Modify mds-server to use mds-base (some regression...)

Signed-off-by: Mattias Andrée <maandree@operamail.com>

11 files changed, 221 insertions, 449 deletions

diff --git a/src/mds-server/globals.c b/src/mds-server/globals.c
index 0d2c6b6..0f0aa9f 100644
--- a/src/mds-server/globals.c
+++ b/src/mds-server/globals.c
@@ -18,17 +18,11 @@
 #include "globals.h"
 
 
-int argc;
-char** argv;
-
 volatile sig_atomic_t running = 1;
-volatile sig_atomic_t reexecing = 0;
-volatile sig_atomic_t terminating = 0;
 
 size_t running_slaves = 0;
 pthread_mutex_t slave_mutex;
 pthread_cond_t slave_cond;
-pthread_t master_thread;
 fd_table_t client_map;
 linked_list_t client_list;
 uint64_t next_client_id = 1;
diff --git a/src/mds-server/globals.h b/src/mds-server/globals.h
index 1016ae7..e9465f0 100644
--- a/src/mds-server/globals.h
+++ b/src/mds-server/globals.h
@@ -18,6 +18,8 @@
 #ifndef MDS_MDS_SERVER_GLOBALS_H
 #define MDS_MDS_SERVER_GLOBALS_H
 
+#include "../mds-base.h" /* Include here so other do not need to. */
+
 
 #include <libmdsserver/linked-list.h>
 #include <libmdsserver/hash-table.h>
@@ -34,32 +36,10 @@
 
 
 /**
- * Number of elements in `argv`
- */
-extern int argc;
-
-/**
- * Command line arguments
- */
-extern char** argv;
-
-
-/**
  * The program run state, 1 when running, 0 when shutting down
  */
 extern volatile sig_atomic_t running;
 
-/**
- * Non-zero when the program is about to re-exec.
- * Most at all times be at least as true as `terminating`.
- */
-extern volatile sig_atomic_t reexecing;
-
-/**
- * Non-zero when the program is about to terminate
- */
-extern volatile sig_atomic_t terminating;
-
 
 /**
  * The number of running slaves
@@ -77,11 +57,6 @@ extern pthread_mutex_t slave_mutex;
 extern pthread_cond_t slave_cond;
 
 /**
- * The thread that runs the master loop
- */
-extern pthread_t master_thread;
-
-/**
  * Map from client socket file descriptor to all information (client_t)
  */
 extern fd_table_t client_map;
diff --git a/src/mds-server/mds-server.c b/src/mds-server/mds-server.c
index 3179ee7..b1008cd 100644
--- a/src/mds-server/mds-server.c
+++ b/src/mds-server/mds-server.c
@@ -22,11 +22,9 @@
 #include "client.h"
 #include "queued_interception.h"
 #include "multicast.h"
-#include "signals.h"
 #include "interceptors.h"
 #include "sending.h"
 #include "slavery.h"
-#include "reexec.h"
 #include "receiving.h"
 
 #include <libmdsserver/config.h>
@@ -47,19 +45,41 @@
 #include <inttypes.h>
 
 
+/**
+ * This variable should declared by the actual server implementation.
+ * It must be configured before `main` is invoked.
+ * 
+ * This tells the server-base how to behave
+ */
+server_characteristics_t server_characteristics =
+  {
+    .require_privileges = 0,
+    .require_display = 0 /* We will service one ourself. */
+  };
+
+
+
+#define __free(I)                                           \
+  if (I >  0)  pthread_mutex_destroy(&slave_mutex);         \
+  if (I >  1)  pthread_cond_destroy(&slave_cond);           \
+  if (I >  2)  pthread_mutex_destroy(&modify_mutex);        \
+  if (I >  3)  pthread_cond_destroy(&modify_cond);          \
+  if (I >= 4)  hash_table_destroy(&modify_map, NULL, NULL); \
+  if (I >= 5)  fd_table_destroy(&client_map, NULL, NULL);   \
+  if (I >= 6)  linked_list_destroy(&client_list)
+  
+#define error_if(I, CONDITION)  \
+  if (CONDITION)  { perror(*argv); __free(I); return 1; }
+
 
 /**
- * Entry point of the server
+ * This function will be invoked before `initialise_server` (if not re-exec:ing)
+ * or before `unmarshal_server` (if re-exec:ing)
  * 
- * @param   argc_  Number of elements in `argv_`
- * @param   argv_  Command line arguments
- * @return         Non-zero on error
+ * @return  Non-zero on error
  */
-int main(int argc_, char** argv_)
+int preinitialise_server(void)
 {
-  int is_respawn = -1;
-  int socket_fd = -1;
-  int reexec = 0;
   int unparsed_args_ptr = 1;
   char* unparsed_args[ARGC_LIMIT + LIBEXEC_ARGC_EXTRA_LIMIT + 1];
   int i;
@@ -69,58 +89,27 @@ int main(int argc_, char** argv_)
 #endif
   
