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Reformatted headings; minor rewrites.

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Michael Kerrisk 2007-06-15 19:53:05 +00:00
parent 8b215c3043
commit 9bfe1b3936
1 changed files with 7 additions and 3 deletions
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10
man7/sem_overview.7
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@ -38,7 +38,8 @@ operation will block until the value becomes greater than zero.
POSIX semaphores come in two forms: named semaphores and
unnamed semaphores.
.SS Named semaphores
.TP
.B Named semaphores
A named semaphore is identified by a name of the form
.IR /somename .
Two processes can operate on the same named semaphore by passing
@ -59,7 +60,8 @@ to close the semaphore.
When all processes have finished using the semaphore,
it can be removed from the system using
.BR sem_unlink (3).
.SS Unnamed semaphores (memory-based semaphores)
.TP
.B Unnamed semaphores (memory-based semaphores)
An unnamed semaphore does not have a name.
Instead the semaphore is placed in a region of memory that
is shared between multiple threads (a
@ -84,7 +86,9 @@ When the semaphore is no longer required,
and before the memory in which it is located is deallocated,
the semaphore should be destroyed using
.BR sem_destroy (3).
.SH LINUX SPECIFIC DETAILS
.PP
The remainder of this section describes some specific details
of the Linux implementation of POSIX semaphores.
.SS Versions
Prior to kernel 2.6, Linux only supported unnamed,
thread-shared semaphores.