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diff --git a/man3p/pthread_mutexattr_gettype.3p b/man3p/pthread_mutexattr_gettype.3p new file mode 100644 index 000000000..14f12a178 --- /dev/null +++ b/man3p/pthread_mutexattr_gettype.3p @@ -0,0 +1,129 @@ +.\" Copyright (c) 2001-2003 The Open Group, All Rights Reserved +.TH "PTHREAD_MUTEXATTR_GETTYPE" P 2003 "IEEE/The Open Group" "POSIX Programmer's Manual" +.\" pthread_mutexattr_gettype +.SH NAME +pthread_mutexattr_gettype, pthread_mutexattr_settype \- get and set +the mutex type attribute +.SH SYNOPSIS +.LP +\fB#include <pthread.h> +.br +.sp +int pthread_mutexattr_gettype(const pthread_mutexattr_t *restrict\fP +\fIattr\fP\fB, +.br +\ \ \ \ \ \ int *restrict\fP \fItype\fP\fB); +.br +int pthread_mutexattr_settype(pthread_mutexattr_t\fP \fI*attr\fP\fB, +int\fP \fItype\fP\fB); \fP +\fB +.br +\fP +.SH DESCRIPTION +.LP +The \fIpthread_mutexattr_gettype\fP() and \fIpthread_mutexattr_settype\fP() +functions, respectively, shall get and set the +mutex \fItype\fP attribute. This attribute is set in the \fItype\fP +parameter to these functions. The default value of the +\fItype\fP attribute is PTHREAD_MUTEX_DEFAULT. +.LP +The type of mutex is contained in the \fItype\fP attribute of the +mutex attributes. Valid mutex types include: +.TP 7 +PTHREAD_MUTEX_NORMAL +.sp +This type of mutex does not detect deadlock. A thread attempting to +relock this mutex without first unlocking it shall deadlock. +Attempting to unlock a mutex locked by a different thread results +in undefined behavior. Attempting to unlock an unlocked mutex +results in undefined behavior. +.TP 7 +PTHREAD_MUTEX_ERRORCHECK +.sp +This type of mutex provides error checking. A thread attempting to +relock this mutex without first unlocking it shall return with +an error. A thread attempting to unlock a mutex which another thread +has locked shall return with an error. A thread attempting to +unlock an unlocked mutex shall return with an error. +.TP 7 +PTHREAD_MUTEX_RECURSIVE +.sp +A thread attempting to relock this mutex without first unlocking it +shall succeed in locking the mutex. The relocking deadlock +which can occur with mutexes of type PTHREAD_MUTEX_NORMAL cannot occur +with this type of mutex. Multiple locks of this mutex shall +require the same number of unlocks to release the mutex before another +thread can acquire the mutex. A thread attempting to unlock +a mutex which another thread has locked shall return with an error. +A thread attempting to unlock an unlocked mutex shall return +with an error. +.TP 7 +PTHREAD_MUTEX_DEFAULT +.sp +Attempting to recursively lock a mutex of this type results in undefined +behavior. Attempting to unlock a mutex of this type which +was not locked by the calling thread results in undefined behavior. +Attempting to unlock a mutex of this type which is not locked +results in undefined behavior. An implementation may map this mutex +to one of the other mutex types. +.sp +.SH RETURN VALUE +.LP +Upon successful completion, the \fIpthread_mutexattr_gettype\fP() +function shall return zero and store the value of the +\fItype\fP attribute of \fIattr\fP into the object referenced by the +\fItype\fP parameter. Otherwise, an error shall be returned +to indicate the error. +.LP +If successful, the \fIpthread_mutexattr_settype\fP() function shall +return zero; otherwise, an error number shall be returned +to indicate the error. +.SH ERRORS +.LP +The \fIpthread_mutexattr_settype\fP() function shall fail if: +.TP 7 +.B EINVAL +The value \fItype\fP is invalid. +.sp +.LP +The \fIpthread_mutexattr_gettype\fP() and \fIpthread_mutexattr_settype\fP() +functions may fail if: +.TP 7 +.B EINVAL +The value specified by \fIattr\fP is invalid. +.sp +.LP +These functions shall not return an error code of [EINTR]. +.LP +\fIThe following sections are informative.\fP +.SH EXAMPLES +.LP +None. +.SH APPLICATION USAGE +.LP +It is advised that an application should not use a PTHREAD_MUTEX_RECURSIVE +mutex with condition variables because the implicit +unlock performed for a \fIpthread_cond_timedwait\fP() or \fIpthread_cond_wait\fP() +may not actually release the mutex (if it had been locked +multiple times). If this happens, no other thread can satisfy the +condition of the predicate. +.SH RATIONALE +.LP +None. +.SH FUTURE DIRECTIONS +.LP +None. +.SH SEE ALSO +.LP +\fIpthread_cond_timedwait\fP() , the Base Definitions volume of +IEEE\ Std\ 1003.1-2001, \fI<pthread.h>\fP +.SH COPYRIGHT +Portions of this text are reprinted and reproduced in electronic form +from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology +-- Portable Operating System Interface (POSIX), The Open Group Base +Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of +Electrical and Electronics Engineers, Inc and The Open Group. In the +event of any discrepancy between this version and the original IEEE and +The Open Group Standard, the original IEEE and The Open Group Standard +is the referee document. The original Standard can be obtained online at +http://www.opengroup.org/unix/online.html . |