   
-  argc = argc_;
-  argv = argv_;
-  
-  
-  /* Drop privileges like it's hot. */
-  fail_if (drop_privileges());
-  
-  /* Sanity check the number of command line arguments. */
-  exit_if (argc > ARGC_LIMIT + LIBEXEC_ARGC_EXTRA_LIMIT,
-	   eprint("that number of arguments is ridiculous, I will not allow it."););
-  
-  
   /* Parse command line arguments. */
   for (i = 1; i < argc; i++)
     {
       char* arg = argv[i];
-      int v;
-      if ((v = strequals(arg, "--initial-spawn")) || /* Initial spawn? */
-	  strequals(arg, "--respawn"))               /* Respawning after crash? */
-	{
-	  exit_if (is_respawn == v,
-		   eprintf("conflicting arguments %s and %s cannot be combined.",
-			   "--initial-spawn", "--respawn"););
-	  is_respawn = !v;
-	}
-      else if (startswith(arg, "--socket-fd=")) /* Socket file descriptor. */
+      if (startswith(arg, "--socket-fd=")) /* Socket file descriptor. */
 	{
 	  exit_if (socket_fd != -1,
 		   eprintf("duplicate declaration of %s.", "--socket-fd"););
 	  exit_if (strict_atoi(arg += strlen("--socket-fd="), &socket_fd, 0, INT_MAX) < 0,
 		   eprintf("invalid value for %s: %s.", "--socket-fd", arg););
 	}
-      else if (strequals(arg, "--re-exec")) /* Re-exec state-marshal. */
-	reexec = 1;
       else if (startswith(arg, "--alarm=")) /* Schedule an alarm signal for forced abort. */
 	alarm((unsigned)min(atoi(arg + strlen("--alarm=")), 60)); /* At most 1 minute. */
       else
-	/* Not recognised, it is probably for another server. */
-	unparsed_args[unparsed_args_ptr++] = arg;
+	if (!strequals(arg, "--initial-spawn") && !strequals(arg, "--respawn"))
+	  /* Not recognised, it is probably for another server. */
+	  unparsed_args[unparsed_args_ptr++] = arg;
     }
   unparsed_args[unparsed_args_ptr] = NULL;
-  if (reexec)
-    {
-      is_respawn = 1;
-      eprint("re-exec performed.");
-    }
-  
   
   /* Check that manditory arguments have been specified. */
-  exit_if (is_respawn < 0,
-	   eprintf("missing state argument, require either %s or %s.",
-		   "--initial-spawn", "--respawn"););
   exit_if (socket_fd < 0,
 	   eprint("missing socket file descriptor argument."););
   
@@ -142,85 +131,91 @@ int main(int argc_, char** argv_)
 	}
     }
   
-#define __free(I) \
-  if (I >= 0)  fd_table_destroy(&client_map, NULL, NULL);  \
-  if (I >= 1)  linked_list_destroy(&client_list);          \
-  if (I >= 2)  pthread_mutex_destroy(&slave_mutex);        \
-  if (I >= 3)  pthread_cond_destroy(&slave_cond);          \
-  if (I >= 4)  pthread_mutex_destroy(&modify_mutex);       \
-  if (I >= 5)  pthread_cond_destroy(&modify_cond);         \
-  if (I >= 6)  hash_table_destroy(&modify_map, NULL, NULL)
-  
-#define error_if(I, CONDITION)  if (CONDITION)  { perror(*argv); __free(I); return 1; }
-  
-  /* Create list and table of clients. */
-  if (reexec == 0)
-    {
-      error_if (0, fd_table_create(&client_map));
-      error_if (1, linked_list_create(&client_list, 32));
-    }
-  
-  /* Store the current thread so it can be killed from elsewhere. */
-  master_thread = pthread_self();
-  
-  /* Set up traps for especially handled signals. */
-  error_if (1, trap_signals() < 0);
   
   /* Create mutex and condition for slave counter. */
-  error_if (1, (errno = pthread_mutex_init(&slave_mutex, NULL)));
-  error_if (2, (errno = pthread_cond_init(&slave_cond, NULL)));
+  error_if (0, (errno = pthread_mutex_init(&slave_mutex, NULL)));
+  error_if (1, (errno = pthread_cond_init(&slave_cond, NULL)));
   
   /* Create mutex, condition and map for message modification. */
-  error_if (3, (errno = pthread_mutex_init(&modify_mutex, NULL)));
-  error_if (4, (errno = pthread_cond_init(&modify_cond, NULL)));
-  error_if (5, hash_table_create(&modify_map));
+  error_if (2, (errno = pthread_mutex_init(&modify_mutex, NULL)));
+  error_if (3, (errno = pthread_cond_init(&modify_cond, NULL)));
+  error_if (4, hash_table_create(&modify_map));
   
