Add shared mem course example code.

Signed-off-by: Jérôme Benoit <jerome.benoit@piment-noir.org>

diff --git a/.gitignore b/.gitignore
index 4e21bb1d67fe2de2ff08a0f6ea46e661bfffce21..728eb363e053263420171ea8f60ea013f9cccfc1 100644 (file)
--- a/.gitignore
+++ b/.gitignore
@@ -1,4 +1,5 @@
 TD3/exo2/monexec/monexec
+mem/mem
 philosophe/philosophe
 prodcons/prodcons
 rw/reader/reader

diff --git a/mem/Makefile b/mem/Makefile
new file mode 100644 (file)
index 0000000..0b7d853
--- /dev/null
+++ b/mem/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=mem
+BUILD_TYPE=debug
+#BUILD_TYPE=release
+LDLIBS=-lrt
+
+# ====================================
+# DO NOT CHANGE STUFF BEYOND THIS LINE
+# ====================================
+
+all: $(BINARY_NAME)
+
+CC=gcc
+LD=gcc
+
+WARN_FLAGS = -Wall -Wextra
+STD_FLAG = -std=gnu11
+
+ifeq ($(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/mem/mem.c b/mem/mem.c
new file mode 100644 (file)
index 0000000..95e43f9
--- /dev/null
+++ b/mem/mem.c
@@ -0,0 +1,49 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <sys/mman.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <fcntl.h>
+
+#define nbchar 4096
+
+int main()
+{
+       int fd, res;
+       char *partage = NULL;
+       char *message = "";
+       fd = shm_open("partage.mem", O_RDWR | O_CREAT, 0600);   /* ouverture du segment partagé */
+       if (fd == -1) {                                             /* et création du nom (du fichier) */
+               perror("shm_open");
+               exit(1);
+       }
+       res = ftruncate(fd, nbchar);    /* choix de la taille du segment */
+       if (res == -1) {
+               perror("ftruncate");
+               exit(1);
+       }
+       partage = (char *)mmap(NULL, nbchar, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
+       if (partage == MAP_FAILED) {
+               perror("mmap");
+               exit(1);
+       }
+       strncpy(partage, message, nbchar);
+       while (strcmp(partage, message) == 0) {
+               sleep(1);
+       }
+       fprintf(stdout, "la réponse est %s\n", partage);
+       res = munmap(partage, nbchar);
+       if (res == -1) {
+               perror("munmap");
+               exit(1);
+       }
+       close(fd);              /* fermeture du fichier */
+       res = shm_unlink("partage.mem");        /* suppression du nom */
+       if (res == -1) {
+               perror("shm_unlink");
+               exit(1);
+       }
+       return 0;
+}