pingpong service with test application script : working

lib/communication.c

@@ -82,8 +82,6 @@ int service_get_new_process (struct process *proc, const char * spath)
     bzero (buf, BUFSIZ);
 
     // read the pipe, get a process to work on
-    int ret;
-
     struct timespec ts = { 0 };
     struct timespec ts2 = { 0 };
 
@@ -307,6 +305,32 @@ int process_open_in (struct process *proc)
     return 0;
 }
 
+int service_proc_open_in (struct process *proc)
+{
+    char fifopathin[PATH_MAX];
+    char fifopathout[PATH_MAX];
+    process_paths (fifopathin, fifopathout, proc->pid, proc->index);
+
+    printf ("opening in %s\n", fifopathin);
+    proc->in = fopen (fifopathin, "wb");
+    printf ("opened : %d\n", proc->in);
+
+    return 0;
+}
+
+int service_proc_open_out (struct process *proc)
+{
+    char fifopathin[PATH_MAX];
+    char fifopathout[PATH_MAX];
+    process_paths (fifopathin, fifopathout, proc->pid, proc->index);
+
+    printf ("opening out %s\n", fifopathout);
+    proc->out = fopen (fifopathout, "rb");
+    printf ("opened\n");
+
+    return 0;
+}
+
 int process_open_out (struct process *proc)
 {
     char fifopathin[PATH_MAX];
@@ -347,12 +371,12 @@ int process_read (struct process *proc, void * buf, size_t * msize)
 {
     int ret;
     if ((ret = process_open_in (proc))) {
-        fprintf(stdout, "error process_create %d\n", ret);
+        fprintf(stdout, "error process_open_in %d\n", ret);
         exit (1);
     }
 
     *msize = fread (buf, 1, *msize, proc->in); // FIXME check errors
-    printf ("DEBUG read, size %ld : %s\n", *msize, buf);
+    // printf ("DEBUG read, size %ld : %s\n", *msize, buf);
 
     if ((ret = process_close_in (proc))) {
         fprintf(stdout, "error process_close_in %d\n", ret);
@@ -381,16 +405,36 @@ int process_write (struct process *proc, void * buf, size_t msize)
 
 int service_read (struct process *proc, void * buf, size_t * msize)
 {
-    if ((*msize = fread (buf, 1, *msize, proc->out)))
-        return *msize;
+    int ret;
+    if ((ret = service_proc_open_out (proc))) {
+        fprintf(stdout, "error process_open_out %d\n", ret);
+        exit (1);
+    }
+
+    *msize = fread (buf, 1, *msize, proc->out); // FIXME check errors
+    // printf ("DEBUG read, size %ld : %s\n", *msize, buf);
+
+    if ((ret = process_close_out (proc))) {
+        fprintf(stdout, "error process_close_out %d\n", ret);
+        exit (1);
+    }
 
     return 0;
 }
 
 int service_write (struct process *proc, void * buf, size_t msize)
 {
-    if ((msize = fwrite (buf, 1, msize, proc->in)))
-        return msize;
+    int ret;
+    if ((ret = service_proc_open_in (proc))) {
+        fprintf(stdout, "error process_open_in %d\n", ret);
+        exit (1);
+    }
 
+    fwrite (buf, 1, msize, proc->in); // FIXME check errors
+
+    if ((ret = process_close_in (proc))) {
+        fprintf(stdout, "error process_close_in %d\n", ret);
+        exit (1);
+    }
     return 0;
 }

lib/communication.h

@@ -60,4 +60,7 @@ int process_destroy (struct process *); // called by the application
 int process_read (struct process *, void * buf, size_t *);
 int process_write (struct process *, void * buf, size_t);
 
+int service_read (struct process *, void * buf, size_t *);
+int service_write (struct process *, void * buf, size_t);
+
 #endif

pingpong/Makefile

@@ -0,0 +1,22 @@
+CC=gcc
+CFLAGS=-Wall -g
+LDFLAGS=
+CFILES=$(wildcard *.c) # CFILES => recompiles everything on a C file change
+EXEC=$(basename $(wildcard *.c))
+SOURCES=$(wildcard ../lib/*.c)
+OBJECTS=$(SOURCES:.c=.o)
+TESTS=$(addsuffix .test, $(EXEC))
+
+all: $(SOURCES) $(EXEC)
+
+$(EXEC): $(OBJECTS) $(CFILES)
+	$(CC) $(CFLAGS) $(LDFLAGS) $(OBJECTS) $@.c -o $@
+
+.c.o:
+	$(CC) -c $(CFLAGS) $< -o $@
+
+clean:
+	-rm $(OBJECTS)
+
+mrproper: clean
+	rm $(EXEC)

