Building
If you want to build with multi-threading support and you are
-running Linux 2.x (with the LinuxThreads library installed:
-that's the linuxthreads and linuxthreads-devel RPMs for RedHat)
-or Digital UNIX 4.x or Solaris 2.x for recentish x (2.5 is OK)
+running one of the following:
+ * Linux 2.x (with the LinuxThreads library installed: that's
+ the linuxthreads and linuxthreads-devel RPMs for RedHat)
+
+ * Digital UNIX 4.x
+
+ * Solaris 2.x for recentish x (2.5 is OK)
+
+ * IRIX 6.2 or newer. 6.2 will require a few os patches.
+ IMPORTANT: Without patch 2401, a kernel bug in IRIX 6.2 will
+ cause your machine to panic and crash when running threaded perl.
+ IRIX 6.3 and up should be OK. See lower down for patch details.
+
then you should be able to use
./Configure -Dusethreads -Doptimize=-g -ders
make
Zap mallocobj and mallocsrc (foo='')
Change d_mymalloc to undef
For Solaris, do the same as for Linux above.
+For IRIX:
+ Add -DUSE_THREADS -DDEBUGGING to ccflags
+ Add -DUSE_THREADS -DDEBUGGING to cppflags
+ Add -lpthread to libs
+ Change optimize to -g
+ For IRIX 6.2, you have to have the following patches installed:
+ 1404 Irix 6.2 Posix 1003.1b man pages
+ 1645 IRIX 6.2 & 6.3 POSIX header file updates
+ 2000 Irix 6.2 Posix 1003.1b support modules
+ 2254 Pthread library fixes
+ 2401 6.2 all platform kernel rollup
+ IMPORTANT: Without patch 2401, a kernel bug in IRIX 6.2 will
+ cause your machine to panic and crash when running threaded perl.
+ IRIX 6.3 and up should be OK.
+
+ For IRIX 6.3 and 6.4 the pthreads should work out of the box.
+ Thanks to Hannu Napari <Hannu.Napari@hut.fi> for the IRIX
+ pthreads patches information.
+For AIX:
+ Change cc to xlc_r or cc_r.
+ Add -DUSE_THREADS -DNEED_PTHREAD_INIT -DDEBUGGING to ccflags and cppflags
+ Change optimize to -g
+ Add -lc_r to libswanted
+ Change -lc in lddflags to be -lpthread -lc_r -lc
Now you can do a
make
-Building the Thread extension
+O/S specific bugs
+
+Solaris qsort uses a hidden mutex for synchronisation. If you die()
+while doing a sort() then the resulting longjmp() leaves the mutex
+locked so you get a deadlock the next time you try to sort().
+
+LinuxThreads 0.5 has a bug which can cause file descriptor 0 to be
+closed after a fork() leading to many strange symptoms. Version 0.6
+has this fixed but the following patch can be applied to 0.5 for now:
+
+----------------------------- cut here -----------------------------
+--- linuxthreads-0.5/pthread.c.ORI Mon Oct 6 13:55:50 1997
++++ linuxthreads-0.5/pthread.c Mon Oct 6 13:57:24 1997
+@@ -312,8 +312,10 @@
+ free(pthread_manager_thread_bos);
+ pthread_manager_thread_bos = pthread_manager_thread_tos = NULL;
+ /* Close the two ends of the pipe */
+- close(pthread_manager_request);
+- close(pthread_manager_reader);
++ if (pthread_manager_request >= 0) {
++ close(pthread_manager_request);
++ close(pthread_manager_reader);
++ }
+ pthread_manager_request = pthread_manager_reader = -1;
+ /* Update the pid of the main thread */
+ self->p_pid = getpid();
+----------------------------- cut here -----------------------------
-Build it away from the perl tree in the usual way. Set your PATH
-environment variable to have your perl build directory first and
-set PERL5LIB to be /your/perl/build/directory/lib (without those,
-I had problems where the config information from the ordinary perl
-on the system would end up in the Makefile). Then
- perl Makefile.PL PERL_SRC=/your/perl/build/directory
- make
-Then you can try some of the tests with
- perl -Mblib create.t
- perl -Mblib join.t
- perl -Mblib lock.t
- perl -Mblib unsync.t
- perl -Mblib unsync2.t
- perl -Mblib unsync3.t
- perl -Mblib io.t
- perl -Mblib queue.t
+Building the Thread extension
+
+The Thread extension is now part of the main perl distribution tree.
+If you did Configure -Dusethreads then it will have been added to
+the list of extensions automatically.
+
+You can try some of the tests with
+ cd ext/Thread
+ perl create.t
+ perl join.t
+ perl lock.t
+ perl io.t
+etc.
The io one leaves a thread reading from the keyboard on stdin so
as the ping messages appear you can type lines and see them echoed.
Try running the main perl test suite too. There are known
-failures for po/misc test 45 (tries to do local(@_) but @_ is
-now lexical) and some tests involving backticks/system/fork
-may or may not work. Under Linux, many tests may appear to fail
-when run under the test harness but work fine when invoked
-manually.
+failures for some of the DBM/DB extensions (if their underlying
+libraries were not compiled to be thread-aware).
Bugs
-* cond.t hasn't been redone since condition variable changed.
-
* FAKE_THREADS should produce a working perl but the Thread
extension won't build with it yet.
of each thread because it causes refcount problems that I
haven't tracked down yet) and there are very probably others too.
-* There are still races where bugs show up under contention.
+* There may still be races where bugs show up under contention.
* Need to document "lock", Thread.pm, Queue.pm, ...
-* Plenty of others
-
Debugging
Some old globals (e.g. stack_sp, op) and some old per-interpreter
variables (e.g. tmps_stack, cxstack) move into struct thread.
-All fields of struct thread (apart from a few only applicable to
-FAKE_THREADS) are of the form Tfoo. For example, stack_sp becomes
+All fields of struct thread which derived from original perl
+variables have names of the form Tfoo. For example, stack_sp becomes
the field Tstack_sp of struct thread. For those fields which moved
from original perl, thread.h does
#define foo (thr->Tfoo)
Mutexes and condition variables
The API is via macros MUTEX_{INIT,LOCK,UNLOCK,DESTROY} and
-COND_{INIT,WAIT,SIGNAL,BROADCAST,DESTROY}. For POSIX threads,
-perl mutexes and condition variables correspond to POSIX ones.
-For FAKE_THREADS, mutexes are stubs and condition variables are
-implmented as lists of waiting threads. For FAKE_THREADS, a thread
+COND_{INIT,WAIT,SIGNAL,BROADCAST,DESTROY}.
+
+A mutex is only required to be a simple, fast mutex (e.g. it does not
+have to be recursive). It is only ever held across very short pieces
+of code. Condition variables are only ever signalled/broadcast while
+their associated mutex is held. (This constraint simplifies the
+implementation of condition variables in certain porting situations.)
+For POSIX threads, perl mutexes and condition variables correspond to
+POSIX ones. For FAKE_THREADS, mutexes are stubs and condition variables
+are implmented as lists of waiting threads. For FAKE_THREADS, a thread
waits on a condition variable by removing itself from the runnable
list, calling SCHEDULE to change thr to the next appropriate
runnable thread and returning op (i.e. the new threads next op).
Malcolm Beattie
mbeattie@sable.ox.ac.uk
-2 October 1997
+Last updated: 27 November 1997
projects / p5sagit/p5-mst-13.2.git / blobdiff