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-rw-r--r--Makeconfig5
-rw-r--r--libc.map3
-rw-r--r--linuxthreads/ChangeLog29
-rw-r--r--linuxthreads/attr.c8
-rw-r--r--linuxthreads/cancel.c6
-rw-r--r--linuxthreads/condvar.c79
-rw-r--r--linuxthreads/internals.h28
-rw-r--r--linuxthreads/join.c28
-rw-r--r--linuxthreads/manager.c79
-rw-r--r--linuxthreads/mutex.c122
-rw-r--r--linuxthreads/pthread.c89
-rw-r--r--linuxthreads/ptlongjmp.c2
-rw-r--r--linuxthreads/queue.h57
-rw-r--r--linuxthreads/rwlock.c47
-rw-r--r--linuxthreads/semaphore.c236
-rw-r--r--linuxthreads/semaphore.h7
-rw-r--r--linuxthreads/signals.c89
-rw-r--r--linuxthreads/spinlock.c123
-rw-r--r--linuxthreads/spinlock.h53
-rw-r--r--linuxthreads/sysdeps/i386/pt-machine.h6
-rw-r--r--linuxthreads/sysdeps/pthread/pthread.h38
-rw-r--r--linuxthreads/sysdeps/unix/sysv/linux/bits/posix_opt.h8
-rw-r--r--sysdeps/unix/sysv/linux/bits/sched.h7
23 files changed, 635 insertions, 514 deletions
diff --git a/Makeconfig b/Makeconfig
index d70c4795ef..1ef0cc571d 100644
--- a/Makeconfig
+++ b/Makeconfig
@@ -564,8 +564,9 @@ endif # $(+cflags) == ""
libio-include = -I$(..)libio
# These are the variables that the implicit compilation rules use.
-CPPFLAGS = $(+includes) $(defines) -include $(..)include/libc-symbols.h \
- $(sysdep-CPPFLAGS) $(CPPFLAGS-$(suffix $@)) $(CPPFLAGS-$(<F)) \
+CPPFLAGS = $($(subdir)-CPPFLAGS) $(+includes) $(defines) \
+ -include $(..)include/libc-symbols.h $(sysdep-CPPFLAGS) \
+ $($(subdir)-CPPFLAGS) $(CPPFLAGS-$(suffix $@)) $(CPPFLAGS-$(<F)) \
$(CPPFLAGS-$(@F))
override CFLAGS = $(filter-out %frame-pointer,$(+cflags)) $(sysdep-CFLAGS) \
$(CFLAGS-$(suffix $@)) $(CFLAGS-$(<F)) $(CFLAGS-$(@F))
diff --git a/libc.map b/libc.map
index 309310929d..3024bbd4af 100644
--- a/libc.map
+++ b/libc.map
@@ -87,7 +87,8 @@ GLIBC_2.0 {
__ffs;
__close; __connect; __fcntl; __lseek; __open; __read; __send; __wait;
__ieee_get_fp_control; __ieee_set_fp_control;
- __dgettext;
+ __dgettext; __sigaction;
+
# libio
_IO_adjust_column; _IO_clearerr; _IO_default_doallocate;
_IO_default_finish; _IO_default_pbackfail; _IO_default_uflow;
diff --git a/linuxthreads/ChangeLog b/linuxthreads/ChangeLog
index 69426bfb7c..882aa41d45 100644
--- a/linuxthreads/ChangeLog
+++ b/linuxthreads/ChangeLog
@@ -1,3 +1,32 @@
+1998-06-25 19:27 Ulrich Drepper <drepper@cygnus.com>
+
+ * attr.c: Finish user stack support. Change locking code to be safe
+ in situations with different priorities.
+ * cancel.c: Likewise.
+ * condvar.c: Likewise.
+ * internals.h: Likewise.
+ * join.c: Likewise.
+ * manager.c: Likewise.
+ * mutex.c: Likewise.
+ * pthread.c: Likewise.
+ * ptlongjmp.c: Likewise.
+ * queue.h: Likewise.
+ * rwlock.c: Likewise.
+ * semaphore.c: Likewise.
+ * semaphore.h: Likewise.
+ * signals.c: Likewise.
+ * spinlock.c: Likewise.
+ * spinlock.h: Likewise.
+ Patches by Xavier leroy.
+
+1998-06-25 Ulrich Drepper <drepper@cygnus.com>
+
+ * sysdeps/pthread/pthread.h: Make [sg]et_stacksize and
+ [sg]et_stackaddr prototypes always available.
+
+ * sysdeps/unix/sysv/linux/bits/posix_opt.h: Define
+ _POSIX_THREAD_ATTR_STACKSIZE and _POSIX_THREAD_ATTR_STACKADDR.
+
1998-06-24 Ulrich Drepper <drepper@cygnus.com>
* manager.c (pthread_free): Undo patch from 980430.
diff --git a/linuxthreads/attr.c b/linuxthreads/attr.c
index 027f69c997..d1f605810f 100644
--- a/linuxthreads/attr.c
+++ b/linuxthreads/attr.c
@@ -19,7 +19,6 @@
#include "pthread.h"
#include "internals.h"
-
int __pthread_attr_init_2_1(pthread_attr_t *attr)
{
size_t ps = __getpagesize ();
@@ -185,11 +184,8 @@ weak_alias (__pthread_attr_getstackaddr, pthread_attr_getstackaddr)
int __pthread_attr_setstacksize(pthread_attr_t *attr, size_t stacksize)
{
- size_t ps = __getpagesize ();
-
- /* We don't accept value smaller than PTHREAD_STACK_MIN or bigger than
- 2MB - pagesize. */
- if (stacksize < PTHREAD_STACK_MIN || stacksize > STACK_SIZE - ps)
+ /* We don't accept value smaller than PTHREAD_STACK_MIN. */
+ if (stacksize < PTHREAD_STACK_MIN)
return EINVAL;
attr->stacksize = stacksize;
diff --git a/linuxthreads/cancel.c b/linuxthreads/cancel.c
index a6a0ecaa5a..cd2bbace12 100644
--- a/linuxthreads/cancel.c
+++ b/linuxthreads/cancel.c
@@ -53,14 +53,14 @@ int pthread_cancel(pthread_t thread)
pthread_handle handle = thread_handle(thread);
int pid;
- acquire(&handle->h_spinlock);
+ __pthread_lock(&handle->h_lock);
if (invalid_handle(handle, thread)) {
- release(&handle->h_spinlock);
+ __pthread_unlock(&handle->h_lock);
return ESRCH;
}
handle->h_descr->p_canceled = 1;
pid = handle->h_descr->p_pid;
- release(&handle->h_spinlock);
+ __pthread_unlock(&handle->h_lock);
kill(pid, PTHREAD_SIG_CANCEL);
return 0;
}
diff --git a/linuxthreads/condvar.c b/linuxthreads/condvar.c
index 6807522edc..91067d2d17 100644
--- a/linuxthreads/condvar.c
+++ b/linuxthreads/condvar.c
@@ -25,42 +25,36 @@
#include "queue.h"
#include "restart.h"
-static void remove_from_queue(pthread_queue * q, pthread_descr th);
-
int pthread_cond_init(pthread_cond_t *cond,
const pthread_condattr_t *cond_attr)
{
- cond->c_spinlock = 0;
- queue_init(&cond->c_waiting);
+ __pthread_init_lock(&cond->c_lock);
+ cond->c_waiting = NULL;
return 0;
}
int pthread_cond_destroy(pthread_cond_t *cond)
{
- pthread_descr head;
-
- acquire(&cond->c_spinlock);
- head = cond->c_waiting.head;
- release(&cond->c_spinlock);
- if (head != NULL) return EBUSY;
+ if (cond->c_waiting != NULL) return EBUSY;
return 0;
}
int pthread_cond_wait(pthread_cond_t *cond, pthread_mutex_t *mutex)
{
volatile pthread_descr self = thread_self();
- acquire(&cond->c_spinlock);
+
+ __pthread_lock(&cond->c_lock);
enqueue(&cond->c_waiting, self);
- release(&cond->c_spinlock);
+ __pthread_unlock(&cond->c_lock);
pthread_mutex_unlock(mutex);
suspend_with_cancellation(self);
pthread_mutex_lock(mutex);
/* This is a cancellation point */
if (self->p_canceled && self->p_cancelstate == PTHREAD_CANCEL_ENABLE) {
/* Remove ourselves from the waiting queue if we're still on it */
- acquire(&cond->c_spinlock);
+ __pthread_lock(&cond->c_lock);
remove_from_queue(&cond->c_waiting, self);
- release(&cond->c_spinlock);
+ __pthread_unlock(&cond->c_lock);
pthread_exit(PTHREAD_CANCELED);
}
return 0;
@@ -77,15 +71,14 @@ pthread_cond_timedwait_relative(pthread_cond_t *cond,
sigjmp_buf jmpbuf;
/* Wait on the condition */
- acquire(&cond->c_spinlock);
+ __pthread_lock(&cond->c_lock);
enqueue(&cond->c_waiting, self);
- release(&cond->c_spinlock);
+ __pthread_unlock(&cond->c_lock);
pthread_mutex_unlock(mutex);
- /* Set up a longjmp handler for the restart signal */
- /* No need to save the signal mask, since PTHREAD_SIG_RESTART will be
- blocked when doing the siglongjmp, and we'll just leave it blocked. */
- if (sigsetjmp(jmpbuf, 0) == 0) {
+ /* Set up a longjmp handler for the restart and cancel signals */
+ if (sigsetjmp(jmpbuf, 1) == 0) {
self->p_signal_jmp = &jmpbuf;
+ self->p_cancel_jmp = &jmpbuf;
self->p_signal = 0;
/* Check for cancellation */
if (self->p_canceled && self->p_cancelstate == PTHREAD_CANCEL_ENABLE) {
@@ -104,28 +97,28 @@ pthread_cond_timedwait_relative(pthread_cond_t *cond,
retsleep = -1;
}
self->p_signal_jmp = NULL;
+ self->p_cancel_jmp = NULL;
/* Here, either the condition was signaled (self->p_signal != 0)
or we got canceled (self->p_canceled != 0)
or the timeout occurred (retsleep == 0)
or another interrupt occurred (retsleep == -1) */
- /* Re-acquire the spinlock */
- acquire(&cond->c_spinlock);
/* This is a cancellation point */
if (self->p_canceled && self->p_cancelstate == PTHREAD_CANCEL_ENABLE) {
+ __pthread_lock(&cond->c_lock);
remove_from_queue(&cond->c_waiting, self);
- release(&cond->c_spinlock);
+ __pthread_unlock(&cond->c_lock);
pthread_mutex_lock(mutex);
pthread_exit(PTHREAD_CANCELED);
}
/* If not signaled: also remove ourselves and return an error code */
if (self->p_signal == 0) {
+ __pthread_lock(&cond->c_lock);
remove_from_queue(&cond->c_waiting, self);
- release(&cond->c_spinlock);
