Mon Oct 1 12:38:00 2001 Robert Collins <rbtcollins@hotmail.com>

        * cygserver.cc (client_request::serve): New function.
        * cygserver_process.cc: Inlude <pthread.h> for pthread_once.
        (process_cache::process_cache): Initialise a crtiical section for write access.
        (process_cache::process): Use the critical section. Also add missing entries to
        the cache.
        (do_process_init): New function to initalise class process static variables.
        (process::process): Ensure that the process access critical section is initialised.
        (process::handle): Close the handle of old process's when they have terminated
        and we are returning the handle for a process with the same pid.
        * cygserver_shm.cc: Run indent.
        Include cygserver_process.h to allow process cache functionality.
        (client_request_shm_get::serve): New parameter for process cache support.
        Use the process cache, not OpenProcess to get a handle to the originating process.
        Fix a handle leak with token_handle.
        * cygserver_shm.h (class client_request_shm_get): Update ::serve for process cache support.
        * cygserver_transport_pipes.cc: Redefine debug_printf to be conditional on DEBUG.
        * include/cygwin/cygserver.h: Do not implement client_request::serve in the header.
        * include/cygwin/cygserver_process.h (class process_cache): Add a write access cri
tical section to prevent races when requests from a  multithreaded application arrive.

8 files changed, 202 insertions, 111 deletions

diff --git a/winsup/cygwin/ChangeLog b/winsup/cygwin/ChangeLog
index 9974fc3a1..b9670a7f0 100644
--- a/winsup/cygwin/ChangeLog
+++ b/winsup/cygwin/ChangeLog
@@ -1,3 +1,24 @@
+Mon Oct  1 12:38:00 2001  Robert Collins <rbtcollins@hotmail.com>
+
+	* cygserver.cc (client_request::serve): New function.
+	* cygserver_process.cc: Inlude <pthread.h> for pthread_once.
+	(process_cache::process_cache): Initialise a crtiical section for write access.
+	(process_cache::process): Use the critical section. Also add missing entries to 
+	the cache.
+	(do_process_init): New function to initalise class process static variables.
+	(process::process): Ensure that the process access critical section is initialised.
+	(process::handle): Close the handle of old process's when they have terminated
+	and we are returning the handle for a process with the same pid.
+	* cygserver_shm.cc: Run indent.
+	Include cygserver_process.h to allow process cache functionality.
+	(client_request_shm_get::serve): New parameter for process cache support.
+	Use the process cache, not OpenProcess to get a handle to the originating process.
+	Fix a handle leak with token_handle.
+	* cygserver_shm.h (class client_request_shm_get): Update ::serve for process cache support.
+	* cygserver_transport_pipes.cc: Redefine debug_printf to be conditional on DEBUG.
+	* include/cygwin/cygserver.h: Do not implement client_request::serve in the header.
+	* include/cygwin/cygserver_process.h (class process_cache): Add a write access critical section to prevent races when requests from a  multithreaded application arrive.
+
 Sun Sep 30 23:41:00 2001  Robert Collins <rbtcollins@hotmail.com>
 
 	* Makefile.in: Add cygserver_process.o to cygserver.exe.
diff --git a/winsup/cygwin/cygserver.cc b/winsup/cygwin/cygserver.cc
index 083df06af..a9b743c58 100755
--- a/winsup/cygwin/cygserver.cc
+++ b/winsup/cygwin/cygserver.cc
@@ -163,6 +163,15 @@ check_and_dup_handle (HANDLE from_process, HANDLE to_process,
 }
 
 void
+client_request::serve (transport_layer_base *conn, class process_cache *cache)
+{
+  printf ("*****************************************\n"
+	  "A call to the base client_request class has occured\n"
+	  "This indicates a mismatch in a virtual function definition somewhere\n");
+  exit (1);
+}
+
+void
 client_request_attach_tty::serve(transport_layer_base *conn, class process_cache *cache)
 {
   HANDLE from_process_handle = NULL;
diff --git a/winsup/cygwin/cygserver_process.cc b/winsup/cygwin/cygserver_process.cc
index 8ec1c03e3..d02905b03 100755
--- a/winsup/cygwin/cygserver_process.cc
+++ b/winsup/cygwin/cygserver_process.cc
@@ -18,24 +18,37 @@
 #include <sys/socket.h>
 #include <netdb.h>
 #include "wincap.h"
+#include <pthread.h>
 #include <cygwin/cygserver_process.h>
 
