+/*
+ * This software is part of the SBCL system. See the README file for
+ * more information.
+ *
+ * This software is derived from the CMU CL system, which was
+ * written at Carnegie Mellon University and released into the
+ * public domain. The software is in the public domain and is
+ * provided with absolutely no warranty. See the COPYING and CREDITS
+ * files for more information.
+ */
+
+#include "sbcl.h"
+
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
+#ifndef LISP_FEATURE_WIN32
#include <sched.h>
+#endif
#include <signal.h>
#include <stddef.h>
#include <errno.h>
#include <sys/types.h>
+#ifndef LISP_FEATURE_WIN32
#include <sys/wait.h>
+#endif
+
+#ifdef LISP_FEATURE_MACH_EXCEPTION_HANDLER
+#include <mach/mach.h>
+#include <mach/mach_error.h>
+#include <mach/mach_types.h>
+#endif
-#include "sbcl.h"
#include "runtime.h"
-#include "validate.h" /* for CONTROL_STACK_SIZE etc */
+#include "validate.h" /* for BINDING_STACK_SIZE etc */
+#include "alloc.h"
#include "thread.h"
#include "arch.h"
#include "target-arch-os.h"
#include "interr.h" /* for lose() */
#include "gc-internal.h"
+#ifdef LISP_FEATURE_WIN32
+/*
+ * Win32 doesn't have SIGSTKSZ, and we're not switching stacks anyway,
+ * so define it arbitrarily
+ */
+#define SIGSTKSZ 1024
+#endif
+
+#if defined(LISP_FEATURE_DARWIN) && defined(LISP_FEATURE_SB_THREAD)
+#define DELAY_THREAD_POST_MORTEM 5
+#define LOCK_CREATE_THREAD
+#endif
+
+#ifdef LISP_FEATURE_FREEBSD
+#define CREATE_CLEANUP_THREAD
+#define LOCK_CREATE_THREAD
+#endif
+
#define ALIEN_STACK_SIZE (1*1024*1024) /* 1Mb size chosen at random */
-int dynamic_values_bytes=4096*sizeof(lispobj); /* same for all threads */
-struct thread *all_threads;
-volatile lispobj all_threads_lock;
+#ifdef LISP_FEATURE_SB_THREAD
+struct thread_post_mortem {
+#ifdef DELAY_THREAD_POST_MORTEM
+ struct thread_post_mortem *next;
+#endif
+ os_thread_t os_thread;
+ pthread_attr_t *os_attr;
+ os_vm_address_t os_address;
+};
+
+#ifdef DELAY_THREAD_POST_MORTEM
+static int pending_thread_post_mortem_count = 0;
+pthread_mutex_t thread_post_mortem_lock = PTHREAD_MUTEX_INITIALIZER;
+#endif
+static struct thread_post_mortem * volatile pending_thread_post_mortem = 0;
+#endif
+
+int dynamic_values_bytes=TLS_SIZE*sizeof(lispobj); /* same for all threads */
+struct thread * volatile all_threads;
extern struct interrupt_data * global_interrupt_data;
-extern int linux_no_threads_p;
-int
+#ifdef LISP_FEATURE_SB_THREAD
+pthread_mutex_t all_threads_lock = PTHREAD_MUTEX_INITIALIZER;
+#ifdef LOCK_CREATE_THREAD
+static pthread_mutex_t create_thread_lock = PTHREAD_MUTEX_INITIALIZER;
+#endif
+#ifdef LISP_FEATURE_GCC_TLS
+__thread struct thread *current_thread;
+#endif
+#endif
+
+#if defined(LISP_FEATURE_X86) || defined(LISP_FEATURE_X86_64)
+extern lispobj call_into_lisp_first_time(lispobj fun, lispobj *args, int nargs);
+#endif
+
+static void
+link_thread(struct thread *th)
+{
+ if (all_threads) all_threads->prev=th;
+ th->next=all_threads;
+ th->prev=0;
+ all_threads=th;
+}
+
+#ifdef LISP_FEATURE_SB_THREAD
+static void
+unlink_thread(struct thread *th)
+{
+ if (th->prev)
+ th->prev->next = th->next;
+ else
+ all_threads = th->next;
+ if (th->next)
+ th->next->prev = th->prev;
+}
+#endif
+
+static int
initial_thread_trampoline(struct thread *th)
{
lispobj function;
+#if defined(LISP_FEATURE_X86) || defined(LISP_FEATURE_X86_64)
lispobj *args = NULL;
- function = th->unbound_marker;
- th->unbound_marker = UNBOUND_MARKER_WIDETAG;
+#endif
+ function = th->no_tls_value_marker;
+ th->no_tls_value_marker = NO_TLS_VALUE_MARKER_WIDETAG;
if(arch_os_thread_init(th)==0) return 1;
+ link_thread(th);
+ th->os_thread=thread_self();
+#ifndef LISP_FEATURE_WIN32
+ protect_control_stack_guard_page(1);
+#endif
- if(th->pid < 1) lose("th->pid not set up right");
- th->state=STATE_RUNNING;
#if defined(LISP_FEATURE_X86) || defined(LISP_FEATURE_X86_64)
return call_into_lisp_first_time(function,args,0);
#else