+ __pthread_unlock(&cond->c_lock);
pthread_mutex_lock(mutex);
return retsleep == 0 ? ETIMEDOUT : EINTR;
}
/* Otherwise, return normally */
- release(&cond->c_spinlock);
pthread_mutex_lock(mutex);
return 0;
}
@@ -151,23 +144,22 @@ int pthread_cond_signal(pthread_cond_t *cond)
{
pthread_descr th;
- acquire(&cond->c_spinlock);
+ __pthread_lock(&cond->c_lock);
th = dequeue(&cond->c_waiting);
- release(&cond->c_spinlock);
+ __pthread_unlock(&cond->c_lock);
if (th != NULL) restart(th);
return 0;
}
int pthread_cond_broadcast(pthread_cond_t *cond)
{
- pthread_queue tosignal;
- pthread_descr th;
+ pthread_descr tosignal, th;
- acquire(&cond->c_spinlock);
+ __pthread_lock(&cond->c_lock);
/* Copy the current state of the waiting queue and empty it */
tosignal = cond->c_waiting;
- queue_init(&cond->c_waiting);
- release(&cond->c_spinlock);
+ cond->c_waiting = NULL;
+ __pthread_unlock(&cond->c_lock);
/* Now signal each process in the queue */
while ((th = dequeue(&tosignal)) != NULL) restart(th);
return 0;
@@ -182,26 +174,3 @@ int pthread_condattr_destroy(pthread_condattr_t *attr)
{
return 0;
}
-
-/* Auxiliary function on queues */
-
-static void remove_from_queue(pthread_queue * q, pthread_descr th)
-{
- pthread_descr t;
-
- if (q->head == NULL) return;
- if (q->head == th) {
- q->head = th->p_nextwaiting;
- if (q->head == NULL) q->tail = NULL;
- th->p_nextwaiting = NULL;
- return;
- }
- for (t = q->head; t->p_nextwaiting != NULL; t = t->p_nextwaiting) {
- if (t->p_nextwaiting == th) {
- t->p_nextwaiting = th->p_nextwaiting;
- if (th->p_nextwaiting == NULL) q->tail = t;
- th->p_nextwaiting = NULL;
- return;
- }
- }
-}
diff --git a/linuxthreads/internals.h b/linuxthreads/internals.h
index ab6b66a857..0a01b61ede 100644
--- a/linuxthreads/internals.h
+++ b/linuxthreads/internals.h
@@ -63,7 +63,7 @@ struct _pthread_descr_struct {
pthread_t p_tid; /* Thread identifier */
int p_pid; /* PID of Unix process */
int p_priority; /* Thread priority (== 0 if not realtime) */
- int * p_spinlock; /* Spinlock for synchronized accesses */
+ struct _pthread_fastlock * p_lock; /* Spinlock for synchronized accesses */
int p_signal; /* last signal received */
sigjmp_buf * p_signal_jmp; /* where to siglongjmp on a signal or NULL */
sigjmp_buf * p_cancel_jmp; /* where to siglongjmp on a cancel or NULL */
@@ -81,6 +81,8 @@ struct _pthread_descr_struct {
int p_errno; /* error returned by last system call */
int * p_h_errnop; /* pointer to used h_errno variable */
int p_h_errno; /* error returned by last netdb function */
+ char * p_in_sighandler; /* stack address of sighandler, or NULL */
+ char p_sigwaiting; /* true if a sigwait() is in progress */
struct pthread_start_args p_start_args; /* arguments for thread creation */
void ** p_specific[PTHREAD_KEY_1STLEVEL_SIZE]; /* thread-specific data */
void * p_libc_specific[_LIBC_TSD_KEY_N]; /* thread-specific data for libc */
@@ -94,8 +96,9 @@ struct _pthread_descr_struct {
typedef struct pthread_handle_struct * pthread_handle;
struct pthread_handle_struct {
- int h_spinlock; /* Spinlock for sychronized access */
+ struct _pthread_fastlock h_lock; /* Fast lock for sychronized access */
pthread_descr h_descr; /* Thread descriptor or NULL if invalid */
+ char * h_bottom; /* Lowest address in the stack thread */
};
/* The type of messages sent to the thread manager thread */
@@ -103,7 +106,8 @@ struct pthread_handle_struct {
struct pthread_request {
pthread_descr req_thread; /* Thread doing the request */
enum { /* Request kind */
- REQ_CREATE, REQ_FREE, REQ_PROCESS_EXIT, REQ_MAIN_THREAD_EXIT
+ REQ_CREATE, REQ_FREE, REQ_PROCESS_EXIT, REQ_MAIN_THREAD_EXIT,
+ REQ_POST, REQ_DEBUG
} req_kind;
union { /* Arguments for request */
struct { /* For REQ_CREATE: */
@@ -118,6 +122,7 @@ struct pthread_request {
struct { /* For REQ_PROCESS_EXIT: */
int code; /* exit status */
} exit;
+ void * post; /* For REQ_POST: the semaphore */
} req_args;
};
@@ -160,6 +165,11 @@ extern pthread_descr __pthread_main_thread;
extern char *__pthread_initial_thread_bos;
+/* Indicate whether at least one thread has a user-defined stack (if 1),
+ or all threads have stacks supplied by LinuxThreads (if 0). */
+
+extern int __pthread_nonstandard_stacks;
+
/* File descriptor for sending requests to the thread manager.
Initially -1, meaning that pthread_initialize must be called. */
@@ -178,6 +188,10 @@ extern char *__pthread_manager_thread_tos;
extern int __pthread_exit_requested, __pthread_exit_code;
+/* Set to 1 by gdb if we're debugging */
+
+extern volatile int __pthread_threads_debug;
+
/* Return the handle corresponding to a thread id */
static inline pthread_handle thread_handle(pthread_t id)
@@ -233,6 +247,8 @@ static inline int invalid_handle(pthread_handle h, pthread_t id)
/* Recover thread descriptor for the current thread */
+extern pthread_descr __pthread_find_self (void) __attribute__ ((const));
+
static inline pthread_descr thread_self (void) __attribute__ ((const));
static inline pthread_descr thread_self (void)
{
@@ -245,6 +261,8 @@ static inline pthread_descr thread_self (void)
else if (sp >= __pthread_manager_thread_bos
&& sp < __pthread_manager_thread_tos)
return &__pthread_manager_thread;
+ else if (__pthread_nonstandard_stacks)
+ return __pthread_find_self();
else
return (pthread_descr)(((unsigned long)sp | (STACK_SIZE-1))+1) - 1;
#endif
@@ -282,8 +300,8 @@ static inline pthread_descr thread_self (void)
void __pthread_destroy_specifics(void);
void __pthread_perform_cleanup(void);
-void __pthread_sighandler(int sig);
-void __pthread_message(char * fmt, long arg, ...);
+int __pthread_initialize_manager(void);
+void __pthread_message(char * fmt, ...);
int __pthread_manager(void *reqfd);
void __pthread_manager_sighandler(int sig);
void __pthread_reset_main_thread(void);
diff --git a/linuxthreads/join.c b/linuxthreads/join.c
index 2bdc189631..c59de6985a 100644
--- a/linuxthreads/join.c
+++ b/linuxthreads/join.c
@@ -35,13 +35,13 @@ void pthread_exit(void * retval)
__pthread_perform_cleanup();
__pthread_destroy_specifics();
/* Store return value */
- acquire(self->p_spinlock);
+ __pthread_lock(self->p_lock);
self->p_retval = retval;
/* Say that we've terminated */
self->p_terminated = 1;
/* See if someone is joining on us */
joining = self->p_joining;
- release(self->p_spinlock);
+ __pthread_unlock(self->p_lock);
/* Restart joining thread if any */
if (joining != NULL) restart(joining);
/* If this is the initial thread, block until all threads have terminated.
@@ -65,36 +65,36 @@ int pthread_join(pthread_t thread_id, void ** thread_return)
pthread_handle handle = thread_handle(thread_id);
pthread_descr th;
- acquire(&handle->h_spinlock);
+ __pthread_lock(&handle->h_lock);
if (invalid_handle(handle, thread_id)) {
- release(&handle->h_spinlock);
+ __pthread_unlock(&handle->h_lock);
return ESRCH;
}
th = handle->h_descr;
if (th == self) {
- release(&handle->h_spinlock);
+ __pthread_unlock(&handle->h_lock);
return EDEADLK;
}
/* If detached or already joined, error */
if (th->p_detached || th->p_joining != NULL) {
- release(&handle->h_spinlock);
+ __pthread_unlock(&handle->h_lock);
return EINVAL;
}
/* If not terminated yet, suspend ourselves. */
if (! th->p_terminated) {
th->p_joining = self;
- release(&handle->h_spinlock);
+ __pthread_unlock(&handle->h_lock);
suspend_with_cancellation(self);
/* This is a cancellation point */
if (self->p_canceled && self->p_cancelstate == PTHREAD_CANCEL_ENABLE) {
th->p_joining = NULL;
pthread_exit(PTHREAD_CANCELED);
}
- acquire(&handle->h_spinlock);
+ __pthread_lock(&handle->h_lock);
}
/* Get return value */
if (thread_return != NULL) *thread_return = th->p_retval;
- release(&handle->h_spinlock);
+ __pthread_unlock(&handle->h_lock);
/* Send notification to thread manager */
if (__pthread_manager_request >= 0) {
request.req_thread = self;
@@ -113,26 +113,26 @@ int pthread_detach(pthread_t thread_id)
pthread_handle handle = thread_handle(thread_id);