 #define debug_printf if (DEBUG) printf
 #define DEBUG 1
 
+/* the cache structures and classes are designed for one cache per server process.
+ * To make multiple process caches, a redesign will be needed
+ */
+
 /* process cache */
 process_cache::process_cache () : head (NULL)
 {
+  /* there can only be one */
+  InitializeCriticalSection (&cache_write_access);
 }
 
 class process *
 process_cache::process (long pid)
 {
   class process_entry *entry = head;
+  /* TODO: make this more granular, so a search doesn't involve the write lock */
+  EnterCriticalSection (&cache_write_access);
   while (entry && entry->process.winpid != pid)
     entry = entry->next;
   if (!entry)
-    return NULL;
+    {
+      entry = new process_entry (pid);
+      entry->next = (process_entry *) InterlockedExchangePointer (&head, entry);
+    }
+  LeaveCriticalSection (&cache_write_access);
   return &entry->process;
 }
 
@@ -45,10 +58,23 @@ process_entry::process_entry (long pid) : next (NULL), process (pid)
 }
 
 /* process's */
+static CRITICAL_SECTION process_access;
+static pthread_once_t process_init;
+
+void
+do_process_init (void)
+{
+  InitializeCriticalSection (&process_access);
+  /* we don't have a cache shutdown capability today */
+}
+
 process::process (long pid) : winpid (pid)
 {
+  pthread_once(&process_init, do_process_init);
+  EnterCriticalSection (&process_access);
   thehandle = OpenProcess (PROCESS_ALL_ACCESS, FALSE, pid);
   debug_printf ("Got handle %p for new cache process %ld\n", thehandle, pid);
+  LeaveCriticalSection (&process_access);
 }
 
 HANDLE
@@ -65,6 +91,8 @@ process::handle ()
   if (exitstate != STILL_ACTIVE)
     {
       /* FIXME: call the cleanup list */
+      CloseHandle (thehandle);
+      debug_printf ("Process id %ld has terminated, attempting to open a new handle\n", winpid);
       thehandle = OpenProcess (PROCESS_ALL_ACCESS, FALSE, winpid);
       /* FIXME: what if this fails */
     }
diff --git a/winsup/cygwin/cygserver_shm.cc b/winsup/cygwin/cygserver_shm.cc
index e4da727e6..3b8bd9dd2 100755
--- a/winsup/cygwin/cygserver_shm.cc
+++ b/winsup/cygwin/cygserver_shm.cc
@@ -45,6 +45,7 @@
 #endif
 //#include "perprocess.h"
 #include "cygserver_shm.h"
+#include <cygwin/cygserver_process.h>
 
 // FIXME IS THIS CORRECT
 /* Implementation notes: We use two shared memory regions per key:
@@ -55,7 +56,8 @@
  * Also, IPC_PRIVATE keys create unique mappings each time. The shm_ids just
  * keep monotonically incrementing - system wide.
  */
-size_t getsystemallocgranularity ()
+size_t
+getsystemallocgranularity ()
 {
   SYSTEM_INFO sysinfo;
   static size_t buffer_offset = 0;
@@ -66,14 +68,15 @@ size_t getsystemallocgranularity ()
   return buffer_offset;
 }
 
-client_request_shm_get::client_request_shm_get () : client_request (CYGSERVER_REQUEST_SHM_GET)
+client_request_shm_get::client_request_shm_get ():client_request (CYGSERVER_REQUEST_SHM_GET)
 {
   header.cb = sizeof (parameters);
   buffer = (char *) &parameters;
   header.error_code = 0;
 }
 
