€•lXŒsphinx.addnodes”Œdocument”“”)”}”(Œ rawsource”Œ”Œchildren”]”(Œ translations”Œ LanguagesNode”“”)”}”(hhh]”(hŒ pending_xref”“”)”}”(hhh]”Œdocutils.nodes”ŒText”“”ŒChinese (Simplified)”…””}”Œparent”hsbaŒ attributes”}”(Œids”]”Œclasses”]”Œnames”]”Œdupnames”]”Œbackrefs”]”Œ refdomain”Œstd”Œreftype”Œdoc”Œ reftarget”Œ%/translations/zh_CN/locking/spinlocks”Œmodname”NŒ classname”NŒ refexplicit”ˆuŒtagname”hhh ubh)”}”(hhh]”hŒChinese (Traditional)”…””}”hh2sbah}”(h]”h ]”h"]”h$]”h&]”Œ refdomain”h)Œreftype”h+Œ reftarget”Œ%/translations/zh_TW/locking/spinlocks”Œmodname”NŒ classname”NŒ refexplicit”ˆuh1hhh ubh)”}”(hhh]”hŒItalian”…””}”hhFsbah}”(h]”h ]”h"]”h$]”h&]”Œ refdomain”h)Œreftype”h+Œ reftarget”Œ%/translations/it_IT/locking/spinlocks”Œmodname”NŒ classname”NŒ refexplicit”ˆuh1hhh ubh)”}”(hhh]”hŒJapanese”…””}”hhZsbah}”(h]”h ]”h"]”h$]”h&]”Œ refdomain”h)Œreftype”h+Œ reftarget”Œ%/translations/ja_JP/locking/spinlocks”Œmodname”NŒ classname”NŒ refexplicit”ˆuh1hhh ubh)”}”(hhh]”hŒKorean”…””}”hhnsbah}”(h]”h ]”h"]”h$]”h&]”Œ refdomain”h)Œreftype”h+Œ reftarget”Œ%/translations/ko_KR/locking/spinlocks”Œmodname”NŒ classname”NŒ refexplicit”ˆuh1hhh ubh)”}”(hhh]”hŒSpanish”…””}”hh‚sbah}”(h]”h ]”h"]”h$]”h&]”Œ refdomain”h)Œreftype”h+Œ reftarget”Œ%/translations/sp_SP/locking/spinlocks”Œmodname”NŒ classname”NŒ refexplicit”ˆuh1hhh ubeh}”(h]”h ]”h"]”h$]”h&]”Œcurrent_language”ŒEnglish”uh1h hhŒ _document”hŒsource”NŒline”NubhŒsection”“”)”}”(hhh]”(hŒtitle”“”)”}”(hŒLocking lessons”h]”hŒLocking lessons”…””}”(hh¨hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h¦hh£hžhhŸŒ?/var/lib/git/docbuild/linux/Documentation/locking/spinlocks.rst”h Kubh¢)”}”(hhh]”(h§)”}”(hŒLesson 1: Spin locks”h]”hŒLesson 1: Spin locks”…””}”(hhºhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h¦hh·hžhhŸh¶h KubhŒ paragraph”“”)”}”(hŒ2The most basic primitive for locking is spinlock::”h]”hŒ1The most basic primitive for locking is spinlock:”…””}”(hhÊhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÈhŸh¶h Khh·hžhubhŒ literal_block”“”)”}”(hŒ¼static DEFINE_SPINLOCK(xxx_lock); unsigned long flags; spin_lock_irqsave(&xxx_lock, flags); ... critical section here .. spin_unlock_irqrestore(&xxx_lock, flags);”h]”hŒ¼static DEFINE_SPINLOCK(xxx_lock); unsigned long flags; spin_lock_irqsave(&xxx_lock, flags); ... critical section here .. spin_unlock_irqrestore(&xxx_lock, flags);”…””}”hhÚsbah}”(h]”h ]”h"]”h$]”h&]”Œ xml:space”Œpreserve”uh1hØhŸh¶h K hh·hžhubhÉ)”}”(hXlThe above is always safe. It will disable interrupts _locally_, but the spinlock itself will guarantee the global lock, so it will guarantee that there is only one thread-of-control within the region(s) protected by that lock. This works well even under UP also, so the code does _not_ need to worry about UP vs SMP issues: the spinlocks work correctly under both.”h]”hXlThe above is always safe. It will disable interrupts _locally_, but the spinlock itself will guarantee the global lock, so it will guarantee that there is only one thread-of-control within the region(s) protected by that lock. This works well even under UP also, so the code does _not_ need to worry about UP vs SMP issues: the spinlocks work correctly under both.”