-#undef error_if
   
+  return 0;
   
-  /* Unmarshal the state of the server. */
-  if (reexec)
-    complete_reexec(socket_fd);
+ pfail:
+  perror(*argv);
+  return 1;
+}
+
+
+/**
+ * This function should initialise the server,
+ * and it not invoked after a re-exec.
+ * 
+ * @return  Non-zero on error
+ */
+int initialise_server(void)
+{
+  /* Create list and table of clients. */
+  error_if (5, fd_table_create(&client_map));
+  error_if (6, linked_list_create(&client_list, 32));
   
+  return 0;
+}
+
+
+/**
+ * This function will be invoked asgter `initialise_server` (if not re-exec:ing)
+ * or after `unmarshal_server` (if re-exec:ing)
+ * 
+ * @return  Non-zero on error
+ */
+int __attribute__((const)) postinitialise_server(void)
+{
+  /* We do not need to initialise anything else. */
+  return 0;
+}
+
+
+/**
+ * Perform the server's mission
+ * 
+ * @return  Non-zero on error
+ */
+int master_loop(void)
+{
   /* Accepting incoming connections. */
   while (running && (terminating == 0))
-    if (accept_connection(socket_fd) == 1)
+    if (accept_connection() == 1)
       break;
   
-  if (reexecing)
-    goto reexec;
-  
   /* Join with all slaves threads. */
   with_mutex (slave_mutex,
 	      while (running_slaves > 0)
 		pthread_cond_wait(&slave_cond, &slave_mutex););
   
-  /* Release resources. */
-  __free(9999);
+  if (reexecing == 0)
+    {
+      /* Release resources. */
+      __free(9999);
+    }
   
   return 0;
-  
-#undef __free
-  
-  
- reexec:
-  perform_reexec(reexec);
-  /* Returning non-zero is important, otherwise the server cannot
-     be respawn if the re-exec fails. */
-  
- pfail:
-  perror(*argv);
-  return 1;
 }
 
 
+#undef error_if
+#undef __free
+
+
 /**
  * Accept an incoming and start a slave thread for it
  * 
- * @param   socket_fd  The file descriptor of the server socket
- * @return             Zero normally, 1 if terminating
+ * @return  Zero normally, 1 if terminating
  */
-int accept_connection(int socket_fd)
+int accept_connection(void)
 {
   pthread_t slave_thread;
   int client_fd;
@@ -255,8 +250,8 @@ int accept_connection(int socket_fd)
  */
 void* slave_loop(void* data)
 {
-  int socket_fd = (int)(intptr_t)data;
-  size_t information_address = fd_table_get(&client_map, (size_t)socket_fd);
+  int slave_fd = (int)(intptr_t)data;
+  size_t information_address = fd_table_get(&client_map, (size_t)slave_fd);
   client_t* information = (client_t*)(void*)information_address;
   char* msgbuf = NULL;
   char buf[] = "To: all";
@@ -267,7 +262,7 @@ void* slave_loop(void* data)
   if (information == NULL) /* Did not re-exec. */
     {
       /* Initialise the client. */
-      fail_if ((information = initialise_client(socket_fd)) == NULL);
+      fail_if ((information = initialise_client(slave_fd)) == NULL);
       
       /* Register client to receive broadcasts. */
       add_intercept_condition(information, buf, 0, 0, 0);
@@ -324,7 +319,7 @@ void* slave_loop(void* data)
   
  fail: /* This done on success as well. */
   /* Close socket and free resources. */
-  close(socket_fd);
+  close(slave_fd);
   free(msgbuf);
   if (information != NULL)
     {
@@ -335,7 +330,7 @@ void* slave_loop(void* data)
   
   /* Unmap client and decrease the slave count. */
   with_mutex (slave_mutex,
-	      fd_table_remove(&client_map, socket_fd);
+	      fd_table_remove(&client_map, slave_fd);
 	      running_slaves--;
 	      pthread_cond_signal(&slave_cond););
   return NULL;
diff --git a/src/mds-server/mds-server.h b/src/mds-server/mds-server.h
index 19f3044..3bce7ed 100644
--- a/src/mds-server/mds-server.h
+++ b/src/mds-server/mds-server.h
@@ -27,10 +27,9 @@
 /**
  * Accept an incoming and start a slave thread for it
  * 
- * @param   socket_fd  The file descriptor of the server socket
- * @return             Zero normally, 1 if terminating
+ * @return  Zero normally, 1 if terminating
  */
-int accept_connection(int socket_fd);
+int accept_connection(void);
 