#endif
}
-/* this is the first thing that clone() runs in the child (which is
- * why the silly calling convention). Basically it calls the user's
- * requested lisp function after doing arch_os_thread_init and
- * whatever other bookkeeping needs to be done
- */
+#define THREAD_STRUCT_SIZE (thread_control_stack_size + BINDING_STACK_SIZE + \
+ ALIEN_STACK_SIZE + dynamic_values_bytes + \
+ 32 * SIGSTKSZ + \
+ THREAD_ALIGNMENT_BYTES)
#ifdef LISP_FEATURE_SB_THREAD
+/* THREAD POST MORTEM CLEANUP
+ *
+ * Memory allocated for the thread stacks cannot be reclaimed while
+ * the thread is still alive, so we need a mechanism for post mortem
+ * cleanups. FIXME: We actually have three, for historical reasons as
+ * the saying goes. Do we really need three? Nikodemus guesses that
+ * not anymore, now that we properly call pthread_attr_destroy before
+ * freeing the stack. */
+
+static struct thread_post_mortem *
+plan_thread_post_mortem(struct thread *corpse)
+{
+ if (corpse) {
+ struct thread_post_mortem *post_mortem = malloc(sizeof(struct thread_post_mortem));
+ gc_assert(post_mortem);
+ post_mortem->os_thread = corpse->os_thread;
+ post_mortem->os_attr = corpse->os_attr;
+ post_mortem->os_address = corpse->os_address;
+#ifdef DELAY_THREAD_POST_MORTEM
+ post_mortem->next = NULL;
+#endif
+ return post_mortem;
+ } else {
+ /* FIXME: When does this happen? */
+ return NULL;
+ }
+}
+
+static void
+perform_thread_post_mortem(struct thread_post_mortem *post_mortem)
+{
+#ifdef CREATE_POST_MORTEM_THREAD
+ pthread_detach(pthread_self());
+#endif
+ if (post_mortem) {
+ gc_assert(!pthread_join(post_mortem->os_thread, NULL));
+ gc_assert(!pthread_attr_destroy(post_mortem->os_attr));
+ free(post_mortem->os_attr);
+ os_invalidate(post_mortem->os_address, THREAD_STRUCT_SIZE);
+ free(post_mortem);
+ }
+}
+
+static void
+schedule_thread_post_mortem(struct thread *corpse)
+{
+ struct thread_post_mortem *post_mortem = NULL;
+ if (corpse) {
+ post_mortem = plan_thread_post_mortem(corpse);
+
+#ifdef DELAY_THREAD_POST_MORTEM
+ pthread_mutex_lock(&thread_post_mortem_lock);
+ /* First stick the new post mortem to the end of the queue. */
+ if (pending_thread_post_mortem) {
+ struct thread_post_mortem *next = pending_thread_post_mortem;
+ while (next->next) {
+ next = next->next;
+ }
+ next->next = post_mortem;
+ } else {
+ pending_thread_post_mortem = post_mortem;
+ }
+ /* Then, if there are enough things in the queue, clean up one
+ * from the head -- or increment the count, and null out the
+ * post_mortem we have. */
+ if (pending_thread_post_mortem_count > DELAY_THREAD_POST_MORTEM) {
+ post_mortem = pending_thread_post_mortem;
+ pending_thread_post_mortem = post_mortem->next;
+ } else {
+ pending_thread_post_mortem_count++;
+ post_mortem = NULL;
+ }
+ pthread_mutex_unlock(&thread_post_mortem_lock);
+ /* Finally run, the cleanup, if any. */
+ perform_thread_post_mortem(post_mortem);
+#elif defined(CREATE_POST_MORTEM_THREAD)
+ gc_assert(!pthread_create(&thread, NULL, perform_thread_post_mortem, post_mortem));
+#else
+ post_mortem = (struct thread_post_mortem *)
+ swap_lispobjs((lispobj *)(void *)&pending_thread_post_mortem,
+ (lispobj)post_mortem);
+ perform_thread_post_mortem(post_mortem);
+#endif
+ }
+}
+
+/* this is the first thing that runs in the child (which is why the
+ * silly calling convention). Basically it calls the user's requested
+ * lisp function after doing arch_os_thread_init and whatever other
+ * bookkeeping needs to be done
+ */
int
new_thread_trampoline(struct thread *th)
{
lispobj function;
- function = th->unbound_marker;
- th->unbound_marker = UNBOUND_MARKER_WIDETAG;
- if(arch_os_thread_init(th)==0) return 1;
+ int result, lock_ret;
+
+ FSHOW((stderr,"/creating thread %lu\n", thread_self()));
+ function = th->no_tls_value_marker;
+ th->no_tls_value_marker = NO_TLS_VALUE_MARKER_WIDETAG;
+ if(arch_os_thread_init(th)==0) {
+ /* FIXME: handle error */