pingpong/README.markdown

@@ -0,0 +1,31 @@
+# Service ping-pong
+
+This service is a brain-dead application. It is only to a pedagogic end.
+
+The purpose is only to communicate with an application once, the application
+sends a message and the service answer with the same message.
+
+# How it works
+
+ * **S**: service
+ * **A**: application
+
+ 1. **S** creates the named pipe /tmp/pingpong, then listens
+ 2. **S** opens the named pipes in & out
+ 3. **A** talks with the test program *pingpong.sh*
+ 4. **S** closes the test program named pipes
+ 5. **S** removes the named pipe /tmp/pingpong after 10 served applications
+
+# pingpong.sh
+
+The script *pingpong.sh* lets you test the service.
+
+Usage :
+
+    pingpong.sh [NB]
+    # NB is the number of exchanged messages
+
+    or
+
+    pingpong.sh clean
+    # it is to clean the /tmp/ipc/ directory

pingpong/pingpong.c

@@ -0,0 +1,88 @@
+#include "../lib/communication.h"
+
+/*
+ * main loop
+ *
+ * opens the application pipes,
+ * reads then writes the same message,
+ * then closes the pipes
+ */
+
+void main_loop (const char *spath)
+{
+    int ret;
+    struct process proc;
+
+    int cnt = 10;
+
+    while (cnt--) {
+        // -1 : error, 0 = no new process, 1 = new process
+        ret = service_get_new_process (&proc, spath);
+        if (ret == -1) {
+            fprintf (stderr, "Error service_get_new_process\n");
+            exit (1);
+        } else if (ret == 0) { // that should not happen
+            continue;
+        }
+
+        // printf ("before print\n");
+        process_print (&proc);
+        // printf ("after print\n");
+
+        // about the message
+        size_t msize = BUFSIZ;
+        char buf[BUFSIZ];
+        bzero(buf, BUFSIZ);
+
+        // printf ("before read\n");
+        if ((ret = service_read (&proc, &buf, &msize))) {
+            fprintf(stdout, "error service_read %d\n", ret);
+            exit (1);
+        }
+        // printf ("after read\n");
+        printf ("read, size %ld : %s\n", msize, buf);
+
+        // printf ("before proc write\n");
+        if ((ret = service_write (&proc, &buf, msize))) {
+            fprintf(stdout, "error service_write %d\n", ret);
+            exit (1);
+        }
+        // printf ("after proc write\n");
+        printf ("\033[32mStill \033[31m%d\033[32m applications to serve\n",cnt);
+    }
+}
+
+/*
+ * service ping-pong
+ *
+ * 1. creates the named pipe /tmp/<service>, then listens
+ * 2. opens the named pipes in & out
+ * 3. talks with the (test) program
+ * 4. closes the test program named pipes
+ * 5. removes the named pipe /tmp/<service>
+ */
+
+int main(int argc, char * argv[])
+{
+    // gets the service path, such as /tmp/<service>
+    char spath[PATH_MAX];
+    service_path (spath, "pingpong");
+
+    // creates the service named pipe, that listens to client applications
+    int ret;
+    if ((ret = service_create (spath))) {
+        fprintf(stdout, "error service_create %d\n", ret);
+        exit (1);
+    }
+
+    // the service will loop until the end of time, a specific message, a signal
+    main_loop (spath);
+
+    // the application will shut down, and remove the service named pipe
+    if ((ret = service_close (spath))) {
+        fprintf(stdout, "error service_close %d\n", ret);
+        exit (1);
+    }
+
+    return EXIT_SUCCESS;
+}