 /**
  * Master function for slave threads
diff --git a/src/mds-server/reexec.c b/src/mds-server/reexec.c
index 2b41112..6667a73 100644
--- a/src/mds-server/reexec.c
+++ b/src/mds-server/reexec.c
@@ -15,7 +15,6 @@
  * You should have received a copy of the GNU General Public License
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
-#include "reexec.h"
 
 #include "globals.h"
 #include "client.h"
@@ -41,51 +40,74 @@
 #include <string.h>
 
 
+
 /**
- * Marshal the server's state into a file
+ * Calculate the number of bytes that will be stored by `marshal_server`
+ * 
+ * On failure the program should `abort()` or exit by other means.
+ * However it should not be possible for this function to fail.
  * 
- * @param   fd  The file descriptor
- * @return      Negative on error
+ * @return  The number of bytes that will be stored by `marshal_server`
  */
-int marshal_server(int fd)
+size_t marshal_server_size(void)
 {
   size_t list_size = linked_list_marshal_size(&client_list);
   size_t map_size = fd_table_marshal_size(&client_map);
   size_t list_elements = 0;
   size_t state_n = 0;
-  char* state_buf = NULL;
-  char* state_buf_;
   ssize_t node;
   
-  
   /* Calculate the grand size of all client information. */
-  for (node = client_list.edge;; list_elements++)
+  foreach_linked_list_node (client_list, node)
     {
-      if ((node = client_list.next[node]) == client_list.edge)
-	break;
       state_n += client_marshal_size((client_t*)(void*)(client_list.values[node]));
+      list_elements++;
     }
   
   /* Add the size of the rest of the program's state. */
   state_n += sizeof(int) + sizeof(sig_atomic_t) + 2 * sizeof(uint64_t) + 2 * sizeof(size_t);
   state_n += list_elements * sizeof(size_t) + list_size + map_size;
   
-  /* Allocate a buffer for all data. */
-  state_buf = state_buf_ = malloc(state_n);
-  fail_if (state_buf == NULL);
+  return state_n;
+}
+
+
+/**
+ * Marshal server implementation specific data into a buffer
+ * 
+ * @param   state_buf  The buffer for the marshalled data
+ * @return             Non-zero on error
+ */
+int marshal_server(char* state_buf)
+{
+  size_t list_size = linked_list_marshal_size(&client_list);
+  size_t list_elements = 0;
+  ssize_t node;
+  
+  
+  /* Release resources. */
+  pthread_mutex_destroy(&slave_mutex);
+  pthread_cond_destroy(&slave_cond);
+  pthread_mutex_destroy(&modify_mutex);
+  pthread_cond_destroy(&modify_cond);
+  hash_table_destroy(&modify_map, NULL, NULL);
+  
   
+  /* Count the number of clients that online. */
+  foreach_linked_list_node (client_list, node)
+    list_elements++;
   
   /* Tell the new version of the program what version of the program it is marshalling. */
-  buf_set_next(state_buf_, int, MDS_SERVER_VARS_VERSION);
+  buf_set_next(state_buf, int, MDS_SERVER_VARS_VERSION);
   
   /* Marshal the miscellaneous state data. */
-  buf_set_next(state_buf_, sig_atomic_t, running);
-  buf_set_next(state_buf_, uint64_t, next_client_id);
-  buf_set_next(state_buf_, uint64_t, next_modify_id);
+  buf_set_next(state_buf, sig_atomic_t, running);
+  buf_set_next(state_buf, uint64_t, next_client_id);
+  buf_set_next(state_buf, uint64_t, next_modify_id);
   
   /* Tell the program how large the marshalled client list is and how any clients are marshalled. */
-  buf_set_next(state_buf_, size_t, list_size);
-  buf_set_next(state_buf_, size_t, list_elements);
+  buf_set_next(state_buf, size_t, list_size);
+  buf_set_next(state_buf, size_t, list_elements);
   
   /* Marshal the clients. */
   foreach_linked_list_node (client_list, node)
@@ -96,27 +118,28 @@ int marshal_server(int fd)
       client_t* value = (client_t*)(void*)value_address;
       
       /* Marshal the address, it is used the the client list and the client map, that will be marshalled. */
-      buf_set_next(state_buf_, size_t, value_address);
+      buf_set_next(state_buf, size_t, value_address);
       /* Marshal the client informationation. */
-      state_buf_ += client_marshal(value, state_buf_) / sizeof(char);
+      state_buf += client_marshal(value, state_buf) / sizeof(char);
     }
   
   /* Marshal the client list. */
-  linked_list_marshal(&client_list, state_buf_);
-  state_buf_ += list_size / sizeof(char);
+  linked_list_marshal(&client_list, state_buf);
+  state_buf += list_size / sizeof(char);
   /* Marshal the client map. */
-  fd_table_marshal(&client_map, state_buf_);
+  fd_table_marshal(&client_map, state_buf);
   