+ lose("arch_os_thread_init failed\n");
+ }
- /* wait here until our thread is linked into all_threads: see below */
- while(th->pid<1) sched_yield();
+ th->os_thread=thread_self();
+ protect_control_stack_guard_page(1);
+ /* Since GC can only know about this thread from the all_threads
+ * list and we're just adding this thread to it there is no danger
+ * of deadlocking even with SIG_STOP_FOR_GC blocked (which it is
+ * not). */
+ lock_ret = pthread_mutex_lock(&all_threads_lock);
+ gc_assert(lock_ret == 0);
+ link_thread(th);
+ lock_ret = pthread_mutex_unlock(&all_threads_lock);
+ gc_assert(lock_ret == 0);
+
+ result = funcall0(function);
+
+ /* Block GC */
+ block_blockable_signals();
+ th->state=STATE_DEAD;
+
+ /* SIG_STOP_FOR_GC is blocked and GC might be waiting for this
+ * thread, but since we are already dead it won't wait long. */
+ lock_ret = pthread_mutex_lock(&all_threads_lock);
+ gc_assert(lock_ret == 0);
+
+ gc_alloc_update_page_tables(BOXED_PAGE_FLAG, &th->alloc_region);
+ unlink_thread(th);
+ pthread_mutex_unlock(&all_threads_lock);
+ gc_assert(lock_ret == 0);
+
+ if(th->tls_cookie>=0) arch_os_thread_cleanup(th);
+ os_invalidate((os_vm_address_t)th->interrupt_data,
+ (sizeof (struct interrupt_data)));
+
+#ifdef LISP_FEATURE_MACH_EXCEPTION_HANDLER
+ FSHOW((stderr, "Deallocating mach port %x\n", THREAD_STRUCT_TO_EXCEPTION_PORT(th)));
+ mach_port_move_member(mach_task_self(),
+ THREAD_STRUCT_TO_EXCEPTION_PORT(th),
+ MACH_PORT_NULL);
+ mach_port_deallocate(mach_task_self(),
+ THREAD_STRUCT_TO_EXCEPTION_PORT(th));
+ mach_port_destroy(mach_task_self(),
+ THREAD_STRUCT_TO_EXCEPTION_PORT(th));
+#endif
- th->state=STATE_RUNNING;
- return funcall0(function);
+ schedule_thread_post_mortem(th);
+ FSHOW((stderr,"/exiting thread %p\n", thread_self()));
+ return result;
}
+
#endif /* LISP_FEATURE_SB_THREAD */
+static void
+free_thread_struct(struct thread *th)
+{
+ if (th->interrupt_data)
+ os_invalidate((os_vm_address_t) th->interrupt_data,
+ (sizeof (struct interrupt_data)));
+ os_invalidate((os_vm_address_t) th->os_address,
+ THREAD_STRUCT_SIZE);
+}
+
/* this is called from any other thread to create the new one, and
- * initialize all parts of it that can be initialized from another
- * thread
+ * initialize all parts of it that can be initialized from another
+ * thread
*/
-struct thread * create_thread_struct(lispobj initial_function) {
+static struct thread *
+create_thread_struct(lispobj initial_function) {
union per_thread_data *per_thread;
- struct thread *th=0; /* subdue gcc */
+ struct thread *th=0; /* subdue gcc */
void *spaces=0;
+ void *aligned_spaces=0;
+#ifdef LISP_FEATURE_SB_THREAD
+ unsigned int i;
+#endif
- /* may as well allocate all the spaces at once: it saves us from
+ /* May as well allocate all the spaces at once: it saves us from
* having to decide what to do if only some of the allocations
- * succeed */
- spaces=os_validate(0,
- THREAD_CONTROL_STACK_SIZE+
- BINDING_STACK_SIZE+
- ALIEN_STACK_SIZE+
- dynamic_values_bytes+
- 32*SIGSTKSZ
- );
- if(!spaces) goto cleanup;
+ * succeed. SPACES must be appropriately aligned, since the GC
+ * expects the control stack to start at a page boundary -- and
+ * the OS may have even more rigorous requirements. We can't rely
+ * on the alignment passed from os_validate, since that might
+ * assume the current (e.g. 4k) pagesize, while we calculate with
+ * the biggest (e.g. 64k) pagesize allowed by the ABI. */
+ spaces=os_validate(0, THREAD_STRUCT_SIZE);
+ if(!spaces)
+ return NULL;
+ /* Aligning up is safe as THREAD_STRUCT_SIZE has
+ * THREAD_ALIGNMENT_BYTES padding. */
+ aligned_spaces = (void *)((((unsigned long)(char *)spaces)
+ + THREAD_ALIGNMENT_BYTES-1)
+ &~(unsigned long)(THREAD_ALIGNMENT_BYTES-1));
per_thread=(union per_thread_data *)
- (spaces+
- THREAD_CONTROL_STACK_SIZE+
- BINDING_STACK_SIZE+
- ALIEN_STACK_SIZE);
+ (aligned_spaces+
+ thread_control_stack_size+
+ BINDING_STACK_SIZE+
+ ALIEN_STACK_SIZE);
