0
@@ -69,6 +69,17 @@
0
 
0
   * Explicitly compare against NULL or zero in many places.
0
 
0
+2007-03-05
0
+	* Steven Grimm <sgrimm@facebook.com>: Per-object-type stats collection
0
+	  support. Specify the object type delimiter with the -D command line
0
+	  option. Turn stats gathering on and off with "stats detail on" and
0
+	  "stats detail off". Dump the per-object-type details with
0
+	  "stats detail dump".
0
+
0
+2007-03-01
0
+	* Steven Grimm <sgrimm@facebook.com>: Fix an off-by-one error in the
0
+	  multithreaded version's message passing code.
0
+
0
 2006-12-23
0
   * fix expirations of items set with absolute expiration times in
0
     the past, before the server's start time.  bug was introduced in
0
@@ -97,10 +108,20 @@
0
   * Steve Peters <steve@fisharerojo.org>: OpenBSD has a malloc.h,
0
   but warns to use stdlib.h instead
0
 
0
+2006-11-22
0
+	* Steven Grimm <sgrimm@facebook.com>: Add support for multithreaded
0
+	  execution. Run configure with "--enable-threads" to enable. See
0
+	  doc/threads.txt for details.
0
+
0
 2006-11-13
0
   * Iain Wade <iwade@optusnet.com.au>: Fix for UDP responses on non-"get"
0
    commands.
0
 
0
+2006-10-15
0
+	* Steven Grimm <sgrimm@facebook.com>: Dynamic sizing of hashtable to
0
+	  reduce collisions on very large caches and conserve memory on
0
+	  small caches.
0
+
0
 2006-10-13
0
   * Steven Grimm <sgrimm@facebook.com>: New faster hash function.
0
 

0
@@ -1,6 +1,6 @@
0
 bin_PROGRAMS = memcached memcached-debug
0
 
0
-memcached_SOURCES = memcached.c slabs.c slabs.h items.c items.h assoc.c assoc.h memcached.h 
0
+memcached_SOURCES = memcached.c slabs.c slabs.h items.c items.h assoc.c assoc.h memcached.h thread.c stats.c stats.h
0
 memcached_debug_SOURCES = $(memcached_SOURCES)
0
 memcached_CPPFLAGS = -DNDEBUG
0
 memcached_LDADD = @LIBOBJS@

0
@@ -12,10 +12,9 @@
0
  *
0
  * $Id$
0
  */
0
-#include "config.h"
0
-#include <sys/types.h>
0
+
0
+#include "memcached.h"
0
 #include <sys/stat.h>
0
-#include <sys/time.h>
0
 #include <sys/socket.h>
0
 #include <sys/signal.h>
0
 #include <sys/resource.h>
0
@@ -24,13 +23,9 @@
0
 #include <stdio.h>
0
 #include <string.h>
0
 #include <unistd.h>
0
-#include <netinet/in.h>
0
 #include <errno.h>
0
-#include <event.h>
0
 #include <assert.h>
0
 
0
-#include "memcached.h"
0
-
0
 /*
0
  * Since the hash function does bit manipulation, it needs to know
0
  * whether it's big or little-endian. ENDIAN_LITTLE and ENDIAN_BIG
0
@@ -142,7 +137,7 @@ and these came close:
0
 }
0
 
0
 #if HASH_LITTLE_ENDIAN == 1
0
-static uint32_t hash(
0
+uint32_t hash(
0
   const void *key,       /* the key to hash */
0
   size_t      length,    /* length of the key */
0
   const uint32_t    initval)   /* initval */
0
@@ -323,7 +318,7 @@ static uint32_t hash(
0
  * from hashlittle() on all machines.  hashbig() takes advantage of
0
  * big-endian byte ordering.
0
  */
0
-static uint32_t hash( const void *key, size_t length, const uint32_t initval)
0
+uint32_t hash( const void *key, size_t length, const uint32_t initval)
0
 {
0
   uint32_t a,b,c;
0
   union { const void *ptr; size_t i; } u; /* to cast key to (size_t) happily */
0
@@ -541,39 +536,41 @@ static void assoc_expand(void) {
0
 
