This reverts commit 7ed25cc, reinstating commit 8ec2cb5.
As of 18-jul-2013 we still do have code in libcurl that makes use of these
memory functions. Commit 8ec2cb5 comment still applies and is yet valid.
These memory functions are solely used in Windows builds, so all related
code is protected with '#ifdef WIN32' preprocessor conditional compilation
directives.
Specifically, wcsdup() _wcsdup() are used when building a Windows target with
UNICODE and USE_WINDOWS_SSPI preprocessor symbols defined. This is the case
when building a Windows UNICODE target with Windows native SSL/TLS support
enabled.
Realizing that wcsdup() _wcsdup() are used is a bit tricky given that usage
of these is hidden behind _tcsdup() which is MS way of dealing with code
that must tolerate UNICODE and non-UNICODE compilation. Additionally, MS
header files and those compatible from other compilers use this preprocessor
conditional compilation directive in order to select at compilation time
whether 'wide' or 'ansi' MS API functions are used.
Without this code, Windows build targets with Windows native SSL/TLS support
enabled and MemoryTracking support enabled misbehave in tracking memory usage,
regardless of being a UNICODE enabled build or not.
HTTP Pipelining with libcurl
============================
Background
Since pipelining implies that one or more requests are sent to a server before
the previous response(s) have been received, we only support it for multi
interface use.
Considerations
When using the multi interface, you create one easy handle for each transfer.
Bascially any number of handles can be created, added and used with the multi
interface - simultaneously. It is an interface designed to allow many
simultaneous transfers while still using a single thread. Pipelining does not
change any of these details.
API
We've added a new option to curl_multi_setopt() called CURLMOPT_PIPELINING
that enables "attempted pipelining" and then all easy handles used on that
handle will attempt to use an existing pipeline.
Details
- A pipeline is only created if a previous connection exists to the same IP
address that the new request is being made to use.
- Pipelines are only supported for HTTP(S) as no other currently supported
protocol has features resemembling this, but we still name this feature
plain 'pipelining' to possibly one day support it for other protocols as
well.
- HTTP Pipelining is for GET and HEAD requests only.
- When a pipeline is in use, we must take precautions so that when used easy
handles (i.e those who still wait for a response) are removed from the multi
handle, we must deal with the outstanding response nicely.
- Explicitly asking for pipelining handle X and handle Y won't be supported.
It isn't easy for an app to do this association. The lib should probably
still resolve the second one properly to make sure that they actually _can_
be considered for pipelining. Also, asking for explicit pipelining on handle
X may be tricky when handle X get a closed connection.
90695fb2c5