…””}”(hhêhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÈhŸh¶h Khh·hžhubhŒ block_quote”“”)”}”(hŒ¥NOTE! Implications of spin_locks for memory are further described in: Documentation/memory-barriers.txt (5) ACQUIRE operations. (6) RELEASE operations. ”h]”(hÉ)”}”(hŒENOTE! Implications of spin_locks for memory are further described in:”h]”hŒENOTE! Implications of spin_locks for memory are further described in:”…””}”(hhþhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÈhŸh¶h Khhúubhù)”}”(hŒXDocumentation/memory-barriers.txt (5) ACQUIRE operations. (6) RELEASE operations. ”h]”(hÉ)”}”(hŒ!Documentation/memory-barriers.txt”h]”hŒ!Documentation/memory-barriers.txt”…””}”(hjhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÈhŸh¶h Khj ubhù)”}”(hŒ1(5) ACQUIRE operations. (6) RELEASE operations. ”h]”hŒenumerated_list”“”)”}”(hhh]”(hŒ list_item”“”)”}”(hŒACQUIRE operations. ”h]”hÉ)”}”(hŒACQUIRE operations.”h]”hŒACQUIRE operations.”…””}”(hj-hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÈhŸh¶h Khj)ubah}”(h]”h ]”h"]”h$]”h&]”uh1j'hj$ubj()”}”(hŒRELEASE operations. ”h]”hÉ)”}”(hŒRELEASE operations.”h]”hŒRELEASE operations.”…””}”(hjEhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÈhŸh¶h KhjAubah}”(h]”h ]”h"]”h$]”h&]”uh1j'hj$ubeh}”(h]”h ]”h"]”h$]”h&]”Œenumtype”Œarabic”Œprefix”Œ(”Œsuffix”Œ)”Œstart”Kuh1j"hjubah}”(h]”h ]”h"]”h$]”h&]”uh1høhŸh¶h Khj ubeh}”(h]”h ]”h"]”h$]”h&]”uh1høhŸh¶h Khhúubeh}”(h]”h ]”h"]”h$]”h&]”uh1høhŸh¶h Khh·hžhubhÉ)”}”(hX-The above is usually pretty simple (you usually need and want only one spinlock for most things - using more than one spinlock can make things a lot more complex and even slower and is usually worth it only for sequences that you **know** need to be split up: avoid it at all cost if you aren't sure).”h]”(hŒæThe above is usually pretty simple (you usually need and want only one spinlock for most things - using more than one spinlock can make things a lot more complex and even slower and is usually worth it only for sequences that you ”…””}”(hjxhžhhŸNh NubhŒstrong”“”)”}”(hŒ**know**”h]”hŒknow”…””}”(hj‚hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1j€hjxubhŒA need to be split up: avoid it at all cost if you aren’t sure).”…””}”(hjxhžhhŸNh Nubeh}”(h]”h ]”h"]”h$]”h&]”uh1hÈhŸh¶h K hh·hžhubhÉ)”}”(hX¹This is really the only really hard part about spinlocks: once you start using spinlocks they tend to expand to areas you might not have noticed before, because you have to make sure the spinlocks correctly protect the shared data structures **everywhere** they are used. The spinlocks are most easily added to places that are completely independent of other code (for example, internal driver data structures that nobody else ever touches).”h]”(hŒòThis is really the only really hard part about spinlocks: once you start using spinlocks they tend to expand to areas you might not have noticed before, because you have to make sure the spinlocks correctly protect the shared data structures ”…””}”(hjšhžhhŸNh Nubj)”}”(hŒ**everywhere**”h]”hŒ everywhere”…””}”(hj¢hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1j€hjšubhŒ¹ they are used. The spinlocks are most easily added to places that are completely independent of other code (for example, internal driver data structures that nobody else ever touches).”…””}”(hjšhžhhŸNh Nubeh}”(h]”h ]”h"]”h$]”h&]”uh1hÈhŸh¶h K&hh·hžhubhù)”}”(hŒÒNOTE! The spin-lock is safe only when you **also** use the lock itself to do locking across CPU's, which implies that EVERYTHING that touches a shared variable has to agree about the spinlock they want to use. ”h]”hÉ)”}”(hŒÑNOTE! The spin-lock is safe only when you **also** use the lock itself to do locking across CPU's, which implies that EVERYTHING that touches a shared variable has to agree about the spinlock they want to use.”h]”(hŒ*NOTE! The spin-lock is safe only when you ”…””}”(hj¾hžhhŸNh Nubj)”}”(hŒ**also**”h]”hŒalso”…””}”(hjÆhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1j€hj¾ubhŒ¡ use the lock itself to do locking across CPU’s, which implies that EVERYTHING that touches a shared variable has to agree about the spinlock they want to use.”