xref: /illumos-gate/usr/src/man/man3c/pthread_mutex_consistent.3c (revision 3ce5372277f4657ad0e52d36c979527c4ca22de2)
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12.\" Copyright (c) 2014, Joyent, Inc.
13.\"
14.Dd "Dec 22, 2014"
15.Dt PTHREAD_MUTEX_CONSISTENT 3C
16.Os
17.Sh NAME
18.Nm pthread_mutex_consistent
19.Nd mark state protected by robust mutex as consistent
20.Sh SYNOPSIS
21.In pthread.h
22.Ft int
23.Fo pthread_mutex_consistent
24.Fa "pthread_mutex_t *mutex"
25.Fc
26.Sh DESCRIPTION
27The
28.Fn pthread_mutex_consistent
29function is used to indicate that a robust lock that is in an
30inconsistent state no longer is.
31.Lp
32A robust lock enters into an inconsistent state when a process or thread
33holding a robust lock exits, such as by calling
34.Xr exit 2
35or
36.Xr thr_exit 3C ,
37or crashes without unlocking the lock.
38At that point, if another process or thread is currently in a call, or calls
39.Xr pthread_mutex_lock 3C ,
40it will obtain the lock; however, the error code
41.Er EOWNERDEAD
42will be returned.
43In such cases, that thread will own the lock and must check and clean up any
44inconsistent state that is protected by the lock.
45When finished, it must call
46.Fn pthread_mutex_consistent
47to indicate that it is in a consistent state again.
48.Lp
49If a process or thread obtains a robust lock while it is in an
50inconsistent state and it crashes or terminates before marking the lock
51as consistent, the next process or thread that obtains the lock will
52receive
53.Er EOWNERDEAD .
54.Sh RETURN VALUES
55Upon successful completion, the
56.Fn pthread_mutex_consistent
57returns zero and marks
58.Va mutex
59as consistent.
60Callers of
61.Fn pthread_mutex_lock
62will not have
63.Er EOWNERDEAD
64returned until another process or thread exits without unlocking.
65Upon failure, an error will be returned which corresponds to one of the errors
66listed below.
67.Sh ERRORS
68The
69.Fn pthread_mutex_consistent
70function will fail if:
71.Bl -tag -width Er
72.It Er EINVAL
73.Va mutex
74is an uninitialized mutex, not a robust mutex, or not in an inconsistent
75state.
76.El
77.Sh INTERFACE STABILITY
78.Sy Committed
79.Sh MT-LEVEL
80.Sy MT-Safe
81.Sh SEE ALSO
82.Xr pthread_mutex_destroy 3C ,
83.Xr pthread_mutex_init 3C ,
84.Xr pthread_mutex_lock 3C ,
85.Xr pthread_mutexattr_getrobust 3C ,
86.Xr pthread 3HEAD ,
87.Xr libpthread 3LIB ,
88.Xr attributes 5 ,
89.Xr mutex 5
90