[haiku-bugs] Re: [Haiku] #4954: Proliferation of BBuffer instances when playing sound
- From: "Haiku" <trac@xxxxxxxxxxxx>
- To: undisclosed-recipients: ;
- Date: Wed, 20 Mar 2019 23:25:02 -0000
#4954: Proliferation of BBuffer instances when playing sound
------------------------------+-----------------------
Reporter: Adek336 | Owner: Barrett
Type: bug | Status: reopened
Priority: normal | Milestone: R1
Component: Kits/Media Kit | Version: R1/alpha1
Resolution: | Keywords:
Blocked By: 14755 | Blocking:
Has a Patch: 0 | Platform: All
------------------------------+-----------------------
Comment (by waddlesplash):
_start_watching_system is already used by the registrar so you are not
going to solve the issue.
Yes, it was added by tqh rather recently in hrev52796. A cursory look
reveals that it should likely be sending notifications for this, but that
code is behind quite a lot of branches and I didn't test it just now.
And I think this syscall is going to be quite heavy, so not a good idea
anyway.
This only shows you do not know what you are talking about here. The
[
http://xref.plausible.coop/source/xref/haiku/src/system/kernel/system_info.cpp#628
syscall implementation] simply calls
[
http://xref.plausible.coop/source/xref/haiku/src/system/kernel/system_info.cpp#StartListening
SystemNotificationService::StartListening], which is not very "heavy" at
all; it just creates a listener and inserts it into a doubly-linked list.
In fact:
{{{
[ 1908] _kern_start_watching_system(0xffffffff, 0x1f, 0xf7, 0x0) =
0x00000000 No error (3 us)
}}}
That's right, **3 microseconds**! This is even faster than a write() to
stdout (5-6 us, depending on length.)
And of course one only need to call it once; after that you simply receive
messages about whatever events occurred to the port specified, same as
with a BRoster watcher.
Actually it is extremely funny that you write this, for in your very next
comment:
I require some due diligence when developing. Maybe it's a too high
level for you, but
And of course you did none of this due diligence yourself when speaking of
_start_watching_system.
However now I realize that you are continuing to trust "someone" else
position on that.
And there you go with the conspiracy theories again...
--
Ticket URL: <
https://dev.haiku-os.org/ticket/4954#comment:25>
Haiku <
https://dev.haiku-os.org>
The Haiku operating system.
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