diff options
author | rpj <rpj> | 2000-07-25 16:14:23 +0000 |
---|---|---|
committer | rpj <rpj> | 2000-07-25 16:14:23 +0000 |
commit | e2fd6e2de322cc12d9153da548ab76379049c11c (patch) | |
tree | 0e055e3496bbe45a4003d3e140e09a763d116fda /FAQ | |
parent | b035ed05977fdef5ced4691028284b7f0ebaba19 (diff) |
2000-07-25 Ross Johnson <rpj@special.ise.canberra.edu.au>
* sched.c (sched_get_priority_max): Handle different WinCE and
Win32 priority values together.
(sched_get_priority_min): Ditto.
- Tristan Savatier <tristan@mpegtv.com>
* create.c (pthread_create): Force new threads to wait until
pthread_create has the new thread's handle; we also retain
a local copy of the handle for internal use until
pthread_create returns.
* private.c (_pthread_threadStart): Initialise ei[].
(_pthread_threadStart): When beginthread is used to start the
thread, force waiting until the creator thread had the
thread handle.
* cancel.c (_pthread_cancel_thread): Include context switch
code for defined(_X86_) environments in addition to _M_IX86.
* rwlock.c (pthread_rwlock_destroy): Assignment changed
to avoid compiler warning.
* private.c (_pthread_get_exception_services_code): Cast
NULL return value to avoid compiler warning.
* cleanup.c (pthread_pop_cleanup): Initialise "cleanup" variable
to avoid compiler warnings.
* misc.c (_pthread_new): Change "new" variable to "t" to avoid
confusion with the C++ keyword of the same name.
* condvar.c (cond_wait_cleanup): Initialise lastWaiter variable.
(cond_timedwait): Remove unused local variables. to avoid
compiler warnings.
* dll.c (dllMain): Remove 2000-07-21 change - problem
appears to be in pthread_create().
2000-07-22 Ross Johnson <rpj@special.ise.canberra.edu.au>
* tsd.c (pthread_key_create): If a destructor was given
and the pthread_mutex_init failed, then would try to
reference a NULL pointer (*key); eliminate this section of
code by using a dynamically initialised mutex
(PTHREAD_MUTEX_INITIALIZER).
* tsd.c (pthread_setspecific): Return an error if
unable to set the value; simplify cryptic conditional.
* tsd.c (pthread_key_delete): Locking threadsLock relied
on mutex_lock returning an error if the key has no destructor.
ThreadsLock is only initialised if the key has a destructor.
Making this mutex a static could reduce the number of mutexes
used by an application since it is actually created only at
first use and it's often destroyed soon after.
2000-07-22 Ross Johnson <rpj@special.ise.canberra.edu.au>
* FAQ: Added Q5 and Q6.
tests/ChangeLog:
2000-07-25 Ross Johnson <rpj@special.ise.canberra.edu.au>
* runtest.bat: modified to work under W98.
* runall.bat: Add new tests; modified to work under W98.
It was ok under NT.
* Makefile: Add new tests.
* exception1.c: New; Test passing exceptions back to the
application and retaining library internal exceptions.
* join0.c: New; Test a single join.
Diffstat (limited to 'FAQ')
-rw-r--r-- | FAQ | 68 |
1 files changed, 68 insertions, 0 deletions
@@ -14,6 +14,10 @@ Q 3 How do I use pthread.dll for Win32 (Visual C++ 5.0) Q 4 Cancelation doesn't work for me, why? +Q 5 Thread won't block after two calls to mutex_lock + +Q 6 How do I generate libpthread.a for use with Mingw32? + ============================================================================= Q 1 Should I use Cygwin or Mingw32 as a development environment? @@ -253,3 +257,67 @@ a thread is going to block on a Win32 handle. These are: Regards. Ross +------------------------------------------------------------------------------ + +Q 5 Thread won't block after two calls to mutex_lock +--- + +A 5 +--- + +> i was testing this pthread for win32 in my prog. +> when i checked if it was blocking mutex_lock calls, i was surprised when it +> didnt lock +> +> pthread_mutex_t DBlock; +> +> pthread_mutex_init( &DBlock, NULL ); +> pthread_mutex_lock( &DBlock ); +> pthread_mutex_lock( &DBlock ); +> +> ^^ these two calls didnt block + +POSIX leaves the result "undefined" for a thread that tries +to recursively lock the same mutex (one that it owns already). +That means the actual semantics are left up to the +implementation, but should not be relied upon for code that +will be ported to different POSIX threads implementations. + +In the pthreads-win32 implementation a thread won't deadlock +itself by relocking the mutex. Subsequent calls to +pthread_mutex_lock() as in your example above increment +the lock count but the thread continues on. Consequently, +the thread must ensure that it unlocks the mutex once for +each lock operation. That is, pthreads-win32 mutexes are +always recursive. + +You may want to look at the other synchronisation devices +available in the library, such as condition variables or +read-write locks. + +Ross + +------------------------------------------------------------------------------ + +Q 6 How do I generate libpthread.a for use with Mingw32? +--- + +A 6 +--- + +> I'm lacking the libpthread.a that +> used to come with the pre-compiled package. The last time this +> library appeared was in 1999-08-12. Without this library I cannot +> use the pre-compiled dll. + +You can create libpthread.a from the .def file, should work along these +lines: + +$(DLLTOOL) --as $(AS) -k --dllname libpthread.dll --output-lib +libpthread.a --def $(srcdir)/libpthread.def + +Where DLLTOOL is i686-pc-cygwin-dlltool +and AS i686-pc-cygwin-as. + +Thomas Sailer <sailer@ife.ee.ethz.ch> + |