pthread_descr th;
- acquire(&handle->h_spinlock);
+ __pthread_lock(&handle->h_lock);
if (invalid_handle(handle, thread_id)) {
- release(&handle->h_spinlock);
+ __pthread_unlock(&handle->h_lock);
return ESRCH;
}
th = handle->h_descr;
/* If already detached, error */
if (th->p_detached) {
- release(&handle->h_spinlock);
+ __pthread_unlock(&handle->h_lock);
return EINVAL;
}
/* If already joining, don't do anything. */
if (th->p_joining != NULL) {
- release(&handle->h_spinlock);
+ __pthread_unlock(&handle->h_lock);
return 0;
}
/* Mark as detached */
th->p_detached = 1;
terminated = th->p_terminated;
- release(&handle->h_spinlock);
+ __pthread_unlock(&handle->h_lock);
/* If already terminated, notify thread manager to reclaim resources */
if (terminated && __pthread_manager_request >= 0) {
request.req_thread = thread_self();
diff --git a/linuxthreads/manager.c b/linuxthreads/manager.c
index ac78d6e4ce..36c592197e 100644
--- a/linuxthreads/manager.c
+++ b/linuxthreads/manager.c
@@ -31,15 +31,22 @@
#include "internals.h"
#include "spinlock.h"
#include "restart.h"
+#include "semaphore.h"
/* Array of active threads. Entry 0 is reserved for the initial thread. */
-
struct pthread_handle_struct __pthread_handles[PTHREAD_THREADS_MAX] =
-{ { 0, &__pthread_initial_thread, 0}, /* All NULLs */ };
+{ { LOCK_INITIALIZER, &__pthread_initial_thread, 0}, /* All NULLs */ };
/* Indicate whether at least one thread has a user-defined stack (if 1),
or if all threads have stacks supplied by LinuxThreads (if 0). */
-int __pthread_nonstandard_stacks;
+int __pthread_nonstandard_stacks = 0;
+
+/* Number of active entries in __pthread_handles (used by gdb) */
+volatile int __pthread_handles_num = 1;
+
+/* Whether to use debugger additional actions for thread creation
+ (set to 1 by gdb) */
+volatile int __pthread_threads_debug = 0;
/* Mapping from stack segment to thread descriptor. */
/* Stack segment numbers are also indices into the __pthread_handles array. */
@@ -93,12 +100,18 @@ int __pthread_manager(void *arg)
/* Set the error variable. */
__pthread_manager_thread.p_errnop = &__pthread_manager_thread.p_errno;
__pthread_manager_thread.p_h_errnop = &__pthread_manager_thread.p_h_errno;
- /* Block all signals except PTHREAD_SIG_RESTART */
+ /* Block all signals except PTHREAD_SIG_RESTART, PTHREAD_SIG_CANCEL
+ and SIGTRAP */
sigfillset(&mask);
sigdelset(&mask, PTHREAD_SIG_RESTART);
+ sigdelset(&mask, PTHREAD_SIG_CANCEL); /* for debugging new threads */
+ sigdelset(&mask, SIGTRAP); /* for debugging purposes */
sigprocmask(SIG_SETMASK, &mask, NULL);
/* Raise our priority to match that of main thread */
__pthread_manager_adjust_prio(__pthread_main_thread->p_priority);
+ /* Synchronize debugging of the thread manager */
+ n = __libc_read(reqfd, (char *)&request, sizeof(request));
+ ASSERT(n == sizeof(request) && request.req_kind == REQ_DEBUG);
/* Enter server loop */
while(1) {
FD_ZERO(&readfds);
@@ -146,6 +159,14 @@ int __pthread_manager(void *arg)
return 0;
}
break;
+ case REQ_POST:
+ sem_post(request.req_args.post);
+ break;
+ case REQ_DEBUG:
+ /* Make gdb aware of new thread */
+ if (__pthread_threads_debug) raise(PTHREAD_SIG_CANCEL);
+ restart(request.req_thread);
+ break;
}
}
}
@@ -156,6 +177,7 @@ int __pthread_manager(void *arg)
static int pthread_start_thread(void *arg)
{
pthread_descr self = (pthread_descr) arg;
+ struct pthread_request request;
void * outcome;
/* Initialize special thread_self processing, if any. */
#ifdef INIT_THREAD_SELF
@@ -171,6 +193,14 @@ static int pthread_start_thread(void *arg)
if (self->p_start_args.schedpolicy >= 0)
__sched_setscheduler(self->p_pid, self->p_start_args.schedpolicy,
&self->p_start_args.schedparam);
+ /* Make gdb aware of new thread */
+ if (__pthread_threads_debug) {
+ request.req_thread = self;
+ request.req_kind = REQ_DEBUG;
+ __libc_write(__pthread_manager_request,
+ (char *) &request, sizeof(request));
+ suspend(self);
+ }
/* Run the thread code */
outcome = self->p_start_args.start_routine(self->p_start_args.arg);
/* Exit with the given return value */
@@ -188,6 +218,7 @@ static int pthread_handle_create(pthread_t *thread, const pthread_attr_t *attr,
char * new_thread_bottom;
pthread_t new_thread_id;
void *guardaddr = NULL;
+ size_t guardsize = 0;
/* Find a free stack segment for the current stack */
for (sseg = 1; ; sseg++)
@@ -211,13 +242,16 @@ static int pthread_handle_create(pthread_t *thread, const pthread_attr_t *attr,
and allocate it if necessary. */
if (attr == NULL || attr->guardsize != 0)
{
+ guardsize = attr ? attr->guardsize : __getpagesize ();
guardaddr = mmap ((caddr_t)((char *)(new_thread+1)
- STACK_SIZE),
- attr ? attr->guardsize : __getpagesize (),
- 0, MAP_FIXED, -1, 0);
+ guardsize, 0, MAP_FIXED, -1, 0);
if (guardaddr == MAP_FAILED)
- /* We don't make this an error. */
- guardaddr = NULL;
+ {
+ /* We don't make this an error. */
+ guardaddr = NULL;
+ guardsize = 0;
+ }
}
break;
}
@@ -238,7 +272,7 @@ static int pthread_handle_create(pthread_t *thread, const pthread_attr_t *attr,
new_thread->p_nextwaiting = NULL;
new_thread->p_tid = new_thread_id;
new_thread->p_priority = 0;
- new_thread->p_spinlock = &(__pthread_handles[sseg].h_spinlock);
+ new_thread->p_lock = &(__pthread_handles[sseg].h_lock);
new_thread->p_signal = 0;
new_thread->p_signal_jmp = NULL;
new_thread->p_cancel_jmp = NULL;
@@ -255,16 +289,15 @@ static int pthread_handle_create(pthread_t *thread, const pthread_attr_t *attr,
new_thread->p_errno = 0;
new_thread->p_h_errnop = &new_thread->p_h_errno;
new_thread->p_h_errno = 0;
+ new_thread->p_in_sighandler = NULL;
+ new_thread->p_sigwaiting = 0;
new_thread->p_guardaddr = guardaddr;
- new_thread->p_guardsize = (guardaddr == NULL
- ? 0
- : (attr == NULL
- ? __getpagesize () : attr->guardsize));
+ new_thread->p_guardsize = guardsize;
new_thread->p_userstack = attr != NULL && attr->stackaddr_set;
memset (new_thread->p_specific, '\0',
PTHREAD_KEY_1STLEVEL_SIZE * sizeof (new_thread->p_specific[0]));
/* Initialize the thread handle */
- __pthread_handles[sseg].h_spinlock = 0; /* should already be 0 */
+ __pthread_init_lock(&__pthread_handles[sseg].h_lock);
__pthread_handles[sseg].h_descr = new_thread;
__pthread_handles[sseg].h_bottom = new_thread_bottom;
/* Determine scheduling parameters for the thread */
@@ -305,6 +338,8 @@ static int pthread_handle_create(pthread_t *thread, const pthread_attr_t *attr,
munmap(new_thread->p_guardaddr, new_thread->p_guardsize);
}
__pthread_handles[sseg].h_descr = NULL;
+ __pthread_handles[sseg].h_bottom = NULL;
+ __pthread_handles_num--;
return errno;
}
/* Insert new thread in doubly linked list of active threads */
@@ -330,10 +365,12 @@ static void pthread_free(pthread_descr th)
ASSERT(th->p_exited);
/* Make the handle invalid */
handle = thread_handle(th->p_tid);
- acquire(&handle->h_spinlock);
+ __pthread_lock(&handle->h_lock);
handle->h_descr = NULL;
handle->h_bottom = (char *)(-1L);
- release(&handle->h_spinlock);
+ __pthread_unlock(&handle->h_lock);
+ /* One fewer threads in __pthread_handles */
+ __pthread_handles_num--;
/* If initial thread, nothing to free */
if (th == &__pthread_initial_thread) return;
if (!th->p_userstack)
@@ -360,10 +397,10 @@ static void pthread_exited(pid_t pid)
th->p_nextlive->p_prevlive = th->p_prevlive;
th->p_prevlive->p_nextlive = th->p_nextlive;
/* Mark thread as exited, and if detached, free its resources */
- acquire(th->p_spinlock);
+ __pthread_lock(th->p_lock);
th->p_exited = 1;
detached = th->p_detached;
- release(th->p_spinlock);
+ __pthread_unlock(th->p_lock);
if (detached) pthread_free(th);
break;
}
@@ -409,16 +446,16 @@ static void pthread_handle_free(pthread_descr th)
} while (t != __pthread_main_thread);
if (t != th) return;
- acquire(th->p_spinlock);
+ __pthread_lock(th->p_lock);
if (th->p_exited) {
- release(th->p_spinlock);
+ __pthread_unlock(th->p_lock);
pthread_free(th);
} else {
/* The Unix process of the thread is still running.
