Optionalize deadline checking

1 files changed, 105 insertions, 0 deletions

diff --git a/src/core/ext/filters/deadline/deadline_filter.h b/src/core/ext/filters/deadline/deadline_filter.h
new file mode 100644
index 0000000000..e1e3f5280b
--- /dev/null
+++ b/src/core/ext/filters/deadline/deadline_filter.h
@@ -0,0 +1,105 @@
+//
+// Copyright 2016, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+//
+
+#ifndef GRPC_CORE_LIB_CHANNEL_DEADLINE_FILTER_H
+#define GRPC_CORE_LIB_CHANNEL_DEADLINE_FILTER_H
+
+#include "src/core/lib/channel/channel_stack.h"
+#include "src/core/lib/iomgr/timer.h"
+
+typedef enum grpc_deadline_timer_state {
+  GRPC_DEADLINE_STATE_INITIAL,
+  GRPC_DEADLINE_STATE_PENDING,
+  GRPC_DEADLINE_STATE_FINISHED
+} grpc_deadline_timer_state;
+
+// State used for filters that enforce call deadlines.
+// Must be the first field in the filter's call_data.
+typedef struct grpc_deadline_state {
+  // We take a reference to the call stack for the timer callback.
+  grpc_call_stack* call_stack;
+  gpr_atm timer_state;
+  grpc_timer timer;
+  grpc_closure timer_callback;
+  // Closure to invoke when the call is complete.
+  // We use this to cancel the timer.
+  grpc_closure on_complete;
+  // The original on_complete closure, which we chain to after our own
+  // closure is invoked.
+  grpc_closure* next_on_complete;
+} grpc_deadline_state;
+
+//
+// NOTE: All of these functions require that the first field in
+// elem->call_data is a grpc_deadline_state.
+//
+
+// assumes elem->call_data is zero'd
+void grpc_deadline_state_init(grpc_exec_ctx* exec_ctx, grpc_call_element* elem,
+                              grpc_call_stack* call_stack);
+void grpc_deadline_state_destroy(grpc_exec_ctx* exec_ctx,
+                                 grpc_call_element* elem);
+
+// Starts the timer with the specified deadline.
+// Should be called from the filter's init_call_elem() method.
+void grpc_deadline_state_start(grpc_exec_ctx* exec_ctx, grpc_call_element* elem,
+                               gpr_timespec deadline);
+
+// Cancels the existing timer and starts a new one with new_deadline.
+//
+// Note: It is generally safe to call this with an earlier deadline
+// value than the current one, but not the reverse.  No checks are done
+// to ensure that the timer callback is not invoked while it is in the
+// process of being reset, which means that attempting to increase the
+// deadline may result in the timer being called twice.
+void grpc_deadline_state_reset(grpc_exec_ctx* exec_ctx, grpc_call_element* elem,
+                               gpr_timespec new_deadline);
+
+// To be called from the client-side filter's start_transport_stream_op()
+// method.  Ensures that the deadline timer is cancelled when the call
+// is completed.
+//
+// Note: It is the caller's responsibility to chain to the next filter if
+// necessary after this function returns.
+void grpc_deadline_state_client_start_transport_stream_op(
+    grpc_exec_ctx* exec_ctx, grpc_call_element* elem,
+    grpc_transport_stream_op* op);
+
+// Should deadline checking be performed (according to channel args)
+bool grpc_deadline_checking_enabled(const grpc_channel_args* args);
+
+// Deadline filters for direct client channels and server channels.
+// Note: Deadlines for non-direct client channels are handled by the
+// client_channel filter.
+extern const grpc_channel_filter grpc_client_deadline_filter;
+extern const grpc_channel_filter grpc_server_deadline_filter;
+
+#endif /* GRPC_CORE_LIB_CHANNEL_DEADLINE_FILTER_H */