Fix shared cache so that reserve size is always initialized properly.

Also change how we detect if shared cache is used. It used to rely on
a name, now it will be used if the shared_cache configuration option
was included by the user.

7 files changed, 36 insertions, 17 deletions

diff --git a/dist/api_data.py b/dist/api_data.py
index ada6f8a9b32..206a09230c9 100644
--- a/dist/api_data.py
+++ b/dist/api_data.py
@@ -262,8 +262,8 @@ connection_runtime_config = [
 		Config('reserve', '0', r'''
 			amount of cache this database is guaranteed to have available
 			from the shared cache. This setting is per database. Defaults
-			to the chunk size'''),
-		Config('name', '', r'''
+			to the chunk size''', type='int'),
+		Config('name', 'pool', r'''
 			name of a cache that is shared between databases'''),
 		Config('size', '500MB', r'''
 			maximum memory to allocate for the shared cache. Setting this
diff --git a/src/config/config_def.c b/src/config/config_def.c
index 6ff187ab824..a5c1345d0a9 100644
--- a/src/config/config_def.c
+++ b/src/config/config_def.c
@@ -86,13 +86,13 @@ const char *
 __wt_confdfl_connection_reconfigure =
 	"cache_size=100MB,error_prefix=,eviction_dirty_target=80,"
 	"eviction_target=80,eviction_trigger=95,shared_cache=(chunk=10MB,"
-	"name=,reserve=0,size=500MB),verbose=";
+	"name=pool,reserve=0,size=500MB),verbose=";
 
 WT_CONFIG_CHECK
 __wt_confchk_shared_cache_subconfigs[] = {
 	{ "chunk", "int", "min=1MB,max=10TB", NULL },
 	{ "name", "string", NULL, NULL },
-	{ "reserve", "string", NULL, NULL },
+	{ "reserve", "int", NULL, NULL },
 	{ "size", "int", "min=1MB,max=10TB", NULL },
 	{ NULL, NULL, NULL, NULL }
 };
@@ -426,9 +426,9 @@ __wt_confdfl_wiredtiger_open =
 	"buffer_alignment=-1,cache_size=100MB,create=0,direct_io=,"
 	"error_prefix=,eviction_dirty_target=80,eviction_target=80,"
 	"eviction_trigger=95,extensions=,hazard_max=1000,logging=0,lsm_merge="
-	",mmap=,multiprocess=0,session_max=50,shared_cache=(chunk=10MB,name=,"
-	"reserve=0,size=500MB),sync=,transactional=,use_environment_priv=0,"
-	"verbose=";
+	",mmap=,multiprocess=0,session_max=50,shared_cache=(chunk=10MB,"
+	"name=pool,reserve=0,size=500MB),sync=,transactional=,"
+	"use_environment_priv=0,verbose=";
 
 WT_CONFIG_CHECK
 __wt_confchk_wiredtiger_open[] = {
diff --git a/src/conn/conn_cache.c b/src/conn/conn_cache.c
index f20538a2354..8e256582a5a 100644
--- a/src/conn/conn_cache.c
+++ b/src/conn/conn_cache.c
@@ -32,7 +32,7 @@ __wt_cache_config(WT_CONNECTION_IMPL *conn, const char *cfg[])
 