-client_request_shm_get::client_request_shm_get (int nshm_id, pid_t npid) : client_request (CYGSERVER_REQUEST_SHM_GET)
+client_request_shm_get::client_request_shm_get (int nshm_id, pid_t npid):
+client_request (CYGSERVER_REQUEST_SHM_GET)
 {
   header.cb = sizeof (parameters);
   buffer = (char *) &parameters;
@@ -84,7 +87,10 @@ client_request_shm_get::client_request_shm_get (int nshm_id, pid_t npid) : clien
 }
 
 client_request_shm_get::client_request_shm_get (key_t nkey, size_t nsize,
-						int nshmflg, char psdbuf[4096], pid_t npid):	client_request (CYGSERVER_REQUEST_SHM_GET)
+						int nshmflg,
+						char psdbuf[4096],
+						pid_t npid):
+client_request (CYGSERVER_REQUEST_SHM_GET)
 {
   header.cb = sizeof (parameters);
   buffer = (char *) &parameters;
@@ -115,10 +121,9 @@ shmat (int shmid, const void *shmaddr, int parameters.in.shmflg)
 
   void *rv = MapViewOfFile (shm->attachmap,
 
-			    
-			    (parameters.in.
-			     shmflg & SHM_RDONLY) ? FILE_MAP_READ :
-			    FILE_MAP_WRITE, 0,
+
+			    (parameters.in.shmflg & SHM_RDONLY) ?
+			    FILE_MAP_READ : FILE_MAP_WRITE, 0,
 			    0, 0);
 
   if (!rv)
@@ -161,7 +166,8 @@ shmat (int shmid, const void *shmaddr, int parameters.in.shmflg)
 /* for dll size */
 #ifdef __INSIDE_CYGWIN__
 void
-client_request_shm_get::serve (transport_layer_base * conn)
+client_request_shm_get::serve (transport_layer_base * conn,
+			       process_cache * cache)
 {
 }
 #else
@@ -171,9 +177,9 @@ extern GENERIC_MAPPING access_mapping;
 extern int
 check_and_dup_handle (HANDLE from_process, HANDLE to_process,
 		      HANDLE from_process_token,
-                      DWORD access,
-                      HANDLE from_handle,
-                      HANDLE* to_handle_ptr, BOOL bInheritHandle);
+		      DWORD access,
+		      HANDLE from_handle,
+		      HANDLE * to_handle_ptr, BOOL bInheritHandle);
 
 //FIXME: where should this live
 static shmnode *shm_head = NULL;
@@ -182,7 +188,8 @@ static long new_id = 0;
 static long new_private_key = 0;
 
 void
-client_request_shm_get::serve (transport_layer_base * conn)
+client_request_shm_get::serve (transport_layer_base * conn,
+			       process_cache * cache)
 {
 //  DWORD sd_size = 4096;
 //  char sd_buf[4096];
@@ -195,26 +202,29 @@ client_request_shm_get::serve (transport_layer_base * conn)
   HANDLE token_handle = NULL;
   DWORD rc;
 
-  from_process_handle = OpenProcess (PROCESS_DUP_HANDLE, FALSE, parameters.in.pid);
+  from_process_handle = cache->process (parameters.in.pid)->handle ();
+  /* possible TODO: reduce the access on the handle before we use it */
+  /* Note that unless we do this, we don't need to call CloseHandle - it's kept open
+   * by the process cache until the process terminates. 
+   * We may need a refcount on the cache however... 
+   */
   if (!from_process_handle)
     {
-      printf ("error opening process (%lu)\n", GetLastError ());
+      debug_printf ("error opening process (%lu)\n", GetLastError ());
       header.error_code = EACCES;
       return;
     }
 
