update documentation

2 files changed, 34 insertions, 48 deletions

diff --git a/man/rb_new.3 b/man/rb_new.3
index 19c5c04..2dc945d 100644
--- a/man/rb_new.3
+++ b/man/rb_new.3
@@ -59,43 +59,21 @@ Proper functions will then return with errno set to
 .B EAGAIN
 and number of elements actually commited.
 This is default behaviour when
+.B O_MULTITHREAD
+flag was
+.B not
+passed and
 .B librb
-is compiler without
-.BR ENABLE_THREADS.
+is working in single thread mode.
 .TP
-.B O_NONTHREAD
+.B O_MULTITHREAD
 this can be set only when library has been compiled with
-.B ENABLE_THREADS
-otherwise, this flag is ignored. If set,
+.BR ENABLE_THREADS ,
+otherwise error will be returned. If set,
 .B librb
-functions will not be using pthread.
-This should be used only when you are sure that
+functions will be using pthreads to provide synchronization of threads accessing
 .I rb
-object will be accessed at most by 1 thread at a time.
-If more than 1 thread will try access
-.I rb
-object when this flag is set, such call will result in undefined behaviour.
-When
-.B O_NONTHREAD
-is set,
-.B O_NONBLOCK
-should also be set so
-all function calls are non-blocking.
-If
-.B ENABLE_THREADS
-is not set, funcions
-behave as (
-.B O_NONTHREAD
-|
-.BR O_NONBLOCK )
-flag was set.
-When this flag is passed to
-.BR rb_new (3),
-user should also set
-.B O_NONBLOCK
-or
-.B EINVAL
-error will be returned to prevent deadlocks.
+object.
 .SH RETURN VALUES
 .PP
 If no errors have been detected, function will return pointer to newly created
@@ -106,11 +84,11 @@ ring buffer, otherwise NULL is returned.
 .I count
 is not a power of two number (like 4, 64, 1024).
 .TP
-.B EINVAL
-.B O_NONTHREAD
+.B ENOSYS
+.B O_MULTITHREAD
 was set but
-.B O_NONBLOCK
-was not (only when library was compiled with pthread support.
+.B librb
+was not compiled with pthread support.
 .TP
 .B ENOMEM
 couldn't allocate memory for given
diff --git a/man/rb_overview.7 b/man/rb_overview.7
index 2d8f6fc..2469616 100644
--- a/man/rb_overview.7
+++ b/man/rb_overview.7
@@ -42,19 +42,27 @@ size_t " count ", unsigned long " flags ");"
 .SH DESCRIPTION
 .PP
 .B librb
-is thread safe and thread aware.
-If there are no resources available while reading or writting, caller thread
-gets locked and doesn't use any resources until data is available.
-Ring buffer can also be configured to work in non-blocking mode, so calls from
+is a simple ring buffer implementation that operates on objects rather than
+raw bytes.
+See
+.BR rb_new (3)
+to know what that means.
+By default library operates in single-thread mode which is way faster than
+multi-thread mode but naturally will break if concurrent thread will try to
+access
+.I rb
+object.
+To relief user from pesky synchronization process, library can optionally be
+thread safe and thread aware by passing
+.B O_MULTITHREAD
+flag to
+.BR rb_new (3).
+In multi-thread mode if there are no resources available while reading or
+writting, caller thread gets locked and doesn't use any resources until data is
+available.
+This behaviour can be altered to work in non-blocking mode, so calls from
 read and write will return immediately when there are not enough resources.
 malloc and free are called only in new and destory functions.
-Thread awarness can be disabled via
-.B O_NONTHREAD
-flags passed to
-.BR rb_new (3).
-In such case all calls to rb function will be non blocking.
-Library can also be compiled without thread support at all, then it can be used
-even in very constrained platforms.
 .PP
 As this library is focused on speed, user can create buffer with only power of
 two count (n^2).
@@ -80,7 +88,7 @@ Please note, that example is missing error handling for simplicity.
         struct rb *rb;
 
         /* initialize ring buffer with 32 1-byte elements */
-        rb = rb_new(32, 1, O_NONBLOCK | O_NONTHREAD);
+        rb = rb_new(32, 1, 0);
 
         /* add data to buffer one byte at a time */
         for (i = '0'; i <= '9'; ++i)