 	if (F_ISSET(conn, WT_CONN_CACHE_POOL) &&
 	    (ret = __wt_config_gets(session, cfg,
-	    "shared_cache.reserve", &cval)) == 0)
+	    "shared_cache.reserve", &cval)) == 0 && cval.val != 0)
 		cache->cp_reserved = (uint64_t)cval.val;
 	else if ((ret = __wt_config_gets(session, cfg,
 	    "shared_cache.chunk", &cval)) == 0)
diff --git a/src/conn/conn_cache_pool.c b/src/conn/conn_cache_pool.c
index 76ea6914c17..bb045065c1b 100644
--- a/src/conn/conn_cache_pool.c
+++ b/src/conn/conn_cache_pool.c
@@ -47,10 +47,12 @@ __wt_conn_cache_pool_config(WT_SESSION_IMPL *session, const char **cfg)
 	if (F_ISSET(conn, WT_CONN_CACHE_POOL))
 		reconfiguring = 1;
 	else {
+		/* Only setup if a shared cache was explicitly configured. */
+		if (__wt_config_gets(session, WT_SKIP_DEFAULT_CONFIG(cfg),
+		    "shared_cache", &cval) == WT_NOTFOUND)
+			return (0);
 		WT_RET_NOTFOUND_OK(
 		    __wt_config_gets(session, cfg, "shared_cache.name", &cval));
-		if (cval.len == 0)
-			return (0);
 		/*
 		 * NOTE: The allocations made when configuring and opening a
 		 * cache pool don't really belong to the connection that
diff --git a/src/include/misc.h b/src/include/misc.h
index e42620b1d5f..3d0d8d3edd6 100644
--- a/src/include/misc.h
+++ b/src/include/misc.h
@@ -165,6 +165,13 @@
 #define	WT_DECL_RET	int ret = 0
 
 /*
+ * Skip the default configuration string in an list of configurations. The
+ * default config is always the first entry in the array, and the array always
+ * has an explicit NULL terminator, so this is safe.
+ */
+#define WT_SKIP_DEFAULT_CONFIG(c) &(c)[1]
+
+/*
  * In diagnostic mode we track the locations from which hazard pointers and
  * scratch buffers were acquired.
  */
diff --git a/src/include/wiredtiger.in b/src/include/wiredtiger.in
index db62acb6871..51d1df3a5b4 100644
--- a/src/include/wiredtiger.in
+++ b/src/include/wiredtiger.in
@@ -1053,10 +1053,10 @@ struct __wt_connection {
 	 * shared cache is redistributed.,an integer between 1MB and 10TB;
 	 * default \c 10MB.}@config{    reserve, amount of
 	 * cache this database is guaranteed to have available from the shared
-	 * cache. This setting is per database. Defaults to the chunk size.,a
-	 * string; default \c 0.}@config{    name, name of a
-	 * cache that is shared between databases.,a string; default
-	 * empty.}@config{    size, maximum memory to
+	 * cache. This setting is per database. Defaults to the chunk size.,an
+	 * integer; default \c 0.}@config{    name, name of
+	 * a cache that is shared between databases.,a string; default \c
+	 * pool.}@config{    size, maximum memory to
 	 * allocate for the shared cache. Setting this will update the value if
 	 * one is already set.,an integer between 1MB and 10TB; default \c
 	 * 500MB.}@config{ ),,}
@@ -1266,10 +1266,10 @@ struct __wt_connection {
  * cache is redistributed.,an integer between 1MB and 10TB; default \c
  * 10MB.}@config{    reserve, amount of cache this database
  * is guaranteed to have available from the shared cache. This setting is per
- * database. Defaults to the chunk size.,a string; default \c
+ * database. Defaults to the chunk size.,an integer; default \c
  * 0.}@config{    name, name of a cache that is shared
- * between databases.,a string; default
- * empty.}@config{    size, maximum memory to allocate for
+ * between databases.,a string; default \c
+ * pool.}@config{    size, maximum memory to allocate for
  * the shared cache. Setting this will update the value if one is already
  * set.,an integer between 1MB and 10TB; default \c 500MB.}@config{ ),,}
  * @config{sync, flush files to stable storage when closing or writing
diff --git a/test/suite/test_shared_cache.py b/test/suite/test_shared_cache.py
index cb1edc46ded..7bf54432e3a 100644
--- a/test/suite/test_shared_cache.py
+++ b/test/suite/test_shared_cache.py
@@ -209,5 +209,15 @@ class test_shared_cache(wttest.WiredTigerTestCase):
         connection.reconfigure("shared_cache=(size=300M)")
         self.closeConnections()
 
+    # Test default config values
+    def test_shared_cache11(self):
+        nops = 1000
+        self.openConnections(['WT_TEST1', 'WT_TEST2'], pool_opts=',shared_cache=()')
+
+        for sess in self.sessions:
+            sess.create(self.uri, "key_format=S,value_format=S")
+            self.add_records(sess, 0, nops)
+        self.closeConnections()
+
 if __name__ == '__main__':
     wttest.run()