health_check_using_rpc: use HealthCheckChannel instead of Channel to hc

src/brpc/channel.cpp

@@ -281,15 +281,6 @@ int Channel::Init(butil::EndPoint server_addr_and_port,
     return InitSingle(server_addr_and_port, "", options);
 }
 
-int Channel::Init(SocketId id, const ChannelOptions* options) {
-    GlobalInitializeOrDie();
-    if (InitChannelOptions(options) != 0) {
-        return -1;
-    }
-    _server_id = id;
-    return 0;
-}
-
 int Channel::InitSingle(const butil::EndPoint& server_addr_and_port,
                         const char* raw_server_address,
                         const ChannelOptions* options) {

src/brpc/channel.h

@@ -215,10 +215,6 @@ protected:
                    const char* raw_server_address,
                    const ChannelOptions* options);
 
-    // Init a channel from a known SocketId. Currently it is
-    // used only by health check using rpc.
-    int Init(SocketId id, const ChannelOptions* options);
-
     butil::EndPoint _server_address;
     SocketId _server_id;
     Protocol::SerializeRequest _serialize_request;

src/brpc/socket.cpp

@@ -50,6 +50,7 @@
 #include "brpc/periodic_task.h"
 #include "brpc/channel.h"
 #include "brpc/controller.h"
+#include "brpc/global.h"
 #if defined(OS_MACOSX)
 #include <sys/event.h>
 #endif
@@ -998,6 +999,23 @@ void HealthCheckTask::OnDestroyingTask() {
     delete this;
 }
 
+class HealthCheckChannel : public brpc::Channel {
+public:
+    HealthCheckChannel() {}
+    ~HealthCheckChannel() {}
+
+    int Init(SocketId id, const ChannelOptions* options);
+};
+
+int HealthCheckChannel::Init(SocketId id, const ChannelOptions* options) {
+    brpc::GlobalInitializeOrDie();
+    if (InitChannelOptions(options) != 0) {
+        return -1;
+    }
+    _server_id = id;
+    return 0;
+}
+
 bool HealthCheckTask::OnTriggeringTask(timespec* next_abstime) {
     SocketUniquePtr ptr;
     const int rc = Socket::AddressFailedAsWell(_id, &ptr);
@@ -1050,7 +1068,7 @@ bool HealthCheckTask::OnTriggeringTask(timespec* next_abstime) {
             options.protocol = "http";
             options.max_retry = 0;
             options.timeout_ms = FLAGS_health_check_timeout_ms;
-            brpc::Channel channel;
+            HealthCheckChannel channel;
             if (channel.Init(_id, &options) != 0) {
                 ptr->SetFailed();
                 ++ ptr->_hc_count;

test/brpc_socket_unittest.cpp

@@ -578,7 +578,7 @@ TEST_F(SocketTest, health_check_using_rpc) {
     ASSERT_EQ(0, server.AddService(&hc_service, brpc::SERVER_DOESNT_OWN_SERVICE));
     ASSERT_EQ(0, server.Start("127.0.0.1:7777", NULL));
 
-    for (int i = 0; i < 3; ++i) {
+    for (int i = 0; i < 4; ++i) {
         // although ::connect would succeed, the stall in hc_service makes
         // the health checking rpc fail.
         brpc::Controller cntl;