pingpong/pingpong.sh

@@ -0,0 +1,37 @@
+#!/bin/dash
+
+REP=/tmp/ipc/
+SERVICE="pingpong"
+NB=3
+
+# CLEAN UP !
+if [ $# -ne 0 ] && [ "$1" = clean ]
+then
+    echo "clean rep ${REP}"
+    rm ${REP}/${SERVICE}
+    rm ${REP}/*-in
+    rm ${REP}/*-out
+
+    exit 0
+fi
+
+if [ $# -ne 0 ]
+then
+    NB=$1
+fi
+
+for pid in `seq 1 ${NB}`
+do
+    # we make the application pipes
+    mkfifo ${REP}/${pid}-1-in 2>/dev/null
+    mkfifo ${REP}/${pid}-1-out 2>/dev/null
+
+    # pid index version
+    echo "${pid} 1 1" > ${REP}/${SERVICE}
+
+    # the purpose is to send something in the pipe
+    cat /dev/urandom | base64 | head -n 1 > ${REP}/${pid}-1-out
+
+    # the the service will answer with our message
+    cat ${REP}/${pid}-1-in
+done

service-test.c

@@ -1,128 +0,0 @@
-#include "lib/communication.h"
-
-/*
- * main loop
- *
- * opens the application pipes,
- * reads then writes the same message,
- * then closes the pipes
- */
-
-void main_loop (const char *spath)
-{
-    int ret;
-    struct process proc;
-#if 1
-    while (1) {
-
-        // -1 : error
-        // 0 = no new process
-        // 1 = new process
-        ret = service_get_new_process (&proc, spath);
-        if (ret == -1) {
-            fprintf (stderr, "Error service_get_new_process\n");
-            exit (1);
-        } else if (ret == 0) {
-            continue;
-        }
-
-        printf ("before print\n");
-        process_print (&proc);
-        printf ("after print\n");
-
-        // about the message
-        size_t msize = BUFSIZ;
-        char buf[BUFSIZ];
-        bzero(buf, BUFSIZ);
-
-        printf ("before read\n");
-        if ((ret = process_read (&proc, &buf, &msize))) {
-            fprintf(stdout, "error process_read %d\n", ret);
-            exit (1);
-        }
-        printf ("after read\n");
-        printf ("read, size %ld : %s\n", msize, buf);
-
-        printf ("before proc write\n");
-        if ((ret = process_write (&proc, &buf, msize))) {
-            fprintf(stdout, "error process_write %d\n", ret);
-            exit (1);
-        }
-        printf ("after proc write\n");
-    }
-#endif
-
-#if 0
-
-    int ret;
-    struct process **proc;
-    int nproc = 0;
-    while (1) {
-        service_get_new_processes (&proc, &nproc, spath);
-
-        // for each process : open, read, write, close
-        for (int i = 0 ; i < nproc ; i++) {
-            printf ("before print\n");
-            process_print (proc[i]);
-            printf ("after print, i = %d\n", i);
-
-            // about the message
-            size_t msize = BUFSIZ;
-            char buf[BUFSIZ];
-            bzero(buf, BUFSIZ);
-
-            printf ("before read\n");
-            if ((ret = process_read (proc[i], &buf, &msize))) {
-                fprintf(stdout, "error process_read %d\n", ret);
-                exit (1);
-            }
-            printf ("after read\n");
-            printf ("read, size %ld : %s\n", msize, buf);
-
-            printf ("before proc write\n");
-            if ((ret = process_write (proc[i], &buf, msize))) {
-                fprintf(stdout, "error process_write %d\n", ret);
-                exit (1);
-            }
-            printf ("after proc write\n");
-        }
-        service_free_processes (proc, nproc);
-        free (proc);
-    }
-#endif
-}
-
-/*
- * service test
- *
- * 1. creates the named pipe /tmp/<service>, then listens
- * 2. opens the named pipes in & out
- * 3. talks with the (test) program
- * 4. closes the test program named pipes
- * 5. removes the named pipe /tmp/<service>
- */
-
-int main(int argc, char * argv[])
-{
-    // gets the service path, such as /tmp/<service>
-    char spath[PATH_MAX];
-    service_path (spath, "windows");
-
-    // creates the service named pipe, that listens to client applications
-    int ret;
-    if ((ret = service_create (spath))) {
-        fprintf(stdout, "error service_create %d\n", ret);
-        exit (1);
-    }
-
-    // the service will loop until the end of time, a specific message, a signal
-    main_loop (spath);
-
-    // the application will shut down, and remove the service named pipe
-    if ((ret = service_close (spath))) {
-        fprintf(stdout, "error service_close %d\n", ret);
-        exit (1);
-    }
-
-    return EXIT_SUCCESS;
-}