Implemented a garbage collector for the slab allocator.

4 files changed, 133 insertions, 2 deletions

diff --git a/tntd/Makefile b/tntd/Makefile
index f40a5e2..196c289 100644
--- a/tntd/Makefile
+++ b/tntd/Makefile
@@ -4,7 +4,7 @@ CFLAGS = -g -O2 -Wall -Wmissing-prototypes -Wstrict-prototypes \
 LDFLAGS = -L ../libetp -L ../libtnttk
 LIBS = -letp -ltnttk -lpthread
 
-OBJECTS = main.o tnt.o tntd.o device.o port.o socket.o rpc.o
+OBJECTS = main.o tnt.o tntd.o device.o port.o socket.o rpc.o gc.o
 
 .PHONY: clean
 
diff --git a/tntd/gc.c b/tntd/gc.c
new file mode 100644
index 0000000..7d5ee75
--- /dev/null
+++ b/tntd/gc.c
@@ -0,0 +1,101 @@
+/*
+ * Copyright (C) 2007 Richard Braun <syn@sceen.net>
+ * Copyright (C) 2007 Stefano Bertinetti <ildoctor@ildoctor.net>
+ *
+ * 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 2 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, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#include <time.h>
+#include <errno.h>
+#include <stdlib.h>
+#include <pthread.h>
+#include <sys/time.h>
+
+#include <tnttk/cache.h>
+
+#include "gc.h"
+#include "output.h"
+
+#define GC_INTERVAL 10
+
+static pthread_t gc_thread;
+
+static pthread_mutex_t gc_mutex;
+
+static pthread_cond_t gc_cond;
+
+static int gc_stop;
+
+static void *
+gc_run(void *arg)
+{
+  struct timespec timeout;
+  struct timeval now;
+  int error;
+
+  output("garbage collector thread running...");
+
+  pthread_mutex_lock(&gc_mutex);
+
+  do
+    {
+      gettimeofday(&now, NULL);
+      timeout.tv_sec = now.tv_sec + GC_INTERVAL;
+      timeout.tv_nsec = now.tv_usec * 1000;
+      error = 0;
+
+      while (!gc_stop && (error != ETIMEDOUT))
+        error = pthread_cond_timedwait(&gc_cond, &gc_mutex, &timeout);
+
+      if (gc_stop)
+        break;
+
+      slab_reclaim();
+    }
+  while (1);
+
+  pthread_mutex_unlock(&gc_mutex);
+
+  output("garbage collector thread stopping...");
+  return NULL;
+}
+
+void
+gc_terminate(void)
+{
+  pthread_mutex_lock(&gc_mutex);
+  gc_stop = 1;
+  pthread_cond_signal(&gc_cond);
+  pthread_mutex_unlock(&gc_mutex);
+  pthread_join(gc_thread, NULL);
+}
+
+void
+gc_init(void)
+{
+  int error;
+
+  pthread_mutex_init(&gc_mutex, NULL);
+  pthread_cond_init(&gc_cond, NULL);
+  gc_stop = 0;
+  error = pthread_create(&gc_thread, NULL, gc_run, NULL);
+
+  if (error)
+    {
+      output_error("unable to start garbage collector thread, error = %d",
+                   error);
+      exit(1);
+    }
+}
diff --git a/tntd/gc.h b/tntd/gc.h
new file mode 100644
index 0000000..31e5f31
--- /dev/null
+++ b/tntd/gc.h
@@ -0,0 +1,26 @@
+/*
+ * Copyright (C) 2007 Richard Braun <syn@sceen.net>
+ * Copyright (C) 2007 Stefano Bertinetti <ildoctor@ildoctor.net>
+ *
+ * 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 2 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, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#ifndef _GC_H
+#define _GC_H
+
+void gc_terminate(void);
+void gc_init(void);
+
+#endif /* _GC_H */
diff --git a/tntd/main.c b/tntd/main.c
index 9b9e42d..3f7b49d 100644
--- a/tntd/main.c
+++ b/tntd/main.c
@@ -30,6 +30,7 @@
 
 #include <tnttk/cache.h>
 
+#include "gc.h"
 #include "ip.h"
 #include "rpc.h"
 #include "port.h"
@@ -74,7 +75,7 @@ main(int argc, char *argv[])
   if (raw_sd == -1)
     {
       perror("unable to create socket");
-      exit(1);
+      return EXIT_FAILURE;
     }
 
   error = getifaddrs(&ifaddrs);
@@ -91,6 +92,7 @@ main(int argc, char *argv[])
   port_init();
   socket_init();
   rpc_init();
+  gc_init();
 
   ip_packet = malloc(buffer_size);
 
@@ -144,10 +146,12 @@ main(int argc, char *argv[])
 
   output("daemon shutting down...");
   free(ip_packet);
+  gc_terminate();
   rpc_terminate();
   socket_terminate();
   port_terminate();
   device_terminate();
+  slab_terminate();
   output("threads and caches destroyed, daemon exiting...");
   return EXIT_SUCCESS;
 }