Add bin and edit workflow

bin/gems/eventmachine-1.2.7/docs/old/PURE_RUBY

@@ -0,0 +1,75 @@
+EventMachine is supplied in three alternative versions.
+
+1) A version that includes a Ruby extension written in C++. This version requires compilation;
+2) A version for JRuby that contains a precompiled JAR file written in Java;
+3) A pure Ruby version that has no external dependencies and can run in any Ruby environment.
+
+The Java version of EventMachine is packaged in a distinct manner and must be installed using a
+special procedure. This version is described fully in a different document, and not considered
+further here.
+
+The C++ and pure-Ruby versions, however, are shipped in the same distribution. You use the same
+files (either tarball or Ruby gem) to install both of these versions.
+
+If you intend to use the C++ version, you must successfully compile EventMachine after you install it.
+(The gem installation attempts to perform this step automatically.)
+
+If you choose not to compile the EventMachine C++ extension, or if your compilation fails for any
+reason, you still have a fully-functional installation of the pure-Ruby version of EM.
+
+However, for technical reasons, a default EM installation (whether or not the compilation succeeds)
+will always assume that the compiled ("extension") implementation should be used.
+
+If you want your EM program to use the pure Ruby version, you must specifically request it. There
+are two ways to do this: by setting either a Ruby global variable, or an environment string.
+
+The following code will invoke the pure-Ruby implementation of EM:
+
+ $eventmachine_library = :pure_ruby
+ require 'eventmachine'
+
+ EM.library_type #=> "pure_ruby"
+
+Notice that this requires a code change and is not the preferred way to select pure Ruby, unless
+for some reason you are absolutely sure you will never want the compiled implementation.
+
+Setting the following environment string has the same effect:
+
+ export EVENTMACHINE_LIBRARY="pure_ruby"
+
+This technique gives you the flexibility to select either version at runtime with no code changes.
+
+Support
+
+The EventMachine development team has committed to support precisely the same APIs for all the
+various implementations of EM.
+
+This means that you can expect any EM program to behave identically, whether you use pure Ruby,
+the compiled C++ extension, or JRuby. Deviations from this behavior are to be considered bugs
+and should be reported as such.
+
+There is a small number of exceptions to this rule, which arise from underlying platform
+distinctions. Notably, EM#epoll is a silent no-op in the pure Ruby implementation.
+
+
+When Should You Use the Pure-Ruby Implementation of EM?
+
+
+Use the pure Ruby implementation of EM when you must support a platform for which no C++ compiler
+is available, or on which the standard EM C++ code can't be compiled.
+
+Keep in mind that you don't need a C++ compiler in order to deploy EM applications that rely on
+the compiled version, so long as appropriate C++ runtime libraries are available on the target platform.
+
+In extreme cases, you may find that you can develop software with the compiled EM version, but are
+not allowed to install required runtime libraries on the deployment system(s). This would be another
+case in which the pure Ruby implementation can be useful.
+
+In general you should avoid the pure Ruby version of EM when performance and scalability are important.
+EM in pure Ruby will necessarily run slower than the compiled version. Depending on your application
+this may or may not be a key issue.
+
+Also, since EPOLL is not supported in pure Ruby, your applications will be affected by Ruby's built-in
+limit of 1024 file and socket descriptors that may be open in a single process. For maximum scalability
+and performance, always use EPOLL if possible.
+