   conn->impersonate_client ();
-  
+
   rc = OpenThreadToken (GetCurrentThread (),
-  			TOKEN_QUERY,
-                        TRUE,
-			&token_handle);
+			TOKEN_QUERY, TRUE, &token_handle);
 
   conn->revert_to_self ();
 
   if (!rc)
     {
-      printf ("error opening thread token (%lu)\n", GetLastError ());
+      debug_printf ("error opening thread token (%lu)\n", GetLastError ());
       header.error_code = EACCES;
       CloseHandle (from_process_handle);
       return;
@@ -229,7 +239,7 @@ client_request_shm_get::serve (transport_layer_base * conn)
   SECURITY_ATTRIBUTES sa;
   sa.nLength = sizeof (sa);
   sa.lpSecurityDescriptor = psd;
-  sa.bInheritHandle = TRUE; /* the memory structures inherit ok */
+  sa.bInheritHandle = TRUE;	/* the memory structures inherit ok */
 
   char *shmname = NULL, *shmaname = NULL;
   char stringbuf[29], stringbuf1[29];
@@ -237,37 +247,39 @@ client_request_shm_get::serve (transport_layer_base * conn)
   if (parameters.in.type == SHM_REATTACH)
     {
       /* just find and fill out the existing shm_id */
-  shmnode *tempnode = shm_head;
-  while (tempnode)
-    {
-      if (tempnode->shm_id == parameters.in.shm_id)
-        {
-          parameters.out.shm_id = tempnode->shm_id;
- 	  parameters.out.key = tempnode->key;
-  if (check_and_dup_handle (GetCurrentProcess (),from_process_handle,
-                           token_handle,
-                           DUPLICATE_SAME_ACCESS,
-		    tempnode->filemap, &parameters.out.filemap, TRUE) != 0)
-    {
-      printf ("error duplicating filemap handle (%lu)\n", GetLastError ());
-      header.error_code = EACCES;
-      CloseHandle (from_process_handle);
-    }
-     if (check_and_dup_handle (GetCurrentProcess (),from_process_handle,
-		token_handle,
-                DUPLICATE_SAME_ACCESS,
-          tempnode->attachmap, &parameters.out.attachmap, TRUE) != 0)
-    {
-      printf ("error duplicating attachmap handle (%lu)\n", GetLastError ());
-      header.error_code = EACCES;
-      CloseHandle (from_process_handle);
-    }
-          return;
-        }
-      tempnode = tempnode->next;
-    }     
-  header.error_code = EINVAL;
-  return;
+      shmnode *tempnode = shm_head;
+      while (tempnode)
+	{
+	  if (tempnode->shm_id == parameters.in.shm_id)
+	    {
+	      parameters.out.shm_id = tempnode->shm_id;
+	      parameters.out.key = tempnode->key;
+	      if (check_and_dup_handle
+		  (GetCurrentProcess (), from_process_handle, token_handle,
+		   DUPLICATE_SAME_ACCESS, tempnode->filemap,
+		   &parameters.out.filemap, TRUE) != 0)
+		{
+		  debug_printf ("error duplicating filemap handle (%lu)\n",
+				GetLastError ());
+		  header.error_code = EACCES;
+		}
+	      if (check_and_dup_handle
+		  (GetCurrentProcess (), from_process_handle, token_handle,
+		   DUPLICATE_SAME_ACCESS, tempnode->attachmap,
+		   &parameters.out.attachmap, TRUE) != 0)
+		{
+		  debug_printf ("error duplicating attachmap handle (%lu)\n",
+				GetLastError ());
+		  header.error_code = EACCES;
+		}
+	      CloseHandle (token_handle);
+	      return;
+	    }
+	  tempnode = tempnode->next;
+	}
+      header.error_code = EINVAL;
+      CloseHandle (token_handle);
+      return;
     }
   /* it's a original request from the users */
 