…””}”(hj¾hžhhŸNh Nubeh}”(h]”h ]”h"]”h$]”h&]”uh1hÈhŸh¶h K-hjºubah}”(h]”h ]”h"]”h$]”h&]”uh1høhŸh¶h K-hh·hžhubeh}”(h]”Œlesson-1-spin-locks”ah ]”h"]”Œlesson 1: spin locks”ah$]”h&]”uh1h¡hh£hžhhŸh¶h KubhŒ transition”“”)”}”(hŒ----”h]”h}”(h]”h ]”h"]”h$]”h&]”uh1jìhŸh¶h K2hh£hžhubh¢)”}”(hhh]”(h§)”}”(hŒ"Lesson 2: reader-writer spinlocks.”h]”hŒ"Lesson 2: reader-writer spinlocks.”…””}”(hjûhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h¦hjøhžhhŸh¶h K5ubhÉ)”}”(hX`If your data accesses have a very natural pattern where you usually tend to mostly read from the shared variables, the reader-writer locks (rw_lock) versions of the spinlocks are sometimes useful. They allow multiple readers to be in the same critical region at once, but if somebody wants to change the variables it has to get an exclusive write lock.”h]”hX`If your data accesses have a very natural pattern where you usually tend to mostly read from the shared variables, the reader-writer locks (rw_lock) versions of the spinlocks are sometimes useful. They allow multiple readers to be in the same critical region at once, but if somebody wants to change the variables it has to get an exclusive write lock.”…””}”(hj hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÈhŸh¶h K7hjøhžhubhù)”}”(hŒ­NOTE! reader-writer locks require more atomic memory operations than simple spinlocks. Unless the reader critical section is long, you are better off just using spinlocks. ”h]”hÉ)”}”(hŒ¬NOTE! reader-writer locks require more atomic memory operations than simple spinlocks. Unless the reader critical section is long, you are better off just using spinlocks.”h]”hŒ¬NOTE! reader-writer locks require more atomic memory operations than simple spinlocks. Unless the reader critical section is long, you are better off just using spinlocks.”…””}”(hjhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÈhŸh¶h K=hjubah}”(h]”h ]”h"]”h$]”h&]”uh1høhŸh¶h K=hjøhžhubhÉ)”}”(hŒ%The routines look the same as above::”h]”hŒ$The routines look the same as above:”…””}”(hj/hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÈhŸh¶h KAhjøhžhubhÙ)”}”(hXprwlock_t xxx_lock = __RW_LOCK_UNLOCKED(xxx_lock); unsigned long flags; read_lock_irqsave(&xxx_lock, flags); .. critical section that only reads the info ... read_unlock_irqrestore(&xxx_lock, flags); write_lock_irqsave(&xxx_lock, flags); .. read and write exclusive access to the info ... write_unlock_irqrestore(&xxx_lock, flags);”h]”hXprwlock_t xxx_lock = __RW_LOCK_UNLOCKED(xxx_lock); unsigned long flags; read_lock_irqsave(&xxx_lock, flags); .. critical section that only reads the info ... read_unlock_irqrestore(&xxx_lock, flags); write_lock_irqsave(&xxx_lock, flags); .. read and write exclusive access to the info ... write_unlock_irqrestore(&xxx_lock, flags);”…””}”hj=sbah}”(h]”h ]”h"]”h$]”h&]”hèhéuh1hØhŸh¶h KChjøhžhubhÉ)”}”(hX The above kind of lock may be useful for complex data structures like linked lists, especially searching for entries without changing the list itself. The read lock allows many concurrent readers. Anything that **changes** the list will have to get the write lock.”h]”(hŒÕThe above kind of lock may be useful for complex data structures like linked lists, especially searching for entries without changing the list itself. The read lock allows many concurrent readers. Anything that ”…””}”(hjKhžhhŸNh Nubj)”}”(hŒ **changes**”h]”hŒchanges”…””}”(hjShžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1j€hjKubhŒ* the list will have to get the write lock.”