-  /* Send the marshalled data into the file. */
-  fail_if (full_write(fd, state_buf, state_n) < 0);
-  free(state_buf);
   
-  return 0;
+  /* Release resources. */
+  foreach_linked_list_node (client_list, node)
+    {
+      client_t* client = (client_t*)(void*)(client_list.values[node]);
+      client_destroy(client);
+    }
+  fd_table_destroy(&client_map, NULL, NULL);
+  linked_list_destroy(&client_list);
   
- pfail:
-  perror(*argv);
-  free(state_buf);
-  return -1;
+  return 0;
 }
 
 
@@ -136,17 +159,16 @@ static size_t unmarshal_remapper(size_t old)
   return hash_table_get(&unmarshal_remap_map, old);
 }
 
+
 /**
- * Unmarshal the server's state from a file
+ * Unmarshal server implementation specific data and update the servers state accordingly
  * 
- * @param   fd  The file descriptor
- * @return      Negative on error
+ * @param   state_buf  The marshalled data that as not been read already
+ * @return             Non-zero on error
  */
-int unmarshal_server(int fd)
+int unmarshal_server(char* state_buf)
 {
   int with_error = 0;
-  char* state_buf;
-  char* state_buf_;
   size_t list_size;
   size_t list_elements;
   size_t i;
@@ -154,35 +176,27 @@ int unmarshal_server(int fd)
   pthread_t slave_thread;
   
   
-  /* Read the file. */
-  if ((state_buf = state_buf_ = full_read(fd)) == NULL)
-    {
-      perror(*argv);
-      return -1;
-    }
-  
   /* Create memory address remapping table. */
   if (hash_table_create(&unmarshal_remap_map))
     {
       perror(*argv);
-      free(state_buf);
       hash_table_destroy(&unmarshal_remap_map, NULL, NULL);
       return -1;
     }
   
   
   /* Get the marshal protocal version. Not needed, there is only the one version right now. */
-  /* buf_get(state_buf_, int, 0, MDS_SERVER_VARS_VERSION); */
-  buf_next(state_buf_, int, 1);
+  /* buf_get(state_buf, int, 0, MDS_SERVER_VARS_VERSION); */
+  buf_next(state_buf, int, 1);
   
   /* Unmarshal the miscellaneous state data. */
-  buf_get_next(state_buf_, sig_atomic_t, running);
-  buf_get_next(state_buf_, uint64_t, next_client_id);
-  buf_get_next(state_buf_, uint64_t, next_modify_id);
+  buf_get_next(state_buf, sig_atomic_t, running);
+  buf_get_next(state_buf, uint64_t, next_client_id);
+  buf_get_next(state_buf, uint64_t, next_modify_id);
   
   /* Get the marshalled size of the client list and how any clients that are marshalled. */
-  buf_get_next(state_buf_, size_t, list_size);
-  buf_get_next(state_buf_, size_t, list_elements);
+  buf_get_next(state_buf, size_t, list_size);
+  buf_get_next(state_buf, size_t, list_elements);
   
   /* Unmarshal the clients. */
   for (i = 0; i < list_elements; i++)
@@ -196,9 +210,9 @@ int unmarshal_server(int fd)
 	goto clients_fail;
       
       /* Unmarshal the address, it is used the the client list and the client map, that are also marshalled. */
-      buf_get_next(state_buf_, size_t, value_address);
+      buf_get_next(state_buf, size_t, value_address);
       /* Unmarshal the client information. */
-      n = client_unmarshal(value, state_buf_);
+      n = client_unmarshal(value, state_buf);
       if (n == 0)
 	goto clients_fail;
       
@@ -208,7 +222,7 @@ int unmarshal_server(int fd)
 	  goto clients_fail;
       
       /* Delayed seeking. */
-      state_buf_ += n / sizeof(char);
+      state_buf += n / sizeof(char);
       
       
       /* On error, seek past all clients. */
@@ -218,29 +232,26 @@ int unmarshal_server(int fd)
       with_error = 1;
       if (value != NULL)
 	{
-	  buf_prev(state_buf_, size_t, 1);
+	  buf_prev(state_buf, size_t, 1);
 	  free(value);
 	}
       for (; i < list_elements; i++)
 	/* There is not need to close the sockets, it is done by
 	   the caller because there are conditions where we cannot
 	   get here anyway. */
-	state_buf_ += client_unmarshal_skip(state_buf_) / sizeof(char);
+	state_buf += client_unmarshal_skip(state_buf) / sizeof(char);
       break;
     }
   
   /* Unmarshal the client list. */
-  if (linked_list_unmarshal(&client_list, state_buf_))
+  if (linked_list_unmarshal(&client_list, state_buf))
     goto critical_fail;
-  state_buf_ += list_size / sizeof(char);
+  state_buf += list_size / sizeof(char);
   
