Add README and LICENCE, remove specific list of files.

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Chris Andrews
2011-01-27 18:19:29 +00:00
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Copyright 2011 Chris Andrews. All rights reserved.
Redistribution and use in source and binary forms, with or without modification, are
permitted provided that the following conditions are met:
1. Redistributions of source code must retain the above copyright notice, this list of
conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright notice, this list
of conditions and the following disclaimer in the documentation and/or other materials
provided with the distribution.
THIS SOFTWARE IS PROVIDED BY CHRIS ANDREWS ``AS IS'' AND ANY EXPRESS OR IMPLIED
WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL CHRIS ANDREWS OR
CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
The views and conclusions contained in the software and documentation are those of the
authors and should not be interpreted as representing official policies, either expressed
or implied, of Chris Andrews.
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# dtrace-provider - Native DTrace providers for Node.js apps.
This extension allows you to create native DTrace providers for your
Node.js applications. That is, to create providers and probes which
expose information specific to your application, rather than
information about the node runtime.
You could use this to expose high-level information about the inner
workings of your application, or to create a specific context in which
to look at information from other runtime or system-level providers.
The provider is not created in the usual way, by declaring it, and
then changing the build process to include it, but dynamically at
runtime. This is done entirely in-process, and there is no background
compiler invocation. The process creating the provider need not run as
root.
## EXAMPLE
Here's a simple example of creating a provider:
var d = require('dtrace-provider');
var dtp = d.createDTraceProvider("nodeapp");
dtp.addProbe("probe1", "int", "int");
dtp.addProbe("probe2", "char *");
dtp.enable();
dtp.fire("probe1", function(p) { return [1, 2]; });
dtp.fire("probe2", function(p) { return ["hello, dtrace"]; });
This example creates a provider called "nodeapp", and adds two
probes. It then enables the provider, at which point the provider
becomes visible to DTrace.
The probes are then fired, which produces this output:
$ sudo dtrace -Z -n 'nodeapp*:::probe1{ trace(arg0); trace(arg1) }' \
-n 'nodeapp*:::probe2{ trace(copyinstr(arg0)); }'
dtrace: description 'nodeapp*:::probe1' matched 0 probes
dtrace: description 'nodeapp*:::probe2' matched 0 probes
CPU ID FUNCTION:NAME
1 123562 func:probe1 1 2
1 123563 func:probe2 hello, dtrace
## PLATFORM SUPPORT
The nature of this extension means that support must be added for each
platform. Right now that support is only in place for OS X, 64 bit,
but Solaris x86 and 32 bit support is on the way.
## LIMITATIONS
The maximum number of probe arguments is 6. There's scope to increase
this, with some extra complexity in the platform-specific code.
The data types supported are "int" and "char *". There's definitely
scope to improve this, with more elaborate argument handling.
## CAVEATS
This is the first working version, and there are a number of important
cleanups to be made. Creating a provider will leak memory, although
firing a probe should not.
Performance is not where it should be, most especially the
disabled-probe effect. Probes are already using the "is-enabled"
feature of DTrace, but too much work needs to be done to get
there. Improving this may imply changes to the API shown in the
example above.
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"keywords" : ["dtrace"],
"homepage" : "https://github.com/chrisa/node-dtrace-provider#readme",
"author" : { "name" : "Chris Andrews", "email": "[email protected]" },
"files" : [ "LICENCE", "README.md", "Makefile", "dtrace-provider.js" ],
"main" : "./dtrace-provider.js",
"repository" : { "type" : "git", "url" : "http://github.com/chrisa/node-dtrace-provider.git" },
"scripts": { "install": "node-waf configure build" }