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1 #ifndef HAP_PLS_H
2 #define HAP_PLS_H
3 
4 /**
5  * Copyright (c) 2019, The Linux Foundation. All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions are
9  * met:
10  *    * Redistributions of source code must retain the above copyright
11  *      notice, this list of conditions and the following disclaimer.
12  *    * Redistributions in binary form must reproduce the above
13  *      copyright notice, this list of conditions and the following
14  *      disclaimer in the documentation and/or other materials provided
15  *      with the distribution.
16  *    * Neither the name of The Linux Foundation nor the names of its
17  *      contributors may be used to endorse or promote products derived
18  *      from this software without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED
21  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
22  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS
24  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
25  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
26  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
27  * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
28  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
29  * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
30  * IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
31  */
32 
33 #include <stdint.h>
34 
35 #ifdef __cplusplus
36 extern "C" {
37 #endif
38 
39 /**
40  * Process local storage is local storage for the hlos process context.
41  *
42  * Warning, this API should only be called from within a thread started by FastRPC, and not from
43  * any user created threads via the qurt apis.
44  *
45  * When used from within a FastRPC started thread this will attach
46  * desturctors to the lifetime of the HLOS process that is making the
47  * rpc calls.  Users can use this to store context for the lifetime of
48  * the calling process on the hlos.
49  *
50  * Recovering instances
51  * --------------------
52  *
53  * To maintain the same instance structure for a caller from the HLOS users
54  * can use the HAP_pls_add_lookup api, which will lookup the key, and add it
55  * if its not already present.
56  * For example:
57  *
58  *    static int my_instance(struct my_struct* me)  {
59  *       return HAP_pls_add_lookup((uintptr_t)my_ctor,   //type, some unique static address
60  *                                  0,                //key, for different type instances
61  *                                  sizeof(*me),      //size of our struture
62  *                                  my_ctor,          //structure ctor
63  *                                  0,                //aditional user context for ctor
64  *                                  my_dtor,          //desturctor
65  *                                  &me);             //result
66  *    }
67  *
68  * First call to my_instance will initialize the structure by allocating it and calling my_ctor.
69  * Second call to my_instance will return the created instance.
70  * This API is thread safe, but when two threads try to intialize the structure the first
71  * time they may both create an instance, but only 1 will be returned.
72  * The destructor will be called when the HLOS process exits.
73  *
74  * See HAP_pls_add and HAP_pls_add_lookup.
75  *
76  * Exit Hooks
77  * ----------
78  *
79  * Users can use either HAP_pls_add_lookup or HAP_pls_add to add a destructor that will be
80  * called when the HLOS process exits.  The main difference between the two functions is that
81  * HAP_pls_add will always add, and the last instance added will be the one returned by
82  * HAP_pls_lookup.
83  *
84  *
85  */
86 
87 /**
88  * adds a new type/key to the local storage, overriding
89  * any previous value at the key.  Overriding the key
90  * does not cause the destructor to run.  Destructors are
91  * run when the HLOS process exits.
92  *
93  * @param type, type part of the key to be used for lookup,
94  *        these should be static addresses, like the address of a function.
95  * @param key, the key to be used for lookup
96  * @param size, the size of the data
97  * @param ctor, constructor that takes a context and memory of size
98  * @param ctx, constructor context passed as the first argument to ctor
99  * @param dtor, destructor to run at pls shutdown
100  * @param ppo, output data
101  * @retval, 0 for success
102  */
103 int HAP_pls_add(uintptr_t type, uintptr_t key, int size, int (*ctor)(void* ctx, void* data), void* ctx, void (*dtor)(void*), void** ppo);
104 
105 /**
106  * Like add, but will only add 1 item, and return the same item on the
107  * next add.  If two threads try to call this function at teh same time
108  * they will both receive the same value as a result, but the constructors
109  * may be called twice.
110  * item if its already there, otherwise tries to add.
111  * ctor may be called twice
112  * callers should avoid calling pls_add for the same type/key which will override the singleton
113  */
114 int HAP_pls_add_lookup(uintptr_t type, uintptr_t key, int size, int (*ctor)(void* ctx, void* data), void* ctx, void (*dtor)(void*), void** ppo);
115 
116 /**
117  * finds the last data pointer added for key to the local storage
118  *
119  * @param key, the key to be used for lookup
120  * @param ppo, output data
121  * @retval, 0 for success
122  */
123 int HAP_pls_lookup(uintptr_t type, uintptr_t key, void** ppo);
124 
125 
126 #ifdef __cplusplus
127 }
128 #endif
129 #endif //HAP_PLS_H
130