From 728d2281e02379abf0d9ca970d63a191ce9b3e01 Mon Sep 17 00:00:00 2001
From: Gregory Burd <greg@basho.com>
Date: Thu, 18 Apr 2013 12:24:49 -0400
Subject: [PATCH] Ensure that we init the shared cache when asking for a cursor
 before asking for a session.

---
 c_src/wterl.c | 61 ++++++++++++++++++++++++++++++++++++---------------
 1 file changed, 43 insertions(+), 18 deletions(-)

diff --git a/c_src/wterl.c b/c_src/wterl.c
index 84d2a2e..fbdb27f 100644
--- a/c_src/wterl.c
+++ b/c_src/wterl.c
@@ -104,6 +104,32 @@ struct wterl_priv_data {
 ASYNC_NIF_INIT(wterl);
 
 
+/**
+ *
+ */
+static int
+__create_new_session_cache(WterlConnHandle *conn_handle, WterlCtx *ctx)
+{
+    /* Create a context for this worker thread to reuse. */
+    enif_mutex_lock(conn_handle->contexts_mutex);
+    if (ctx->session != NULL) {
+        enif_mutex_unlock(conn_handle->contexts_mutex);
+        return 0;
+    }
+
+    WT_CONNECTION *conn = conn_handle->conn;
+    int rc = conn->open_session(conn, NULL, conn_handle->session_config, &ctx->session);
+    if (rc != 0) {
+        enif_mutex_unlock(conn_handle->contexts_mutex);
+        return rc;
+    }
+    ctx->cursors = kh_init(cursors);
+    conn_handle->num_contexts++;
+    enif_mutex_unlock(conn_handle->contexts_mutex);
+
+    return 0;
+}
+
 /**
  * Get the per-worker reusable WT_SESSION for a worker_id.
  */
@@ -111,22 +137,13 @@ static int
 __session_for(WterlConnHandle *conn_handle, unsigned int worker_id, WT_SESSION **session)
 {
     WterlCtx *ctx = &conn_handle->contexts[worker_id];
+    int rc = 0;
+
+    if (ctx->session == NULL)
+        rc = __create_new_session_cache(conn_handle, ctx);
+
     *session = ctx->session;
-    if (*session == NULL) {
-	/* Create a context for this worker thread to reuse. */
-        enif_mutex_lock(conn_handle->contexts_mutex);
-	WT_CONNECTION *conn = conn_handle->conn;
-	int rc = conn->open_session(conn, NULL, conn_handle->session_config, session);
-	if (rc != 0) {
-            enif_mutex_unlock(conn_handle->contexts_mutex);
-	    return rc;
-        }
-	ctx->session = *session;
-	ctx->cursors = kh_init(cursors);
-        conn_handle->num_contexts++;
-        enif_mutex_unlock(conn_handle->contexts_mutex);
-    }
-    return 0;
+    return rc;
 }
 
 /**
@@ -197,8 +214,15 @@ __retain_cursor(WterlConnHandle *conn_handle, unsigned int worker_id, const char
 {
     /* Check to see if we have a cursor open for this uri and if so reuse it. */
     WterlCtx *ctx = &conn_handle->contexts[worker_id];
-    khash_t(cursors) *h = ctx->cursors;
-    khiter_t itr = kh_get(cursors, h, (char *)uri);
+    khash_t(cursors) *h = NULL;
+    khiter_t itr;
+    int rc;
+
+    if (ctx->session == NULL)
+        __create_new_session_cache(conn_handle, ctx); // TODO: check return value
+
+    h = ctx->cursors;
+    itr = kh_get(cursors, h, (char *)uri);
     if (itr != kh_end(h)) {
 	// key exists in hash table, retrieve it
 	*cursor = (WT_CURSOR*)kh_value(h, itr);
@@ -206,7 +230,7 @@ __retain_cursor(WterlConnHandle *conn_handle, unsigned int worker_id, const char
 	// key does not exist in hash table, create and insert one
         enif_mutex_lock(conn_handle->contexts_mutex);
 	WT_SESSION *session = conn_handle->contexts[worker_id].session;
-	int rc = session->open_cursor(session, uri, NULL, "overwrite,raw", cursor);
+	rc = session->open_cursor(session, uri, NULL, "overwrite,raw", cursor);
 	if (rc != 0) {
             enif_mutex_unlock(conn_handle->contexts_mutex);
 	    return rc;
@@ -221,6 +245,7 @@ __retain_cursor(WterlConnHandle *conn_handle, unsigned int worker_id, const char
         memcpy(key, uri, 128);
         int itr_status;
         itr = kh_put(cursors, h, key, &itr_status);
+        //assert(itr != kh_end());
 	kh_value(h, itr) = *cursor;
         enif_mutex_unlock(conn_handle->contexts_mutex);
     }