- th=&per_thread->thread;
- if(all_threads) {
- memcpy(per_thread,arch_os_get_current_thread(),
- dynamic_values_bytes);
- } else {
#ifdef LISP_FEATURE_SB_THREAD
- int i;
- for(i=0;i<(dynamic_values_bytes/sizeof(lispobj));i++)
- per_thread->dynamic_values[i]=UNBOUND_MARKER_WIDETAG;
- if(SymbolValue(FREE_TLS_INDEX,0)==UNBOUND_MARKER_WIDETAG)
- SetSymbolValue
- (FREE_TLS_INDEX,
- make_fixnum(MAX_INTERRUPTS+
- sizeof(struct thread)/sizeof(lispobj)),
- 0);
+ for(i = 0; i < (dynamic_values_bytes / sizeof(lispobj)); i++)
+ per_thread->dynamic_values[i] = NO_TLS_VALUE_MARKER_WIDETAG;
+ if (all_threads == 0) {
+ if(SymbolValue(FREE_TLS_INDEX,0)==UNBOUND_MARKER_WIDETAG) {
+ SetSymbolValue
+ (FREE_TLS_INDEX,
+ /* FIXME: should be MAX_INTERRUPTS -1 ? */
+ make_fixnum(MAX_INTERRUPTS+
+ sizeof(struct thread)/sizeof(lispobj)),
+ 0);
+ SetSymbolValue(TLS_INDEX_LOCK,make_fixnum(0),0);
+ }
#define STATIC_TLS_INIT(sym,field) \
((struct symbol *)(sym-OTHER_POINTER_LOWTAG))->tls_index= \
make_fixnum(THREAD_SLOT_OFFSET_WORDS(field))
-
- STATIC_TLS_INIT(BINDING_STACK_START,binding_stack_start);
- STATIC_TLS_INIT(BINDING_STACK_POINTER,binding_stack_pointer);
- STATIC_TLS_INIT(CONTROL_STACK_START,control_stack_start);
- STATIC_TLS_INIT(CONTROL_STACK_END,control_stack_end);
- STATIC_TLS_INIT(ALIEN_STACK,alien_stack_pointer);
-#ifdef LISP_FEATURE_X86
- STATIC_TLS_INIT(PSEUDO_ATOMIC_ATOMIC,pseudo_atomic_atomic);
- STATIC_TLS_INIT(PSEUDO_ATOMIC_INTERRUPTED,pseudo_atomic_interrupted);
+
+ STATIC_TLS_INIT(BINDING_STACK_START,binding_stack_start);
+ STATIC_TLS_INIT(BINDING_STACK_POINTER,binding_stack_pointer);
+ STATIC_TLS_INIT(CONTROL_STACK_START,control_stack_start);
+ STATIC_TLS_INIT(CONTROL_STACK_END,control_stack_end);
+ STATIC_TLS_INIT(ALIEN_STACK,alien_stack_pointer);
+#if defined(LISP_FEATURE_X86) || defined (LISP_FEATURE_X86_64)
+ STATIC_TLS_INIT(PSEUDO_ATOMIC_BITS,pseudo_atomic_bits);
#endif
#undef STATIC_TLS_INIT
-#endif
}
+#endif
- th->control_stack_start = spaces;
+ th=&per_thread->thread;
+ th->os_address = spaces;
+ th->control_stack_start = aligned_spaces;
th->binding_stack_start=
- (lispobj*)((void*)th->control_stack_start+THREAD_CONTROL_STACK_SIZE);
+ (lispobj*)((void*)th->control_stack_start+thread_control_stack_size);
th->control_stack_end = th->binding_stack_start;
th->alien_stack_start=
- (lispobj*)((void*)th->binding_stack_start+BINDING_STACK_SIZE);
+ (lispobj*)((void*)th->binding_stack_start+BINDING_STACK_SIZE);
th->binding_stack_pointer=th->binding_stack_start;
th->this=th;
- th->pid=0;
- th->state=STATE_STOPPED;
+ th->os_thread=0;
+#ifdef LISP_FEATURE_SB_THREAD
+ th->os_attr=malloc(sizeof(pthread_attr_t));
+#endif
+ th->state=STATE_RUNNING;
#ifdef LISP_FEATURE_STACK_GROWS_DOWNWARD_NOT_UPWARD
th->alien_stack_pointer=((void *)th->alien_stack_start
- + ALIEN_STACK_SIZE-N_WORD_BYTES);
+ + ALIEN_STACK_SIZE-N_WORD_BYTES);
#else
th->alien_stack_pointer=((void *)th->alien_stack_start);
#endif
#if defined(LISP_FEATURE_X86) || defined (LISP_FEATURE_X86_64)
- th->pseudo_atomic_interrupted=0;
- th->pseudo_atomic_atomic=0;
+ th->pseudo_atomic_bits=0;
#endif
#ifdef LISP_FEATURE_GENCGC
gc_set_region_empty(&th->alloc_region);
#ifndef LISP_FEATURE_SB_THREAD
/* the tls-points-into-struct-thread trick is only good for threaded
* sbcl, because unithread sbcl doesn't have tls. So, we copy the
- * appropriate values from struct thread here, and make sure that
+ * appropriate values from struct thread here, and make sure that
* we use the appropriate SymbolValue macros to access any of the
* variable quantities from the C runtime. It's not quite OAOOM,
* it just feels like it */
#if defined(LISP_FEATURE_X86) || defined (LISP_FEATURE_X86_64)
SetSymbolValue(BINDING_STACK_POINTER,(lispobj)th->binding_stack_pointer,th);
SetSymbolValue(ALIEN_STACK,(lispobj)th->alien_stack_pointer,th);
- SetSymbolValue(PSEUDO_ATOMIC_ATOMIC,(lispobj)th->pseudo_atomic_atomic,th);
