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 <stdlib.h>
23 
24 #define THREAD_NAME_MAX 16
25 
26 typedef struct reactor_t reactor_t;
27 typedef struct thread_t thread_t;
28 
29 typedef void (*thread_fn)(void* context);
30 
31 // Creates and starts a new thread with the given name. Only THREAD_NAME_MAX
32 // bytes from |name| will be assigned to the newly-created thread. Returns a
33 // thread object if the thread was successfully started, NULL otherwise. The
34 // returned thread object must be freed with |thread_free|. |name| may not
35 // be NULL.
36 thread_t* thread_new(const char* name);
37 
38 // Similar to |thread_new| but creates with a given queue |size|.
39 thread_t* thread_new_sized(const char* name, size_t size);
40 
41 // Frees the given |thread|. If the thread is still running, it is stopped
42 // and the calling thread will block until |thread| terminates. |thread|
43 // may be NULL.
44 void thread_free(thread_t* thread);
45 
46 // Waits for |thread_stop|. Upon returning, the only other operations a caller
47 // may perform on |thread| are |thread_free| and |thread_join|. |thread_join|
48 // is idempotent and may be called from any thread. |thread| may not be NULL.
49 void thread_join(thread_t* thread);
50 
51 // Call |func| with the argument |context| on |thread|. This function typically
52 // does not block unless there are an excessive number of functions posted to
53 // |thread| that have not been dispatched yet. Neither |thread| nor |func| may
54 // be NULL. |context| may be NULL.
55 // Return true on success, otherwise false.
56 bool thread_post(thread_t* thread, thread_fn func, void* context);
57 
58 // Requests |thread| to stop. Only |thread_free| and |thread_name| may be called
59 // after calling |thread_stop|. This function is guaranteed to not block.
60 // |thread| may not be NULL.
61 void thread_stop(thread_t* thread);
62 
63 // Attempts to sets the |priority| of a given |thread|.
64 // The |thread| has to be running for this call to succeed.
65 // Returns true on success.
66 bool thread_set_priority(thread_t* thread, int priority);
67 
68 // Attempts to set |thread| to the real-time SCHED_FIFO |priority|.
69 // The |thread| has to be running for this call to succeed.
70 // Priority values are valid in the range sched_get_priority_max(SCHED_FIFO)
71 // to sched_get_priority_min(SCHED_FIFO).  Larger values are higher priority.
72 // Returns true on success.
73 bool thread_set_rt_priority(thread_t* thread, int priority);
74 
75 // Returns true if the current thread is the same as the one represented by
76 // |thread|.
77 // |thread| may not be NULL.
78 bool thread_is_self(const thread_t* thread);
79 
80 // Returns the reactor for the given |thread|. |thread| may not be NULL.
81 reactor_t* thread_get_reactor(const thread_t* thread);
82 
83 // Returns the name of the given |thread|. |thread| may not be NULL.
84 const char* thread_name(const thread_t* thread);
85