0
     primary_hashtable = calloc(hashsize(hashpower + 1), sizeof(void *));
0
     if (primary_hashtable) {
0
-    if (settings.verbose > 1)
0
-        fprintf(stderr, "Hash table expansion starting\n");
0
+        if (settings.verbose > 1)
0
+            fprintf(stderr, "Hash table expansion starting\n");
0
         hashpower++;
0
         expanding = 1;
0
         expand_bucket = 0;
0
-    assoc_move_next_bucket();
0
+        do_assoc_move_next_bucket();
0
     } else {
0
         primary_hashtable = old_hashtable;
0
-    /* Bad news, but we can keep running. */
0
+        /* Bad news, but we can keep running. */
0
     }
0
 }
0
 
0
 /* migrates the next bucket to the primary hashtable if we're expanding. */
0
-void assoc_move_next_bucket(void) {
0
+void do_assoc_move_next_bucket(void) {
0
     item *it, *next;
0
     int bucket;
0
 
0
     if (expanding) {
0
         for (it = old_hashtable[expand_bucket]; NULL != it; it = next) {
0
-        next = it->h_next;
0
+            next = it->h_next;
0
 
0
             bucket = hash(ITEM_key(it), it->nkey, 0) & hashmask(hashpower);
0
             it->h_next = primary_hashtable[bucket];
0
             primary_hashtable[bucket] = it;
0
-    }
0
+        }
0
 
0
-    expand_bucket++;
0
-    if (expand_bucket == hashsize(hashpower - 1)) {
0
-        expanding = 0;
0
-        free(old_hashtable);
0
-        if (settings.verbose > 1)
0
-            fprintf(stderr, "Hash table expansion done\n");
0
-    }
0
+        old_hashtable[expand_bucket] = NULL;
0
+
0
+        expand_bucket++;
0
+        if (expand_bucket == hashsize(hashpower - 1)) {
0
+            expanding = 0;
0
+            free(old_hashtable);
0
+            if (settings.verbose > 1)
0
+                fprintf(stderr, "Hash table expansion done\n");
0
+        }
0
     }
0
 }
0
 

0
@@ -3,4 +3,5 @@ void assoc_init(void);
0
 item *assoc_find(const char *key, const size_t nkey);
0
 int assoc_insert(item *item);
0
 void assoc_delete(const char *key, const size_t nkey);
0
-void assoc_move_next_bucket(void);
0
+void do_assoc_move_next_bucket(void);
0
+uint32_t hash( const void *key, size_t length, const uint32_t initval);

0
@@ -94,6 +94,7 @@ dnl ----------------------------------------------------------------------------
0
 AC_SEARCH_LIBS(socket, socket)
0
 AC_SEARCH_LIBS(gethostbyname, nsl)
0
 AC_SEARCH_LIBS(mallinfo, malloc)
0
+AC_SEARCH_LIBS(pthread_create, pthread)
0
 
0
 AC_CHECK_FUNC(daemon,AC_DEFINE([HAVE_DAEMON],,[Define this if you have daemon()]),[AC_LIBOBJ(daemon)])
0
 
0
@@ -156,6 +157,15 @@ fi
0
 
0
 AC_C_ENDIAN
0
 
0
+dnl Check whether the user wants threads or not
0
+AC_ARG_ENABLE(threads,
0
+  [AS_HELP_STRING([--enable-threads],[support multithreaded execution])],
0
+  [if test "$ac_cv_search_pthread_create" != "no"; then
0
+    AC_DEFINE([USE_THREADS],,[Define this if you want to use pthreads])
0
+   else
0
+    AC_MSG_ERROR([Can't enable threads without the POSIX thread library.])
0
+   fi])
0
+
0
 AC_CHECK_FUNCS(mlockall)
0
 