- SetSymbolValue(PSEUDO_ATOMIC_INTERRUPTED,th->pseudo_atomic_interrupted,th);
+ SetSymbolValue(PSEUDO_ATOMIC_BITS,(lispobj)th->pseudo_atomic_bits,th);
#else
current_binding_stack_pointer=th->binding_stack_pointer;
current_control_stack_pointer=th->control_stack_start;
#endif
-#endif
+#endif
bind_variable(CURRENT_CATCH_BLOCK,make_fixnum(0),th);
- bind_variable(CURRENT_UNWIND_PROTECT_BLOCK,make_fixnum(0),th);
+ bind_variable(CURRENT_UNWIND_PROTECT_BLOCK,make_fixnum(0),th);
bind_variable(FREE_INTERRUPT_CONTEXT_INDEX,make_fixnum(0),th);
bind_variable(INTERRUPT_PENDING, NIL,th);
bind_variable(INTERRUPTS_ENABLED,T,th);
+ bind_variable(ALLOW_WITH_INTERRUPTS,T,th);
+ bind_variable(GC_PENDING,NIL,th);
+ bind_variable(ALLOC_SIGNAL,NIL,th);
+#ifdef LISP_FEATURE_SB_THREAD
+ bind_variable(STOP_FOR_GC_PENDING,NIL,th);
+#endif
+
+ th->interrupt_data = (struct interrupt_data *)
+ os_validate(0,(sizeof (struct interrupt_data)));
+ if (!th->interrupt_data) {
+ free_thread_struct(th);
+ return 0;
+ }
+ th->interrupt_data->pending_handler = 0;
+ th->no_tls_value_marker=initial_function;
- th->interrupt_data =
- os_validate(0,(sizeof (struct interrupt_data)));
- if(all_threads)
- memcpy(th->interrupt_data,
- arch_os_get_current_thread()->interrupt_data,
- sizeof (struct interrupt_data));
- else
- memcpy(th->interrupt_data,global_interrupt_data,
- sizeof (struct interrupt_data));
-
- th->unbound_marker=initial_function;
+ th->stepping = NIL;
return th;
- cleanup:
- /* if(th && th->tls_cookie>=0) os_free_tls_pointer(th); */
- if(spaces) os_invalidate(spaces,
- THREAD_CONTROL_STACK_SIZE+BINDING_STACK_SIZE+
- ALIEN_STACK_SIZE+dynamic_values_bytes);
- return 0;
}
-void link_thread(struct thread *th,pid_t kid_pid)
-{
- sigset_t newset,oldset;
- sigemptyset(&newset);
- sigaddset_blockable(&newset);
- sigprocmask(SIG_BLOCK, &newset, &oldset);
+#ifdef LISP_FEATURE_MACH_EXCEPTION_HANDLER
+mach_port_t setup_mach_exception_handling_thread();
+kern_return_t mach_thread_init(mach_port_t thread_exception_port);
- get_spinlock(&all_threads_lock,kid_pid);
- th->next=all_threads;
- all_threads=th;
- /* note that th->pid is 0 at this time. We rely on all_threads_lock
- * to ensure that we don't have >1 thread with pid=0 on the list at once
- */
- protect_control_stack_guard_page(th->pid,1);
- release_spinlock(&all_threads_lock);
-
- sigprocmask(SIG_SETMASK,&oldset,0);
- th->pid=kid_pid; /* child will not start until this is set */
-}
+#endif
void create_initial_thread(lispobj initial_function) {
struct thread *th=create_thread_struct(initial_function);
- pid_t kid_pid=getpid();
- if(th && kid_pid>0) {
- link_thread(th,kid_pid);
- initial_thread_trampoline(all_threads); /* no return */
- } else lose("can't create initial thread");
+ if(th) {
+#ifdef LISP_FEATURE_MACH_EXCEPTION_HANDLER
+ setup_mach_exception_handling_thread();
+#endif
+ initial_thread_trampoline(th); /* no return */
+ } else lose("can't create initial thread\n");
}
#ifdef LISP_FEATURE_SB_THREAD
-pid_t create_thread(lispobj initial_function) {
- struct thread *th;
- pid_t kid_pid=0;
- if(linux_no_threads_p) return 0;
- th=create_thread_struct(initial_function);
- if(th==0) return 0;
- kid_pid=clone(new_thread_trampoline,
- (((void*)th->control_stack_start)+
- THREAD_CONTROL_STACK_SIZE-4),
- CLONE_FILES|SIG_THREAD_EXIT|CLONE_VM,th);
-
- if(kid_pid>0) {
- link_thread(th,kid_pid);
- return th->pid;
- } else {
- os_invalidate((os_vm_address_t) th->control_stack_start,
- ((sizeof (lispobj))
- * (th->control_stack_end-th->control_stack_start)) +
- BINDING_STACK_SIZE+ALIEN_STACK_SIZE+dynamic_values_bytes+
- 32*SIGSTKSZ);
- return 0;
- }
-}
+#ifndef __USE_XOPEN2K
+extern int pthread_attr_setstack (pthread_attr_t *__attr, void *__stackaddr,
+ size_t __stacksize);
#endif
-/* unused */
-void destroy_thread (struct thread *th)
+boolean create_os_thread(struct thread *th,os_thread_t *kid_tid)
{
- /* precondition: the unix task has already been killed and exited.
