re PR libgcj/11801 (Problems with Process.waitFor() and exitValue())

2004-08-12  David Daney  <ddaney@avtrex.com>

	PR libgcj/11801
	* java/lang/PosixProcess.java: Rewrote.
	* java/lang/natPosixProcess.cc: Rewrote.
	* java/lang/Runtime.java (execInternal): Declare throws IOException.
	* gcj/javaprims.h (ConcreteProcess$ProcessManager): Declare.
	* posix-threads.cc (block_sigchld) New function.
	(_Jv_ThreadRegister) Use it.
	(_Jv_ThreadStart) Use it.
	* configure.in (PLATFORM_INNER_NAT_HDRS): New AC_SUBST() used in...
	* Makefile.am: ... to specify extra native headers.
	* configure: Regenerated.
	* include/config.h: Regenerated.
	* Makefile.in: Regenerated.
	* gcj/Makefile.in: Regenerated.
	* include/Makefile.in: Regenerated.
	* testsuite/Makefile.in: Regenerated.

From-SVN: r85880

1 files changed, 156 insertions, 64 deletions

diff --git a/libjava/java/lang/natPosixProcess.cc b/libjava/java/lang/natPosixProcess.cc
index fb97020..f6b6f67 100644
--- a/libjava/java/lang/natPosixProcess.cc
+++ b/libjava/java/lang/natPosixProcess.cc
@@ -21,12 +21,16 @@ details.  */
 #include <string.h>
 #include <stdlib.h>
 #include <stdio.h>
+#include <unistd.h>
+#include <pthread.h>
 
 #include <gcj/cni.h>
 #include <jvm.h>
 
+#include <java/lang/ConcreteProcess$ProcessManager.h>
 #include <java/lang/ConcreteProcess.h>
 #include <java/lang/IllegalThreadStateException.h>
+#include <java/lang/InternalError.h>
 #include <java/lang/InterruptedException.h>
 #include <java/lang/NullPointerException.h>
 #include <java/lang/Thread.h>
@@ -42,44 +46,6 @@ using gnu::java::nio::channels::FileChannelImpl;
 
 extern char **environ;
 
-void
-java::lang::ConcreteProcess::destroy (void)
-{
-  if (! hasExited)
-    {
-      // Really kill it.
-      kill ((pid_t) pid, SIGKILL);
-    }
-}
-
-jint
-java::lang::ConcreteProcess::waitFor (void)
-{
-  if (! hasExited)
-    {
-      int wstat;
-      int r = waitpid ((pid_t) pid, &wstat, 0);
-
-      if (r == -1)
-        {
-	  if (java::lang::Thread::interrupted())
-	    throw new InterruptedException (JvNewStringLatin1 (strerror
-	      (errno)));
-	}
-      else
-	{
-	  hasExited = true;
-
-	  if (WIFEXITED (wstat))
-	    status = WEXITSTATUS (wstat);
-	  else
-	    status = -1;
-	}
-    }
-
-  return status;
-}
-
 static char *
 new_string (jstring string)
 {
@@ -120,14 +86,134 @@ myclose (int &fd)
   fd = -1;
 }
 
+// There has to be a signal handler in order to be able to
+// sigwait() on SIGCHLD.  The information passed is ignored as it
+// will be recovered by the waitpid() call.
+static void
+sigchld_handler (int)
+{
+  // Ignore.
+}
+
+
+// Get ready to enter the main reaper thread loop.
 void
-java::lang::ConcreteProcess::startProcess (jstringArray progarray,
-					   jstringArray envp,
-					   java::io::File *dir)
+java::lang::ConcreteProcess$ProcessManager::init ()
 {
-  using namespace java::io;
+  using namespace java::lang;
+  // Remenber our PID so other threads can kill us.
+  reaperPID = (jlong) pthread_self ();
+
+  // SIGCHLD is blocked in all threads in posix-threads.cc.
+  // Setup the SIGCHLD handler.
+  struct sigaction sa;
+  memset (&sa, 0, sizeof (sa));
+
+  sa.sa_handler = sigchld_handler;
+  // We only want signals when the things exit.
+  sa.sa_flags = SA_NOCLDSTOP;
+
+  if (-1 == sigaction (SIGCHLD, &sa, NULL))
+    goto error;
+
+  // All OK.
+  return;
+
+error:
+  throw new InternalError (JvNewStringUTF (strerror (errno)));
+}
+
+void
+java::lang::ConcreteProcess$ProcessManager::waitForSignal ()
+{
+  using namespace java::lang;
+
+  sigset_t mask;
+  // Wait for SIGCHLD
+  sigemptyset (&mask);
+  sigaddset (&mask, SIGCHLD);
+
+  int sig;
+  int c = sigwait (&mask, &sig);
+
+  if (c != 0)
+    goto error;
 