@@ -280,22 +292,22 @@ client_request_shm_get::serve (transport_layer_base * conn)
       /* create the mapping name (CYGWINSHMKPRIVATE_0x01234567 */
       /* The K refers to Key, the actual mapped area has D */
       long private_key = (int) InterlockedIncrement (&new_private_key);
-      snprintf (stringbuf , 29, "CYGWINSHMKPRIVATE_0x%0x", private_key);
-	shmname = stringbuf;
-	snprintf (stringbuf1, 29, "CYGWINSHMDPRIVATE_0x%0x", private_key);
-	shmaname = stringbuf1;
+      snprintf (stringbuf, 29, "CYGWINSHMKPRIVATE_0x%0x", private_key);
+      shmname = stringbuf;
+      snprintf (stringbuf1, 29, "CYGWINSHMDPRIVATE_0x%0x", private_key);
+      shmaname = stringbuf1;
     }
   else
     {
-  /* create the mapping name (CYGWINSHMK0x0123456789abcdef */
-  /* The K refers to Key, the actual mapped area has D */
-
-  snprintf (stringbuf , 29, "CYGWINSHMK0x%0qx", parameters.in.key);
-  shmname = stringbuf;
-  snprintf (stringbuf1, 29, "CYGWINSHMD0x%0qx", parameters.in.key);
-  shmaname = stringbuf1;
-  debug_printf ("system id strings are \n%s\n%s\n",shmname,shmaname);
-  debug_printf ("key input value is 0x%0qx\n", parameters.in.key);
+      /* create the mapping name (CYGWINSHMK0x0123456789abcdef */
+      /* The K refers to Key, the actual mapped area has D */
+
+      snprintf (stringbuf, 29, "CYGWINSHMK0x%0qx", parameters.in.key);
+      shmname = stringbuf;
+      snprintf (stringbuf1, 29, "CYGWINSHMD0x%0qx", parameters.in.key);
+      shmaname = stringbuf1;
+      debug_printf ("system id strings are \n%s\n%s\n", shmname, shmaname);
+      debug_printf ("key input value is 0x%0qx\n", parameters.in.key);
     }
 
   /* attempt to open the key */
@@ -322,6 +334,7 @@ client_request_shm_get::serve (transport_layer_base * conn)
 	      && tempnode->shmds->shm_segsz < parameters.in.size)
 	    {
 	      header.error_code = EINVAL;
+	      CloseHandle (token_handle);
 	      return;
 	    }
 	  /* FIXME: can the same process call this twice without error ? test 
@@ -331,8 +344,11 @@ client_request_shm_get::serve (transport_layer_base * conn)
 	      && (parameters.in.shmflg & IPC_EXCL))
 	    {
 	      header.error_code = EEXIST;
-	      debug_printf ("attempt to exclusively create already created shm_area with key 0x%0qx\n",parameters.in.key);
+	      debug_printf
+		("attempt to exclusively create already created shm_area with key 0x%0qx\n",
+		 parameters.in.key);
 	      // FIXME: free the mutex
+	      CloseHandle (token_handle);
 	      return;
 	    }
 	  // FIXME: do we need to other tests of the requested mode with the 
@@ -345,29 +361,34 @@ client_request_shm_get::serve (transport_layer_base * conn)
 	   * let them attempt the open.
 	   */
 	  parameters.out.shm_id = tempnode->shm_id;
-if (check_and_dup_handle (GetCurrentProcess (),from_process_handle,
-                           token_handle,
-              DUPLICATE_SAME_ACCESS,
-                    tempnode->filemap, &parameters.out.filemap,TRUE) != 0)
-    {
-      printf ("error duplicating filemap handle (%lu)\n", GetLastError ());
-      header.error_code = EACCES;
+	  if (check_and_dup_handle (GetCurrentProcess (), from_process_handle,
+				    token_handle,
+				    DUPLICATE_SAME_ACCESS,
+				    tempnode->filemap,
+				    &parameters.out.filemap, TRUE) != 0)
+	    {
+	      printf ("error duplicating filemap handle (%lu)\n",
+		      GetLastError ());
+	      header.error_code = EACCES;
 /*mutex*/
-      CloseHandle (from_process_handle);
- return;
-    }
-if (check_and_dup_handle (GetCurrentProcess (),from_process_handle,
-                            token_handle,
-                            DUPLICATE_SAME_ACCESS,
-          tempnode->attachmap, &parameters.out.attachmap, TRUE) != 0)
-    {
-      printf ("error duplicating attachmap handle (%lu)\n", GetLastError ());
-      header.error_code = EACCES;
+	      CloseHandle (token_handle);
+	      return;
+	    }
+	  if (check_and_dup_handle (GetCurrentProcess (), from_process_handle,
+				    token_handle,
+				    DUPLICATE_SAME_ACCESS,
+				    tempnode->attachmap,
+				    &parameters.out.attachmap, TRUE) != 0)
+	    {
+	      printf ("error duplicating attachmap handle (%lu)\n",
+		      GetLastError ());
+	      header.error_code = EACCES;
 /*mutex*/
-      CloseHandle (from_process_handle);
-return;
-    }
+	      CloseHandle (token_handle);
+	      return;
+	    }
 