Mark the thread as detached so that the thread manager will
deallocate its resources when the Unix process exits. */
th->p_detached = 1;
- release(th->p_spinlock);
+ __pthread_unlock(th->p_lock);
}
}
diff --git a/linuxthreads/mutex.c b/linuxthreads/mutex.c
index 3b40ac04c5..54504bfbc3 100644
--- a/linuxthreads/mutex.c
+++ b/linuxthreads/mutex.c
@@ -26,23 +26,18 @@
int __pthread_mutex_init(pthread_mutex_t * mutex,
const pthread_mutexattr_t * mutex_attr)
{
- mutex->m_spinlock = 0;
- mutex->m_count = 0;
- mutex->m_owner = NULL;
+ __pthread_init_lock(&mutex->m_lock);
mutex->m_kind =
mutex_attr == NULL ? PTHREAD_MUTEX_FAST_NP : mutex_attr->mutexkind;
- queue_init(&mutex->m_waiting);
+ mutex->m_count = 0;
+ mutex->m_owner = NULL;
return 0;
}
weak_alias (__pthread_mutex_init, pthread_mutex_init)
int __pthread_mutex_destroy(pthread_mutex_t * mutex)
{
- int count;
- acquire(&mutex->m_spinlock);
- count = mutex->m_count;
- release(&mutex->m_spinlock);
- if (count > 0) return EBUSY;
+ if (mutex->m_lock.status != 0) return EBUSY;
return 0;
}
weak_alias (__pthread_mutex_destroy, pthread_mutex_destroy)
@@ -50,40 +45,33 @@ weak_alias (__pthread_mutex_destroy, pthread_mutex_destroy)
int __pthread_mutex_trylock(pthread_mutex_t * mutex)
{
pthread_descr self;
+ int retcode;
- acquire(&mutex->m_spinlock);
switch(mutex->m_kind) {
case PTHREAD_MUTEX_FAST_NP:
- if (mutex->m_count == 0) {
- mutex->m_count = 1;
- release(&mutex->m_spinlock);
- return 0;
- }
- break;
+ retcode = __pthread_trylock(&mutex->m_lock);
+ return retcode;
case PTHREAD_MUTEX_RECURSIVE_NP:
self = thread_self();
- if (mutex->m_count == 0 || mutex->m_owner == self) {
+ if (mutex->m_owner == self) {
mutex->m_count++;
- mutex->m_owner = self;
- release(&mutex->m_spinlock);
return 0;
}
- break;
- case PTHREAD_MUTEX_ERRORCHECK_NP:
- self = thread_self();
- if (mutex->m_count == 0) {
- mutex->m_count = 1;
+ retcode = __pthread_trylock(&mutex->m_lock);
+ if (retcode == 0) {
mutex->m_owner = self;
- release(&mutex->m_spinlock);
- return 0;
+ mutex->m_count = 0;
+ }
+ return retcode;
+ case PTHREAD_MUTEX_ERRORCHECK_NP:
+ retcode = __pthread_trylock(&mutex->m_lock);
+ if (retcode == 0) {
+ mutex->m_owner = thread_self();
}
- break;
+ return retcode;
default:
- release(&mutex->m_spinlock);
return EINVAL;
}
- release(&mutex->m_spinlock);
- return EBUSY;
}
weak_alias (__pthread_mutex_trylock, pthread_mutex_trylock)
@@ -91,87 +79,55 @@ int __pthread_mutex_lock(pthread_mutex_t * mutex)
{
pthread_descr self;
- acquire(&mutex->m_spinlock);
switch(mutex->m_kind) {
case PTHREAD_MUTEX_FAST_NP:
- if (mutex->m_count == 0) {
- mutex->m_count = 1;
- release(&mutex->m_spinlock);
- return 0;
- }
- self = thread_self();
- break;
+ __pthread_lock(&mutex->m_lock);
+ return 0;
case PTHREAD_MUTEX_RECURSIVE_NP:
self = thread_self();
- if (mutex->m_count == 0 || mutex->m_owner == self) {
+ if (mutex->m_owner == self) {
mutex->m_count++;
- mutex->m_owner = self;
- release(&mutex->m_spinlock);
return 0;
}
- break;
+ __pthread_lock(&mutex->m_lock);
+ mutex->m_owner = self;
+ mutex->m_count = 0;
+ return 0;
case PTHREAD_MUTEX_ERRORCHECK_NP:
self = thread_self();
- if (mutex->m_count == 0) {
- mutex->m_count = 1;
- mutex->m_owner = self;
- release(&mutex->m_spinlock);
- return 0;
- } else if (mutex->m_owner == self) {
- release(&mutex->m_spinlock);
- return EDEADLK;
- }
- break;
+ if (mutex->m_owner == self) return EDEADLK;
+ __pthread_lock(&mutex->m_lock);
+ mutex->m_owner = self;
+ return 0;
default:
- release(&mutex->m_spinlock);
return EINVAL;
}
- /* Suspend ourselves */
- enqueue(&mutex->m_waiting, self);
- release(&mutex->m_spinlock);
- suspend(self); /* This is not a cancellation point */
- /* Now we own the mutex */
- ASSERT(mutex->m_count == 1);
- mutex->m_owner = self; /* for recursive and errorcheck mutexes */
- return 0;
}
weak_alias (__pthread_mutex_lock, pthread_mutex_lock)
int __pthread_mutex_unlock(pthread_mutex_t * mutex)
{
- pthread_descr th;
-
- acquire(&mutex->m_spinlock);
switch (mutex->m_kind) {
case PTHREAD_MUTEX_FAST_NP:
- break;
+ __pthread_unlock(&mutex->m_lock);
+ return 0;
case PTHREAD_MUTEX_RECURSIVE_NP:
- if (mutex->m_count >= 2) {
+ if (mutex->m_count > 0) {
mutex->m_count--;
- release(&mutex->m_spinlock);
return 0;
}
- break;
+ mutex->m_owner = NULL;
+ __pthread_unlock(&mutex->m_lock);
+ return 0;
case PTHREAD_MUTEX_ERRORCHECK_NP:
- if (mutex->m_count == 0 || mutex->m_owner != thread_self()) {
- release(&mutex->m_spinlock);
+ if (mutex->m_owner != thread_self() || mutex->m_lock.status == 0)
return EPERM;
- }
- break;
+ mutex->m_owner = NULL;
+ __pthread_unlock(&mutex->m_lock);
+ return 0;
default:
- release(&mutex->m_spinlock);
return EINVAL;
}
- th = dequeue(&mutex->m_waiting);
- /* If no waiters, unlock the mutex */
- if (th == NULL) mutex->m_count = 0;
- release(&mutex->m_spinlock);
- /* If there is a waiter, restart it with the mutex still locked */
- if (th != NULL) {
- mutex->m_owner = NULL; /* we no longer own the mutex */
- restart(th);
- }
- return 0;
}
weak_alias (__pthread_mutex_unlock, pthread_mutex_unlock)
diff --git a/linuxthreads/pthread.c b/linuxthreads/pthread.c
index 83d160622d..e95b352b72 100644
--- a/linuxthreads/pthread.c
+++ b/linuxthreads/pthread.c
@@ -35,7 +35,7 @@ struct _pthread_descr_struct __pthread_initial_thread = {
PTHREAD_THREADS_MAX, /* pthread_t p_tid */
0, /* int p_pid */
0, /* int p_priority */
- &__pthread_handles[0].h_spinlock, /* int * p_spinlock */
+ &__pthread_handles[0].h_lock, /* struct _pthread_fastlock * p_lock */
0, /* int p_signal */
NULL, /* sigjmp_buf * p_signal_buf */
NULL, /* sigjmp_buf * p_cancel_buf */
@@ -53,6 +53,8 @@ struct _pthread_descr_struct __pthread_initial_thread = {
0, /* int p_errno */
NULL, /* int *p_h_errnop */
0, /* int p_h_errno */
+ NULL, /* char * p_in_sighandler */
+ 0, /* char p_sigwaiting */
PTHREAD_START_ARGS_INITIALIZER, /* struct pthread_start_args p_start_args */
{NULL} /* void * p_specific[PTHREAD_KEYS_MAX] */
};
@@ -68,7 +70,7 @@ struct _pthread_descr_struct __pthread_manager_thread = {
0, /* int p_tid */
0, /* int p_pid */
0, /* int p_priority */
- NULL, /* int * p_spinlock */
+ NULL, /* struct _pthread_fastlock * p_lock */
0, /* int p_signal */
NULL, /* sigjmp_buf * p_signal_buf */
NULL, /* sigjmp_buf * p_cancel_buf */
@@ -86,6 +88,8 @@ struct _pthread_descr_struct __pthread_manager_thread = {
0, /* int p_errno */
NULL, /* int *p_h_errnop */
0, /* int p_h_errno */
+ NULL, /* char * p_in_sighandler */
+ 0, /* char p_sigwaiting */
PTHREAD_START_ARGS_INITIALIZER, /* struct pthread_start_args p_start_args */
{NULL} /* void * p_specific[PTHREAD_KEYS_MAX] */
};
@@ -119,6 +123,15 @@ char *__pthread_manager_thread_tos = NULL;
int __pthread_exit_requested = 0;
int __pthread_exit_code = 0;
+/* Communicate relevant LinuxThreads constants to gdb */
+
+const int __pthread_threads_max = PTHREAD_THREADS_MAX;
+const int __pthread_sizeof_handle = sizeof(struct pthread_handle_struct);
+const int __pthread_offsetof_descr = offsetof(struct pthread_handle_struct,
+ h_descr);
+const int __pthread_offsetof_pid = offsetof(struct _pthread_descr_struct,
+ p_pid);
+
/* Signal numbers used for the communication. */
int __pthread_sig_restart;
int __pthread_sig_cancel;
@@ -131,6 +144,7 @@ extern int _h_errno;
static void pthread_exit_process(int retcode, void *arg);
static void pthread_handle_sigcancel(int sig);
+static void pthread_handle_sigrestart(int sig);
/* Initialize the pthread library.
Initialization is split in two functions:
@@ -148,6 +162,10 @@ static void pthread_initialize(void)
/* If already done (e.g. by a constructor called earlier!), bail out */
if (__pthread_initial_thread_bos != NULL) return;
+#ifdef TEST_FOR_COMPARE_AND_SWAP
+ /* Test if compare-and-swap is available */
+ __pthread_has_cas = compare_and_swap_is_available();
+#endif
/* For the initial stack, reserve at least STACK_SIZE bytes of stack
below the current stack address, and align that on a
STACK_SIZE boundary. */
@@ -178,14 +196,14 @@ static void pthread_initialize(void)
/* Setup signal handlers for the initial thread.
Since signal handlers are shared between threads, these settings
will be inherited by all other threads. */
- sa.sa_handler = __pthread_sighandler;
+ sa.sa_handler = pthread_handle_sigrestart;
sigemptyset(&sa.sa_mask);
sa.sa_flags = SA_RESTART; /* does not matter for regular threads, but
better for the thread manager */
- sigaction(PTHREAD_SIG_RESTART, &sa, NULL);
+ __sigaction(PTHREAD_SIG_RESTART, &sa, NULL);
sa.sa_handler = pthread_handle_sigcancel;
sa.sa_flags = 0;
- sigaction(PTHREAD_SIG_CANCEL, &sa, NULL);
+ __sigaction(PTHREAD_SIG_CANCEL, &sa, NULL);
/* Initially, block PTHREAD_SIG_RESTART. Will be unblocked on demand. */
sigemptyset(&mask);
@@ -197,10 +215,11 @@ static void pthread_initialize(void)
__on_exit(pthread_exit_process, NULL);
}
-static int pthread_initialize_manager(void)
+int __pthread_initialize_manager(void)
{
int manager_pipe[2];
int pid;
+ struct pthread_request request;
/* If basic initialization not done yet (e.g. we're called from a
constructor run before our constructor), do it now */
@@ -228,6 +247,11 @@ static int pthread_initialize_manager(void)
__pthread_manager_request = manager_pipe[1]; /* writing end */
__pthread_manager_reader = manager_pipe[0]; /* reading end */
__pthread_manager_thread.p_pid = pid;
+ /* Make gdb aware of new thread manager */
+ if (__pthread_threads_debug) raise(PTHREAD_SIG_CANCEL);
+ /* Synchronize debugging of the thread manager */
+ request.req_kind = REQ_DEBUG;
+ __libc_write(__pthread_manager_request, (char *) &request, sizeof(request));
return 0;
}
@@ -239,7 +263,7 @@ int __pthread_create_2_1(pthread_t *thread, const pthread_attr_t *attr,
pthread_descr self = thread_self();
struct pthread_request request;
if (__pthread_manager_request < 0) {
- if (pthread_initialize_manager() < 0) return EAGAIN;
+ if (__pthread_initialize_manager() < 0) return EAGAIN;
}
request.req_thread = self;
request.req_kind = REQ_CREATE;
@@ -296,6 +320,24 @@ int pthread_equal(pthread_t thread1, pthread_t thread2)
return thread1 == thread2;
}
+/* Helper function for thread_self in the case of user-provided stacks */
+
+#ifndef THREAD_SELF
+
+pthread_descr __pthread_find_self()
+{
+ char * sp = CURRENT_STACK_FRAME;
+ pthread_handle h;
+
+ /* __pthread_handles[0] is the initial thread, handled specially in
+ thread_self(), so start at 1 */
+ h = __pthread_handles + 1;
+ while (! (sp <= (char *) h->h_descr && sp >= h->h_bottom)) h++;
+ return h->h_descr;
+}
+
+#endif
+
/* Thread scheduling */
int pthread_setschedparam(pthread_t thread, int policy,
@@ -304,18 +346,18 @@ int pthread_setschedparam(pthread_t thread, int policy,
pthread_handle handle = thread_handle(thread);
pthread_descr th;
- acquire(&handle->h_spinlock);
+ __pthread_lock(&handle->h_lock);
if (invalid_handle(handle, thread)) {
- release(&handle->h_spinlock);
+ __pthread_unlock(&handle->h_lock);
return ESRCH;
}
th = handle->h_descr;
if (__sched_setscheduler(th->p_pid, policy, param) == -1) {
- release(&handle->h_spinlock);
+ __pthread_unlock(&handle->h_lock);
return errno;
}
th->p_priority = policy == SCHED_OTHER ? 0 : param->sched_priority;
- release(&handle->h_spinlock);
+ __pthread_unlock(&handle->h_lock);
if (__pthread_manager_request >= 0)
__pthread_manager_adjust_prio(th->p_priority);
return 0;
@@ -327,13 +369,13 @@ int pthread_getschedparam(pthread_t thread, int *policy,
pthread_handle handle = thread_handle(thread);
int pid, pol;
- acquire(&handle->h_spinlock);
+ __pthread_lock(&handle->h_lock);
if (invalid_handle(handle, thread)) {
- release(&handle->h_spinlock);
+ __pthread_unlock(&handle->h_lock);
return ESRCH;
}
pid = handle->h_descr->p_pid;
- release(&handle->h_spinlock);
+ __pthread_unlock(&handle->h_lock);
pol = __sched_getscheduler(pid);
if (pol == -1) return errno;
if (__sched_getparam(pid, param) == -1) return errno;
@@ -364,11 +406,11 @@ static void pthread_exit_process(int retcode, void *arg)
/* The handler for the RESTART signal just records the signal received
in the thread descriptor, and optionally performs a siglongjmp
- (for pthread_cond_timedwait). Also used in sigwait.