-  hasExited = false;
+  // All OK.
+  return;
+
+error:
+  throw new InternalError (JvNewStringUTF (strerror (c)));
+}
+
+jboolean java::lang::ConcreteProcess$ProcessManager::reap ()
+{
+  using namespace java::lang;
+
+  pid_t pid;
+
+  for (;;)
+    {
+      // Get the return code from a dead child process.
+      int status;
+      pid = waitpid ((pid_t) - 1, &status, WNOHANG);
+      if (pid == -1)
+	{
+	  if (errno == ECHILD)
+	    return false;
+	  else
+	    goto error;
+	}
+
+      if (pid == 0)
+        return true;   // No children to wait for.
+
+      // Look up the process in our pid map.
+      ConcreteProcess * process = removeProcessFromMap ((jlong) pid);
+
+      if (process)
+	{
+	  JvSynchronize sync (process);
+	  process->status = WIFEXITED (status) ? WEXITSTATUS (status) : -1;
+	  process->state = ConcreteProcess::STATE_TERMINATED;
+          process->processTerminationCleanup();
+	  process->notifyAll ();
+	}
+      else
+	{
+	  // Unknown child.  How did this happen?
+	  fprintf (stderr, "Reaped unknown child pid = %ld\n", (long) pid);
+	}
+    }
+
+error:
+  throw new InternalError (JvNewStringUTF (strerror (errno)));
+}
+
+void
+java::lang::ConcreteProcess$ProcessManager::signalReaper ()
+{
+  int c = pthread_kill ((pthread_t) reaperPID, SIGCHLD);
+  if (c == 0)
+    return;
+  // pthread_kill() failed.
+  throw new InternalError (JvNewStringUTF (strerror (c)));
+}
+
+void
+java::lang::ConcreteProcess::nativeDestroy ()
+{
+  int c = kill ((pid_t) pid, SIGKILL);
+  if (c == 0)
+    return;
+  // kill() failed.
+  throw new InternalError (JvNewStringUTF (strerror (errno)));
+}
+
+void
+java::lang::ConcreteProcess::nativeSpawn ()
+{
+  using namespace java::io;
 
   // Initialize all locals here to make cleanup simpler.
   char **args = NULL;
@@ -142,7 +228,6 @@ java::lang::ConcreteProcess::startProcess (jstringArray progarray,
   errp[1] = -1;
   msgp[0] = -1;
   msgp[1] = -1;
-  java::lang::Throwable *exc = NULL;
   errorStream = NULL;
   inputStream = NULL;
   outputStream = NULL;
@@ -150,8 +235,7 @@ java::lang::ConcreteProcess::startProcess (jstringArray progarray,
   try
     {
       // Transform arrays to native form.
-      args = (char **) _Jv_Malloc ((progarray->length + 1)
-				   * sizeof (char *));
+    args = (char **) _Jv_Malloc ((progarray->length + 1) * sizeof (char *));
 
       // Initialize so we can gracefully recover.
       jstring *elts = elements (progarray);
@@ -185,24 +269,32 @@ java::lang::ConcreteProcess::startProcess (jstringArray progarray,
       // status.
       if (pipe (inp) || pipe (outp) || pipe (errp) || pipe (msgp)
 	  || fcntl (msgp[1], F_SETFD, FD_CLOEXEC))
-	throw new IOException (JvNewStringLatin1 (strerror (errno)));
+      throw new IOException (JvNewStringUTF (strerror (errno)));
 