+	  CloseHandle (token_handle);
 	  return;
 	}
       tempnode = tempnode->next;
@@ -395,6 +416,7 @@ return;
       // free the mutex
       // we can assume that it exists, and that it was an access problem.
       header.error_code = EACCES;
+      CloseHandle (token_handle);
       return;
     }
 
@@ -412,19 +434,21 @@ return;
 	  /* FIXME free mutex */
 	  CloseHandle (filemap);
 	  header.error_code = EEXIST;
+	  CloseHandle (token_handle);
 	  return;
 	}
     }
 
-    /* we created a new mapping */
-    if (parameters.in.key != IPC_PRIVATE &&
-	(parameters.in.shmflg & IPC_CREAT) == 0)
-      {
-        CloseHandle (filemap);
-        /* FIXME free mutex */
-        header.error_code = ENOENT;
-        return;
-      }
+  /* we created a new mapping */
+  if (parameters.in.key != IPC_PRIVATE &&
+      (parameters.in.shmflg & IPC_CREAT) == 0)
+    {
+      CloseHandle (filemap);
+      /* FIXME free mutex */
+      header.error_code = ENOENT;
+      CloseHandle (token_handle);
+      return;
+    }
 
   conn->impersonate_client ();
   void *mapptr = MapViewOfFile (filemap, FILE_MAP_WRITE, 0, 0, 0);
@@ -436,6 +460,7 @@ return;
       //FIXME: close filemap and free the mutex
       /* we couldn't access the mapped area with the requested permissions */
       header.error_code = EACCES;
+      CloseHandle (token_handle);
       return;
     }
 
@@ -459,6 +484,7 @@ return;
       UnmapViewOfFile (mapptr);
       CloseHandle (filemap);
       /* FIXME exit the mutex */
+      CloseHandle (token_handle);
       return;
     }
 
@@ -471,6 +497,7 @@ return;
       CloseHandle (filemap);
       CloseHandle (attachmap);
       /* FIXME exit mutex */
+      CloseHandle (token_handle);
       return;
     }
 
@@ -501,31 +528,35 @@ return;
 
   /* we now have the area in the daemon list, opened. 
 
