| /* |
| * |
| * Copyright 2015, 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_IOMGR_TIMER_H |
| #define GRPC_CORE_LIB_IOMGR_TIMER_H |
| |
| #include <grpc/support/port_platform.h> |
| #include <grpc/support/time.h> |
| #include "src/core/lib/iomgr/exec_ctx.h" |
| #include "src/core/lib/iomgr/iomgr.h" |
| |
| typedef struct grpc_timer { |
| gpr_timespec deadline; |
| uint32_t heap_index; /* INVALID_HEAP_INDEX if not in heap */ |
| int triggered; |
| struct grpc_timer *next; |
| struct grpc_timer *prev; |
| grpc_closure closure; |
| } grpc_timer; |
| |
| /* Initialize *timer. When expired or canceled, timer_cb will be called with |
| *timer_cb_arg and error set to indicate if it expired (GRPC_ERROR_NONE) or |
| was canceled (GRPC_ERROR_CANCELLED). timer_cb is guaranteed to be called |
| exactly once, and application code should check the error to determine |
| how it was invoked. The application callback is also responsible for |
| maintaining information about when to free up any user-level state. */ |
| void grpc_timer_init(grpc_exec_ctx *exec_ctx, grpc_timer *timer, |
| gpr_timespec deadline, grpc_iomgr_cb_func timer_cb, |
| void *timer_cb_arg, gpr_timespec now); |
| |
| /* Note that there is no timer destroy function. This is because the |
| timer is a one-time occurrence with a guarantee that the callback will |
| be called exactly once, either at expiration or cancellation. Thus, all |
| the internal timer event management state is destroyed just before |
| that callback is invoked. If the user has additional state associated with |
| the timer, the user is responsible for determining when it is safe to |
| destroy that state. */ |
| |
| /* Cancel an *timer. |
| There are three cases: |
| 1. We normally cancel the timer |
| 2. The timer has already run |
| 3. We can't cancel the timer because it is "in flight". |
| |
| In all of these cases, the cancellation is still considered successful. |
| They are essentially distinguished in that the timer_cb will be run |
| exactly once from either the cancellation (with error GRPC_ERROR_CANCELLED) |
| or from the activation (with error GRPC_ERROR_NONE). |
| |
| Note carefully that the callback function MAY occur in the same callstack |
| as grpc_timer_cancel. It's expected that most timers will be cancelled (their |
| primary use is to implement deadlines), and so this code is optimized such |
| that cancellation costs as little as possible. Making callbacks run inline |
| matches this aim. |
| |
| Requires: cancel() must happen after init() on a given timer */ |
| void grpc_timer_cancel(grpc_exec_ctx *exec_ctx, grpc_timer *timer); |
| |
| /* iomgr internal api for dealing with timers */ |
| |
| /* Check for timers to be run, and run them. |
| Return true if timer callbacks were executed. |
| If next is non-null, TRY to update *next with the next running timer |
| IF that timer occurs before *next current value. |
| *next is never guaranteed to be updated on any given execution; however, |
| with high probability at least one thread in the system will see an update |
| at any time slice. */ |
| bool grpc_timer_check(grpc_exec_ctx *exec_ctx, gpr_timespec now, |
| gpr_timespec *next); |
| void grpc_timer_list_init(gpr_timespec now); |
| void grpc_timer_list_shutdown(grpc_exec_ctx *exec_ctx); |
| |
| /* the following must be implemented by each iomgr implementation */ |
| |
| void grpc_kick_poller(void); |
| |
| #endif /* GRPC_CORE_LIB_IOMGR_TIMER_H */ |