+ (for pthread_cond_timedwait).
For the thread manager thread, redirect the signal to
__pthread_manager_sighandler. */
-void __pthread_sighandler(int sig)
+static void pthread_handle_sigrestart(int sig)
{
pthread_descr self = thread_self();
if (self == &__pthread_manager_thread) {
@@ -380,13 +422,24 @@ void __pthread_sighandler(int sig)
}
/* The handler for the CANCEL signal checks for cancellation
- (in asynchronous mode) and for process-wide exit and exec requests. */
+ (in asynchronous mode), for process-wide exit and exec requests.
+ For the thread manager thread, we ignore the signal.
+ The debugging strategy is as follows:
+ On reception of a REQ_DEBUG request (sent by new threads created to
+ the thread manager under debugging mode), the thread manager throws
+ PTHREAD_SIG_CANCEL to itself. The debugger (if active) intercepts
+ this signal, takes into account new threads and continue execution
+ of the thread manager by propagating the signal because it doesn't
+ know what it is specifically done for. In the current implementation,
+ the thread manager simply discards it. */
static void pthread_handle_sigcancel(int sig)
{
pthread_descr self = thread_self();
sigjmp_buf * jmpbuf;
+ if (self == &__pthread_manager_thread)
+ return;
if (__pthread_exit_requested) {
/* Main thread should accumulate times for thread manager and its
children, so that timings for main thread account for all threads. */
@@ -469,7 +522,7 @@ weak_alias (__pthread_getconcurrency, pthread_getconcurrency)
#ifdef DEBUG
#include <stdarg.h>
-void __pthread_message(char * fmt, long arg)
+void __pthread_message(char * fmt, ...)
{
char buffer[1024];
va_list args;
diff --git a/linuxthreads/ptlongjmp.c b/linuxthreads/ptlongjmp.c
index c5704f9e9a..580ae93f88 100644
--- a/linuxthreads/ptlongjmp.c
+++ b/linuxthreads/ptlongjmp.c
@@ -37,6 +37,8 @@ static void pthread_cleanup_upto(__jmp_buf target)
c = c->prev)
c->routine(c->arg);
self->p_cleanup = c;
+ if (self->p_in_sighandler && _JMPBUF_UNWINDS(target, self->p_in_sighandler))
+ self->p_in_sighandler = NULL;
}
void siglongjmp(sigjmp_buf env, int val)
diff --git a/linuxthreads/queue.h b/linuxthreads/queue.h
index 60039cce6e..fa8c5d861d 100644
--- a/linuxthreads/queue.h
+++ b/linuxthreads/queue.h
@@ -14,49 +14,42 @@
/* Waiting queues */
-typedef struct _pthread_queue pthread_queue;
+/* Waiting queues are represented by lists of thread descriptors
+ linked through their p_nextwaiting field. The lists are kept
+ sorted by decreasing priority, and then decreasing waiting time. */
-static inline void queue_init(pthread_queue * q)
+static inline void enqueue(pthread_descr * q, pthread_descr th)
{
- q->head = q->tail = NULL;
-}
-
-static inline void enqueue(pthread_queue * q, pthread_descr th)
-{
- int prio;
- pthread_descr * elt;
-
+ int prio = th->p_priority;
ASSERT(th->p_nextwaiting == NULL);
- if (q->tail == NULL) {
- q->head = th;
- q->tail = th;
- return;
- }
- prio = th->p_priority;
- if (prio > 0) {
- /* Insert in queue according to priority order */
- for (elt = &(q->head); *elt != NULL; elt = &((*elt)->p_nextwaiting)) {
- if (prio > (*elt)->p_priority) {
- th->p_nextwaiting = *elt;
- *elt = th;
- return;
- }
+ for (; *q != NULL; q = &((*q)->p_nextwaiting)) {
+ if (prio > (*q)->p_priority) {
+ th->p_nextwaiting = *q;
+ *q = th;
+ return;
}
}
- /* Priority is no greater than any thread in the queue.
- Insert at end of queue */
- q->tail->p_nextwaiting = th;
- q->tail = th;
+ *q = th;
}
-static inline pthread_descr dequeue(pthread_queue * q)
+static inline pthread_descr dequeue(pthread_descr * q)
{
pthread_descr th;
- th = q->head;
+ th = *q;
if (th != NULL) {
- q->head = th->p_nextwaiting;
- if (q->head == NULL) q->tail = NULL;
+ *q = th->p_nextwaiting;
th->p_nextwaiting = NULL;
}
return th;
}
+
+static inline void remove_from_queue(pthread_descr * q, pthread_descr th)
+{
+ for (; *q != NULL; q = &((*q)->p_nextwaiting)) {
+ if (*q == th) {
+ *q = th->p_nextwaiting;
+ th->p_nextwaiting = NULL;
+ return;
+ }
+ }
+}
diff --git a/linuxthreads/rwlock.c b/linuxthreads/rwlock.c
index c6b281551a..99209f75da 100644
--- a/linuxthreads/rwlock.c
+++ b/linuxthreads/rwlock.c
@@ -30,12 +30,11 @@ int
pthread_rwlock_init (pthread_rwlock_t *rwlock,
const pthread_rwlockattr_t *attr)
{
- rwlock->rw_spinlock = 0;
+ __pthread_init_lock(&rwlock->rw_lock);
rwlock->rw_readers = 0;
rwlock->rw_writer = NULL;
-
- queue_init(&rwlock->rw_read_waiting);
- queue_init(&rwlock->rw_write_waiting);
+ rwlock->rw_read_waiting = NULL;
+ rwlock->rw_write_waiting = NULL;
if (attr == NULL)
{
@@ -58,10 +57,10 @@ pthread_rwlock_destroy (pthread_rwlock_t *rwlock)
int readers;
_pthread_descr writer;
- acquire (&rwlock->rw_spinlock);
+ __pthread_lock (&rwlock->rw_lock);
readers = rwlock->rw_readers;
writer = rwlock->rw_writer;
- release (&rwlock->rw_spinlock);
+ __pthread_unlock (&rwlock->rw_lock);
if (readers > 0 || writer != NULL)
return EBUSY;
@@ -77,7 +76,7 @@ pthread_rwlock_rdlock (pthread_rwlock_t *rwlock)
while (1)
{
- acquire (&rwlock->rw_spinlock);
+ __pthread_lock (&rwlock->rw_lock);
if (rwlock->rw_writer == NULL
|| (rwlock->rw_kind == PTHREAD_RWLOCK_PREFER_READER_NP
&& rwlock->rw_readers != 0))
@@ -87,12 +86,12 @@ pthread_rwlock_rdlock (pthread_rwlock_t *rwlock)
/* Suspend ourselves, then try again */
self = thread_self ();
enqueue (&rwlock->rw_read_waiting, self);
- release (&rwlock->rw_spinlock);
+ __pthread_unlock (&rwlock->rw_lock);
suspend (self); /* This is not a cancellation point */
}
++rwlock->rw_readers;
- release (&rwlock->rw_spinlock);
+ __pthread_unlock (&rwlock->rw_lock);
return 0;
}
@@ -103,7 +102,7 @@ pthread_rwlock_tryrdlock (pthread_rwlock_t *rwlock)
{
int result = EBUSY;
- acquire (&rwlock->rw_spinlock);
+ __pthread_lock (&rwlock->rw_lock);
if (rwlock->rw_writer == NULL
|| (rwlock->rw_kind == PTHREAD_RWLOCK_PREFER_READER_NP
&& rwlock->rw_readers != 0))
@@ -111,7 +110,7 @@ pthread_rwlock_tryrdlock (pthread_rwlock_t *rwlock)
++rwlock->rw_readers;
result = 0;
}
- release (&rwlock->rw_spinlock);
+ __pthread_unlock (&rwlock->rw_lock);
return result;
}
@@ -124,17 +123,17 @@ pthread_rwlock_wrlock (pthread_rwlock_t *rwlock)
while(1)
{
- acquire (&rwlock->rw_spinlock);
+ __pthread_lock (&rwlock->rw_lock);
if (rwlock->rw_readers == 0 && rwlock->rw_writer == NULL)
{
rwlock->rw_writer = self;
- release (&rwlock->rw_spinlock);
+ __pthread_unlock (&rwlock->rw_lock);
return 0;
}
/* Suspend ourselves, then try again */
enqueue (&rwlock->rw_write_waiting, self);
- release (&rwlock->rw_spinlock);
+ __pthread_unlock (&rwlock->rw_lock);
suspend (self); /* This is not a cancellation point */
}
}
@@ -145,13 +144,13 @@ pthread_rwlock_trywrlock (pthread_rwlock_t *rwlock)
{
int result = EBUSY;
- acquire (&rwlock->rw_spinlock);
+ __pthread_lock (&rwlock->rw_lock);
if (rwlock->rw_readers == 0 && rwlock->rw_writer == NULL)
{
rwlock->rw_writer = thread_self ();
result = 0;
}
- release (&rwlock->rw_spinlock);
+ __pthread_unlock (&rwlock->rw_lock);
return result;
}
@@ -160,16 +159,16 @@ pthread_rwlock_trywrlock (pthread_rwlock_t *rwlock)
int
pthread_rwlock_unlock (pthread_rwlock_t *rwlock)
{
- struct _pthread_queue torestart;
+ pthread_descr torestart;
pthread_descr th;
- acquire (&rwlock->rw_spinlock);
+ __pthread_lock (&rwlock->rw_lock);
if (rwlock->rw_writer != NULL)
{
/* Unlocking a write lock. */
if (rwlock->rw_writer != thread_self ())
{
- release (&rwlock->rw_spinlock);
+ __pthread_unlock (&rwlock->rw_lock);
return EPERM;
}
rwlock->rw_writer = NULL;
@@ -179,15 +178,15 @@ pthread_rwlock_unlock (pthread_rwlock_t *rwlock)
{
/* Restart all waiting readers. */
torestart = rwlock->rw_read_waiting;
- queue_init (&rwlock->rw_read_waiting);
- release (&rwlock->rw_spinlock);
+ rwlock->rw_read_waiting = NULL;
+ __pthread_unlock (&rwlock->rw_lock);
while ((th = dequeue (&torestart)) != NULL)
restart (th);
}
else
{
/* Restart one waiting writer. */
- release (&rwlock->rw_spinlock);
+ __pthread_unlock (&rwlock->rw_lock);
restart (th);
}
}
@@ -196,7 +195,7 @@ pthread_rwlock_unlock (pthread_rwlock_t *rwlock)
/* Unlocking a read lock. */
if (rwlock->rw_readers == 0)
{
- release (&rwlock->rw_spinlock);
+ __pthread_unlock (&rwlock->rw_lock);
return EPERM;
}
@@ -207,7 +206,7 @@ pthread_rwlock_unlock (pthread_rwlock_t *rwlock)
else
th = NULL;
- release (&rwlock->rw_spinlock);
+ __pthread_unlock (&rwlock->rw_lock);
if (th != NULL)
restart (th);
}
diff --git a/linuxthreads/semaphore.c b/linuxthreads/semaphore.c
index bd07439cde..7ca609f6b2 100644
--- a/linuxthreads/semaphore.c
+++ b/linuxthreads/semaphore.c
@@ -17,69 +17,13 @@
#include "pthread.h"
#include "semaphore.h"
#include "internals.h"
-#include "restart.h"
-
-
-#if !defined HAS_COMPARE_AND_SWAP && !defined TEST_FOR_COMPARE_AND_SWAP
-/* If we have no atomic compare and swap, fake it using an extra spinlock. */
-
-#include "spinlock.h"
-static inline int sem_compare_and_swap(sem_t *sem, long oldval, long newval)
-{
- int ret;
- acquire(&sem->sem_spinlock);
- ret = (sem->sem_status == oldval);
- if (ret) sem->sem_status = newval;
- release(&sem->sem_spinlock);
- return ret;
-}
-
-#elif defined TEST_FOR_COMPARE_AND_SWAP
-
#include "spinlock.h"
-static int has_compare_and_swap = -1; /* to be determined at run-time */
-
