1 /* 2 * Copyright 2008, Ingo Weinhold, ingo_weinhold@gmx.de. 3 * Copyright 2002-2008, Axel Dörfler, axeld@pinc-software.de. 4 * Distributed under the terms of the MIT License. 5 * 6 * Copyright 2001-2002, Travis Geiselbrecht. All rights reserved. 7 * Distributed under the terms of the NewOS License. 8 */ 9 #ifndef _KERNEL_LOCK_H 10 #define _KERNEL_LOCK_H 11 12 #include <OS.h> 13 #include <debug.h> 14 15 16 struct mutex_waiter; 17 18 typedef struct mutex { 19 const char* name; 20 struct mutex_waiter* waiters; 21 #ifdef KDEBUG 22 thread_id holder; 23 #else 24 int32 count; 25 #endif 26 uint8 flags; 27 } mutex; 28 29 #define MUTEX_FLAG_CLONE_NAME 0x1 30 31 32 typedef struct recursive_lock { 33 mutex lock; 34 #ifndef KDEBUG 35 thread_id holder; 36 #endif 37 int recursion; 38 } recursive_lock; 39 40 41 struct rw_lock_waiter; 42 43 typedef struct rw_lock { 44 const char* name; 45 struct rw_lock_waiter* waiters; 46 thread_id holder; 47 int32 reader_count; 48 int32 writer_count; 49 int32 owner_count; 50 uint32 flags; 51 } rw_lock; 52 53 #define RW_LOCK_FLAG_CLONE_NAME 0x1 54 55 56 #if KDEBUG 57 # define KDEBUG_RW_LOCK_DEBUG 0 58 // Define to 1 if you want to use ASSERT_READ_LOCKED_RW_LOCK(). 59 // The rw_lock will just behave like a recursive locker then. 60 # define ASSERT_LOCKED_RECURSIVE(r) \ 61 { ASSERT(find_thread(NULL) == (r)->lock.holder); } 62 # define ASSERT_LOCKED_MUTEX(m) { ASSERT(find_thread(NULL) == (m)->holder); } 63 # define ASSERT_WRITE_LOCKED_RW_LOCK(l) \ 64 { ASSERT(find_thread(NULL) == (l)->holder); } 65 # if KDEBUG_RW_LOCK_DEBUG 66 # define ASSERT_READ_LOCKED_RW_LOCK(l) \ 67 { ASSERT(find_thread(NULL) == (l)->holder); } 68 # else 69 # define ASSERT_READ_LOCKED_RW_LOCK(l) do {} while (false) 70 # endif 71 #else 72 # define ASSERT_LOCKED_RECURSIVE(r) do {} while (false) 73 # define ASSERT_LOCKED_MUTEX(m) do {} while (false) 74 # define ASSERT_WRITE_LOCKED_RW_LOCK(m) do {} while (false) 75 # define ASSERT_READ_LOCKED_RW_LOCK(l) do {} while (false) 76 #endif 77 78 79 // static initializers 80 #ifdef KDEBUG 81 # define MUTEX_INITIALIZER(name) { name, NULL, -1, 0 } 82 # define RECURSIVE_LOCK_INITIALIZER(name) { MUTEX_INITIALIZER(name), 0 } 83 #else 84 # define MUTEX_INITIALIZER(name) { name, NULL, 0, 0 } 85 # define RECURSIVE_LOCK_INITIALIZER(name) { MUTEX_INITIALIZER(name), -1, 0 } 86 #endif 87 88 #define RW_LOCK_INITIALIZER(name) { name, NULL, -1, 0, 0, 0 } 89 90 91 #ifdef __cplusplus 92 extern "C" { 93 #endif 94 95 extern void recursive_lock_init(recursive_lock *lock, const char *name); 96 // name is *not* cloned nor freed in recursive_lock_destroy() 97 extern void recursive_lock_init_etc(recursive_lock *lock, const char *name, 98 uint32 flags); 99 extern void recursive_lock_destroy(recursive_lock *lock); 100 extern status_t recursive_lock_lock(recursive_lock *lock); 101 extern status_t recursive_lock_trylock(recursive_lock *lock); 102 extern void recursive_lock_unlock(recursive_lock *lock); 103 extern int32 recursive_lock_get_recursion(recursive_lock *lock); 104 105 extern void rw_lock_init(rw_lock* lock, const char* name); 106 // name is *not* cloned nor freed in rw_lock_destroy() 107 extern void rw_lock_init_etc(rw_lock* lock, const char* name, uint32 flags); 108 extern void rw_lock_destroy(rw_lock* lock); 109 extern status_t rw_lock_read_lock(rw_lock* lock); 110 extern status_t rw_lock_read_unlock(rw_lock* lock); 111 extern status_t rw_lock_write_lock(rw_lock* lock); 112 extern status_t rw_lock_write_unlock(rw_lock* lock); 113 114 extern void mutex_init(mutex* lock, const char* name); 115 // name is *not* cloned nor freed in mutex_destroy() 116 extern void mutex_init_etc(mutex* lock, const char* name, uint32 flags); 117 extern void mutex_destroy(mutex* lock); 118 extern status_t mutex_switch_lock(mutex* from, mutex* to); 119 // Unlocks "from" and locks "to" such that unlocking and starting to wait 120 // for the lock is atomically. I.e. if "from" guards the object "to" belongs 121 // to, the operation is safe as long as "from" is held while destroying 122 // "to". 123 124 // implementation private: 125 extern status_t _mutex_lock(mutex* lock, bool threadsLocked); 126 extern void _mutex_unlock(mutex* lock, bool threadsLocked); 127 extern status_t _mutex_trylock(mutex* lock); 128 129 130 static inline status_t 131 mutex_lock(mutex* lock) 132 { 133 #ifdef KDEBUG 134 return _mutex_lock(lock, false); 135 #else 136 if (atomic_add(&lock->count, -1) < 0) 137 return _mutex_lock(lock, false); 138 return B_OK; 139 #endif 140 } 141 142 143 static inline status_t 144 mutex_lock_threads_locked(mutex* lock) 145 { 146 #ifdef KDEBUG 147 return _mutex_lock(lock, true); 148 #else 149 if (atomic_add(&lock->count, -1) < 0) 150 return _mutex_lock(lock, true); 151 return B_OK; 152 #endif 153 } 154 155 156 static inline status_t 157 mutex_trylock(mutex* lock) 158 { 159 #ifdef KDEBUG 160 return _mutex_trylock(lock); 161 #else 162 if (atomic_test_and_set(&lock->count, -1, 0) != 0) 163 return B_WOULD_BLOCK; 164 return B_OK; 165 #endif 166 } 167 168 169 static inline void 170 mutex_unlock(mutex* lock) 171 { 172 #if !defined(KDEBUG) 173 if (atomic_add(&lock->count, 1) < -1) 174 #endif 175 _mutex_unlock(lock, false); 176 } 177 178 179 static inline void 180 mutex_transfer_lock(mutex* lock, thread_id thread) 181 { 182 #ifdef KDEBUG 183 lock->holder = thread; 184 #endif 185 } 186 187 188 extern void lock_debug_init(); 189 190 #ifdef __cplusplus 191 } 192 #endif 193 194 #endif /* _KERNEL_LOCK_H */ 195