LinuxThreads library.

1998-03-11 00:42  Wolfram Gloger  <wmglo@dent.med.uni-muenchen.de>
	* linuxthreads/manager.c: Enable resetting of the thread
	scheduling policy to SCHED_OTHER when the parent thread
	has a different one.
1998-02-01 13:51  Ulrich Drepper  <drepper@cygnus.com>
	* sysdeps/unix/sysv/linux/bits/posix_opt.h: Define
	_POSIX_ASYNCHRONOUS_IO.
	* sysdeps/pthread/pthread.h: Define bits for Unix98 variants of
	mutexes.
	* mutex.c: Implement new mutex types.
	* internals.h: Include <signal.h>.
	* libpthread.map: Add __erno_location and __h_errno_location.
	* errno.c: Return pointer to variable actually in use.  This might
	not be the one in the thread structure.
	* internals.h (struct _pthread_descr_struct): Add new fields p_errnop
	and p_h_errnop.
	* manager.c (__pthread_manager): Set p_errnop and p_h_errnop member
	of manager thread structure.
	(pthread_handle_create): Set p_errnop and p_h_errnop members for new
	thread.
	* pthread.c: Adapt initializer for thread structures.
	(__pthread_initial_thread): Set p_errnop and p_h_errnop member.
	(__pthread_reset_main_thread): Reset p_errnop and p_h_errnop of
	current thread to global variables.
1998-01-31 17:27  Ulrich Drepper  <drepper@cygnus.com>
	* rwlock.c: New file.
	* Makefile (libpthread-routines): Add rwlock.
	* sysdeps/pthread/pthread.h: Define data structures and declare
	functions.
	* libpthread.map: Add new functions.
1997-12-18 13:50  Philip Blundell  <pb@nexus.co.uk>
	* sysdeps/arm/pt-machine.h: New file; add ARM support.
	* sysdeps/arm/Implies: likewise.
	* README: Document it.
1997-12-13  Andreas Schwab  <schwab@issan.informatik.uni-dortmund.de>
	* signals.c: Remove unneeded initializer for sigwaited, saving a
1997-04-11 01:18  Andreas Schwab  <schwab@issan.informatik.uni-dortmund.de>
	* semaphore.c (sem_init): Set sem_spinlock only if available.
1997-12-04 01:48  Ulrich Drepper  <drepper@cygnus.com>
	* mutex.c: Implement PTHREAD_MUTEX_CHECKERROR.
	* sysdeps/pthread/pthread.h: Define PTHREAD_MUTEX_CHECKERROR.
	* Makefile: Update from LinuxThreads 0.7.
	* internals.h. Likewise.
	* manager.c: Likewise.
	* mutex.c: Likewise.
	* pthread.c: Likewise.
	* signals.c: Likewise.
	* specific.c: Likewise.
	* Examples/ex3.c: Likewise.
1997-11-20 18:13  Ulrich Drepper  <drepper@cygnus.com>
	* pthread.c (__pthread_reset_main_thread): Close pipe only if still
	open.
1997-10-29 05:38  Ulrich Drepper  <drepper@cygnus.com>

	* wrapsyscall.c: Add socket functions which are also cancelation
	points.

1997-10-19 21:40  Wolfram Gloger  <wg@wolfram.dent.med.uni-muenchen.de>

	* specific.c (__libc_internal_tsd_set, __libc_internal_tsd_get):
	New functions for fast thread specific data within libc.

	* internals.h: Add new array p_libc_specific to struct
	_pthread_descr_struct.

	* sysdeps/pthread/bits/libc-lock.h: Declare new functions.

1997-10-13 05:39  Ulrich Drepper  <drepper@cygnus.com>

	* semaphore.h: Add __BEGIN_DECLS/__END_DECLS.
	Reported by Ralf Corsepius <corsepiu@faw.uni-ulm.de>.

1997-08-29 03:05  Ulrich Drepper  <drepper@cygnus.com>

	* internals.h (struct _pthread_descr_struct): Add definitions for
	two-level specific key handling.
	* manager.c (pthread_handle_create): Initialize specific memory array.
	* specific.c: Implement two-level key handling.
	* weaks.c: Don't provide dummy key handling.
	* sysdeps/pthread/bits/libc-lock.h: Typedef __libc_lock_t (no #define).
	Add definition of __libc_key_t.
	* sysdeps/unix/sysv/linux/bits/local_lim.h: Define PTHREAD_KEYS_MAX
	as 1024.
	Add definition of _POSIX_THREAD_DESTRUCTOR_ITERATIONS and
	PTHREAD_DESTRUCTOR_ITERATIONS.