0
 AC_CONFIG_FILES(Makefile doc/Makefile)

0
@@ -84,6 +84,18 @@ Print memcached and libevent licenses.
0
 .TP
0
 .B \-P <filename>
0
 Print pidfile to <filename>, only used under -d option.
0
+.TP
0
+.B \-t <threads>
0
+Number of threads to use to process incoming requests. This option is only
0
+meaningful if memcached was compiled with thread support enabled. It is 
0
+typically not useful to set this higher than the number of CPU cores on the
0
+memcached server.
0
+.TP
0
+.B \-D <char>
0
+Use <char> as the delimiter between key prefixes and IDs. This is used for
0
+per-prefix stats reporting. The default is ":" (colon). If this option is
0
+specified, stats collection is turned on automatically; if not, then it may
0
+be turned on by sending the "stats detail on" command to the server.
0
 .br
0
 .SH LICENSE
0
 The memcached daemon is copyright Danga Interactive and is distributed under 

0
@@ -1,8 +1,7 @@
0
 /* -*- Mode: C; tab-width: 4; c-basic-offset: 4; indent-tabs-mode: nil -*- */
0
 /* $Id$ */
0
-#include <sys/types.h>
0
+#include "memcached.h"
0
 #include <sys/stat.h>
0
-#include <sys/time.h>
0
 #include <sys/socket.h>
0
 #include <sys/signal.h>
0
 #include <sys/resource.h>
0
@@ -11,14 +10,10 @@
0
 #include <stdio.h>
0
 #include <string.h>
0
 #include <unistd.h>
0
-#include <netinet/in.h>
0
 #include <errno.h>
0
 #include <time.h>
0
-#include <event.h>
0
 #include <assert.h>
0
 
0
-#include "memcached.h"
0
-
0
 /* Forward Declarations */
0
 static void item_link_q(item *it);
0
 static void item_unlink_q(item *it);
0
@@ -44,6 +39,17 @@ void item_init(void) {
0
     }
0
 }
0
 
0
+/* Enable this for reference-count debugging. */
0
+#if 0
0
+# define DEBUG_REFCNT(it,op) \
0
+                fprintf(stderr, "item %x refcnt(%c) %d %c%c%c\n", \
0
+                        it, op, it->refcount, \
0
+                        (it->it_flags & ITEM_LINKED) ? 'L' : ' ', \
0
+                        (it->it_flags & ITEM_SLABBED) ? 'S' : ' ', \
0
+                        (it->it_flags & ITEM_DELETED) ? 'D' : ' ')
0
+#else
0
+# define DEBUG_REFCNT(it,op) while(0)
0
+#endif
0
 
0
 /*
0
  * Generates the variable-sized part of the header for an object.
0
@@ -65,7 +71,7 @@ static size_t item_make_header(const uint8_t nkey, const int flags, const int nb
0
 }
0
 
0
 /*@null@*/
0
-item *item_alloc(char *key, const size_t nkey, const int flags, const rel_time_t exptime, const int nbytes) {
0
+item *do_item_alloc(char *key, const size_t nkey, const int flags, const rel_time_t exptime, const int nbytes) {
0
     uint8_t nsuffix;
0
     item *it;
0
     char suffix[40];
0
@@ -98,9 +104,12 @@ item *item_alloc(char *key, const size_t nkey, const int flags, const rel_time_t
0
 
0
         for (search = tails[id]; tries > 0 && search != NULL; tries--, search=search->prev) {
0
             if (search->refcount == 0) {
0
-               if (search->exptime > current_time)
0
+               if (search->exptime > current_time) {
0
+                       STATS_LOCK();
0
                        stats.evictions++;
0
-                item_unlink(search);
0
+                       STATS_UNLOCK();
0
+                }
0
+                do_item_unlink(search);
0
                 break;
0
             }
0
         }
0
@@ -115,7 +124,8 @@ item *item_alloc(char *key, const size_t nkey, const int flags, const rel_time_t
0
     assert(it != heads[it->slabs_clsid]);
0
 
