This is the mail archive of the mailing list for the pthreas-win32 project.

Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

Re: How is pthread_self() implemented?

Will Bryant wrote:

John Bossom's original design also allows for pre-existing Win32 threads
to use any POSIX routines, and therefore fully interact with POSIX
threads, by creating a one-time-only on-the-fly detached POSIX thread
handle for the Win32 thread.

So it is safe to use all pthreads-win32 functions from threads not created using the pthreads interface? I have an application where nearly all of the code only needs to use standard windows threads, but there are a couple of condition variables that I'd like to be able to use...

Note that non-POSIX threads are regarded by pthreads-win32 as detached and deferred-cancelable initially. However, I don't think there's any reason a non-POSIX thread can't subsequently change it's cancelability type. There's no way it can make itself joinable though. Apart from that, just about everything should work.

In particular, for condition variables I haven't proven the following but I believe it should all work properly. And since this should work, then so should POSIX read-write locks. Note that you odn't need to explicitly call pthread_self() unless you need the POSIX thread handle. Any routine that needs it internally will cause the POSIX handle to be created implicitly.

// Global

pthread_t    posixGuest[MAX_GUESTS];
pthread_mutex_t    CVLock = PTHREAD_MUTEX_INITIALIZER;
pthread_cond_t    CV = PTHREAD_COND_INITIALIZER;
int champaigneChilled = 0;
int cakeIced = 0;
int chaos = 0;
int mayhem = 0;
long    guest = 0;

// Thread A (Win32 or POSIX thread):

// Party guest thread
if ((guest = InterLockedIncremement(&guest)) >= MAX_GUESTS)
posixGuest[guest] = pthread_self(); // Only needed sometimes e.g. see thread D
// Mingle
while ( ! (champaigneChilled && cakeIced ) ) {
pthread_cond_wait(&CV, &CVLock);


// Thread B (Win32 or POSIX thread):

   // Ice cake thread
   cakeIced = 1;

// Thread C (Win32 or POSIX thread):

   // Chill champaigne thread
   champaigeChilled = 1;

// Thread D (Win32 or POSIX thread):

// Monitor party thread
if (chaos && meyhem) {
// Evict our guests
for (i = 0; i < MAX_GUESTS && pthread_kill(posixGuest[i], 0) == 0; i++)

Regards. Ross

Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]