   /* Unmarshal the client map. */
-  if (fd_table_unmarshal(&client_map, state_buf_, unmarshal_remapper))
+  if (fd_table_unmarshal(&client_map, state_buf, unmarshal_remapper))
     goto critical_fail;
   
-  /* Release the raw data. */
-  free(state_buf);
-  
   /* Remove non-found elements from the fd table. */
 #define __bit(I, _OP_)  client_map.used[I / 64] _OP_ ((uint64_t)1 << (I % 64))
   if (with_error)
@@ -262,116 +273,38 @@ int unmarshal_server(int fd)
 	{
 	  /* Start the clients. (Errors do not need to be reported.) */
 	  client_t* client = (client_t*)(void*)new_address;
-	  int socket_fd = client->socket_fd;
+	  int slave_fd = client->socket_fd;
 	  
 	  /* Increase number of running slaves. */
 	  with_mutex (slave_mutex, running_slaves++;);
 	  
 	  /* Start slave thread. */
-	  create_slave(&slave_thread, socket_fd);
+	  create_slave(&slave_thread, slave_fd);
 	}
     }
   
   /* Release the remapping table's resources. */
   hash_table_destroy(&unmarshal_remap_map, NULL, NULL);
   
-  return -with_error;
-
- critical_fail:
-  perror(*argv);
-  abort();
-}
-
-
-/**
- * Marshal and re-execute the server
- * 
- * @param  reexec  Whether the server was previously re-executed
- */
-void perform_reexec(int reexec)
-{
-  pid_t pid = getpid();
-  int reexec_fd;
-  char shm_path[NAME_MAX + 1];
-  ssize_t node;
-  
-  /* Join with all slaves threads. */
-  with_mutex (slave_mutex,
-	      while (running_slaves > 0)
-		pthread_cond_wait(&slave_cond, &slave_mutex););
+  return with_error;
   
-  /* Release resources. */
-  pthread_mutex_destroy(&slave_mutex);
-  pthread_cond_destroy(&slave_cond);
-  pthread_mutex_destroy(&modify_mutex);
-  pthread_cond_destroy(&modify_cond);
-  hash_table_destroy(&modify_map, NULL, NULL);
   
-  /* Marshal the state of the server. */
-  xsnprintf(shm_path, SHM_PATH_PATTERN, (unsigned long int)pid);
-  reexec_fd = shm_open(shm_path, O_RDWR | O_CREAT | O_EXCL, S_IRWXU);
-  if (reexec_fd < 0)
-    {
-      perror(*argv);
-      return;
-    }
-  fail_if (marshal_server(reexec_fd) < 0);
-  close(reexec_fd);
-  reexec_fd = -1;
-  
-  /* Release resources. */
-  foreach_linked_list_node (client_list, node)
-    {
-      client_t* client = (client_t*)(void*)(client_list.values[node]);
-      client_destroy(client);
-    }
-  fd_table_destroy(&client_map, NULL, NULL);
-  linked_list_destroy(&client_list);
-  
-  /* Re-exec the server. */
-  reexec_server(argc, argv, reexec);
-  
- pfail:
+ critical_fail:
   perror(*argv);
-  if (reexec_fd >= 0)
-    close(reexec_fd);
-  shm_unlink(shm_path);
+  abort();
 }
 
 
 /**
- * Attempt to reload the server after a re-execution
+ * Attempt to recover from an re-exec failure that has been
+ * detected after the server successfully updated it execution image
  * 
- * @param  socket_fd  The file descriptor of the server socket
+ * @return  Non-zero on error
  */
-void complete_reexec(int socket_fd)
+int reexec_failure_recover(void)
 {
-  pid_t pid = getpid();
-  int reexec_fd, r;
-  char shm_path[NAME_MAX + 1];
-  
-  /* Acquire access to marshalled data. */
-  xsnprintf(shm_path, SHM_PATH_PATTERN, (unsigned long int)pid);
-  reexec_fd = shm_open(shm_path, O_RDONLY, S_IRWXU);
-  fail_if (reexec_fd < 0); /* Critical. */
-  
-  /* Unmarshal state. */
-  r = unmarshal_server(reexec_fd);
-  
-  /* Close and unlink marshalled data. */
-  close(reexec_fd);
-  shm_unlink(shm_path);
-  
-  /* Recover after failure. */
-  if (r < 0)
-    {
-      /* Close all files (hopefully sockets) we do not know what they are. */
-      close_files((fd > 2) && (fd != socket_fd) && (fd_table_contains_key(&client_map, fd) == 0));
-    }
-  
-  return;
- pfail:
-  perror(*argv);
-  abort();
+  /* Close all files (hopefully sockets) we do not know what they are. */
+  close_files((fd > 2) && (fd != socket_fd) && (fd_table_contains_key(&client_map, fd) == 0));
+  return 0;
 }
 
