From 912658502558d4881fceed04e0fdda7574f4af13 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 12:24:19 +0100
Subject: [PATCH] Add for real the philosophe code snippet.
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Signed-off-by: Jérôme Benoit <jerome.benoit@piment-noir.org>
---
 .gitignore              |  1 -
 philosophe/Makefile     | 83 +++++++++++++++++++++++++++++++++++++++++
 philosophe/philosophe.c | 56 +++++++++++++++++++++++++++
 3 files changed, 139 insertions(+), 1 deletion(-)
 create mode 100644 philosophe/Makefile
 create mode 100644 philosophe/philosophe.c

diff --git a/.gitignore b/.gitignore
index 469e01a..435d966 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,4 +1,3 @@
-philosophe
 *.static
 *.dynamic
 # for cygwin
diff --git a/philosophe/Makefile b/philosophe/Makefile
new file mode 100644
index 0000000..4ca690e
--- /dev/null
+++ b/philosophe/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=philosophe
+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/philosophe/philosophe.c b/philosophe/philosophe.c
new file mode 100644
index 0000000..72b740e
--- /dev/null
+++ b/philosophe/philosophe.c
@@ -0,0 +1,56 @@
+// programme philosophe.c
+#include <stdio.h>
+#include <unistd.h>
+#include <pthread.h>
+#include <semaphore.h>
+
+#define N 5
+// nombre de philosophes
+#define G (i + 1) % N
+// fourchette gauche du philosophe i
+#define D i
+// fourchette droite du philosophe i
+#define libre 1
+#define occupe 0
+int fourch[N] = { libre, libre, libre, libre, libre };
+
+sem_t mutex;
+
+void *philosophe(void *num)
+{
+	int i = *(int *)num, nb = 2;
+	while (nb) {
+		sleep(1);	// penser
+		sem_wait(&mutex);	// essayer de prendre les fourchettes pour manger
+		if (fourch[G] == libre && fourch[D] == libre) {
+			fourch[G] = occupe;
+			fourch[D] = occupe;
+			sem_post(&mutex);
+			nb--;
+			printf("philosophe[%d] mange\n", i);
+			sleep(1);	// manger
+			printf("philosophe[%d] a fini de manger\n", i);
+			sem_wait(&mutex);	// libérer les fourchettes
+			fourch[G] = libre;
+			fourch[D] = libre;
+			sem_post(&mutex);
+		} else
+			sem_post(&mutex);
+	}
+	return NULL;
+}
+
+int main()
+{
+	int i, NumPhi[N] = { 0, 1, 2, 3, 4 };
+	pthread_t th[N];
+	sem_init(&mutex, 0, 1);
+	// création des N philosophes
+	for (i = 0; i < N; i++)
+		pthread_create(&th[i], NULL, philosophe, &NumPhi[i]);
+	// attendre la fin des threads
+	for (i = 0; i < N; i++)
+		pthread_join(th[i], NULL);
+	printf("fin des threads \n");
+	return 0;
+}
-- 
2.34.1