- * This is called by the parent or some other thread */
-#ifdef LISP_FEATURE_GENCGC
- gc_alloc_update_page_tables(0, &th->alloc_region);
-#endif
- get_spinlock(&all_threads_lock,th->pid);
- th->unbound_marker=0; /* for debugging */
- if(th==all_threads)
- all_threads=th->next;
- else {
- struct thread *th1=all_threads;
- while(th1 && th1->next!=th) th1=th1->next;
- if(th1) th1->next=th->next; /* unlink */
+ /* The new thread inherits the restrictive signal mask set here,
+ * and enables signals again when it is set up properly. */
+ sigset_t newset,oldset;
+ boolean r=1;
+ int retcode = 0, initcode;
+
+ FSHOW_SIGNAL((stderr,"/create_os_thread: creating new thread\n"));
+
+#ifdef LOCK_CREATE_THREAD
+ retcode = pthread_mutex_lock(&create_thread_lock);
+ gc_assert(retcode == 0);
+ FSHOW_SIGNAL((stderr,"/create_os_thread: got lock\n"));
+#endif
+ sigemptyset(&newset);
+ /* Blocking deferrable signals is enough, no need to block
+ * SIG_STOP_FOR_GC because the child process is not linked onto
+ * all_threads until it's ready. */
+ sigaddset_deferrable(&newset);
+ thread_sigmask(SIG_BLOCK, &newset, &oldset);
+
+ if((initcode = pthread_attr_init(th->os_attr)) ||
+ /* call_into_lisp_first_time switches the stack for the initial thread. For the
+ * others, we use this. */
+ (pthread_attr_setstack(th->os_attr,th->control_stack_start,thread_control_stack_size)) ||
+ (retcode = pthread_create
+ (kid_tid,th->os_attr,(void *(*)(void *))new_thread_trampoline,th))) {
+ FSHOW_SIGNAL((stderr, "init = %d\n", initcode));
+ FSHOW_SIGNAL((stderr, printf("pthread_create returned %d, errno %d\n", retcode, errno)));
+ FSHOW_SIGNAL((stderr, "wanted stack size %d, min stack size %d\n",
+ cstack_size, PTHREAD_STACK_MIN));
+ if(retcode < 0) {
+ perror("create_os_thread");
+ }
+ r=0;
}
- release_spinlock(&all_threads_lock);
- if(th && th->tls_cookie>=0) arch_os_thread_cleanup(th);
- os_invalidate((os_vm_address_t) th->control_stack_start,
- ((sizeof (lispobj))
- * (th->control_stack_end-th->control_stack_start)) +
- BINDING_STACK_SIZE+ALIEN_STACK_SIZE+dynamic_values_bytes+
- 32*SIGSTKSZ);
+
+ thread_sigmask(SIG_SETMASK,&oldset,0);
+#ifdef LOCK_CREATE_THREAD
+ retcode = pthread_mutex_unlock(&create_thread_lock);
+ gc_assert(retcode == 0);
+ FSHOW_SIGNAL((stderr,"/create_os_thread: released lock\n"));
+#endif
+ return r;
}
-struct thread *find_thread_by_pid(pid_t pid)
-{
+os_thread_t create_thread(lispobj initial_function) {
struct thread *th;
- for_each_thread(th)
- if(th->pid==pid) return th;
- return 0;
-}
+ os_thread_t kid_tid;
-#if defined LISP_FEATURE_SB_THREAD
-/* This is not needed unless #+SB-THREAD, as there's a trivial null
- * unithread definition. */
+ /* Assuming that a fresh thread struct has no lisp objects in it,
+ * linking it to all_threads can be left to the thread itself
+ * without fear of gc lossage. initial_function violates this
+ * assumption and must stay pinned until the child starts up. */
+ th = create_thread_struct(initial_function);
+ if(th==0) return 0;
-void mark_dead_threads()
-{
- pid_t kid;
- int status;
- while(1) {
- kid=waitpid(-1,&status,__WALL|WNOHANG);
- if(kid<=0) break;
- if(WIFEXITED(status) || WIFSIGNALED(status)) {
- struct thread *th=find_thread_by_pid(kid);
- if(th) th->state=STATE_DEAD;
- }
+ if (create_os_thread(th,&kid_tid)) {
+ return kid_tid;
+ } else {
+ free_thread_struct(th);
+ return 0;
}
}
-void reap_dead_threads()