0
     it->next = it->prev = it->h_next = 0;
0
-    it->refcount = 0;
0
+    it->refcount = 1;     /* the caller will have a reference */
0
+    DEBUG_REFCNT(it, '*');
0
     it->it_flags = 0;
0
     it->nkey = nkey;
0
     it->nbytes = nbytes;
0
@@ -136,6 +146,7 @@ void item_free(item *it) {
0
     /* so slab size changer can tell later if item is already free or not */
0
     it->slabs_clsid = 0;
0
     it->it_flags |= ITEM_SLABBED;
0
+    DEBUG_REFCNT(it, 'F');
0
     slabs_free(it, ntotal);
0
 }
0
 
0
@@ -192,57 +203,66 @@ static void item_unlink_q(item *it) {
0
     return;
0
 }
0
 
0
-int item_link(item *it) {
0
+int do_item_link(item *it) {
0
     assert((it->it_flags & (ITEM_LINKED|ITEM_SLABBED)) == 0);
0
     assert(it->nbytes < 1048576);
0
     it->it_flags |= ITEM_LINKED;
0
     it->time = current_time;
0
     assoc_insert(it);
0
 
0
+    STATS_LOCK();
0
     stats.curr_bytes += ITEM_ntotal(it);
0
     stats.curr_items += 1;
0
     stats.total_items += 1;
0
+    STATS_UNLOCK();
0
 
0
     item_link_q(it);
0
 
0
     return 1;
0
 }
0
 
0
-void item_unlink(item *it) {
0
+void do_item_unlink(item *it) {
0
     if ((it->it_flags & ITEM_LINKED) != 0) {
0
         it->it_flags &= ~ITEM_LINKED;
0
+        STATS_LOCK();
0
         stats.curr_bytes -= ITEM_ntotal(it);
0
         stats.curr_items -= 1;
0
+        STATS_UNLOCK();
0
         assoc_delete(ITEM_key(it), it->nkey);
0
         item_unlink_q(it);
0
+        if (it->refcount == 0) item_free(it);
0
     }
0
-    if (it->refcount == 0) item_free(it);
0
 }
0
 
0
-void item_remove(item *it) {
0
+void do_item_remove(item *it) {
0
     assert((it->it_flags & ITEM_SLABBED) == 0);
0
-    if (it->refcount != 0) it->refcount--;
0
+    if (it->refcount != 0) {
0
+        it->refcount--;
0
+        DEBUG_REFCNT(it, '-');
0
+    }
0
     assert((it->it_flags & ITEM_DELETED) == 0 || it->refcount != 0);
0
     if (it->refcount == 0 && (it->it_flags & ITEM_LINKED) == 0) {
0
         item_free(it);
0
     }
0
 }
0
 
0
-void item_update(item *it) {
0
+void do_item_update(item *it) {
0
     if (it->time < current_time - ITEM_UPDATE_INTERVAL) {
0
         assert((it->it_flags & ITEM_SLABBED) == 0);
0
 
0
-        item_unlink_q(it);
0
-        it->time = current_time;
0
-        item_link_q(it);
0
+        if (it->it_flags & ITEM_LINKED) {
0
+            item_unlink_q(it);
0
+            it->time = current_time;
0
+            item_link_q(it);
0
+        }
0
     }
0
 }
0
 
0
-int item_replace(item *it, item *new_it) {
0
+int do_item_replace(item *it, item *new_it) {
0
     assert((it->it_flags & ITEM_SLABBED) == 0);
0
 
0
-    item_unlink(it);
0
-    return item_link(new_it);
0
+    do_item_unlink(it);
0
+    return do_item_link(new_it);
0
 }
0
 
0
 /*@null@*/
0
@@ -337,8 +357,59 @@ char* item_stats_sizes(int *bytes) {
0
     return buf;
0
 }
0
 
