From 66c9107fcb99df4eec36a84db41f78eb946cc224 Mon Sep 17 00:00:00 2001
From: =?utf8?q?J=C3=A9r=C3=B4me=20Benoit?= <jerome.benoit@piment-noir.org>
Date: Mon, 12 Feb 2018 12:18:02 +0100
Subject: [PATCH] Add the prod cons code snippet.
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Signed-off-by: Jérôme Benoit <jerome.benoit@piment-noir.org>
---
 prodcons/Makefile   | 83 +++++++++++++++++++++++++++++++++++++++++++++
 prodcons/prodcons.c | 61 +++++++++++++++++++++++++++++++++
 2 files changed, 144 insertions(+)
 create mode 100644 prodcons/Makefile
 create mode 100644 prodcons/prodcons.c

diff --git a/prodcons/Makefile b/prodcons/Makefile
new file mode 100644
index 0000000..63d44c5
--- /dev/null
+++ b/prodcons/Makefile
@@ -0,0 +1,83 @@
+# Sample Makefile to build simple project.
+#
+# This Makefile expect all source files (.c) to be at the same level, in the
+# current working directory.
+#
+# It will automatically generate dependencies, compile all files, and produce a
+# binary using the provided name.
+#
+# Set BINARY_NAME to the name of the binary file to build.
+# Set BUILD_TYPE to either debug or release
+#
+# Automatic dependencies code from:
+# http://make.mad-scientist.net/papers/advanced-auto-dependency-generation/#tldr
+BINARY_NAME=prodcons
+BUILD_TYPE=debug
+#BUILD_TYPE=release
+LDLIBS=-lpthread
+
+# ====================================
+# DO NOT CHANGE STUFF BEYOND THIS LINE
+# ====================================
+
+all: $(BINARY_NAME)
+
+CC=gcc
+LD=gcc
+
+WARN_FLAGS = -Wall -Wextra
+STD_FLAG = -std=c11
+
+ifeq ($(BUILD_TYPE),debug)
+BUILDDIR := .build/debug
+DEBUG_FLAG = -g
+DEBUG = 1
+STRIP_FLAG =
+OPTI_FLAG = -O0
+else
+BUILDDIR := .build/release
+DEBUG_FLAG =
+DEBUG = 0
+STRIP_FLAG = -s
+OPTI_FLAG = -O3
+endif
+
+CFLAGS := -DDEBUG=$(DEBUG) $(CFLAGS) $(WARN_FLAGS) $(STD_FLAG) $(OPTI_FLAG) $(DEBUG_FLAG)
+LDFLAGS := $(LDFLAGS) $(STRIP_FLAG)
+
+OBJDIR := $(BUILDDIR)/objs
+$(shell mkdir -p $(OBJDIR))
+
+SRCS=$(wildcard *.c)
+OBJS=$(patsubst %.c,$(OBJDIR)/%.o,$(SRCS))
+
+DEPDIR := $(BUILDDIR)/deps
+$(shell mkdir -p $(DEPDIR))
+DEPFLAGS = -MT $@ -MMD -MP -MF $(DEPDIR)/$*.Td
+POSTCOMPILE = mv -f $(DEPDIR)/$*.Td $(DEPDIR)/$*.d
+
+$(BINARY_NAME): $(OBJS)
+	@echo "[LD ] $@"
+	@$(LD) $(CFLAGS) $(LDFLAGS) $^ $(LDLIBS) -o $@
+
+$(OBJDIR)/%.o: %.c $(DEPDIR)/%.d
+	@echo "[C  ] $*"
+	@$(CC) $(DEPFLAGS) $(CFLAGS) -c $< -o $@
+	@$(POSTCOMPILE)
+
+$(DEPDIR)/%.d: ;
+
+.PRECIOUS: $(DEPDIR)/%.d
+
+include $(wildcard $(patsubst %,$(DEPDIR)/%.d,$(basename $(SRCS))))
+
+clean:
+	@echo "[CLN]"
+	-@rm -r $(BUILDDIR)
+	-@rm $(BINARY_NAME)
+
+disassemble: $(BINARY_NAME)
+	objdump -d $< | less
+
+symbols: $(BINARY_NAME)
+	objdump -t $< | sort | less
diff --git a/prodcons/prodcons.c b/prodcons/prodcons.c
new file mode 100644
index 0000000..a533b48
--- /dev/null
+++ b/prodcons/prodcons.c
@@ -0,0 +1,61 @@
+#include <semaphore.h>
+#include <unistd.h>
+#include <pthread.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#define MAX 6
+#define BUF_SIZE 3
+typedef struct args {
+	sem_t sem_free;
+	sem_t sem_busy;
+} args_t;
+static int buf[BUF_SIZE];
+void *prod(void *arg);
+void *cons(void *arg);
+
+int main()
+{
+	pthread_t t1, t2;
+	args_t args;
+	sem_init(&args.sem_free, 0, BUF_SIZE);
+	sem_init(&args.sem_busy, 0, 0);
+	pthread_create(&t1, NULL, prod, &args);
+	pthread_create(&t2, NULL, cons, &args);
+	pthread_join(t1, NULL);
+	pthread_join(t2, NULL);
+	printf("exit\n");
+	return EXIT_SUCCESS;
+}
+
+void *prod(void *arg)
+{
+	int ip = 0, nbprod = 0, obj = 1001;
+	args_t *args = (args_t *) arg;
+	while (nbprod < MAX) {
+		sem_wait(&args->sem_free);
+		buf[ip] = obj;
+		sem_post(&args->sem_busy);
+		printf("prod: buf[%d]=%d\n", ip, obj);
+		obj++;
+		nbprod++;
+		ip = (ip + 1) % BUF_SIZE;
+	}
+	return NULL;
+}
+
+void *cons(void *arg)
+{
+	int ic = 0, nbcons = 0, obj;
+	args_t *args = (args_t *) arg;
+	while (nbcons < MAX) {
+		sleep(1);
+		sem_wait(&args->sem_busy);
+		obj = buf[ic];
+		sem_post(&args->sem_free);
+		printf("cons: buf[%d]=%d\n", ic, obj);
+		nbcons++;
+		ic = (ic + 1) % BUF_SIZE;
+	}
+	return NULL;
+}
-- 
2.34.1