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authorUlrich Drepper <drepper@redhat.com>1998-03-11 12:42:25 +0000
committerUlrich Drepper <drepper@redhat.com>1998-03-11 12:42:25 +0000
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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.
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+ 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.