xref: /haiku/headers/private/kernel/condition_variable.h (revision 52f7c9389475e19fc21487b38064b4390eeb6fea)
1 /*
2  * Copyright 2007-2011, Ingo Weinhold, ingo_weinhold@gmx.de.
3  * Copyright 2019, Haiku, Inc. All rights reserved.
4  * Distributed under the terms of the MIT License.
5  */
6 #ifndef _KERNEL_CONDITION_VARIABLE_H
7 #define _KERNEL_CONDITION_VARIABLE_H
8 
9 
10 #include <OS.h>
11 
12 #include <debug.h>
13 
14 #ifdef __cplusplus
15 
16 #include <util/DoublyLinkedList.h>
17 #include <util/OpenHashTable.h>
18 
19 
20 struct mutex;
21 struct recursive_lock;
22 struct ConditionVariable;
23 
24 
25 struct ConditionVariableEntry
26 	: DoublyLinkedListLinkImpl<ConditionVariableEntry> {
27 public:
28 								ConditionVariableEntry();
29 								~ConditionVariableEntry();
30 
31 			bool				Add(const void* object);
32 			status_t			Wait(uint32 flags = 0, bigtime_t timeout = 0);
33 			status_t			Wait(const void* object, uint32 flags = 0,
34 									bigtime_t timeout = 0);
35 
36 			ConditionVariable*	Variable() const;
37 
38 private:
39 	inline	void				_AddToLockedVariable(ConditionVariable* variable);
40 			void				_RemoveFromVariable();
41 
42 private:
43 			ConditionVariable*	fVariable;
44 			Thread*				fThread;
45 			status_t			fWaitStatus;
46 
47 			friend struct ConditionVariable;
48 };
49 
50 
51 struct ConditionVariable {
52 public:
53 			void				Init(const void* object,
54 									const char* objectType);
55 									// for anonymous (unpublished) cvars
56 
57 			void				Publish(const void* object,
58 									const char* objectType);
59 			void				Unpublish();
60 
61 	inline	void				NotifyOne(status_t result = B_OK);
62 	inline	void				NotifyAll(status_t result = B_OK);
63 
64 	static	void				NotifyOne(const void* object, status_t result);
65 	static	void				NotifyAll(const void* object, status_t result);
66 
67 			void				Add(ConditionVariableEntry* entry);
68 
69 	// Convenience methods, no ConditionVariableEntry required.
70 			status_t			Wait(uint32 flags = 0, bigtime_t timeout = 0);
71 			status_t			Wait(mutex* lock, uint32 flags = 0, bigtime_t timeout = 0);
72 			status_t			Wait(recursive_lock* lock, uint32 flags = 0, bigtime_t timeout = 0);
73 
74 			const void*			Object() const		{ return fObject; }
75 			const char*			ObjectType() const	{ return fObjectType; }
76 
77 	static	void				ListAll();
78 			void				Dump() const;
79 
80 private:
81 	static 	void				_Notify(const void* object, bool all, status_t result);
82 			void				_Notify(bool all, status_t result);
83 			void				_NotifyLocked(bool all, status_t result);
84 
85 protected:
86 			typedef DoublyLinkedList<ConditionVariableEntry> EntryList;
87 
88 			const void*			fObject;
89 			const char*			fObjectType;
90 
91 			spinlock			fLock;
92 			EntryList			fEntries;
93 			int32				fEntriesCount;
94 
95 			ConditionVariable*	fNext;
96 
97 			friend struct ConditionVariableEntry;
98 			friend struct ConditionVariableHashDefinition;
99 };
100 
101 
102 inline void
103 ConditionVariable::NotifyOne(status_t result)
104 {
105 	_Notify(false, result);
106 }
107 
108 
109 inline void
110 ConditionVariable::NotifyAll(status_t result)
111 {
112 	_Notify(true, result);
113 }
114 
115 
116 extern "C" {
117 #endif	// __cplusplus
118 
119 extern void condition_variable_init();
120 
121 #ifdef __cplusplus
122 }	// extern "C"
123 #endif
124 
125 #endif	/* _KERNEL_CONDITION_VARIABLE_H */
126