1 /****************************************************************************** 2 * 3 * Copyright 2014 Google, Inc. 4 * 5 * Licensed under the Apache License, Version 2.0 (the "License"); 6 * you may not use this file except in compliance with the License. 7 * You may obtain a copy of the License at: 8 * 9 * http://www.apache.org/licenses/LICENSE-2.0 10 * 11 * Unless required by applicable law or agreed to in writing, software 12 * distributed under the License is distributed on an "AS IS" BASIS, 13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14 * See the License for the specific language governing permissions and 15 * limitations under the License. 16 * 17 ******************************************************************************/ 18 19 #pragma once 20 21 #include <stdbool.h> 22 #include <stdint.h> 23 24 typedef struct alarm_t alarm_t; 25 typedef struct fixed_queue_t fixed_queue_t; 26 typedef struct thread_t thread_t; 27 28 // Prototype for the alarm callback function. 29 typedef void (*alarm_callback_t)(void* data); 30 31 // Creates a new one-time off alarm object with user-assigned 32 // |name|. |name| may not be NULL, and a copy of the string will 33 // be stored internally. The value of |name| has no semantic 34 // meaning. It is recommended that the name is unique (for 35 // better debuggability), but that is not enforced. The returned 36 // object must be freed by calling |alarm_free|. Returns NULL on 37 // failure. 38 alarm_t* alarm_new(const char* name); 39 40 // Creates a new periodic alarm object with user-assigned |name|. 41 // |name| may not be NULL, and a copy of the string will be 42 // stored internally. The value of |name| has no semantic 43 // meaning. It is recommended that the name is unique (for better 44 // debuggability), but that is not enforced. The returned object 45 // must be freed by calling |alarm_free|. Returns NULL on 46 // failure. 47 alarm_t* alarm_new_periodic(const char* name); 48 49 // Frees an |alarm| object created by |alarm_new| or 50 // |alarm_new_periodic|. |alarm| may be NULL. If the alarm is 51 // pending, it will be cancelled first. It is not safe to call 52 // |alarm_free| from inside the callback of |alarm|. 53 void alarm_free(alarm_t* alarm); 54 55 // Sets an |alarm| to execute a callback in the future. The |cb| 56 // callback is called after the given |interval_ms|, where 57 // |interval_ms| is the number of milliseconds relative to the 58 // current time. If |alarm| was created with 59 // |alarm_new_periodic|, the alarm is scheduled to fire 60 // periodically every |interval_ms|, otherwise it is a one time 61 // only alarm. A periodic alarm repeats every |interval_ms| until 62 // it is cancelled or freed. When the alarm fires, the |cb| 63 // callback is called with the context argument |data|: 64 // 65 // void cb(void *data) {...} 66 // 67 // The |data| argument may be NULL, but the |cb| callback may not 68 // be NULL. All |cb| callbacks scheduled through this call are 69 // called within a single (internally created) thread. That 70 // thread is not same as the caller’s thread. If two (or more) 71 // alarms are set back-to-back with the same |interval_ms|, the 72 // callbacks will be called in the order the alarms are set. 73 void alarm_set(alarm_t* alarm, uint64_t interval_ms, alarm_callback_t cb, 74 void* data); 75 76 // Sets an |alarm| to execute a callback in the main message loop. This function 77 // is same as |alarm_set| except that the |cb| callback is scheduled for 78 // execution in the context of the main message loop. 79 void alarm_set_on_mloop(alarm_t* alarm, uint64_t interval_ms, 80 alarm_callback_t cb, void* data); 81 82 // This function cancels the |alarm| if it was previously set. 83 // When this call returns, the caller has a guarantee that the 84 // callback is not in progress and will not be called if it 85 // hasn't already been called. This function is idempotent. 86 // |alarm| may not be NULL. 87 void alarm_cancel(alarm_t* alarm); 88 89 // Tests whether the |alarm| is scheduled. 90 // Return true if the |alarm| is scheduled or NULL, otherwise false. 91 bool alarm_is_scheduled(const alarm_t* alarm); 92 93 // Figure out how much time until next expiration. 94 // Returns 0 if not armed. |alarm| may not be NULL. 95 // TODO: Remove this function once PM timers can be re-factored 96 uint64_t alarm_get_remaining_ms(const alarm_t* alarm); 97 98 // Cleanup the alarm internal state. 99 // This function should be called by the OSI module cleanup during 100 // graceful shutdown. 101 void alarm_cleanup(void); 102 103 // Dump alarm-related statistics and debug info to the |fd| file descriptor. 104 // The information is in user-readable text format. The |fd| must be valid. 105 void alarm_debug_dump(int fd); 106