	* manager.c (pthread_handle_create): Compare mmap result with
	MAP_FAILED.

	* ptfork.c: Rename to __pthread_atfork and make old name a weak alias.
	* sysdeps/pthread/bits/pthread.h: Add prototype for __pthread_atfork.

1997-08-22 19:04  Richard Henderson  <rth@cygnus.com>

	sysdeps/sparc -> sysdeps/sparc/sparc32
	sysdeps/sparc64 -> sysdeps/sparc/sparc64

	* internals.h: Change definition of THREAD_SELF to be an expression,
	not a statement that did a return.
	* sysdeps/alpha/pt-machine.h (THREAD_SELF): Update accordingly.
	* sysdeps/sparc/sparc32/pt-machine.h (THREAD_SELF, INIT_THREAD_SELF):
	Follow Solaris and use a "system reserved" register (%g6) to hold
	the thread descriptor.
	* sysdeps/sparc/sparc64/pt-machine.h: Likewise.

1997-08-03 00:09  Ulrich Drepper  <drepper@cygnus.com>

	* mutex.c: Correct pthread_once.  Patch by Xavier Leroy.
	* sysdeps/pthread/pthread.h: Add prototype for __pthread_once.
	* sysdeps/pthread/bits/pthread.h: Add macros for __libc_once.

	* semaphore.c: Include spinlock.h only when needed.

	* specific.c (__pthread_setsepcific, __pthread_getspecific): Reject
	keys for entries not in use.

	* weaks.c: Implement key handling functions for real.

1997-06-29  01:04  Richard Henderson  <richard@gnu.ai.mit.edu>

	Initial sparc64-linux support:
	* linuxthreads/sysdeps/sparc64/Implies: New file.
	* linuxthreads/sysdeps/sparc64/pt-machine.h: Likewise.

1997-06-29 00:48  Ulrich Drepper  <drepper@cygnus.com>

	* semaphore.c: Include spinlock.h at correct place.
	Patch by HJ Lu.

1997-06-13 10:06  Richard Henderson  <rth@tamu.edu>

	The Great Bit File Move:
	* sysdeps/alpha/semaphorebits.h: -> .../bits/semaphore.h.
	* sysdeps/powerpc/semaphorebits.h: Likewise.
	* sysdeps/pthread/cmpxchg/semaphorebits.h: Likewise.
	* sysdeps/pthread/no-cmpxchg/semaphorebits.h: Likewise.
	* sysdeps/pthread/libc-lock.h: -> bits/
	* sysdeps/pthread/stdio-lock.h: Likewise.
	* sysdeps/unix/sysv/linux/local_lim.h: Likewise.
	* sysdeps/unix/sysv/linux/posix_opt.h: Likewise.
	* semaphore.h: Likewise.
	* sysdeps/pthread/pthread.h: Likewise.

	* lockfile.c: <foo.h> -> <bits/foo.h>.
	* semaphore.h: Likewise.

	* Makefile: (headers): foo.h -> bits/foo.h.
	* sysdeps/pthread/Makefile: Likewise.

1997-04-11 01:18  Andreas Schwab  <schwab@issan.informatik.uni-dortmund.de>

	* semaphore.c (sem_init): Set sem_spinlock only if available.

	* sysdeps/m68k/pt-machine.h (testandset, __compare_and_swap): Fix
	asm constraints.

1997-04-09 03:00  Ulrich Drepper  <drepper@cygnus.com>

	Update from LinuxThreads 0.6.

	* attr.c (pthread_attr_getdetachstate): Use __sched_get_priority_max
	and __sched_get_priority_min instead of names without `__'.

	* manager.c: Rewrite large parts to implement opaque pthread_t.

	* cancel.c: Adapt for opaque pthread_t type.
	* condvar.c: Likewise.
	* errno.c: Likewise.
	* join.c: Likewise.
	* mutex.c: Likewise.
	* pthread.c: Likewise.
	* signals.c: Likewise.
	* specific.c: Likewise.
	* restart.h: Likewise.
	* queue.h: Likewise.
	* Examples/ex3.c: Likewise.
	* Examples/ex4.c: Likewise.
	* sysdeps/pthread/pthread.h: Likewise.

	* pthread.c: Accumulate time for all threads in thread manager.

	* semaphore.c: Implement fallback implementation for architectures
	sometimes missing compare-exchange operations.

	* cancel.c (pthread_cancel): Validate handle argument.
	* join.c (pthread_join): Likewise.
	(pthread_detach): Likewise.
	* signals.c (pthread_kill): Likewise.

	* spinlock.h (acquire): Use __sched_yield not sched_yield.

	* queue.h (enqueue): Enqueue thread according to priority.