-static inline int sem_compare_and_swap(sem_t *sem, long oldval, long newval)
-{
- int ret;
-
- if (has_compare_and_swap == 1)
- return __compare_and_swap(&sem->sem_status, oldval, newval);
-
- acquire(&sem->sem_spinlock);
- ret = (sem->sem_status == oldval);
- if (ret) sem->sem_status = newval;
- release(&sem->sem_spinlock);
- return ret;
-}
-
-#else
-/* But if we do have an atomic compare and swap, use it! */
-
-static inline int sem_compare_and_swap(sem_t *sem, long oldval, long newval)
-{
- return __compare_and_swap(&sem->sem_status, oldval, newval);
-}
-
-#endif
-
-
-/* The state of a semaphore is represented by a long int encoding
- either the semaphore count if >= 0 and no thread is waiting on it,
- or the head of the list of threads waiting for the semaphore.
- To distinguish the two cases, we encode the semaphore count N
- as 2N+1, so that it has the lowest bit set.
-
- A sequence of sem_wait operations on a semaphore initialized to N
- result in the following successive states:
- 2N+1, 2N-1, ..., 3, 1, &first_waiting_thread, &second_waiting_thread, ...
-*/
-
-static void sem_restart_list(pthread_descr waiting);
+#include "restart.h"
+#include "queue.h"
int sem_init(sem_t *sem, int pshared, unsigned int value)
{
- if ((long)value > SEM_VALUE_MAX) {
+ if (value > SEM_VALUE_MAX) {
errno = EINVAL;
return -1;
}
@@ -87,150 +31,104 @@ int sem_init(sem_t *sem, int pshared, unsigned int value)
errno = ENOSYS;
return -1;
}
-#ifdef TEST_FOR_COMPARE_AND_SWAP
- if (has_compare_and_swap == -1) {
- has_compare_and_swap = compare_and_swap_is_available();
- }
-#endif
-#if !defined HAS_COMPARE_AND_SWAP || defined TEST_FOR_COMPARE_AND_SWAP
- sem->sem_spinlock = 0;
-#endif
- sem->sem_status = ((long)value << 1) + 1;
+ __pthread_init_lock((struct _pthread_fastlock *) &sem->sem_lock);
+ sem->sem_value = value;
+ sem->sem_waiting = NULL;
return 0;
}
int sem_wait(sem_t * sem)
{
- long oldstatus, newstatus;
- volatile pthread_descr self = thread_self();
- pthread_descr * th;
+ volatile pthread_descr self;
- while (1) {
- do {
- oldstatus = sem->sem_status;
- if ((oldstatus & 1) && (oldstatus != 1))
- newstatus = oldstatus - 2;
- else {
- newstatus = (long) self;
- self->p_nextwaiting = (pthread_descr) oldstatus;
- }
- }
- while (! sem_compare_and_swap(sem, oldstatus, newstatus));
- if (newstatus & 1)
- /* We got the semaphore. */
- return 0;
- /* Wait for sem_post or cancellation */
- suspend_with_cancellation(self);
- /* This is a cancellation point */
- if (self->p_canceled && self->p_cancelstate == PTHREAD_CANCEL_ENABLE) {
- /* Remove ourselves from the waiting list if we're still on it */
- /* First check if we're at the head of the list. */
- do {
- oldstatus = sem->sem_status;
- if (oldstatus != (long) self) break;
- newstatus = (long) self->p_nextwaiting;
- }
- while (! sem_compare_and_swap(sem, oldstatus, newstatus));
- /* Now, check if we're somewhere in the list.
- There's a race condition with sem_post here, but it does not matter:
- the net result is that at the time pthread_exit is called,
- self is no longer reachable from sem->sem_status. */
- if (oldstatus != (long) self && (oldstatus & 1) == 0) {
- for (th = &(((pthread_descr) oldstatus)->p_nextwaiting);
- *th != NULL && *th != (pthread_descr) 1;
- th = &((*th)->p_nextwaiting)) {
- if (*th == self) {
- *th = self->p_nextwaiting;
- break;
- }
- }
- }
- pthread_exit(PTHREAD_CANCELED);
- }
+ __pthread_lock((struct _pthread_fastlock *) &sem->sem_lock);
+ if (sem->sem_value > 0) {
+ sem->sem_value--;
+ __pthread_unlock((struct _pthread_fastlock *) &sem->sem_lock);
+ return 0;
+ }
+ self = thread_self();
+ enqueue(&sem->sem_waiting, self);
+ /* Wait for sem_post or cancellation */
+ __pthread_unlock((struct _pthread_fastlock *) &sem->sem_lock);
+ suspend_with_cancellation(self);
+ /* This is a cancellation point */
+ if (self->p_canceled && self->p_cancelstate == PTHREAD_CANCEL_ENABLE) {
+ /* Remove ourselves from the waiting list if we're still on it */
+ __pthread_lock((struct _pthread_fastlock *) &sem->sem_lock);
+ remove_from_queue(&sem->sem_waiting, self);
+ __pthread_unlock((struct _pthread_fastlock *) &sem->sem_lock);
+ pthread_exit(PTHREAD_CANCELED);
}
+ /* We got the semaphore */
+ return 0;
}
int sem_trywait(sem_t * sem)
{
- long oldstatus, newstatus;
-
- do {
- oldstatus = sem->sem_status;
- if ((oldstatus & 1) == 0 || (oldstatus == 1)) {
- errno = EAGAIN;
- return -1;
- }
- newstatus = oldstatus - 2;
+ int retval;
+
+ __pthread_lock((struct _pthread_fastlock *) &sem->sem_lock);
+ if (sem->sem_value == 0) {
+ errno = EAGAIN;
+ retval = -1;
+ } else {
+ sem->sem_value--;
+ retval = 0;
}
- while (! sem_compare_and_swap(sem, oldstatus, newstatus));
- return 0;
+ return retval;
}
int sem_post(sem_t * sem)
{
- long oldstatus, newstatus;
-
- do {
- oldstatus = sem->sem_status;
- if ((oldstatus & 1) == 0)
- newstatus = 3;
- else {
- if (oldstatus >= SEM_VALUE_MAX) {
+ pthread_descr self = thread_self();
+ pthread_descr th;
+ struct pthread_request request;
+
+ if (self->p_in_sighandler == NULL) {
+ __pthread_lock((struct _pthread_fastlock *) &sem->sem_lock);
+ if (sem->sem_waiting == NULL) {
+ if (sem->sem_value >= SEM_VALUE_MAX) {
/* Overflow */
errno = ERANGE;
+ __pthread_unlock((struct _pthread_fastlock *) &sem->sem_lock);
+ return -1;
+ }
+ sem->sem_value++;
+ __pthread_unlock((struct _pthread_fastlock *) &sem->sem_lock);
+ } else {
+ th = dequeue(&sem->sem_waiting);
+ __pthread_unlock((struct _pthread_fastlock *) &sem->sem_lock);
+ restart(th);
+ }
+ } else {
+ /* If we're in signal handler, delegate post operation to
+ the thread manager. */
+ if (__pthread_manager_request < 0) {
+ if (__pthread_initialize_manager() < 0) {
+ errno = EAGAIN;
return -1;
}
- newstatus = oldstatus + 2;
}
+ request.req_kind = REQ_POST;
+ request.req_args.post = sem;
+ __libc_write(__pthread_manager_request,
+ (char *) &request, sizeof(request));
}
- while (! sem_compare_and_swap(sem, oldstatus, newstatus));
- if ((oldstatus & 1) == 0)
- sem_restart_list((pthread_descr) oldstatus);
return 0;
}
int sem_getvalue(sem_t * sem, int * sval)
{
- long status = sem->sem_status;
- if (status & 1)
- *sval = (int)((unsigned long) status >> 1);
- else
- *sval = 0;
+ *sval = sem->sem_value;
return 0;
}
int sem_destroy(sem_t * sem)
{
- if ((sem->sem_status & 1) == 0) {
+ if (sem->sem_waiting != NULL) {
errno = EBUSY;
return -1;
}
return 0;
}
-
-/* Auxiliary function for restarting all threads on a waiting list,
- in priority order. */
-
-static void sem_restart_list(pthread_descr waiting)
-{
- pthread_descr th, towake, *p;
-
- /* Sort list of waiting threads by decreasing priority (insertion sort) */
- towake = NULL;
- while (waiting != (pthread_descr) 1) {
- th = waiting;
- waiting = waiting->p_nextwaiting;
- p = &towake;
- while (*p != NULL && th->p_priority < (*p)->p_priority)
- p = &((*p)->p_nextwaiting);
- th->p_nextwaiting = *p;
- *p = th;
- }
- /* Wake up threads in priority order */
- while (towake != NULL) {
- th = towake;
- towake = towake->p_nextwaiting;
- th->p_nextwaiting = NULL;
- restart(th);
- }
-}
diff --git a/linuxthreads/semaphore.h b/linuxthreads/semaphore.h
index 9f01a7f4fa..0740962902 100644
--- a/linuxthreads/semaphore.h
+++ b/linuxthreads/semaphore.h
@@ -21,8 +21,11 @@
#define SEM_VALUE_MAX INT_MAX
-/* Get the semaphore structure definition. */
-#include <bits/semaphore.h>
+typedef struct {
+ struct { long status; int spinlock; } sem_lock;
+ int sem_value;
+ _pthread_descr sem_waiting;
+} sem_t;
__BEGIN_DECLS
diff --git a/linuxthreads/signals.c b/linuxthreads/signals.c
index 905e11e5fe..4a83b14d83 100644
--- a/linuxthreads/signals.c
+++ b/linuxthreads/signals.c
@@ -53,83 +53,88 @@ int pthread_kill(pthread_t thread, int signo)
pthread_handle handle = thread_handle(thread);
int pid;
- acquire(&handle->h_spinlock);
+ __pthread_lock(&handle->h_lock);
if (invalid_handle(handle, thread)) {
- release(&handle->h_spinlock);
+ __pthread_unlock(&handle->h_lock);
return ESRCH;
}
pid = handle->h_descr->p_pid;
- release(&handle->h_spinlock);
+ __pthread_unlock(&handle->h_lock);
if (kill(pid, signo) == -1)
return errno;
else
return 0;
}
-/* The set of signals on which some thread is doing a sigwait */
-static sigset_t sigwaited;
-static pthread_mutex_t sigwaited_mut = PTHREAD_MUTEX_INITIALIZER;
-static pthread_cond_t sigwaited_changed = PTHREAD_COND_INITIALIZER;
+/* User-provided signal handlers */
+static __sighandler_t sighandler[NSIG];
+
+/* The wrapper around user-provided signal handlers */
+static void pthread_sighandler(int signo)
+{
+ pthread_descr self = thread_self();
+ char * in_sighandler;
+ /* If we're in a sigwait operation, just record the signal received
+ and return without calling the user's handler */
+ if (self->p_sigwaiting) {
+ self->p_sigwaiting = 0;
+ self->p_signal = signo;
+ return;
+ }
+ /* Record that we're in a signal handler and call the user's
+ handler function */
+ in_sighandler = self->p_in_sighandler;
+ if (in_sighandler == NULL) self->p_in_sighandler = CURRENT_STACK_FRAME;
+ sighandler[signo](signo);
+ if (in_sighandler == NULL) self->p_in_sighandler = NULL;
+}
+
+int sigaction(int sig, const struct sigaction * act,
+ struct sigaction * oact)
+{
+ struct sigaction newact;
+
+ if (sig == PTHREAD_SIG_RESTART || sig == PTHREAD_SIG_CANCEL)
