiled Headers
-*.gch
-*.pch
-
-# Libraries
-*.lib
-*.a
-*.la
-*.lo
-
-# Shared objects (inc. Windows DLLs)
-*.dll
-*.so
-*.so.*
-*.dylib
-
-# Executables
-*.exe
-*.out
-*.app
-*.i*86
-*.x86_64
-*.hex
-
-# Debug files
-*.dSYM/
-*.su
-*.idb
-*.pdb
-
-# Kernel Module Compile Results
-*.mod*
-*.cmd
-.tmp_versions/
-modules.order
-Module.symvers
-Mkfile.old
-dkms.conf
+*.dSYM
+build/

Makefile

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+# the executables will be built in the "build" directory.
+# the executables can be run in a terminal/shell
+# cmd: ./pathto/executable
+# for tests where files have to be passed as arguments
+# cmd: ./pathto/executable pathto/file1 pathto/file2
+
+# Directories
+SRC_DIR = src
+TEST_DIR = test
+TEST_SUBDIRS = $(shell find $(TEST_DIR) -type d)
+INCLUDE_DIR = include
+BUILD_DIR = build
+
+# Source files
+SRCS = $(wildcard $(SRC_DIR)/*.c)
+TEST_SRCS = $(foreach dir, $(TEST_SUBDIRS), $(wildcard $(dir)/*.c))
+
+# Object files
+OBJS = $(patsubst $(SRC_DIR)/%.c, $(BUILD_DIR)/%.o, $(SRCS))
+
+# Target
+TEST_TARGET = $(foreach test_src, $(TEST_SRCS), $(patsubst $(TEST_DIR)/%.c, $(BUILD_DIR)/%, $(test_src)))
+
+# Compiler
+CC = clang
+
+# Compiler flags
+CFLAGS = -Wall -Wextra -I$(INCLUDE_DIR) -pthread -g -gdwarf-4
+
+# Default rule
+all: $(TEST_TARGET)
+
+# Rule for compiling test source files into test targets
+$(BUILD_DIR)/%: $(TEST_DIR)/%.c $(OBJS) | $(BUILD_DIR) 
+	$(CC) $(CFLAGS) $(OBJS) $< -o $@
+
+# Rule for compiling source files into object files
+$(BUILD_DIR)/%.o: $(SRC_DIR)/%.c | $(BUILD_DIR)
+	$(CC) $(CFLAGS) -c $< -o $@
+
+# Create build directory if it doesn't exist
+$(BUILD_DIR):
+	mkdir -p $(BUILD_DIR)
+
+# Create build subsdirectories if they don't exist
+$(foreach dir, $(TEST_SUBDIRS), $(shell mkdir -p $(patsubst $(TEST_DIR)/%, $(BUILD_DIR)/%, $(dir))))
+
+# Clean up
+clean:
+	rm -rf $(BUILD_DIR)
+
+.PHONY: all clean
+
+.PHONY: pack
+pack:
+	zip -r submission.zip src/

README.md

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+# README
+
+## Lock-free Ringbuffer
+
+This is a thread-safe implementation of the lock-free ringbuffer introduced by the following guide: https://ferrous-systems.com/blog/lock-free-ring-buffer/.
+
+## Compilation
+
+Use the make command to compile the project. The executable(s) will be placed in the build directory.
+For the daemon, you can use the 'rndtxt.txt' files, and comprare them against the 'rndtxt_lsg.txt' files in the 'test' directory, to see if the daemon works correctly.

include/daemon.h

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+#ifndef DAEMON_H
+#define DAEMON_H
+
+typedef struct {
+    int from;
+    int to;
+    char* filename;
+} connection_t;
+
+#define MESSAGE_SIZE 128    
+#define MINIMUM_PORT 0          /* this will always be 0 */
+#define MAXIMUM_PORT 128
+#define NUMBER_OF_PROCESSING_THREADS 4
+
+/**
+ * @brief simpledaemon
+ * 
+ * @param connections 
+ * @param number_of_connections
+ * @return int
+ */
+int simpledaemon(connection_t *connections, int number_of_connections);
+
+#endif

include/ringbuf.h

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+#ifndef RINGBUF_H
+#define RINGBUF_H
+
+#include <stdint.h>
+#include <stdlib.h>
+#include <pthread.h>
+#include <assert.h>
+#include <string.h>
+#include <time.h>
+#include <errno.h>
+
+#define SUCCESS 0
+#define RINGBUFFER_FULL 1
+#define RINGBUFFER_EMPTY 2
+#define OUTPUT_BUFFER_TOO_SMALL 3
+
+#define RBUF_TIMEOUT 1
+
+typedef struct {
+    uint8_t* read;
+    uint8_t* write;
+    uint8_t* begin;
+    uint8_t* end; //1 step AFTER the last readable address
+    pthread_mutex_t mutex_read;
+    pthread_mutex_t mutex_write;
+    pthread_cond_t signal_read;
+    pthread_cond_t signal_write;
+} rbctx_t;
+
+/**
+ * Initialize a thread-safe lock-free ringbuffer.
+ * Generate ringbuffer context and memory before initialization.
+ * 
+ * @param context ringbuffer context.
+ * @param buffer_location the first byte location of the ringbuffer in memory
+ * @param buffer_size size of the ringbuffer (and memory)
+ */
+void ringbuffer_init(rbctx_t *context, void *buffer_location, size_t buffer_size);
+
+/**
+ * Write to the ringbuffer.
+ * 
+ * @param context ringbuffer context
+ * @param message The message to be placed in the ringbuffer
+ * @param message_len size of the message
+ * @return SUCESS on succes, RINGBUFFER_FULL when message doesn't fit
+ */
+int ringbuffer_write(rbctx_t *context, void *message, size_t message_len);
+
+/**
+ * Read from the ringbuffer.
+ * 
+ * @param context ringbuffer context
+ * @param buffer reads to this location
+ * @param buffer_len_ptr size of the message buffer. Size of message received from ringbuffer is stored here
+ * @return SUCCESS on succes, RINGBUFFER_EMPTY if no data to read, OUTPUT_BUFFER_TOO_SMALL when read message doesn't fit
+ */
+int ringbuffer_read(rbctx_t *context, void *buffer, size_t *buffer_len_ptr);
+
+/**
+ * Frees all memory allocated and syncronization variables created during initialization.
+ * 
+ * @param context ringbuffer context
+ */
+void ringbuffer_destroy(rbctx_t *context);
+
+#endif //RINGBUF_H