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c7b8998ebb
Change pg_bsd_indent to follow upstream rules for placement of comments to the right of code, and remove pgindent hack that caused comments following #endif to not obey the general rule. Commit e3860ffa4dd0dad0dd9eea4be9cc1412373a8c89 wasn't actually using the published version of pg_bsd_indent, but a hacked-up version that tried to minimize the amount of movement of comments to the right of code. The situation of interest is where such a comment has to be moved to the right of its default placement at column 33 because there's code there. BSD indent has always moved right in units of tab stops in such cases --- but in the previous incarnation, indent was working in 8-space tab stops, while now it knows we use 4-space tabs. So the net result is that in about half the cases, such comments are placed one tab stop left of before. This is better all around: it leaves more room on the line for comment text, and it means that in such cases the comment uniformly starts at the next 4-space tab stop after the code, rather than sometimes one and sometimes two tabs after. Also, ensure that comments following #endif are indented the same as comments following other preprocessor commands such as #else. That inconsistency turns out to have been self-inflicted damage from a poorly-thought-through post-indent "fixup" in pgindent. This patch is much less interesting than the first round of indent changes, but also bulkier, so I thought it best to separate the effects. Discussion: https://postgr.es/m/E1dAmxK-0006EE-1r@gemulon.postgresql.org Discussion: https://postgr.es/m/30527.1495162840@sss.pgh.pa.us
60 lines
2.3 KiB
C
60 lines
2.3 KiB
C
/*-------------------------------------------------------------------------
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*
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* condition_variable.h
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* Condition variables
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*
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* A condition variable is a method of waiting until a certain condition
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* becomes true. Conventionally, a condition variable supports three
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* operations: (1) sleep; (2) signal, which wakes up one process sleeping
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* on the condition variable; and (3) broadcast, which wakes up every
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* process sleeping on the condition variable. In our implementation,
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* condition variables put a process into an interruptible sleep (so it
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* can be cancelled prior to the fulfillment of the condition) and do not
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* use pointers internally (so that they are safe to use within DSMs).
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*
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* Portions Copyright (c) 1996-2017, PostgreSQL Global Development Group
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* Portions Copyright (c) 1994, Regents of the University of California
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*
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* src/include/storage/condition_variable.h
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*
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*-------------------------------------------------------------------------
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*/
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#ifndef CONDITION_VARIABLE_H
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#define CONDITION_VARIABLE_H
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#include "storage/s_lock.h"
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#include "storage/proclist_types.h"
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typedef struct
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{
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slock_t mutex;
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proclist_head wakeup;
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} ConditionVariable;
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/* Initialize a condition variable. */
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extern void ConditionVariableInit(ConditionVariable *);
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/*
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* To sleep on a condition variable, a process should use a loop which first
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* checks the condition, exiting the loop if it is met, and then calls
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* ConditionVariableSleep. Spurious wakeups are possible, but should be
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* infrequent. After exiting the loop, ConditionVariableCancelSleep should
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* be called to ensure that the process is no longer in the wait list for
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* the condition variable.
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*/
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extern void ConditionVariableSleep(ConditionVariable *, uint32 wait_event_info);
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extern void ConditionVariableCancelSleep(void);
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/*
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* The use of this function is optional and not necessary for correctness;
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* for efficiency, it should be called prior entering the loop described above
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* if it is thought that the condition is unlikely to hold immediately.
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*/
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extern void ConditionVariablePrepareToSleep(ConditionVariable *);
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/* Wake up a single waiter (via signal) or all waiters (via broadcast). */
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extern bool ConditionVariableSignal(ConditionVariable *);
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extern int ConditionVariableBroadcast(ConditionVariable *);
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#endif /* CONDITION_VARIABLE_H */
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