-  FIXME: leave the system wide shm mutex */
+     FIXME: leave the system wide shm mutex */
 
   parameters.out.shm_id = tempnode->shm_id;
-if (check_and_dup_handle (GetCurrentProcess (),from_process_handle,
-                           token_handle,
-              DUPLICATE_SAME_ACCESS,
-                    tempnode->filemap, &parameters.out.filemap, TRUE) != 0)
+  if (check_and_dup_handle (GetCurrentProcess (), from_process_handle,
+			    token_handle,
+			    DUPLICATE_SAME_ACCESS,
+			    tempnode->filemap, &parameters.out.filemap,
+			    TRUE) != 0)
     {
       printf ("error duplicating filemap handle (%lu)\n", GetLastError ());
       header.error_code = EACCES;
-      CloseHandle (from_process_handle);
+      CloseHandle (token_handle);
 /* mutex et al */
-return;
+      return;
     }
-if (check_and_dup_handle (GetCurrentProcess (),from_process_handle,
-                            token_handle,
-                           DUPLICATE_SAME_ACCESS,
-          tempnode->attachmap, &parameters.out.attachmap, TRUE) != 0)
+  if (check_and_dup_handle (GetCurrentProcess (), from_process_handle,
+			    token_handle,
+			    DUPLICATE_SAME_ACCESS,
+			    tempnode->attachmap, &parameters.out.attachmap,
+			    TRUE) != 0)
     {
       printf ("error duplicating attachmap handle (%lu)\n", GetLastError ());
       header.error_code = EACCES;
       CloseHandle (from_process_handle);
+      CloseHandle (token_handle);
 /* more cleanup... yay! */
-return;
+      return;
     }
+  CloseHandle (token_handle);
   return;
 }
 #endif
diff --git a/winsup/cygwin/cygserver_shm.h b/winsup/cygwin/cygserver_shm.h
index e4ac62e4c..25f747fb0 100644
--- a/winsup/cygwin/cygserver_shm.h
+++ b/winsup/cygwin/cygserver_shm.h
@@ -20,7 +20,7 @@ details. */
 class client_request_shm_get : public client_request
 {
   public:
-  virtual void serve (transport_layer_base *conn);
+  virtual void serve (transport_layer_base *conn, process_cache *cache);
   client_request_shm_get::client_request_shm_get(key_t, size_t, int, char psdbuf[4096], pid_t);
   client_request_shm_get::client_request_shm_get();
   client_request_shm_get::client_request_shm_get(int,pid_t);
diff --git a/winsup/cygwin/cygserver_transport_pipes.cc b/winsup/cygwin/cygserver_transport_pipes.cc
index 487ea5281..d9accce1e 100755
--- a/winsup/cygwin/cygserver_transport_pipes.cc
+++ b/winsup/cygwin/cygserver_transport_pipes.cc
@@ -25,7 +25,8 @@
 #ifndef __OUTSIDE_CYGWIN__
 #include "winsup.h"
 #else
-#define debug_printf printf
+#define DEBUG 0
+#define debug_printf if (DEBUG) printf
 #endif
 
 transport_layer_pipes::transport_layer_pipes (HANDLE new_pipe)
diff --git a/winsup/cygwin/include/cygwin/cygserver.h b/winsup/cygwin/include/cygwin/cygserver.h
index 4bf30241b..ad7dd3ce3 100755
--- a/winsup/cygwin/include/cygwin/cygserver.h
+++ b/winsup/cygwin/include/cygwin/cygserver.h
@@ -87,7 +87,7 @@ class client_request
   public:
   client_request (cygserver_request_code id);
   virtual void send (transport_layer_base *conn);
-  virtual void serve (transport_layer_base *conn, class process_cache *cache) {};
+  virtual void serve (transport_layer_base *conn, class process_cache *cache);
   virtual operator struct request_header ();
   cygserver_request_code req_id () {return header.req_id;};
   virtual ~client_request();
diff --git a/winsup/cygwin/include/cygwin/cygserver_process.h b/winsup/cygwin/include/cygwin/cygserver_process.h
index e761af3e2..35abf48bd 100755
--- a/winsup/cygwin/include/cygwin/cygserver_process.h
+++ b/winsup/cygwin/include/cygwin/cygserver_process.h
@@ -38,6 +38,7 @@ class process_cache
     class process *process (long);
   private:
     class process_entry *head;
+    CRITICAL_SECTION cache_write_access;
 };
 
 #endif /* _CYGSERVER_PROCESS_ */