From 6af0f110bbd879fe4c49c2ebd64715a6e692e7c0 Mon Sep 17 00:00:00 2001
From: Michael Stapelberg <michael@stapelberg.de>
Date: Mon, 13 Dec 2010 14:36:00 +0100
Subject: debug-output eingebaut, sofern man mit -DDEBUG kompiliert

---
 aufgabe4/main.c  |  2 +-
 aufgabe4/queue.c | 42 +++++++++++++++++++++++++++++++++++++++++-
 2 files changed, 42 insertions(+), 2 deletions(-)

(limited to 'aufgabe4')

diff --git a/aufgabe4/main.c b/aufgabe4/main.c
index 3f6edec..979ee4b 100644
--- a/aufgabe4/main.c
+++ b/aufgabe4/main.c
@@ -61,7 +61,7 @@ pid_t fork_child(funcptr work, funcptr cleanup) {
     }
 
     /* parent process */
-    printf("forked\n");
+    printf("forked, pid = %d\n", pid);
     fflush(stdout);
     return pid;
 }
diff --git a/aufgabe4/queue.c b/aufgabe4/queue.c
index e376331..b882255 100644
--- a/aufgabe4/queue.c
+++ b/aufgabe4/queue.c
@@ -7,6 +7,8 @@
 #include <stdint.h>
 #include <stdlib.h>
 #include <stdio.h>
+#include <stdarg.h>
+#include <time.h>
 #include <unistd.h>
 #include <sys/mman.h>
 #include <sys/stat.h>
@@ -90,6 +92,31 @@ void queue_init() {
     }
 }
 
+#ifdef DEBUG
+static void vlog(char *fmt, va_list args) {
+    char timebuf[64];
+
+    pid_t p = getpid();
+    /* Get current time */
+    time_t t = time(NULL);
+    /* Convert time to local time (determined by the locale) */
+    struct tm *tmp = localtime(&t);
+    /* Generate time prefix */
+    strftime(timebuf, sizeof(timebuf), "%X - ", tmp);
+    printf("[%d] %s", p, timebuf);
+    vprintf(fmt, args);
+    fflush(stdout);
+}
+
+static void log(char *fmt, ...) {
+    va_list args;
+
+    va_start(args, fmt);
+    vlog(fmt, args);
+    va_end(args);
+}
+#endif
+
 /*
  * Hängt den übergebenen Wert in die Queue.
  *
@@ -110,7 +137,11 @@ struct msg *queue_write(uint8_t dir, uint8_t data) {
     }
 
     struct msg *curmsg = shmdata + (shmheader->cur * sizeof(struct msg));
-    struct msg *nextmsg = shmdata + (next * sizeof(struct msg));
+
+#ifdef DEBUG
+    log("queue_write(), next = %d, nextmsg = %p, cur = %d, cur->dir = %d\n",
+            next, nextmsg, shmheader->cur, curmsg->dir);
+#endif
     memcpy(nextmsg, &msg, sizeof(struct msg));
     if (curmsg->dir == D_INVALID)
         shmheader->cur = next;
@@ -125,6 +156,10 @@ struct msg *queue_write(uint8_t dir, uint8_t data) {
  */
 uint8_t queue_get_dir() {
     struct msg *curmsg = shmdata + (shmheader->cur * sizeof(struct msg));
+#ifdef DEBUG
+    log("queue_get_dir(), cur = %d, cur->dir = %d\n",
+            shmheader->cur, curmsg->dir);
+#endif
     return curmsg->dir;
 }
 
@@ -137,6 +172,11 @@ uint8_t queue_get_data() {
     uint8_t data;
 
     struct msg *curmsg = shmdata + (shmheader->cur * sizeof(struct msg));
+
+#ifdef DEBUG
+    log("queue_get_data(), cur = %d, cur->dir = %d\n",
+            shmheader->cur, curmsg->dir);
+#endif
     data = curmsg->data;
 
     lock();
-- 
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