.TH "compat" 3 "Wed Mar 25 2020" "LMDB" \" -*- nroff -*-
.ad l
.nh
.SH NAME
compat \- A bunch of macros to minimize the amount of platform-specific ifdefs needed throughout the rest of the code\&. When the features this library needs are similar enough to POSIX to be hidden in a one-or-two line replacement, this macro approach is used\&.  

.SH SYNOPSIS
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.PP
.SS "Macros"

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.RI "#define \fBMDB_DEVEL\fP   0"
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.RI "#define \fBmdb_func_\fP   '<mdb_unknown>'"
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.RI "#define \fBMDB_NO_ROOT\fP   (\fBMDB_LAST_ERRCODE\fP + 10)"
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.RI "#define \fBMDB_USE_ROBUST\fP   1"
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.RI "#define \fBTHREAD_RET\fP   void *"
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.RI "#define \fBTHREAD_CREATE\fP(thr,  start,  arg)   pthread_create(&thr,NULL,start,arg)"
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.RI "#define \fBTHREAD_FINISH\fP(thr)   pthread_join(thr,NULL)"
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.RI "#define \fBZ\fP   'z'"
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.RI "#define \fBMDB_PIDLOCK\fP   1"
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.RI "#define \fBLOCK_MUTEX0\fP(mutex)   pthread_mutex_lock(mutex)"
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.RI "#define \fBUNLOCK_MUTEX\fP(mutex)   pthread_mutex_unlock(mutex)"
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.RI "#define \fBmdb_mutex_consistent\fP(mutex)   pthread_mutex_consistent(mutex)"
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.RI "#define \fBErrCode\fP()   errno"
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.RI "#define \fBHANDLE\fP   int"
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.RI "#define \fBINVALID_HANDLE_VALUE\fP   (\-1)"
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.RI "#define \fBGET_PAGESIZE\fP(x)   ((x) = sysconf(_SC_PAGE_SIZE))"
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.RI "#define \fBMNAME_LEN\fP   (sizeof(pthread_mutex_t))"
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.SS "Typedefs"

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.RI "typedef pthread_mutex_t \fBmdb_mutex_t\fP[1]"
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.RI "typedef pthread_mutex_t * \fBmdb_mutexref_t\fP"
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.SH "Detailed Description"
.PP 
A bunch of macros to minimize the amount of platform-specific ifdefs needed throughout the rest of the code\&. When the features this library needs are similar enough to POSIX to be hidden in a one-or-two line replacement, this macro approach is used\&. 


.SH "Macro Definition Documentation"
.PP 
.SS "#define MDB_DEVEL   0"
Features under development 
.SS "#define mdb_func_   '<mdb_unknown>'"
Wrapper around \fBfunc\fP, which is a C99 feature 
.SS "#define MDB_USE_ROBUST   1"
Some platforms define the EOWNERDEAD error code even though they don't support Robust Mutexes\&. Compile with -DMDB_USE_ROBUST=0, or use some other mechanism like -DMDB_USE_POSIX_SEM instead of -DMDB_USE_POSIX_MUTEX\&. (Posix semaphores are not robust\&.) 
.SS "#define Z   'z'"
printf format modifier for size_t 
.SS "#define MDB_PIDLOCK   1"
For MDB_LOCK_FORMAT: True if readers take a pid lock in the lockfile 
.SS "#define LOCK_MUTEX0(mutex)   pthread_mutex_lock(mutex)"
Lock the reader or writer mutex\&. Returns 0 or a code to give mdb_mutex_failed(), as in LOCK_MUTEX()\&. 
.SS "#define UNLOCK_MUTEX(mutex)   pthread_mutex_unlock(mutex)"
Unlock the reader or writer mutex\&. 
.SS "#define mdb_mutex_consistent(mutex)   pthread_mutex_consistent(mutex)"
Mark mutex-protected data as repaired, after death of previous owner\&. 
.SS "#define ErrCode()   errno"
Get the error code for the last failed system function\&. 
.SS "#define HANDLE   int"
An abstraction for a file handle\&. On POSIX systems file handles are small integers\&. On Windows they're opaque pointers\&. 
.SS "#define INVALID_HANDLE_VALUE   (\-1)"
A value for an invalid file handle\&. Mainly used to initialize file variables and signify that they are unused\&. 
.SS "#define GET_PAGESIZE(x)   ((x) = sysconf(_SC_PAGE_SIZE))"
Get the size of a memory page for the system\&. This is the basic size that the platform's memory manager uses, and is fundamental to the use of memory-mapped files\&. 
.SH "Typedef Documentation"
.PP 
.SS "typedef pthread_mutex_t mdb_mutex_t[1]"
Shared mutex/semaphore as the original is stored\&.
.PP
Not for copies\&. Instead it can be assigned to an \fBmdb_mutexref_t\fP\&. When mdb_mutexref_t is a pointer and mdb_mutex_t is not, then it is array[size 1] so it can be assigned to the pointer\&. 
.SS "typedef pthread_mutex_t* \fBmdb_mutexref_t\fP"
Reference to an \fBmdb_mutex_t\fP 
.SH "Author"
.PP 
Generated automatically by Doxygen for LMDB from the source code\&.