+ return EINVAL;
+ newact = *act;
+ if (act->sa_handler != SIG_IGN && act->sa_handler != SIG_DFL)
+ newact.sa_handler = pthread_sighandler;
+ if (__sigaction(sig, &newact, oact) == -1)
+ return -1;
+ if (oact != NULL) oact->sa_handler = sighandler[sig];
+ sighandler[sig] = act->sa_handler;
+ return 0;
+}
int sigwait(const sigset_t * set, int * sig)
{
volatile pthread_descr self = thread_self();
sigset_t mask;
int s;
- struct sigaction action, saved_signals[NSIG];
sigjmp_buf jmpbuf;
- pthread_mutex_lock(&sigwaited_mut);
- /* Make sure no other thread is waiting on our signals */
-test_again:
- for (s = 1; s < NSIG; s++) {
- if (sigismember(set, s) && sigismember(&sigwaited, s)) {
- pthread_cond_wait(&sigwaited_changed, &sigwaited_mut);
- goto test_again;
- }
- }
/* Get ready to block all signals except those in set
and the cancellation signal */
sigfillset(&mask);
sigdelset(&mask, PTHREAD_SIG_CANCEL);
- /* Signals in set are assumed blocked on entrance */
- /* Install our signal handler on all signals in set,
- and unblock them in mask.
- Also mark those signals as being sigwaited on */
- for (s = 1; s < NSIG; s++) {
- if (sigismember(set, s) && s != PTHREAD_SIG_CANCEL) {
+ for (s = 1; s <= NSIG; s++) {
+ if (sigismember(set, s) && s != PTHREAD_SIG_CANCEL)
sigdelset(&mask, s);
- action.sa_handler = __pthread_sighandler;
- sigemptyset(&action.sa_mask);
- action.sa_flags = 0;
- sigaction(s, &action, &(saved_signals[s]));
- sigaddset(&sigwaited, s);
- }
}
- pthread_mutex_unlock(&sigwaited_mut);
-
/* Test for cancellation */
if (sigsetjmp(jmpbuf, 1) == 0) {
self->p_cancel_jmp = &jmpbuf;
if (! (self->p_canceled && self->p_cancelstate == PTHREAD_CANCEL_ENABLE)) {
/* Reset the signal count */
self->p_signal = 0;
+ /* Say we're in sigwait */
+ self->p_sigwaiting = 1;
/* Unblock the signals and wait for them */
sigsuspend(&mask);
}
}
self->p_cancel_jmp = NULL;
- /* The signals are now reblocked. Restore the sighandlers. */
- pthread_mutex_lock(&sigwaited_mut);
- for (s = 1; s < NSIG; s++) {
- if (sigismember(set, s) && s != PTHREAD_SIG_CANCEL) {
- sigaction(s, &(saved_signals[s]), NULL);
- sigdelset(&sigwaited, s);
- }
- }
- pthread_cond_broadcast(&sigwaited_changed);
- pthread_mutex_unlock(&sigwaited_mut);
- /* Check for cancellation */
+ /* The signals are now reblocked. Check for cancellation */
pthread_testcancel();
/* We should have self->p_signal != 0 and equal to the signal received */
*sig = self->p_signal;
diff --git a/linuxthreads/spinlock.c b/linuxthreads/spinlock.c
index 170d9ae8d0..dba5d38fd2 100644
--- a/linuxthreads/spinlock.c
+++ b/linuxthreads/spinlock.c
@@ -12,15 +12,130 @@
/* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the */
/* GNU Library General Public License for more details. */
-/* Spin locks */
+/* Internal locks */
#include <sched.h>
#include <time.h>
#include "pthread.h"
#include "internals.h"
#include "spinlock.h"
+#include "restart.h"
-/* This function is called if the inlined test-and-set in acquire() failed */
+/* The status field of a fastlock has the following meaning:
+ 0: fastlock is free
+ 1: fastlock is taken, no thread is waiting on it
+ ADDR: fastlock is taken, ADDR is address of thread descriptor for
+ first waiting thread, other waiting threads are linked via
+ their p_nextwaiting field.
+ The waiting list is not sorted by priority order.
+ Actually, we always insert at top of list (sole insertion mode
+ that can be performed without locking).
+ For __pthread_unlock, we perform a linear search in the list
+ to find the highest-priority, oldest waiting thread.
+ This is safe because there are no concurrent __pthread_unlock
+ operations -- only the thread that locked the mutex can unlock it. */
+
+void __pthread_lock(struct _pthread_fastlock * lock)
+{
+ long oldstatus, newstatus;
+ pthread_descr self = NULL;
+
+ do {
+ oldstatus = lock->status;
+ if (oldstatus == 0) {
+ newstatus = 1;
+ } else {
+ self = thread_self();
+ self->p_nextwaiting = (pthread_descr) oldstatus;
+ newstatus = (long) self;
+ }
+ } while(! compare_and_swap(&lock->status, oldstatus, newstatus,
+ &lock->spinlock));
+ if (oldstatus != 0) suspend(self);
+}
+
+int __pthread_trylock(struct _pthread_fastlock * lock)
+{
+ long oldstatus;
+
+ do {
+ oldstatus = lock->status;
+ if (oldstatus != 0) return EBUSY;
+ } while(! compare_and_swap(&lock->status, 0, 1, &lock->spinlock));
+ return 0;
+}
+
+void __pthread_unlock(struct _pthread_fastlock * lock)
+{
+ long oldstatus;
+ pthread_descr thr, * ptr, * maxptr;
+ int maxprio;
+
+again:
+ oldstatus = lock->status;
+ if (oldstatus == 1) {
+ /* No threads are waiting for this lock */
+ if (! compare_and_swap(&lock->status, 1, 0, &lock->spinlock)) goto again;
+ return;
+ }
+ /* Find thread in waiting queue with maximal priority */
+ ptr = (pthread_descr *) &lock->status;
+ thr = (pthread_descr) oldstatus;
+ maxprio = 0;
+ maxptr = ptr;
+ while (thr != (pthread_descr) 1) {
+ if (thr->p_priority >= maxprio) {
+ maxptr = ptr;
+ maxprio = thr->p_priority;
+ }
+ ptr = &(thr->p_nextwaiting);
+ thr = *ptr;
+ }
+ /* Remove max prio thread from waiting list. */
+ if (maxptr == (pthread_descr *) &lock->status) {
+ /* If max prio thread is at head, remove it with compare-and-swap
+ to guard against concurrent lock operation */
+ thr = (pthread_descr) oldstatus;
+ if (! compare_and_swap(&lock->status,
+ oldstatus, (long)(thr->p_nextwaiting),
+ &lock->spinlock))
+ goto again;
+ } else {
+ /* No risk of concurrent access, remove max prio thread normally */
+ thr = *maxptr;
+ *maxptr = thr->p_nextwaiting;
+ }
+ /* Wake up the selected waiting thread */
+ thr->p_nextwaiting = NULL;
+ restart(thr);
+}
+
+/* Compare-and-swap emulation with a spinlock */
+
+#ifdef TEST_FOR_COMPARE_AND_SWAP
+int __pthread_has_cas = 0;
+#endif
+
+#ifndef HAS_COMPARE_AND_SWAP
+
+static void __pthread_acquire(int * spinlock);
+
+int __pthread_compare_and_swap(long * ptr, long oldval, long newval,
+ int * spinlock)
+{
+ int res;
+ if (testandset(spinlock)) __pthread_acquire(spinlock);
+ if (*ptr == oldval) {
+ *ptr = newval; res = 1;
+ } else {
+ res = 0;
+ }
+ *spinlock = 0;
+ return res;
+}
+
+/* This function is called if the inlined test-and-set
+ in __pthread_compare_and_swap() failed */
/* The retry strategy is as follows:
- We test and set the spinlock MAX_SPIN_COUNT times, calling
@@ -40,7 +155,7 @@
- When nanosleep() returns, we try again, doing MAX_SPIN_COUNT
sched_yield(), then sleeping again if needed. */
-void __pthread_acquire(int * spinlock)
+static void __pthread_acquire(int * spinlock)
{
int cnt = 0;
struct timespec tm;
@@ -57,3 +172,5 @@ void __pthread_acquire(int * spinlock)
}
}
}
+
+#endif
diff --git a/linuxthreads/spinlock.h b/linuxthreads/spinlock.h
index 1707d3e42a..d21a967202 100644
--- a/linuxthreads/spinlock.h
+++ b/linuxthreads/spinlock.h
@@ -1,7 +1,6 @@
/* Linuxthreads - a simple clone()-based implementation of Posix */
/* threads for Linux. */
-/* Copyright (C) 1996 Xavier Leroy (Xavier.Leroy@inria.fr) and */
-/* Richard Henderson (rth@tamu.edu) */
+/* Copyright (C) 1998 Xavier Leroy (Xavier.Leroy@inria.fr) */
/* */
/* This program is free software; you can redistribute it and/or */
/* modify it under the terms of the GNU Library General Public License */
@@ -13,20 +12,52 @@
/* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the */
/* GNU Library General Public License for more details. */
-/* Spin locks */
+/* Internal locks */
-extern void __pthread_acquire(int * spinlock);
+extern void __pthread_lock(struct _pthread_fastlock * lock);
+extern int __pthread_trylock(struct _pthread_fastlock * lock);
+extern void __pthread_unlock(struct _pthread_fastlock * lock);
-static inline void acquire(int * spinlock)
+static inline void __pthread_init_lock(struct _pthread_fastlock * lock)
{
- if (testandset(spinlock)) __pthread_acquire(spinlock);
+ lock->status = 0;
+ lock->spinlock = 0;
}
-static inline void release(int * spinlock)
+#define LOCK_INITIALIZER {0, 0}
+
+#if defined(TEST_FOR_COMPARE_AND_SWAP)
+
+extern int __pthread_has_cas;
+extern int __pthread_compare_and_swap(long * ptr, long oldval, long newval,
+ int * spinlock);
+
+static inline int compare_and_swap(long * ptr, long oldval, long newval,
+ int * spinlock)
+{
+ if (__pthread_has_cas)
+ return __compare_and_swap(ptr, oldval, newval);
+ else
+ return __pthread_compare_and_swap(ptr, oldval, newval, spinlock);
+}
+
+#elif defined(HAS_COMPARE_AND_SWAP)
+
+static inline int compare_and_swap(long * ptr, long oldval, long newval,
+ int * spinlock)
{
-#ifndef RELEASE
- *spinlock = 0;
+ return __compare_and_swap(ptr, oldval, newval);
+}
+
#else
- RELEASE(spinlock);
-#endif
+
+extern int __pthread_compare_and_swap(long * ptr, long oldval, long newval,
+ int * spinlock);
+
+static inline int compare_and_swap(long * ptr, long oldval, long newval,
+ int * spinlock)
+{
+ return __pthread_compare_and_swap(ptr, oldval, newval, spinlock);
}
+
+#endif
diff --git a/linuxthreads/sysdeps/i386/pt-machine.h b/linuxthreads/sysdeps/i386/pt-machine.h
index ef4df2a1a3..c2a7d0883f 100644
--- a/linuxthreads/sysdeps/i386/pt-machine.h
+++ b/linuxthreads/sysdeps/i386/pt-machine.h
@@ -1,6 +1,6 @@
/* Machine-dependent pthreads configuration and inline functions.
