Add zookeeper watch

src/core/client_config/resolvers/zookeeper_resolver.c

@@ -49,8 +49,6 @@
 
 /** Zookeeper session expiration time in milliseconds */
 #define GRPC_ZOOKEEPER_SESSION_TIMEOUT 15000
-/** Set zookeeper watch */
-#define GRPC_ZOOKEEPER_WATCH 1
 
 typedef struct {
   /** base class: must be first */
@@ -86,7 +84,7 @@ typedef struct {
   grpc_resolved_addresses *resolved_addrs;
   /** total number of addresses to be resolved */
   int resolved_total;
-  /** resolved number of addresses */
+  /** number of addresses resolved */
   int resolved_num;
 } zookeeper_resolver;
 
@@ -132,6 +130,7 @@ static void zookeeper_next(grpc_resolver *resolver,
                            grpc_client_config **target_config,
                            grpc_iomgr_closure *on_complete) {
   zookeeper_resolver *r = (zookeeper_resolver *)resolver;
+  gpr_log(GPR_INFO, "zookeeper_next");
   gpr_mu_lock(&r->mu);
   GPR_ASSERT(r->next_completion == NULL);
   r->next_completion = on_complete;
@@ -144,6 +143,34 @@ static void zookeeper_next(grpc_resolver *resolver,
   gpr_mu_unlock(&r->mu);
 }
 
+/** Zookeeper global watcher for connection management */
+static void zookeeper_global_watcher(zhandle_t *zookeeper_handle, int type, int state,
+                              const char *path, void *watcher_ctx) {
+  if (type == ZOO_SESSION_EVENT) {
+    if (state == ZOO_EXPIRED_SESSION_STATE) {
+      gpr_log(GPR_ERROR, "Zookeeper session expired");
+    } else if (state == ZOO_AUTH_FAILED_STATE) {
+      gpr_log(GPR_ERROR, "Zookeeper authentication failed");
+    }
+  }
+}
+
+/** Zookeeper watcher for handling updates to watched nodes */
+static void zookeeper_watcher(zhandle_t *zookeeper_handle, int type, int state,
+                              const char *path, void *watcher_ctx) {
+  if (watcher_ctx != NULL) {
+    zookeeper_resolver *r = (zookeeper_resolver *)watcher_ctx;
+    gpr_log(GPR_INFO, "tpye = %d, state = %d", type, state);
+    if (state == ZOO_CONNECTED_STATE){
+      gpr_mu_lock(&r->mu);
+      if (r->resolving == 0) {
+        zookeeper_start_resolving_locked(r);
+      }
+      gpr_mu_unlock(&r->mu);
+    }
+  } 
+}
+
 static void zookeeper_on_resolved(void *arg,
                                   grpc_resolved_addresses *addresses) {
   zookeeper_resolver *r = arg;
@@ -272,6 +299,7 @@ static void zookeeper_get_children_node_completion(int rc, const char *value,
   gpr_free(buffer);
   if (address != NULL) {
     /** Further resolve address by DNS */
+    gpr_log(GPR_INFO, address);
     grpc_resolve_address(address, NULL, zookeeper_dns_resolved, r);
     gpr_free(address);
   } else {
@@ -315,8 +343,7 @@ static void zookeeper_get_children_completion(
     strcat(path, r->name);
     strcat(path, "/");
     strcat(path, children->data[i]);
-    status = zoo_aget(r->zookeeper_handle, path, GRPC_ZOOKEEPER_WATCH,
-                      zookeeper_get_children_node_completion, r);
+    status = zoo_awget(r->zookeeper_handle, path, zookeeper_watcher, r, zookeeper_get_children_node_completion, r);
     gpr_free(path);
     if (status != 0) {
       gpr_log(GPR_ERROR, "Error in getting zookeeper node %s", path);
@@ -332,7 +359,6 @@ static void zookeeper_get_node_completion(int rc, const char *value,
   char *address = NULL;
   char *buffer = NULL;
   zookeeper_resolver *r = (zookeeper_resolver *)arg;
-
   r->resolved_addrs = NULL;
   r->resolved_total = 0;
   r->resolved_num = 0;
@@ -342,13 +368,13 @@ static void zookeeper_get_node_completion(int rc, const char *value,
     return;
   }
 
-  /** If zookeeper node of path r->name does not have address 
-      (i.e. service node), get its children */
+  /** If zookeeper node of path r->name does not have address (i.e. service node), get its children */
   buffer = gpr_malloc(value_len);
   memcpy(buffer, value, value_len);
   address = zookeeper_parse_address(buffer, value_len);
   gpr_free(buffer);
   if (address != NULL) {
+    gpr_log(GPR_INFO, address);
     r->resolved_addrs = gpr_malloc(sizeof(grpc_resolved_addresses));
     r->resolved_addrs->addrs = NULL;
     r->resolved_addrs->naddrs = 0;
@@ -359,8 +385,7 @@ static void zookeeper_get_node_completion(int rc, const char *value,
     return;
   }
 
-  status = zoo_aget_children(r->zookeeper_handle, r->name, GRPC_ZOOKEEPER_WATCH,
-                             zookeeper_get_children_completion, r);
+  status = zoo_awget_children(r->zookeeper_handle, r->name, zookeeper_watcher, r, zookeeper_get_children_completion, r);
   if (status != 0) {
     gpr_log(GPR_ERROR, "Error in getting zookeeper children of %s", r->name);
   }
@@ -368,8 +393,7 @@ static void zookeeper_get_node_completion(int rc, const char *value,
 
 static void zookeeper_resolve_address(zookeeper_resolver *r) {
   int status;
-  status = zoo_aget(r->zookeeper_handle, r->name, GRPC_ZOOKEEPER_WATCH,
-                    zookeeper_get_node_completion, r);
+  status = zoo_awget(r->zookeeper_handle, r->name, zookeeper_watcher, r, zookeeper_get_node_completion, r);
   if (status != 0) {
     gpr_log(GPR_ERROR, "Error in getting zookeeper node %s", r->name);
   }
@@ -379,7 +403,7 @@ static void zookeeper_start_resolving_locked(zookeeper_resolver *r) {
   GRPC_RESOLVER_REF(&r->base, "zookeeper-resolving");
   GPR_ASSERT(r->resolving == 0);
   r->resolving = 1;
-
+  gpr_log(GPR_INFO, "zookeeper_start_resolving_locked");
   zookeeper_resolve_address(r);
 }
 
@@ -407,12 +431,6 @@ static void zookeeper_destroy(grpc_resolver *gr) {
   gpr_free(r);
 }
 
-/** Zookeeper watcher function - handle updates to any watched nodes */
-static void zookeeper_watcher(zhandle_t *zookeeper_handle, int type, int state,
-                              const char *path, void *watcher_ctx) {
-
-}
-
 static grpc_resolver *zookeeper_create(
     grpc_uri *uri,
     grpc_lb_policy *(*lb_policy_factory)(grpc_subchannel **subchannels,
@@ -440,7 +458,7 @@ static grpc_resolver *zookeeper_create(
 
   /** Initialize zookeeper client */
   zoo_set_debug_level(ZOO_LOG_LEVEL_WARN);
-  r->zookeeper_handle = zookeeper_init(uri->authority, zookeeper_watcher,
+  r->zookeeper_handle = zookeeper_init(uri->authority, zookeeper_global_watcher,
                                        GRPC_ZOOKEEPER_SESSION_TIMEOUT, 0, 0, 0);
   if (r->zookeeper_handle == NULL) {
     gpr_log(GPR_ERROR, "Unable to connect to zookeeper server");