…””}”(hjKhžhhŸNh Nubeh}”(h]”h ]”h"]”h$]”h&]”uh1hÈhŸh¶h KOhjøhžhubhù)”}”(hŒ}NOTE! RCU is better for list traversal, but requires careful attention to design detail (see Documentation/RCU/listRCU.rst). ”h]”hÉ)”}”(hŒ|NOTE! RCU is better for list traversal, but requires careful attention to design detail (see Documentation/RCU/listRCU.rst).”h]”hŒ|NOTE! RCU is better for list traversal, but requires careful attention to design detail (see Documentation/RCU/listRCU.rst).”…””}”(hjohžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÈhŸh¶h KThjkubah}”(h]”h ]”h"]”h$]”h&]”uh1høhŸh¶h KThjøhžhubhÉ)”}”(hŒÂAlso, you cannot "upgrade" a read-lock to a write-lock, so if you at _any_ time need to do any changes (even if you don't do it every time), you have to get the write-lock at the very beginning.”h]”hŒÈAlso, you cannot “upgrade†a read-lock to a write-lock, so if you at _any_ time need to do any changes (even if you don’t do it every time), you have to get the write-lock at the very beginning.”…””}”(hjƒhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÈhŸh¶h KWhjøhžhubhù)”}”(hŒÀNOTE! We are working hard to remove reader-writer spinlocks in most cases, so please don't add a new one without consensus. (Instead, see Documentation/RCU/rcu.rst for complete information.) ”h]”hÉ)”}”(hŒ¿NOTE! We are working hard to remove reader-writer spinlocks in most cases, so please don't add a new one without consensus. (Instead, see Documentation/RCU/rcu.rst for complete information.)”h]”hŒÁNOTE! We are working hard to remove reader-writer spinlocks in most cases, so please don’t add a new one without consensus. (Instead, see Documentation/RCU/rcu.rst for complete information.)”…””}”(hj•hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÈhŸh¶h K[hj‘ubah}”(h]”h ]”h"]”h$]”h&]”uh1høhŸh¶h K[hjøhžhubeh}”(h]”Œ lesson-2-reader-writer-spinlocks”ah ]”h"]”Œ"lesson 2: reader-writer spinlocks.”ah$]”h&]”uh1h¡hh£hžhhŸh¶h K5ubjí)”}”(hŒ----”h]”h}”(h]”h ]”h"]”h$]”h&]”uh1jìhŸh¶h K_hh£hžhubh¢)”}”(hhh]”(h§)”}”(hŒLesson 3: spinlocks revisited.”h]”hŒLesson 3: spinlocks revisited.”…””}”(hj¾hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h¦hj»hžhhŸh¶h KbubhÉ)”}”(hX›The single spin-lock primitives above are by no means the only ones. They are the most safe ones, and the ones that work under all circumstances, but partly **because** they are safe they are also fairly slow. They are slower than they'd need to be, because they do have to disable interrupts (which is just a single instruction on a x86, but it's an expensive one - and on other architectures it can be worse).”h]”(hŒThe single spin-lock primitives above are by no means the only ones. They are the most safe ones, and the ones that work under all circumstances, but partly ”…””}”(hjÌhžhhŸNh Nubj)”}”(hŒ **because**”h]”hŒbecause”…””}”(hjÔhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1j€hjÌubhŒ÷ they are safe they are also fairly slow. They are slower than they’d need to be, because they do have to disable interrupts (which is just a single instruction on a x86, but it’s an expensive one - and on other architectures it can be worse).”