	* internals.c (struct pthread_start_args): New struct for passing
	args to cloning function.
	(struct _pthread): Rename to _pthread_descr_struct and adapt for
	opaque pthread_t.

	* Examples/Makefile (clean): Pass -f option to rm.

	* sysdeps/i386/pt-machine.h: Add check for compare-exchange instruction
	and define TEST_FOR_COMPARE_AND_SWAP.
	* sysdeps/i386/i486/pt-machine.h: Removed.

	* sysdeps/unix/sysv/linux/local_lim.h (PTHREAD_THREADS_MAX): Increase
	to 1024.

1997-04-04 16:38  Ulrich Drepper  <drepper@cygnus.com>

	* restart.h (suspend): Clear p_signal before suspending.
	(suspend_with_cancellation): Likewise.
	Patch by Xavier Leroy <Xavier.Leroy@inria.fr>.

	* weaks.c: Make __pthread_key_create return 1.
	* sysdeps/pthread/libc-lock.h: Define __libc_key_create,
	__libc_getspecific, __libc_setspecific, and __libc_key_t.
	* sysdeps/pthread/stdio-lock.h: Don't care for implementation not
	using libio.

1997-03-19 15:13  Miguel de Icaza  <miguel@nuclecu.unam.mx>

	* sysdeps/sparc/pt-machine (RELEASE): Fix.

1997-03-01 07:55  Geoff Keating  <geoffk@ozemail.com.au>

	* sysdeps/powerpc/Implies: Added.
	* sysdeps/powerpc/pt-machine.h: Added.
	* sysdeps/powerpc/semaphorebits.h: Added.

1997-01-22 01:22  Ulrich Drepper  <drepper@cygnus.com>

	* linuxtheads/pthread.c (__pthread_initial_thread): Correct
	initializer.
	(__pthread_manager_thread): Likewise.
	Reported by Andreas Jaeger.

1997-01-18 22:15  Richard Henderson  <rth@tamu.edu>

	Since sigset_t no longer fits in a register, we can't pass in the
	thread's initial mask so easily.  Take this opportunity to simplify
	the clone implementation by only accepting a single void* argument.

	* linuxthreads/manager.c (__pthread_manager): Put thread vitals
	in the thread struct instead of as arguments through clone.
	(pthread_start_thread): Look for them there.
	* linuxthreads/internals.h (struct _pthread): Add p_initial_fn,
	p_initial_fn_arg, p_initial_mask.  Fix __pthread_manager proto.
	* linuxthreads/pthread.c (pthread_initialize_manager): Revise
	clone invocation.

