making stuff a bit more readable

library/DFProcess-linux-SHM.cpp

@@ -125,45 +125,49 @@ SHMProcess::SHMProcess(vector <memory_info> & known_versions)
      */
     if ((d->my_shmid = shmget(SHM_KEY, SHM_SIZE, 0666)) < 0)
     {
-        perror("shmget");
+        return;
     }
-    else
+    
-    {
+    /*
+     * Attach the segment
+     */
     if ((d->my_shm = (char *) shmat(d->my_shmid, NULL, 0)) == (char *) -1)
     {
-            perror("shmat");
+        return;
     }
-        else
+    
-        {
-            struct shmid_ds descriptor;
-            shmctl(d->my_shmid, IPC_STAT, &descriptor); 
     /*
-            * Now we attach the segment to our data space.
+     * Check if there are two processes connected to the segment
      */
-            
+    struct shmid_ds descriptor;
+    shmctl(d->my_shmid, IPC_STAT, &descriptor); 
     if(descriptor.shm_nattch != 2)// badness
     {
         fprintf(stderr,"dfhack: no DF or different client already connected\n");
+        return;
     }
-            else
+    
-            {
+    /*
+     * Test bridge version, will also detect when we connect to something that doesn't respond
+     */
     bool bridgeOK;
     if(!d->DF_TestBridgeVersion(bridgeOK))
     {
         fprintf(stderr,"DF terminated during reading\n");
+        return;
     }
-                else
-                {
     if(!bridgeOK)
     {
         fprintf(stderr,"SHM bridge version mismatch\n");
+        return;
     }
-                    else
+    /*
-                    {
+     * get the PID from DF
+     */
     if(d->DF_GetPID(d->my_pid))
     {
+        // find its binary
         sprintf(exe_link_name,"/proc/%d/exe", d->my_pid);
-                            // resolve /proc/PID/exe link
         target_result = readlink(exe_link_name, target_name, sizeof(target_name)-1);
         if (target_result == -1)
         {
@@ -171,21 +175,16 @@ SHMProcess::SHMProcess(vector <memory_info> & known_versions)
             return;
         }
         // make sure we have a null terminated string...
+        // see http://www.opengroup.org/onlinepubs/000095399/functions/readlink.html
         target_name[target_result] = 0;
         
-                            // is this the regular linux DF?
+        // try to identify the DF version
-                            // create linux process, add it to the vector
         d->validate(target_name, d->my_pid, known_versions);
         d->my_window = new DFWindow(this);
     }
-                    }
+    // at this point, DF is stopped and waiting for commands. make it run again
-                }
-                // make sure we restart the process
     ((shm_cmd *)d->my_shm)->pingpong = DFPP_RUNNING;
 }
-        }
-    }
-}
 
 bool SHMProcess::isSuspended()
 {
@@ -233,9 +232,13 @@ SHMProcess::~SHMProcess()
     }
     // destroy data model. this is assigned by processmanager
     if(d->my_datamodel)
+    {
         delete d->my_datamodel;
+    }
     if(d->my_window)
+    {
         delete d->my_window;
+    }
     delete d;
 }
 
@@ -297,12 +300,18 @@ bool SHMProcess::suspend()
 {
     int status;
     if(!d->attached)
+    {
         return false;
+    }
     if(d->suspended)
+    {
         return true;
+    }
     ((shm_cmd *)d->my_shm)->pingpong = DFPP_SUSPEND;
     if(!d->waitWhile(DFPP_SUSPEND))
+    {
         return false;
+    }
     d->suspended = true;
     return true;
 }
@@ -346,10 +355,17 @@ bool SHMProcess::attach()
 
 bool SHMProcess::detach()
 {
-    if(!d->attached) return false;
+    if(!d->attached)
-    if(d->suspended) resume();
+    {
+        return false;
+    }
+    if(d->suspended)
+    {
+        resume();
+    }
     d->attached = false;
     d->suspended = false;
+    return true;
 }