+/* Send the signo to os_thread, retry if the rt signal queue is
+ * full. */
+int
+kill_thread_safely(os_thread_t os_thread, int signo)
{
- struct thread *th,*next,*prev=0;
- th=all_threads;
- while(th) {
- next=th->next;
- if(th->state==STATE_DEAD) {
- funcall1(SymbolFunction(HANDLE_THREAD_EXIT),make_fixnum(th->pid));
-#ifdef LISP_FEATURE_GENCGC
- gc_alloc_update_page_tables(0, &th->alloc_region);
-#endif
- get_spinlock(&all_threads_lock,th->pid);
- if(prev) prev->next=next;
- else all_threads=next;
- release_spinlock(&all_threads_lock);
- if(th->tls_cookie>=0) arch_os_thread_cleanup(th);
- os_invalidate((os_vm_address_t) th->control_stack_start,
- ((sizeof (lispobj))
- * (th->control_stack_end-th->control_stack_start)) +
- BINDING_STACK_SIZE+ALIEN_STACK_SIZE+dynamic_values_bytes+
- 32*SIGSTKSZ);
- } else
- prev=th;
- th=next;
+ int r;
+ /* The man page does not mention EAGAIN as a valid return value
+ * for either pthread_kill or kill. But that's theory, this is
+ * practice. By waiting here we assume that the delivery of this
+ * signal is not necessary for the delivery of the signals in the
+ * queue. In other words, we _assume_ there are no deadlocks. */
+ while ((r=pthread_kill(os_thread,signo))==EAGAIN) {
+ /* wait a bit then try again in the hope of the rt signal
+ * queue not being full */
+ FSHOW_SIGNAL((stderr,"/rt signal queue full\n"));
+ /* FIXME: some kind of backoff (random, exponential) would be
+ * nice. */
+ sleep(1);
}
+ return r;
}
-/* These are not needed unless #+SB-THREAD, and since sigwaitinfo()
- * doesn't seem to be easily available everywhere (OpenBSD...) it's
- * more trouble than it's worth to compile it when not needed. */
-void block_sigcont(void)
-{
- /* don't allow ourselves to receive SIGCONT while we're in the
- * "ambiguous" state of being on the queue but not actually stopped.
- */
- sigset_t newset;
- sigemptyset(&newset);
- sigaddset(&newset,SIG_DEQUEUE);
- sigprocmask(SIG_BLOCK, &newset, 0);
-}
-
-void unblock_sigcont_and_sleep(void)
+int signal_interrupt_thread(os_thread_t os_thread)
{
- sigset_t set;
- sigemptyset(&set);
- sigaddset(&set,SIG_DEQUEUE);
- do {
- errno=0;
- sigwaitinfo(&set,0);
- }while(errno==EINTR);
- sigprocmask(SIG_UNBLOCK,&set,0);
-}
-
-int interrupt_thread(pid_t pid, lispobj function)
-{
- union sigval sigval;
- struct thread *th;
- sigval.sival_int=function;
- for_each_thread(th)
- if((th->pid==pid) && (th->state != STATE_DEAD))
- return sigqueue(pid, SIG_INTERRUPT_THREAD, sigval);
- errno=EPERM; return -1;
-}
-
-int signal_thread_to_dequeue (pid_t pid)
-{
- return kill (pid, SIG_DEQUEUE);
+ int status = kill_thread_safely(os_thread, SIG_INTERRUPT_THREAD);
+ if (status == 0) {
+ return 0;
+ } else if (status == ESRCH) {
+ return -1;
+ } else {
+ lose("cannot send SIG_INTERRUPT_THREAD to thread=%lu: %d, %s\n",
+ os_thread, status, strerror(status));
+ }
}
-
-/* stopping the world is a two-stage process. From this thread we signal
+/* stopping the world is a two-stage process. From this thread we signal
* all the others with SIG_STOP_FOR_GC. The handler for this signal does
- * the usual pseudo-atomic checks (we don't want to stop a thread while
- * it's in the middle of allocation) then kills _itself_ with SIGSTOP.
+ * the usual pseudo-atomic checks (we don't want to stop a thread while
+ * it's in the middle of allocation) then waits for another SIG_STOP_FOR_GC.
