[myserver-commit] [2953] Use a pipe to synchronize between fork server processes.

[Giuseppe Scrivano]

Revision: 2953
          http://svn.sv.gnu.org/viewvc/?view=rev&root=myserver&revision=2953
Author:   gscrivano
Date:     2008-11-09 22:35:20 +0000 (Sun, 09 Nov 2008)

Log Message:
-----------
Use a pipe to synchronize between fork server processes.  Specify the `int' 
length with fork server sockets operations.

Modified Paths:
--------------
    trunk/myserver/include/base/process/fork_server.h
    trunk/myserver/src/base/process/fork_server.cpp

Modified: trunk/myserver/include/base/process/fork_server.h
===================================================================
--- trunk/myserver/include/base/process/fork_server.h   2008-11-09 20:22:44 UTC 
(rev 2952)
+++ trunk/myserver/include/base/process/fork_server.h   2008-11-09 22:35:20 UTC 
(rev 2953)
@@ -39,11 +39,11 @@
   int startForkServer ();
 
   int writeInt (Socket *socket, int num);
-  int writeString (Socket *socket, const char* str, u_long len);
+  int writeString (Socket *socket, const char* str, int len);
   int readInt (Socket *sock, int *dest);
   int readString (Socket *sock, char **out);
 
-  int handleRequest (Socket sin, Socket sout);
+  int handleRequest (Socket sin, Socket sout, Socket *serverSock);
   int forkServerLoop (Socket *socket);
 
   int getConnection (Socket *socket, Socket *socket2);

Modified: trunk/myserver/src/base/process/fork_server.cpp
===================================================================
--- trunk/myserver/src/base/process/fork_server.cpp     2008-11-09 20:22:44 UTC 
(rev 2952)
+++ trunk/myserver/src/base/process/fork_server.cpp     2008-11-09 22:35:20 UTC 
(rev 2953)
@@ -18,6 +18,7 @@
 
 #include <include/base/process/fork_server.h>
 #include <include/base/process/process.h>
+#include <include/base/pipe/pipe.h>
 
 #ifdef NOT_WIN
 #include <unistd.h>
@@ -32,7 +33,7 @@
 {
   u_long nbw;
 
-  if (socket->write ((const char*)&num, sizeof (num), &nbw))
+  if (socket->write ((const char*)&num, 4, &nbw))
     return 1;
 
   return 0;
@@ -46,14 +47,14 @@
  *\param str string to write.
  *\param len string length.
  */
-int ForkServer::writeString (Socket *socket, const char* str, u_long len)
+int ForkServer::writeString (Socket *socket, const char* str, int len)
 {
   u_long nbw;
 
   if (str == NULL)
     len = 0;
 
-  if (socket->write ((const char*)&len, sizeof (len), &nbw))
+  if (socket->write ((const char*)&len, 4, &nbw))
     return 1;
 
   if (len && socket->write (str, len, &nbw))
@@ -120,7 +121,7 @@
 /*!
  *Handle a request on the socket.
  */
-int ForkServer::handleRequest (Socket sin, Socket sout)
+int ForkServer::handleRequest (Socket sin, Socket sout, Socket *serverSock)
 {
 #ifdef NOT_WIN
   int ret, flags, stdIn, stdOut, stdErr;
@@ -200,32 +201,42 @@
   spi.cmd.assign (exec);
   spi.arg.assign (arg);
   spi.cwd.assign (cwd);
+
+  Pipe syncPipe;
+  syncPipe.create ();
   /* spi.cmdLine is used only under Windows and 
-   * the fork server doesn't work there. */
-
+   * the fork server doesn't work there.  */
   ret = fork ();
 
   if (ret)
     {
+      u_long nbw;
       writeInt (&sout, ret);
       writeInt (&sout, stdInPort);
 
       /* Synchronize with the child process.  It avoids that the
        * child process starts to write on `sout' before the process
        * information are sent back.  */
-      writeInt (&sin, 1);
+      syncPipe.write ("1", 1, &nbw);
+      syncPipe.close ();
     }
 
   /* Code already present in process.cpp, refactoring needed.  */
   if (ret == 0) // child
     {
-      int syncInt;
+      u_long nbr;
+      char syncB;
       const char *envp[100];
       const char *args[100];
 
-      /* The parent process sent an ack when the child can start its 
execution.  */
-      readInt (&sin, &syncInt);
-      
+      /* The parent process sent an ack when the child can start 
+       * its execution.  */
+      syncPipe.read (&syncB, 1, &nbr);
+      syncPipe.close ();
+
+      /* Close the fork server descriptor in the child process.  */
+      serverSock->close ();
+     
       if (Process::generateArgList (args, spi.cmd.c_str (), spi.arg))
         exit (1);
 
@@ -239,9 +250,18 @@
             exit (1);
         }
       if ((long)spi.stdIn == -1)
+      {
         spi.stdIn = (FileHandle)open ("/dev/null", O_RDONLY);
+      }
+
+      if ((long)spi.stdIn == -1 || flags & FLAG_STDIN_SOCKET)
+        sin.close ();
+
       if ((long)spi.stdOut == -1)
+      {
         spi.stdOut = (FileHandle)open ("/dev/null", O_WRONLY);
+        sout.close ();
+      }
 
       ret = close(0);
       if (ret == -1)
@@ -321,7 +341,7 @@
           exit (0);
           return 0;
         case 'r':
-          if (handleRequest (sin, sout))
+          if (handleRequest (sin, sout, socket))
             {
               sin.shutdown (2);
               sin.close ();