       // We create the streams before forking.  Otherwise if we had an
       // error while creating the streams we would have run the child
       // with no way to communicate with it.
-      errorStream = new FileInputStream (new FileChannelImpl(errp[0], FileChannelImpl::READ));
-      inputStream = new FileInputStream (new FileChannelImpl(inp[0], FileChannelImpl::READ));
-      outputStream = new FileOutputStream (new FileChannelImpl(outp[1], FileChannelImpl::WRITE));
+    errorStream =
+      new FileInputStream (new
+                           FileChannelImpl (errp[0], FileChannelImpl::READ));
+    inputStream =
+      new FileInputStream (new
+                           FileChannelImpl (inp[0], FileChannelImpl::READ));
+    outputStream =
+      new FileOutputStream (new FileChannelImpl (outp[1],
+                                             FileChannelImpl::WRITE));
 
       // We don't use vfork() because that would cause the local
       // environment to be set by the child.
-      if ((pid = (jlong) fork ()) == -1)
-	throw new IOException (JvNewStringLatin1 (strerror (errno)));
 
-      if (pid == 0)
+    // Use temporary for fork result to avoid dirtying an extra page.
+    pid_t pid_tmp;
+    if ((pid_tmp = fork ()) == -1)
+      throw new IOException (JvNewStringUTF (strerror (errno)));
+
+    if (pid_tmp == 0)
 	{
 	  // Child process, so remap descriptors, chdir and exec.
-
 	  if (envp)
 	    {
 	      // Preserve PATH and LD_LIBRARY_PATH unless specified
@@ -212,16 +304,16 @@ java::lang::ConcreteProcess::startProcess (jstringArray progarray,
 	      environ = env;
 	      if (path_val && getenv ("PATH") == NULL)
 		{
-		  char *path_env = (char *) _Jv_Malloc (strlen (path_val)
-							+ 5 + 1);
+		char *path_env =
+                  (char *) _Jv_Malloc (strlen (path_val) + 5 + 1);
 		  strcpy (path_env, "PATH=");
 		  strcat (path_env, path_val);
 		  putenv (path_env);
 		}
 	      if (ld_path_val && getenv ("LD_LIBRARY_PATH") == NULL)
 		{
-		  char *ld_path_env
-		    = (char *) _Jv_Malloc (strlen (ld_path_val) + 16 + 1);
+		char *ld_path_env =
+                  (char *) _Jv_Malloc (strlen (ld_path_val) + 16 + 1);
 		  strcpy (ld_path_env, "LD_LIBRARY_PATH=");
 		  strcat (ld_path_env, ld_path_val);
 		  putenv (ld_path_env);
@@ -264,6 +356,8 @@ java::lang::ConcreteProcess::startProcess (jstringArray progarray,
 
       // Parent.  Close extra file descriptors and mark ours as
       // close-on-exec.
+      pid = (jlong) pid_tmp;
+
       myclose (outp[0]);
       myclose (inp[1]);
       myclose (errp[1]);
@@ -272,9 +366,9 @@ java::lang::ConcreteProcess::startProcess (jstringArray progarray,
       char c;
       int r = read (msgp[0], &c, 1);
       if (r == -1)
-	throw new IOException (JvNewStringLatin1 (strerror (errno)));
+      throw new IOException (JvNewStringUTF (strerror (errno)));
       else if (r != 0)
-	throw new IOException (JvNewStringLatin1 (strerror (c)));
+      throw new IOException (JvNewStringUTF (strerror (c)));
     }
   catch (java::lang::Throwable *thrown)
     {
@@ -324,15 +418,13 @@ java::lang::ConcreteProcess::startProcess (jstringArray progarray,
       myclose (errp[1]);
       myclose (msgp[1]);
 
-      exc = thrown;
+    exception = thrown;
     }
 
   myclose (msgp[0]);
   cleanup (args, env, path);
 
-  if (exc != NULL)
-    throw exc;
-  else
+  if (exception == NULL)
     {
       fcntl (outp[1], F_SETFD, FD_CLOEXEC);
       fcntl (inp[0], F_SETFD, FD_CLOEXEC);