…””}”(hjÌhžhhŸNh Nubeh}”(h]”h ]”h"]”h$]”h&]”uh1hÈhŸh¶h Kdhj»hžhubhÉ)”}”(hXIf you have a case where you have to protect a data structure across several CPU's and you want to use spinlocks you can potentially use cheaper versions of the spinlocks. IFF you know that the spinlocks are never used in interrupt handlers, you can use the non-irq versions::”h]”hXIf you have a case where you have to protect a data structure across several CPU’s and you want to use spinlocks you can potentially use cheaper versions of the spinlocks. IFF you know that the spinlocks are never used in interrupt handlers, you can use the non-irq versions:”…””}”(hjìhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÈhŸh¶h Kkhj»hžhubhÙ)”}”(hŒ)spin_lock(&lock); ... spin_unlock(&lock);”h]”hŒ)spin_lock(&lock); ... spin_unlock(&lock);”…””}”hjúsbah}”(h]”h ]”h"]”h$]”h&]”hèhéuh1hØhŸh¶h Kphj»hžhubhÉ)”}”(hX(and the equivalent read-write versions too, of course). The spinlock will guarantee the same kind of exclusive access, and it will be much faster. This is useful if you know that the data in question is only ever manipulated from a "process context", ie no interrupts involved.”h]”hX(and the equivalent read-write versions too, of course). The spinlock will guarantee the same kind of exclusive access, and it will be much faster. This is useful if you know that the data in question is only ever manipulated from a “process contextâ€, ie no interrupts involved.”…””}”(hjhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÈhŸh¶h Kthj»hžhubhÉ)”}”(hŒ}The reasons you mustn't use these versions if you have interrupts that play with the spinlock is that you can get deadlocks::”h]”hŒ~The reasons you mustn’t use these versions if you have interrupts that play with the spinlock is that you can get deadlocks:”…””}”(hjhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÈhŸh¶h Kyhj»hžhubhÙ)”}”(hŒVspin_lock(&lock); ... <- interrupt comes in: spin_lock(&lock);”h]”hŒVspin_lock(&lock); ... <- interrupt comes in: spin_lock(&lock);”…””}”hj$sbah}”(h]”h ]”h"]”h$]”h&]”hèhéuh1hØhŸh¶h K|hj»hžhubhÉ)”}”(hX¤where an interrupt tries to lock an already locked variable. This is ok if the other interrupt happens on another CPU, but it is _not_ ok if the interrupt happens on the same CPU that already holds the lock, because the lock will obviously never be released (because the interrupt is waiting for the lock, and the lock-holder is interrupted by the interrupt and will not continue until the interrupt has been processed).”h]”hX¤where an interrupt tries to lock an already locked variable. This is ok if the other interrupt happens on another CPU, but it is _not_ ok if the interrupt happens on the same CPU that already holds the lock, because the lock will obviously never be released (because the interrupt is waiting for the lock, and the lock-holder is interrupted by the interrupt and will not continue until the interrupt has been processed).”…””}”(hj2hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÈhŸh¶h Khj»hžhubhÉ)”}”(hX9(This is also the reason why the irq-versions of the spinlocks only need to disable the _local_ interrupts - it's ok to use spinlocks in interrupts on other CPU's, because an interrupt on another CPU doesn't interrupt the CPU that holds the lock, so the lock-holder can continue and eventually releases the lock).”h]”hX?(This is also the reason why the irq-versions of the spinlocks only need to disable the _local_ interrupts - it’s ok to use spinlocks in interrupts on other CPU’s, because an interrupt on another CPU doesn’t interrupt the CPU that holds the lock, so the lock-holder can continue and eventually releases the lock).”