*/
+/* To avoid deadlocks when gc stops the world all clients of each
+ * mutex must enable or disable SIG_STOP_FOR_GC for the duration of
+ * holding the lock, but they must agree on which. */
void gc_stop_the_world()
{
- /* stop all other threads by sending them SIG_STOP_FOR_GC */
struct thread *p,*th=arch_os_get_current_thread();
- pid_t old_pid;
- int finished;
- do {
- finished=1;
- for(p=all_threads,old_pid=p->pid; p; p=p->next) {
- if(p==th) continue;
- if(p->state==STATE_RUNNING) {
- p->state=STATE_STOPPING;
- if(kill(p->pid,SIG_STOP_FOR_GC)==-1) {
- /* we can't kill the process; assume because it
- * died already (and its parent is dead so never
- * saw the SIGCHLD) */
- p->state=STATE_DEAD;
- }
- }
- if((p->state!=STATE_STOPPED) &&
- (p->state!=STATE_DEAD)) {
- finished=0;
- }
- }
- if(old_pid!=all_threads->pid) {
- finished=0;
- }
- } while(!finished);
+ int status, lock_ret;
+#ifdef LOCK_CREATE_THREAD
+ /* KLUDGE: Stopping the thread during pthread_create() causes deadlock
+ * on FreeBSD. */
+ FSHOW_SIGNAL((stderr,"/gc_stop_the_world:waiting on create_thread_lock, thread=%lu\n",
+ th->os_thread));
+ lock_ret = pthread_mutex_lock(&create_thread_lock);
+ gc_assert(lock_ret == 0);
+ FSHOW_SIGNAL((stderr,"/gc_stop_the_world:got create_thread_lock, thread=%lu\n",
+ th->os_thread));
+#endif
+ FSHOW_SIGNAL((stderr,"/gc_stop_the_world:waiting on lock, thread=%lu\n",
+ th->os_thread));
+ /* keep threads from starting while the world is stopped. */
+ lock_ret = pthread_mutex_lock(&all_threads_lock); \
+ gc_assert(lock_ret == 0);
+
+ FSHOW_SIGNAL((stderr,"/gc_stop_the_world:got lock, thread=%lu\n",
+ th->os_thread));
+ /* stop all other threads by sending them SIG_STOP_FOR_GC */
+ for(p=all_threads; p; p=p->next) {
+ gc_assert(p->os_thread != 0);
+ FSHOW_SIGNAL((stderr,"/gc_stop_the_world: p->state: %x\n", p->state));
+ if((p!=th) && ((p->state==STATE_RUNNING))) {
+ FSHOW_SIGNAL((stderr,"/gc_stop_the_world: suspending %x, os_thread %x\n",
+ p, p->os_thread));
+ status=kill_thread_safely(p->os_thread,SIG_STOP_FOR_GC);
+ if (status==ESRCH) {
+ /* This thread has exited. */
+ gc_assert(p->state==STATE_DEAD);
+ } else if (status) {
+ lose("cannot send suspend thread=%lu: %d, %s\n",
+ p->os_thread,status,strerror(status));
+ }
+ }
+ }
+ FSHOW_SIGNAL((stderr,"/gc_stop_the_world:signals sent\n"));
+ /* wait for the running threads to stop or finish */
+ for(p=all_threads;p;) {
+ FSHOW_SIGNAL((stderr,"/gc_stop_the_world: th: %p, p: %p\n", th, p));
+ if((p!=th) && (p->state==STATE_RUNNING)) {
+ sched_yield();
+ } else {
+ p=p->next;
+ }
+ }
+ FSHOW_SIGNAL((stderr,"/gc_stop_the_world:end\n"));
}
void gc_start_the_world()
{
struct thread *p,*th=arch_os_get_current_thread();
+ int status, lock_ret;
/* if a resumed thread creates a new thread before we're done with
- * this loop, the new thread will get consed on the front of *
- * all_threads_lock, but it won't have been stopped so won't need
+ * this loop, the new thread will get consed on the front of
+ * all_threads, but it won't have been stopped so won't need
* restarting */
+ FSHOW_SIGNAL((stderr,"/gc_start_the_world:begin\n"));
for(p=all_threads;p;p=p->next) {
- if((p==th) || (p->state==STATE_DEAD)) continue;
- p->state=STATE_RUNNING;
- kill(p->pid,SIG_STOP_FOR_GC);
+ gc_assert(p->os_thread!=0);
+ if((p!=th) && (p->state!=STATE_DEAD)) {
+ if(p->state!=STATE_SUSPENDED) {
+ lose("gc_start_the_world: wrong thread state is %d\n",
+ fixnum_value(p->state));
+ }
+ FSHOW_SIGNAL((stderr, "/gc_start_the_world: resuming %lu\n",
+ p->os_thread));
+ p->state=STATE_RUNNING;
+
+#if defined(SIG_RESUME_FROM_GC)
+ status=kill_thread_safely(p->os_thread,SIG_RESUME_FROM_GC);
+#else
+ status=kill_thread_safely(p->os_thread,SIG_STOP_FOR_GC);
+#endif
+ if (status) {
+ lose("cannot resume thread=%lu: %d, %s\n",
+ p->os_thread,status,strerror(status));
+ }
+ }
}
+ /* If we waited here until all threads leave STATE_SUSPENDED, then
+ * SIG_STOP_FOR_GC wouldn't need to be a rt signal. That has some
+ * performance implications, but does away with the 'rt signal
+ * queue full' problem. */
+
+ lock_ret = pthread_mutex_unlock(&all_threads_lock);
+ gc_assert(lock_ret == 0);
+#ifdef LOCK_CREATE_THREAD
+ lock_ret = pthread_mutex_unlock(&create_thread_lock);
+ gc_assert(lock_ret == 0);
+#endif
+
+ FSHOW_SIGNAL((stderr,"/gc_start_the_world:end\n"));
}
#endif
+
+int
+thread_yield()
+{
+#ifdef LISP_FEATURE_SB_THREAD
+ return sched_yield();
+#else
+ return 0;
+#endif
+}