i386 version.
- Copyright (C) 1996, 1997 Free Software Foundation, Inc.
+ Copyright (C) 1996, 1997, 1998 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Richard Henderson <rth@tamu.edu>.
@@ -45,7 +45,9 @@ register char * stack_pointer __asm__ ("%esp");
We test dynamically whether it's available or not. */
#define HAS_COMPARE_AND_SWAP
-#define TEST_FOR_COMPARE_AND_SWAP
+#ifndef __i686__
+# define TEST_FOR_COMPARE_AND_SWAP
+#endif
extern inline int
__compare_and_swap (long int *p, long int oldval, long int newval)
diff --git a/linuxthreads/sysdeps/pthread/pthread.h b/linuxthreads/sysdeps/pthread/pthread.h
index 9f5e9deef2..127e15deef 100644
--- a/linuxthreads/sysdeps/pthread/pthread.h
+++ b/linuxthreads/sysdeps/pthread/pthread.h
@@ -43,21 +43,24 @@ typedef unsigned long int pthread_t;
/* Thread descriptors */
typedef struct _pthread_descr_struct *_pthread_descr;
-/* Waiting queues (not abstract because mutexes and conditions aren't). */
-struct _pthread_queue
+/* Fast locks (not abstract because mutexes and conditions aren't abstract). */
+struct _pthread_fastlock
{
- _pthread_descr head; /* First element, or NULL if queue empty. */
- _pthread_descr tail; /* Last element, or NULL if queue empty. */
+ long status; /* "Free" or "taken" or head of waiting list */
+ int spinlock; /* For compare-and-swap emulation */
};
/* Mutexes (not abstract because of PTHREAD_MUTEX_INITIALIZER). */
+/* (The layout is unnatural to maintain binary compatibility
+ with earlier releases of LinuxThreads.) */
+
typedef struct
{
- int m_spinlock; /* Spin lock to guarantee mutual exclusion. */
- int m_count; /* 0 if free, > 0 if taken. */
- _pthread_descr m_owner; /* Owner of mutex (for recursive mutexes) */
- int m_kind; /* Kind of mutex */
- struct _pthread_queue m_waiting; /* Threads waiting on this mutex. */
+ int m_reserved; /* Reserved for future use */
+ int m_count; /* Depth of recursive locking */
+ _pthread_descr m_owner; /* Owner thread (if recursive or errcheck) */
+ int m_kind; /* Mutex kind: fast, recursive or errcheck */
+ struct _pthread_fastlock m_lock; /* Underlying fast lock */
} pthread_mutex_t;
#define PTHREAD_MUTEX_INITIALIZER \
@@ -68,21 +71,21 @@ typedef struct
/* Conditions (not abstract because of PTHREAD_COND_INITIALIZER */
typedef struct
{
- int c_spinlock; /* Spin lock to protect the queue. */
- struct _pthread_queue c_waiting; /* Threads waiting on this condition. */
+ struct _pthread_fastlock c_lock; /* Protect against concurrent access */
+ _pthread_descr c_waiting; /* Threads waiting on this condition */
} pthread_cond_t;
-#define PTHREAD_COND_INITIALIZER {0, {0, 0}}
+#define PTHREAD_COND_INITIALIZER {{0, 0}, 0}
#ifdef __USE_UNIX98
/* Read-write locks. */
typedef struct
{
- int rw_spinlock; /* Spin lock to guarantee mutual exclusion */
+ struct _pthread_fastlock rw_lock; /* Lock to guarantee mutual exclusion */
int rw_readers; /* Number of readers */
_pthread_descr rw_writer; /* Identity of writer, or NULL if none */
- struct _pthread_queue rw_read_waiting; /* Threads waiting for reading */
- struct _pthread_queue rw_write_waiting; /* Threads waiting for writing */
+ _pthread_descr rw_read_waiting; /* Threads waiting for reading */
+ _pthread_descr rw_write_waiting; /* Threads waiting for writing */
int rw_kind; /* Reader/Writer preference selection */
int rw_pshared; /* Shared between processes or not */
} pthread_rwlock_t;
@@ -231,7 +234,8 @@ extern int pthread_detach __P ((pthread_t __th));
/* Functions for handling attributes. */
/* Initialize thread attribute *ATTR with default attributes
- (detachstate is PTHREAD_JOINABLE, scheduling policy is SCHED_OTHER). */
+ (detachstate is PTHREAD_JOINABLE, scheduling policy is SCHED_OTHER,
+ no user-provided stack). */
extern int pthread_attr_init __P ((pthread_attr_t *__attr));
/* Destroy thread attribute *ATTR. */
@@ -288,6 +292,7 @@ extern int __pthread_attr_getguardsize __P ((__const pthread_attr_t *__attr,
size_t *__guardsize));
extern int pthread_attr_getguardsize __P ((__const pthread_attr_t *__attr,
size_t *__guardsize));
+#endif
/* Set the starting address of the stack of the thread to be created.
Depending on whether the stack grows up or doen the value must either
@@ -317,7 +322,6 @@ extern int __pthread_attr_getstacksize __P ((__const pthread_attr_t *__attr,
size_t *__stacksize));
extern int pthread_attr_getstacksize __P ((__const pthread_attr_t *__attr,
size_t *__stacksize));
-#endif
/* Functions for scheduling control. */
diff --git a/linuxthreads/sysdeps/unix/sysv/linux/bits/posix_opt.h b/linuxthreads/sysdeps/unix/sysv/linux/bits/posix_opt.h
index feb4e10c6e..fe68ab7183 100644
--- a/linuxthreads/sysdeps/unix/sysv/linux/bits/posix_opt.h
+++ b/linuxthreads/sysdeps/unix/sysv/linux/bits/posix_opt.h
@@ -1,5 +1,5 @@
/* Define POSIX options for Linux.
- Copyright (C) 1996, 1997 Free Software Foundation, Inc.
+ Copyright (C) 1996, 1997, 1998 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
@@ -82,6 +82,12 @@
/* We provide priority scheduling for threads. */
#define _POSIX_THREAD_PRIORITY_SCHEDULING 1
+/* We support user-defined stack sizes. */
+#define _POSIX_THREAD_ATTR_STACKSIZE 1
+
+/* We support user-defined stacks. */
+#define _POSIX_THREAD_ATTR_STACKADDR 1
+
/* We support POSIX.1b semaphores, but only the non-shared form for now. */
/*#define _POSIX_SEMAPHORES 1 XXX We are not quite there now. */
diff --git a/sysdeps/unix/sysv/linux/bits/sched.h b/sysdeps/unix/sysv/linux/bits/sched.h
index 0ac5409172..187039b2dc 100644
--- a/sysdeps/unix/sysv/linux/bits/sched.h
+++ b/sysdeps/unix/sysv/linux/bits/sched.h
@@ -1,6 +1,6 @@
/* Definitions of constants and data structure for POSIX 1003.1b-1993
scheduling interface.
- Copyright (C) 1996, 1997 Free Software Foundation, Inc.
+ Copyright (C) 1996, 1997, 1998 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
@@ -38,10 +38,11 @@ struct sched_param
/* Cloning flags. */
# define CSIGNAL 0x000000ff /* Signal mask to be sent at exit. */
# define CLONE_VM 0x00000100 /* Set if VM shared between processes. */
-# define CLONE_FS 0x00000200 /* Set if fs info shared between processes.*/
-# define CLONE_FILES 0x00000400 /* Set if open files shared between processes*/
+# define CLONE_FS 0x00000200 /* Set if fs info shared between processes. */
+# define CLONE_FILES 0x00000400 /* Set if open files shared between processes. */
# define CLONE_SIGHAND 0x00000800 /* Set if signal handlers shared. */
# define CLONE_PID 0x00001000 /* Set if pid shared. */
+# define CLONE_PTRACE 0x00002000 /* Set if tracing continues on the child. */
#endif
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-15 03:44:56 +0000