…””}”(hj@hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÈhŸh¶h Kˆhj»hžhubhù)”}”(hŒLinus ”h]”hÉ)”}”(hŒLinus”h]”hŒLinus”…””}”(hjRhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÈhŸh¶h KŽhjNubah}”(h]”h ]”h"]”h$]”h&]”uh1høhŸh¶h KŽhj»hžhubeh}”(h]”Œlesson-3-spinlocks-revisited”ah ]”h"]”Œlesson 3: spinlocks revisited.”ah$]”h&]”uh1h¡hh£hžhhŸh¶h Kbubjí)”}”(hŒ----”h]”h}”(h]”h ]”h"]”h$]”h&]”uh1jìhŸh¶h Khh£hžhubh¢)”}”(hhh]”(h§)”}”(hŒReference information:”h]”hŒReference information:”…””}”(hj{hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h¦hjxhžhhŸh¶h K“ubhÉ)”}”(hŒRFor dynamic initialization, use spin_lock_init() or rwlock_init() as appropriate::”h]”hŒQFor dynamic initialization, use spin_lock_init() or rwlock_init() as appropriate:”…””}”(hj‰hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÈhŸh¶h K•hjxhžhubhÙ)”}”(hŒ±spinlock_t xxx_lock; rwlock_t xxx_rw_lock; static int __init xxx_init(void) { spin_lock_init(&xxx_lock); rwlock_init(&xxx_rw_lock); ... } module_init(xxx_init);”h]”hŒ±spinlock_t xxx_lock; rwlock_t xxx_rw_lock; static int __init xxx_init(void) { spin_lock_init(&xxx_lock); rwlock_init(&xxx_rw_lock); ... } module_init(xxx_init);”…””}”hj—sbah}”(h]”h ]”h"]”h$]”h&]”hèhéuh1hØhŸh¶h K˜hjxhžhubhÉ)”}”(hŒƒFor static initialization, use DEFINE_SPINLOCK() / DEFINE_RWLOCK() or __SPIN_LOCK_UNLOCKED() / __RW_LOCK_UNLOCKED() as appropriate.”h]”hŒƒFor static initialization, use DEFINE_SPINLOCK() / DEFINE_RWLOCK() or __SPIN_LOCK_UNLOCKED() / __RW_LOCK_UNLOCKED() as appropriate.”…””}”(hj¥hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÈhŸh¶h K¤hjxhžhubeh}”(h]”Œreference-information”ah ]”h"]”Œreference information:”ah$]”h&]”uh1h¡hh£hžhhŸh¶h K“ubeh}”(h]”Œlocking-lessons”ah ]”h"]”Œlocking lessons”ah$]”h&]”uh1h¡hhhžhhŸh¶h Kubeh}”(h]”h ]”h"]”h$]”h&]”Œsource”h¶uh1hŒcurrent_source”NŒ current_line”NŒsettings”Œdocutils.frontend”ŒValues”“”)”}”(h¦NŒ generator”NŒ datestamp”NŒ source_link”NŒ source_url”NŒ toc_backlinks”Œentry”Œfootnote_backlinks”KŒ sectnum_xform”KŒstrip_comments”NŒstrip_elements_with_classes”NŒ strip_classes”NŒ report_level”KŒ halt_level”KŒexit_status_level”KŒdebug”NŒwarning_stream”NŒ traceback”ˆŒinput_encoding”Œ utf-8-sig”Œinput_encoding_error_handler”Œstrict”Œoutput_encoding”Œutf-8”Œoutput_encoding_error_handler”jæŒerror_encoding”Œutf-8”Œerror_encoding_error_handler”Œbackslashreplace”Œ language_code”Œen”Œrecord_dependencies”NŒconfig”NŒ id_prefix”hŒauto_id_prefix”Œid”Œ dump_settings”NŒdump_internals”NŒdump_transforms”NŒdump_pseudo_xml”NŒexpose_internals”NŒstrict_visitor”NŒ_disable_config”NŒ_source”h¶Œ _destination”NŒ _config_files”]”Œ7/var/lib/git/docbuild/linux/Documentation/docutils.conf”aŒfile_insertion_enabled”ˆŒ raw_enabled”KŒline_length_limit”M'Œpep_references”NŒ pep_base_url”Œhttps://peps.python.org/”Œpep_file_url_template”Œpep-%04d”Œrfc_references”NŒ rfc_base_url”Œ&https://datatracker.ietf.org/doc/html/”Œ tab_width”KŒtrim_footnote_reference_space”‰Œsyntax_highlight”Œlong”Œ smart_quotes”ˆŒsmartquotes_locales”]”Œcharacter_level_inline_markup”‰Œdoctitle_xform”‰Œ docinfo_xform”KŒsectsubtitle_xform”‰Œ image_loading”Œlink”Œembed_stylesheet”‰Œcloak_email_addresses”ˆŒsection_self_link”‰Œenv”NubŒreporter”NŒindirect_targets”]”Œsubstitution_defs”}”Œsubstitution_names”}”Œrefnames”}”Œrefids”}”Œnameids”}”(jÀj½jéjæj®j«jkjhj¸jµuŒ nametypes”}”(jÀ‰jé‰j®‰jk‰j¸‰uh}”(j½h£jæh·j«jøjhj»jµjxuŒ footnote_refs”}”Œ citation_refs”}”Œ autofootnotes”]”Œautofootnote_refs”]”Œsymbol_footnotes”]”Œsymbol_footnote_refs”]”Œ footnotes”]”Œ citations”]”Œautofootnote_start”KŒsymbol_footnote_start”KŒ id_counter”Œ collections”ŒCounter”“”}”…”R”Œparse_messages”]”hŒsystem_message”“”)”}”(hhh]”hÉ)”}”(hŒ:Enumerated list start value not ordinal-1: "5" (ordinal 5)”h]”hŒ>Enumerated list start value not ordinal-1: “5†(ordinal 5)”…””}”(hjMhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÈhjJubah}”(h]”h ]”h"]”h$]”h&]”Œlevel”KŒtype”ŒINFO”Œsource”h¶Œline”Kuh1jHhjubaŒtransform_messages”]”Œ transformer”NŒ include_log”]”Œ decoration”Nhžhub.