0
+/* returns true if a deleted item's delete-locked-time is over, and it
0
+   should be removed from the namespace */
0
+int item_delete_lock_over (item *it) {
0
+    assert(it->it_flags & ITEM_DELETED);
0
+    return (current_time >= it->exptime);
0
+}
0
+
0
+/* wrapper around assoc_find which does the lazy expiration/deletion logic */
0
+item *do_item_get_notedeleted(char *key, size_t nkey, int *delete_locked) {
0
+    item *it = assoc_find(key, nkey);
0
+    if (delete_locked) *delete_locked = 0;
0
+    if (it && (it->it_flags & ITEM_DELETED)) {
0
+        /* it's flagged as delete-locked.  let's see if that condition
0
+           is past due, and the 5-second delete_timer just hasn't
0
+           gotten to it yet... */
0
+        if (! item_delete_lock_over(it)) {
0
+            if (delete_locked) *delete_locked = 1;
0
+            it = 0;
0
+        }
0
+    }
0
+    if (it && settings.oldest_live && settings.oldest_live <= current_time &&
0
+        it->time <= settings.oldest_live) {
0
+        do_item_unlink(it);           // MTSAFE - cache_lock held
0
+        it = 0;
0
+    }
0
+    if (it && it->exptime && it->exptime <= current_time) {
0
+        do_item_unlink(it);           // MTSAFE - cache_lock held
0
+        it = 0;
0
+    }
0
+
0
+    if (it) {
0
+        it->refcount++;
0
+        DEBUG_REFCNT(it, '+');
0
+    }
0
+    return it;
0
+}
0
+
0
+item *item_get(char *key, size_t nkey) {
0
+    return item_get_notedeleted(key, nkey, 0);
0
+}
0
+
0
+/* returns an item whether or not it's delete-locked or expired. */
0
+item *do_item_get_nocheck(char *key, size_t nkey) {
0
+    item *it = assoc_find(key, nkey);
0
+    if (it) {
0
+        it->refcount++;
0
+        DEBUG_REFCNT(it, '+');
0
+    }
0
+    return it;
0
+}
0
+
0
 /* expires items that are more recent than the oldest_live setting. */
0
-void item_flush_expired(void) {
0
+void do_item_flush_expired(void) {
0
     int i;
0
     item *iter, *next;
0
     if (settings.oldest_live == 0)
0
@@ -353,7 +424,7 @@ void item_flush_expired(void) {
0
             if (iter->time >= settings.oldest_live) {
0
                 next = iter->next;
0
                 if ((iter->it_flags & ITEM_SLABBED) == 0) {
0
-                    item_unlink(iter);
0
+                    do_item_unlink(iter);
0
                 }
0
             } else {
0
                 /* We've hit the first old item. Continue to the next queue. */

0
@@ -1,15 +1,15 @@
0
 /* See items.c */
0
 void item_init(void);
0
 /*@null@*/
0
-item *item_alloc(char *key, const size_t nkey, const int flags, const rel_time_t exptime, const int nbytes);
0
+item *do_item_alloc(char *key, const size_t nkey, const int flags, const rel_time_t exptime, const int nbytes);
0
 void item_free(item *it);
0
 bool item_size_ok(const size_t nkey, const int flags, const int nbytes);
0
 
0
-int item_link(item *it);    /* may fail if transgresses limits */
0
-void item_unlink(item *it);
0
-void item_remove(item *it);
0
-void item_update(item *it);   /* update LRU time to current and reposition */
0
-int item_replace(item *it, item *new_it);
0
+int  do_item_link(item *it);     /* may fail if transgresses limits */
0
+void do_item_unlink(item *it);
0
+void do_item_remove(item *it);
0
+void do_item_update(item *it);   /* update LRU time to current and reposition */
0
+int  do_item_replace(item *it, item *new_it);
0
 
0
 /*@null@*/
0
 char *item_cachedump(const unsigned int slabs_clsid, const unsigned int limit, unsigned int *bytes);
0
@@ -17,4 +17,8 @@ void item_stats(char *buffer, const int buflen);
0
 
0
 /*@null@*/
0
 char *item_stats_sizes(int *bytes);
0
-void item_flush_expired(void);
0
+void do_item_flush_expired(void);
0
+item *item_get(char *key, size_t nkey);
0
+
0
+item *do_item_get_notedeleted(char *key, size_t nkey, int *delete_locked);
0
+item *do_item_get_nocheck(char *key, size_t nkey);