Recreate the epoll file descriptor after a fork(). It will ensure
that all processes will not share their epoll_fd. Some side effects
were encountered because of this, such as epoll_wait() returning an
FD which was previously deleted, in multi-process mode.
Compare the results of recv/send with the parameter passed and
detect whether the system has no free buffer space for send()
or has no data anymore for recv(). This dramatically reduces
the number of syscalls (by about 23%).
A second occurrence of read-timeout rearming was present in stream_sock.c.
To fix the problem, it was necessary to put the shutdown information in
the buffer (already planned).
There is a long-time bug causing busy loops when either client-side
or server-side enters a SHUTR state. When writing data to the FD,
it was possible to re-arm the read side if the write had been paused.
ETERNITY is not 0 anymore, so all timeouts will not be initialized
to ETERNITY by a simple calloc(). We have to explictly assign them.
This bug caused random session aborts.
- fixed ev_sepoll again by rewriting the state machine
- switched all timeouts to timevals instead of milliseconds
- improved memory management using mempools v2.
- several minor optimizations
wake_expired_tasks() used a hint to avoid scanning the tree in most cases,
but it looks like the hint is more expensive than reaching the first node
in the tree. Disable it for now.
Introduction of timeval timers broke *poll-based pollers, because the call to
tv_ms_remain may return 0 while the event is not elapsed yet. Now we carefully
check for those cases and round the result up by 1 ms.
When we're interrupted by another instance, it is very likely
that the other one will need some memory. Now we know how to
free what is not used, so let's do it.
Also only free non-null pointers. Previously, pool_destroy()
did implicitly check for this case which was incidentely
needed.
- keep the number of users of each pool
- call the garbage collector on out of memory conditions
- sort the pools by size for faster creation
- force the alignment size to 16 bytes instead of 4*sizeof(void *)
Also during this process, a bug was found in appsession_refresh().
It would not automatically requeue the task in the queue, so the
old sessions would not vanish.
Aleksandar Lazic has collected many hashing algorithms and put them
in one file to ease benchmarking. Some algos look promising, some
of them have been checked further with uri_hash. Some results on
various systems/hardware are stored in hash_results.txt.
It was possible in ev_sepoll() to ignore certain events if
all speculative events had been processed at once, because
the epoll_wait() timeout was not cleared, thus delaying the
events delivery.
The state machine was complicated, it has been rewritten.
It seems faster and more correct right now.
The timeout functions were difficult to manipulate because they were
rounding results to the millisecond. Thus, it was difficult to compare
and to check what expired and what did not. Also, the comparison
functions were heavy with multiplies and divides by 1000. Now, all
timeouts are stored in timevals, reducing the number of operations
for updates and leading to cleaner and more efficient code.
Two states were missing in the speculative epoll state transition
matrix. This could cause some timeouts and unhandled events. The
problem showed up in TCP mode with a fast server at high session
rates, but could in theory also affect HTTP mode.
- several fixes in ev_sepoll
- fixed some expiration dates on some tasks
- fixed a bug in connection establishment detection due to speculative I/O
- fixed rare bug occuring on TCP with early close (reported by Andy Smith)
- implemented URI hashing algorithm (Guillaume Dallaire)
- implemented SMTP health checks (Peter van Dijk)
- replaced the rbtree with ul2tree from old scheduler project
- new framework for generic ACL support
- added the 'acl' and 'block' keywords to the config language
- added several ACL criteria and matches (IP, port, URI, ...)
- cleaned up and better modularization for some time functions
- fixed list macros
- fixed useless memory allocation in str2net()
- store the original destination address in the session
The time subsystem really needs fixing. It was still possible
that some tasks with expiration date below the millisecond in
the future caused busy loop around poll() waiting for the
timeout to happen.
Peter van Dijk contributed this patch which implements the "smtpchk"
option, which is to SMTP what "httpchk" is to HTTP. By default, it sends
"HELO localhost" to the servers, and waits for the 250 message, but it
can also send a specific request.
The file client.c now provides acl_fetch_dip and acl_fetch_dport
to be able to check the client's destination address and port. The
corresponding ACL keywords 'dst' and 'dport' have been added.