1 files changed, 163 insertions, 0 deletions

diff --git a/linuxthreads/README b/linuxthreads/README
new file mode 100644
index 0000000..e824dd5
--- /dev/null
+++ b/linuxthreads/README
@@ -0,0 +1,163 @@
+        Linuxthreads - POSIX 1003.1c kernel threads for Linux
+
+      Copyright 1996, 1997 Xavier Leroy (Xavier.Leroy@inria.fr)
+
+
+DESCRIPTION:
+
+This is release 0.7 (late beta) of LinuxThreads, a BiCapitalized
+implementation of the Posix 1003.1c "pthread" interface for Linux.
+
+LinuxThreads provides kernel-level threads: each thread is a separate
+Unix process, sharing its address space with the other threads through
+the new system call clone(). Scheduling between threads is handled by
+the kernel scheduler, just like scheduling between Unix processes.
+
+
+REQUIREMENTS:
+
+- Linux version 2.0 and up (requires the new clone() system call
+  and the new realtime scheduler).
+
+- For Intel platforms: libc 5.2.18 or later is required.
+  5.2.18 or 5.4.12 or later are recommended;
+  5.3.12 and 5.4.7 have problems (see the FAQ.html file for more info).
+
+- Also supports glibc 2 (a.k.a. libc 6), which actually comes with
+  a specially-adapted version of this library.
+
+- Currently supports Intel, Alpha, Sparc, Motorola 68k, ARM and MIPS
+  platforms.
+
+- Multiprocessors are supported.
+
+
+INSTALLATION:
+
+- Edit the Makefile, set the variables in the "Configuration" section.
+
+- Do "make".
+
+- Do "make install".
+
+
+USING LINUXTHREADS:
+
+        gcc -D_REENTRANT ... -lpthread
+
+A complete set of manual pages is included. Also see the subdirectory
+Examples/ for some sample programs.
+
+
+STATUS:
+
+- All functions in the Posix 1003.1c base interface implemented.
+  Also supports priority scheduling.
+
+- For users of libc 5 (H.J.Lu's libc), a number of C library functions
+  are reimplemented or wrapped to make them thread-safe, including:
+  * malloc functions
+  * stdio functions (define _REENTRANT before including <stdio.h>)
+  * per-thread errno variable (define _REENTRANT before including <errno.h>)
+  * directory reading functions (opendir(), etc)
+  * sleep()
+  * gmtime(), localtime()
+
+  New library functions provided:
+  * flockfile(), funlockfile(), ftrylockfile()
+  * reentrant versions of network database functions (gethostbyname_r(), etc)
+    and password functions (getpwnam_r(), etc).
+
+- libc 6 (glibc 2) provides much better thread support than libc 5,
+  and comes with a specially-adapted version of LinuxThreads.
+  For serious multithreaded programming, you should consider switching
+  to glibc 2. It is available from prep.ai.mit.edu:/pub/gnu and its mirrors.
+
+
+WARNING:
+
+Many existing libraries are not compatible with LinuxThreads,
+either because they are not inherently thread-safe, or because they
+have not been compiled with the -D_REENTRANT.  For more info, see the
+FAQ.html file in this directory.
+
+A prime example of the latter is Xlib. If you link it with
+LinuxThreads, you'll probably get an "unknown 0 error" very
+early. This is just a consequence of the Xlib binaries using the
+global variable "errno" to fetch error codes, while LinuxThreads and
+the C library use the per-thread "errno" location.
+
+See the file README.Xfree3.3 for info on how to compile the Xfree 3.3
+libraries to make them compatible with LinuxThreads.
+
+
+KNOWN BUGS AND LIMITATIONS:
+
+- Threads share pretty much everything they should share according
+  to the standard: memory space, file descriptors, signal handlers,
+  current working directory, etc. One thing that they do not share
+  is their pid's and parent pid's. According to the standard, they
+  should have the same, but that's one thing we cannot achieve
+  in this implementation (until the CLONE_PID flag to clone() becomes
+  usable).
+
+- The current implementation uses the two signals SIGUSR1 and SIGUSR2,
+  so user-level code cannot employ them. Ideally, there should be two
+  signals reserved for this library. One signal is used for restarting
+  threads blocked on mutexes or conditions; the other is for thread
+  cancellation.
+
+- The stacks for the threads are allocated high in the memory space,
+  below the stack of the initial process, and spaced 2M apart.
+  Stacks are allocated with the "grow on demand" flag, so they don't
+  use much virtual space initially (4k, currently), but can grow
+  up to 2M if needed.
+
+  Reserving such a large address space for each thread means that,
+  on a 32-bit architecture, no more than about 1000 threads can
+  coexist (assuming a 2Gb address space for user processes),
+  but this is reasonable, since each thread uses up one entry in the
+  kernel's process table, which is usually limited to 512 processes.
+
+  Another potential problem of the "grow on demand" scheme is that
+  nothing prevents the user from mmap'ing something in the 2M address
+  window reserved for a thread stack, possibly causing later extensions of
+  that stack to fail. Mapping at fixed addresses should be avoided
+  when using this library.
+
+- Signal handling does not fully conform to the Posix standard,
+  due to the fact that threads are here distinct processes that can be
+  sent signals individually, so there's no notion of sending a signal
+  to "the" process (the collection of all threads).
+  More precisely, here is a summary of the standard requirements
+  and how they are met by the implementation:
+
+  1- Synchronous signals (generated by the thread execution, e.g. SIGFPE)
+     are delivered to the thread that raised them.
+     (OK.)
+
+  2- A fatal asynchronous signal terminates all threads in the process.
+     (OK. The thread manager notices when a thread dies on a signal
+      and kills all other threads with the same signal.)
+
+  3- An asynchronous signal will be delivered to one of the threads
+     of the program which does not block the signal (it is unspecified
+     which).
+     (No, the signal is delivered to the thread it's been sent to,
+      based on the pid of the thread. If that thread is currently
+      blocking the signal, the signal remains pending.)
+
+  4- The signal will be delivered to at most one thread.
+     (OK, except for signals generated from the terminal or sent to
+      the process group, which will be delivered to all threads.)
+
+- The current implementation of the MIPS support assumes a MIPS ISA II
+  processor or better.  These processors support atomic operations by
+  ll/sc instructions.  Older R2000/R3000 series processors are not
+  supported yet; support for these will have higher overhead.
+
+- The current implementation of the ARM support assumes that the SWP
+  (atomic swap register with memory) instruction is available.  This is
+  the case for all processors except for the ARM1 and ARM2.  On StrongARM,
+  the SWP instruction does not bypass the cache, so multi-processor support
+  will be more troublesome.