diff --git a/src/mds-server/reexec.h b/src/mds-server/reexec.h
deleted file mode 100644
index 266fdfd..0000000
--- a/src/mds-server/reexec.h
+++ /dev/null
@@ -1,54 +0,0 @@
-/**
- * mds — A micro-display server
- * Copyright © 2014  Mattias Andrée (maandree@member.fsf.org)
- * 
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
- * 
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- * 
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
- */
-#ifndef MDS_MDS_SERVER_REEXEC_H
-#define MDS_MDS_SERVER_REEXEC_H
-
-
-/**
- * Marshal the server's state into a file
- * 
- * @param   fd  The file descriptor
- * @return      Negative on error
- */
-int marshal_server(int fd);
-
-/**
- * Unmarshal the server's state from a file
- * 
- * @param   fd  The file descriptor
- * @return      Negative on error
- */
-int unmarshal_server(int fd);
-
-/**
- * Marshal and re-execute the server
- * 
- * @param  reexec  Whether the server was previously re-executed
- */
-void perform_reexec(int reexec);
-
-/**
- * Attempt to reload the server after a re-execution
- * 
- * @param  socket_fd  The file descriptor of the server socket
- */
-void complete_reexec(int socket_fd);
-
-
-#endif
-
diff --git a/src/mds-server/sending.c b/src/mds-server/sending.c
index 8c40cc4..ec29a81 100644
--- a/src/mds-server/sending.c
+++ b/src/mds-server/sending.c
@@ -38,13 +38,13 @@
 /**
  * Get the client by its socket's file descriptor in a synchronised manner
  * 
- * @param   socket_fd  The file descriptor of the client's socket
+ * @param   client_fd  The file descriptor of the client's socket
  * @return             The client
  */
-static client_t* client_by_socket(int socket_fd)
+static client_t* client_by_socket(int client_fd)
 {
   size_t address;
-  with_mutex (slave_mutex, address = fd_table_get(&client_map, socket_fd););
+  with_mutex (slave_mutex, address = fd_table_get(&client_map, client_fd););
   return (client_t*)(void*)address;
 }
 
diff --git a/src/mds-server/signals.c b/src/mds-server/signals.c
index b16b28a..325fa35 100644
--- a/src/mds-server/signals.c
+++ b/src/mds-server/signals.c
@@ -15,20 +15,16 @@
  * You should have received a copy of the GNU General Public License
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
-#include "signals.h"
 
 #include "globals.h"
 #include "client.h"
 
 #include <libmdsserver/linked-list.h>
 #include <libmdsserver/macros.h>
-#include <libmdsserver/util.h>
 
 #include <stdio.h>
-#include <errno.h>
-#include <stdlib.h>
 #include <pthread.h>
-#include <signal.h>
+#include <errno.h>
 
 
 /**
@@ -58,12 +54,14 @@ static void signal_all(int signo)
 
 
 /**
- * Called with the signal SIGUSR1 is caught.
- * This function should cue a re-exec of the program.
+ * This function is called when a signal that
+ * signals the server to re-exec has been received
  * 
- * @param  signo  The caught signal
+ * When this function is invoked, it should set `reexecing` to a non-zero value
+ * 
+ * @param  signo  The signal that has been received
  */
-static void sigusr1_trap(int signo)
+void received_reexec(int signo)
 {
   if (reexecing == 0)
     {
@@ -75,57 +73,20 @@ static void sigusr1_trap(int signo)
 
 
 /**
- * Called with the signal SIGTERM is caught.
- * This function should cue a termination of the program.
+ * This function is called when a signal that
+ * signals the server to re-exec has been received
  * 
- * @param  signo  The caught signal
- */
-static void sigterm_trap(int signo)
-{
-  if (terminating == 0)
-    {
-      terminating = 1;
-      eprint("terminate signal received.");
-      signal_all(signo);
-    }
-}
-
-
-/**
- * Called with the signal SIGINT is caught.
- * This function should cue a termination of the program.
+ * When this function is invoked, it should set `terminating` to a non-zero value
  * 
- * @param  signo  The caught signal
+ * @param  signo  The signal that has been received
  */
-static void sigint_trap(int signo)
+void received_terminate(int signo)
 {
   if (terminating == 0)
     {
       terminating = 1;
-      eprint("terminal interrupt signal received.");
+      eprint("terminate signal received.");
       signal_all(signo);
     }
 }
 
