Now liblzma only uses "mythread" functions and types
which are defined in mythread.h matching the desired
threading method.
Before Windows Vista, there is no direct equivalent to
pthread condition variables. Since this package doesn't
use pthread_cond_broadcast(), pre-Vista threading can
still be kept quite simple. The pre-Vista code doesn't
use anything that wasn't already available in Windows 95,
so the binaries should run even on Windows 95 if someone
happens to care.
Use gettimeofday() if clock_gettime() isn't available
(e.g. Darwin).
The test for availability of pthread_condattr_setclock()
and CLOCK_MONOTONIC was incorrect. Instead of fixing the
#ifdefs, use an Autoconf test. That way if there exists a
system that supports them but doesn't specify the matching
POSIX #defines, the features will still get detected.
Don't try to use pthread_sigmask() on OpenVMS. It doesn't
have that function.
Guard mythread.h against being #included multiple times.
This adds:
- mythread_sync() macro to create synchronized blocks
- mythread_cond structure and related functions
and macros for condition variables with timed
waiting using a relative timeout
- mythread_create() to create a thread with all
signals blocked
Some of these wouldn't need to be inline functions,
but I'll keep them this way for now for simplicity.
For timed waiting on a condition variable, librt is
now required on some systems to use clock_gettime().
configure.ac was updated to handle this.
Half of developers were already forgetting to use these
functions, which could have caused total breakage in some future
liblzma version or even now if --enable-small was used. Now
liblzma uses pthread_once() to do the initializations unless
it has been built with --disable-threads which make these
initializations thread-unsafe.
When --enable-small isn't used, liblzma currently gets needlessly
linked against libpthread (on systems that have it). While it is
stupid for now, liblzma will need threads in future anyway, so
this stupidity will be temporary only.
When --enable-small is used, different code CRC32 and CRC64 is
now used than without --enable-small. This made the resulting
binary slightly smaller, but the main reason was to clean it up
and to handle the lack of lzma_init_check().
The pkg-config file lzma.pc was renamed to liblzma.pc. I'm not
sure if it works correctly and portably for static linking
(Libs.private includes -pthread or other operating system
specific flags). Hopefully someone complains if it is bad.
lzma_rc_prices[] is now included as a precomputed array even
with --enable-small. It's just 128 bytes now that it uses uint8_t
instead of uint32_t. Smaller array seemed to be at least as fast
as the more bloated uint32_t array on x86; hopefully it's not bad
on other architectures.
Lasse Collin