"Any two of the parameters, readfds, writefds, or exceptfds, can be
given as null. At least one must be non-null, and any non-null
descriptor set must contain at least one handle to a socket."
http://msdn.microsoft.com/en-ca/library/windows/desktop/ms740141(v=vs.85).aspx
When using select(), cURL doesn't adhere to this (WinSock-specific)
rule, and can ask to monitor empty fd_sets, which leads to select()
returning WSAEINVAL (i.e. EINVAL) and connections failing in mysterious
ways as a result (at least when using the curl_multi_socket_action()
interface).
Bug: http://curl.haxx.se/mail/lib-2014-05/0278.html
This commit renames lib/setup.h to lib/curl_setup.h and
renames lib/setup_once.h to lib/curl_setup_once.h.
Removes the need and usage of a header inclusion guard foreign
to libcurl. [1]
Removes the need and presence of an alarming notice we carried
in old setup_once.h [2]
----------------------------------------
1 - lib/setup_once.h used __SETUP_ONCE_H macro as header inclusion guard
up to commit ec691ca3 which changed this to HEADER_CURL_SETUP_ONCE_H,
this single inclusion guard is enough to ensure that inclusion of
lib/setup_once.h done from lib/setup.h is only done once.
Additionally lib/setup.h has always used __SETUP_ONCE_H macro to
protect inclusion of setup_once.h even after commit ec691ca3, this
was to avoid a circular header inclusion triggered when building a
c-ares enabled version with c-ares sources available which also has
a setup_once.h header. Commit ec691ca3 exposes the real nature of
__SETUP_ONCE_H usage in lib/setup.h, it is a header inclusion guard
foreign to libcurl belonging to c-ares's setup_once.h
The renaming this commit does, fixes the circular header inclusion,
and as such removes the need and usage of a header inclusion guard
foreign to libcurl. Macro __SETUP_ONCE_H no longer used in libcurl.
2 - Due to the circular interdependency of old lib/setup_once.h and the
c-ares setup_once.h header, old file lib/setup_once.h has carried
back from 2006 up to now days an alarming and prominent notice about
the need of keeping libcurl's and c-ares's setup_once.h in sync.
Given that this commit fixes the circular interdependency, the need
and presence of mentioned notice is removed.
All mentioned interdependencies come back from now old days when
the c-ares project lived inside a curl subdirectory. This commit
removes last traces of such fact.
This reverts renaming and usage of lib/*.h header files done
28-12-2012, reverting 2 commits:
f871de0... build: make use of 76 lib/*.h renamed files
ffd8e12... build: rename 76 lib/*.h files
This also reverts removal of redundant include guard (redundant thanks
to changes in above commits) done 2-12-2013, reverting 1 commit:
c087374... curl_setup.h: remove redundant include guard
This also reverts renaming and usage of lib/*.c source files done
3-12-2013, reverting 3 commits:
13606bb... build: make use of 93 lib/*.c renamed files
5b6e792... build: rename 93 lib/*.c files
7d83dff... build: commit 13606bbfde follow-up 1
Start of related discussion thread:
http://curl.haxx.se/mail/lib-2013-01/0012.html
Asking for confirmation on pushing this revertion commit:
http://curl.haxx.se/mail/lib-2013-01/0048.html
Confirmation summary:
http://curl.haxx.se/mail/lib-2013-01/0079.html
NOTICE: The list of 2 files that have been modified by other
intermixed commits, while renamed, and also by at least one
of the 6 commits this one reverts follows below. These 2 files
will exhibit a hole in history unless git's '--follow' option
is used when viewing logs.
lib/curl_imap.h
lib/curl_smtp.h
We found a problem with ftp transfer using libcurl (7.23 and 7.25)
inside an application which is receiving unix signals (SIGUSR1,
SIGUSR2...) almost continuously. (Linux 2.4, PowerPC, HAVE_POLL_FINE
defined).
Curl_socket_check() uses poll() to wait for the socket, and retries it
when a signal is received (EINTR). However, if a signal is received and
it also happens that the timeout has been reached, Curl_socket_check()
returns -1 instead of 0 (indicating an error instead of a timeout).
In our case, the result is an aborted connection even before the ftp
banner is received from the server, and a return value of
CURLE_OUT_OF_MEMORY from curl_easy_perform() (Curl_pp_multi_statemach(),
in pingpong.c, actually returns OOM if Curl_socket_check() fails :-)
Funny to debug on a system on which OOM is a possible cause).
Bug: http://curl.haxx.se/mail/lib-2012-07/0122.html
If a socket is larger than FD_SETSIZE, avoid using FD_SET() on the
platforms where this is possible.
Bug: http://curl.haxx.se/bug/view.cgi?id=3413274
Reported by: Tim Starling
Just internal stuff...
Curl_safefree is now a macro defined in memdebug.h instead of a function
prototyped in url.h and implemented in url.c, so inclusion of url.h is no
longer required in order to simply use Curl_safefree.
Provide definition of macro WHILE_FALSE in setup_once.h in order to allow
other macros such as DEBUGF and DEBUGASSERT, and code using it, to compile
without 'conditional expression is constant' warnings.
The WHILE_FALSE stuff fixes 150+ MSVC compiler warnings.
POLLIN, and sets POLLERR without setting POLLIN and POLLOUT. In some
libcurl code execution paths this could trigger busy wait loops with
high CPU usage until a timeout condition aborted the loop.
This fix for Curl_poll adresses the above in a libcurl-wide mode.
select/poll calls will only be retried upon EINTR failures as
it previously was in lib/select.c revision 1.29
In this way Curl_socket_ready() and Curl_poll() will again fail
on any select/poll errors different than EINTR.
to find that it crashed miserably, and this was due to some select()isms left
in the code. This was due to API restrictions in c-ares 1.3.x, but with the
upcoming c-ares 1.4.0 this is no longer the case so now libcurl runs much
better with c-ares and the multi interface with > 1024 file descriptors in
use.
I also switched from calloc() to malloc() as a minor performance boost since
the rest of the code fills in the structs fine anyway - and they must for the
case when we use the stack-based auto variable array instead of the allocated
one.
I made the loop filling in poll_fds[] break when poll_nfds is reached as a
minor speed improvement.
Curl_socket_ready(), Curl_poll() and Curl_select() when these are called
with a zero timeout or a timeout value indicating a blocking call should
be performed.
These unnecessary calls to gettimeofday() got introduced in 7.16.2 when
fixing 'timeout would restart when signal caught while awaiting socket
events' on 20 March 2007.
- Move some loop breaking logic from the while clause into the loop,
avoiding compiler warning 'assignment within conditional expression'
function that deprecates the curl_multi_socket() function. Using the new
function the application tell libcurl what action that was found in the
socket that it passes in. This gives a significant performance boost as it
allows libcurl to avoid a call to poll()/select() for every call to
curl_multi_socket*().
to complete with no delay and actually find out what happened with
the socket. As well as detection of socket send()able condition.
This also allows removal of a Cygwin specific block of code.
or Curl_poll() with a non-zero timeout both functions would restart the
specified timeout. This could even lead to the extreme case that if a
signal arrived with a frecuency lower to the specified timeout neither
function would ever exit.
Added experimental symbol definition check CURL_ACKNOWLEDGE_EINTR in
Curl_select() and Curl_poll(). When compiled with CURL_ACKNOWLEDGE_EINTR
defined both functions will return as soon as a signal is caught. Use it
at your own risk, all calls to these functions in the library should be
revisited and checked before fully supporting this feature.
Curl_poll() which is called whenever not a single valid file descriptor is
passed to these functions.
Improve readibility using a poll() macro to replace WSApoll().