-
-/**
- * Set up signal traps for all especially handled signals
- * 
- * @return  Zero on success, -1 on error
- */
-int trap_signals(void)
-{
-  /* Make the server update without all slaves dying on SIGUSR1. */
-  fail_if (xsigaction(SIGUSR1, sigusr1_trap) < 0);
-  
-  /* Implement clean exit on SIGTERM. */
-  fail_if (xsigaction(SIGTERM, sigterm_trap) < 0);
-  
-  /* Implement clean exit on SIGINT. */
-  fail_if (xsigaction(SIGINT, sigint_trap) < 0);
-  
-  return 0;
- pfail:
-  return -1;
-}
-
diff --git a/src/mds-server/signals.h b/src/mds-server/signals.h
deleted file mode 100644
index b4a49ed..0000000
--- a/src/mds-server/signals.h
+++ /dev/null
@@ -1,31 +0,0 @@
-/**
- * mds — A micro-display server
- * Copyright © 2014  Mattias Andrée (maandree@member.fsf.org)
- * 
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
- * 
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- * 
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
- */
-#ifndef MDS_MDS_SERVER_SIGNALS_H
-#define MDS_MDS_SERVER_SIGNALS_H
-
-
-/**
- * Set up signal traps for all especially handled signals
- * 
- * @return  Zero on success, -1 on error
- */
-int trap_signals(void);
-
-
-#endif
-
diff --git a/src/mds-server/slavery.c b/src/mds-server/slavery.c
index 627bde0..4b92154 100644
--- a/src/mds-server/slavery.c
+++ b/src/mds-server/slavery.c
@@ -71,13 +71,13 @@ int fetch_message(client_t* client)
 /**
  * Create, start and detache a slave thread
  * 
- * @param   thread     The address at where to store the thread
- * @param   socket_fd  The file descriptor of the slave's socket
- * @return             Zero on success, -1 on error, error message will have been printed
+ * @param   thread    The address at where to store the thread
+ * @param   slave_fd  The file descriptor of the slave's socket
+ * @return            Zero on success, -1 on error, error message will have been printed
  */
-int create_slave(pthread_t* thread_slot, int socket_fd)
+int create_slave(pthread_t* thread_slot, int slave_fd)
 {
-  if ((errno = pthread_create(thread_slot, NULL, slave_loop, (void*)(intptr_t)socket_fd)))
+  if ((errno = pthread_create(thread_slot, NULL, slave_loop, (void*)(intptr_t)slave_fd)))
     {
       perror(*argv);
       with_mutex (slave_mutex, running_slaves--;);
@@ -95,10 +95,10 @@ int create_slave(pthread_t* thread_slot, int socket_fd)
 /**
  * Initialise a client, except for threading
  * 
- * @param   socket_fd  The file descriptor of the client's socket
+ * @param   client_fd  The file descriptor of the client's socket
  * @return             The client information, NULL on error
  */
-client_t* initialise_client(int socket_fd)
+client_t* initialise_client(int client_fd)
 {
   ssize_t entry = LINKED_LIST_UNUSED;
   int locked = 0;
@@ -117,14 +117,14 @@ client_t* initialise_client(int socket_fd)
   fail_if (entry == LINKED_LIST_UNUSED);
   
   /* Add client to table. */
-  tmp = fd_table_put(&client_map, socket_fd, (size_t)(void*)information);
+  tmp = fd_table_put(&client_map, client_fd, (size_t)(void*)information);
   fail_if ((tmp == 0) && errno);
   pthread_mutex_unlock(&slave_mutex);
   locked = 0;
   
   /* Fill information table. */
   information->list_entry = entry;
-  information->socket_fd = socket_fd;
+  information->socket_fd = client_fd;
   information->open = 1;
   fail_if (mds_message_initialise(&(information->message)));
   
diff --git a/src/mds-server/slavery.h b/src/mds-server/slavery.h
index 0b94e7d..92144fd 100644
--- a/src/mds-server/slavery.h
+++ b/src/mds-server/slavery.h
@@ -35,19 +35,19 @@ int fetch_message(client_t* client);
 /**
  * Create, start and detache a slave thread
  * 
- * @param   thread     The address at where to store the thread
- * @param   socket_fd  The file descriptor of the slave's socket
- * @return             Zero on success, -1 on error, error message will have been printed
+ * @param   thread    The address at where to store the thread
+ * @param   slave_fd  The file descriptor of the slave's socket
+ * @return            Zero on success, -1 on error, error message will have been printed
  */
-int create_slave(pthread_t* thread_slot, int socket_fd);
+int create_slave(pthread_t* thread_slot, int slave_fd);
 
 /**
  * Initialise a client, except for threading
  * 
- * @param   socket_fd  The file descriptor of the client's socket
+ * @param   client_fd  The file descriptor of the client's socket
  * @return             The client information, NULL on error
  */
-client_t* initialise_client(int socket_fd);
+client_t* initialise_client(int client_fd);
 
 
 #endif