cleanup

[nestedvm.git] / src / org / ibex / nestedvm / UnixRuntime.java

diff --git a/src/org/ibex/nestedvm/UnixRuntime.java b/src/org/ibex/nestedvm/UnixRuntime.java
index 6c986e5..723af47 100644 (file)
--- a/src/org/ibex/nestedvm/UnixRuntime.java
+++ b/src/org/ibex/nestedvm/UnixRuntime.java
@@ -4,6 +4,8 @@ import org.ibex.nestedvm.util.*;
 import java.io.*;
 import java.util.*;
 
+// FEATURE: vfork
+
 public abstract class UnixRuntime extends Runtime implements Cloneable {
     /** The pid of this "process" */
     private int pid;
@@ -84,14 +86,21 @@ public abstract class UnixRuntime extends Runtime implements Cloneable {
         UnixRuntime[] tasks = gs.tasks;
         synchronized(gs) {
             if(pid != 0) {
-                if(tasks[pid] == null || tasks[pid].pid != pid) throw new Error("should never happen");
+                UnixRuntime prev = tasks[pid];
+                if(prev == null || prev == this || prev.pid != pid || prev.parent != parent)
+                    throw new Error("should never happen");
+                synchronized(parent.children) {
+                    int i = parent.activeChildren.indexOf(prev);
+                    if(i == -1) throw new Error("should never happen");
+                    parent.activeChildren.set(i,this);
+                }
             } else {
                 int newpid = -1;
                 int nextPID = gs.nextPID;
-                    for(int i=nextPID;i<tasks.length;i++) if(tasks[i] == null) { newpid = i; break; }
-                    if(newpid == -1) for(int i=1;i<nextPID;i++) if(tasks[i] == null) { newpid = i; break; }
-                    if(newpid == -1) throw new ProcessTableFullExn();
-                    pid = newpid;
+                for(int i=nextPID;i<tasks.length;i++) if(tasks[i] == null) { newpid = i; break; }
+                if(newpid == -1) for(int i=1;i<nextPID;i++) if(tasks[i] == null) { newpid = i; break; }
+                if(newpid == -1) throw new ProcessTableFullExn();
+                pid = newpid;
                 gs.nextPID = newpid + 1;
             }
             tasks[pid] = this;
@@ -114,6 +123,7 @@ public abstract class UnixRuntime extends Runtime implements Cloneable {
             case SYS_exec: return sys_exec(a,b,c);
             case SYS_getdents: return sys_getdents(a,b,c,d);
             case SYS_unlink: return sys_unlink(a);
+            case SYS_getppid: return sys_getppid();
 
             default: return super._syscall(syscall,a,b,c,d);
         }
@@ -122,6 +132,10 @@ public abstract class UnixRuntime extends Runtime implements Cloneable {
     FD _open(String path, int flags, int mode) throws ErrnoException {
         return gs.open(this,normalizePath(path),flags,mode);
     }
+    
+    private int sys_getppid() {
+        return parent == null ? 1 : parent.pid;
+    }
 
     /** The kill syscall.
        SIGSTOP, SIGTSTO, SIGTTIN, and SIGTTOUT pause the process.
@@ -217,7 +231,7 @@ public abstract class UnixRuntime extends Runtime implements Cloneable {
                 if(parent == null) {
                     gs.tasks[pid] = null;
                 } else {
-                    parent.activeChildren.remove(this);
+                    if(!parent.activeChildren.remove(this)) throw new Error("should never happen _exited: pid: " + pid);
                     parent.exitedChildren.add(this);
                     parent.children.notify();
                 }
@@ -529,7 +543,7 @@ public abstract class UnixRuntime extends Runtime implements Cloneable {
             }
         }
         
-        private static class MP {
+        private static class MP implements Comparable {
             public MP(String path, FS fs) { this.path = path; this.fs = fs; }
             public String path;
             public FS fs;
@@ -635,6 +649,9 @@ public abstract class UnixRuntime extends Runtime implements Cloneable {
         }
 
         public synchronized Object exec(UnixRuntime r, String path) throws ErrnoException {
+            // FIXME: Hideous hack to make a standalone busybox possible
+            if(path.equals("bin/busybox") && Boolean.valueOf(getSystemProperty("nestedvm.busyboxhack")).booleanValue())
+                return r.getClass();
             FStat fstat = stat(r,path);
             if(fstat == null) return null;
             long mtime = fstat.mtime();
@@ -969,16 +986,12 @@ public abstract class UnixRuntime extends Runtime implements Cloneable {
         }
         
         private FD devZeroFD = new FD() {
-            public boolean readable() { return true; }
-            public boolean writable() { return true; }
             public int read(byte[] a, int off, int length) { Arrays.fill(a,off,off+length,(byte)0); return length; }
             public int write(byte[] a, int off, int length) { return length; }
             public int seek(int n, int whence) { return 0; }
             public FStat _fstat() { return new DevFStat(){ public int inode() { return ZERO_INODE; } }; }
         };
         private FD devNullFD = new FD() {
-            public boolean readable() { return true; }
-            public boolean writable() { return true; }
             public int read(byte[] a, int off, int length) { return 0; }
             public int write(byte[] a, int off, int length) { return length; }
             public int seek(int n, int whence) { return 0; }