Return gracefully, rather than aborting, when the maximum concurrent

threads per process has been reached. Return EAGAIN, as per spec.

Approved by:	re/blanket libthr

6 files changed, 27 insertions, 10 deletions

diff --git a/lib/libthr/arch/i386/i386/_setcurthread.c b/lib/libthr/arch/i386/i386/_setcurthread.c
index 0483120..2cd27ca 100644
--- a/lib/libthr/arch/i386/i386/_setcurthread.c
+++ b/lib/libthr/arch/i386/i386/_setcurthread.c
@@ -87,13 +87,15 @@ _retire_thread(void *entry)
 }
 
 void *
-_set_curthread(ucontext_t *uc, struct pthread *thr)
+_set_curthread(ucontext_t *uc, struct pthread *thr, int *err)
 {
 	union descriptor desc;
 	void **ldt_entry;
 	int ldt_index;
 	int error;
 
+	*err = 0;
+
 	/*
 	 * If we are setting up the initial thread, the gs register
 	 * won't be setup for the current thread. In any case, we
@@ -106,8 +108,11 @@ _set_curthread(ucontext_t *uc, struct pthread *thr)
 	if (ldt_inited == NULL)
 		ldt_init();
 
-	if (ldt_free == NULL)
-		abort();
+	if (ldt_free == NULL) {
+		/* Concurrent thread limit reached */
+		*err = curthread->error = EAGAIN;
+		return (NULL);
+	}
 
 	/*
 	 * Pull one off of the free list and update the free list pointer.
diff --git a/lib/libthr/arch/ia64/ia64/_curthread.c b/lib/libthr/arch/ia64/ia64/_curthread.c
index 3744f7c..6c3de0e 100644
--- a/lib/libthr/arch/ia64/ia64/_curthread.c
+++ b/lib/libthr/arch/ia64/ia64/_curthread.c
@@ -48,9 +48,9 @@ _retire_thread(void *v)
 }
 
 void *
-_set_curthread(ucontext_t *uc, struct pthread *thread)
+_set_curthread(ucontext_t *uc, struct pthread *thread, int *err)
 {
-
+	*err = 0;
 	if (uc != NULL)
 		uc->uc_mcontext.mc_special.tp = (uint64_t)thread;
 	else
diff --git a/lib/libthr/arch/sparc64/sparc64/_setcurthread.c b/lib/libthr/arch/sparc64/sparc64/_setcurthread.c
index 4f1a303..4c0fb88 100644
--- a/lib/libthr/arch/sparc64/sparc64/_setcurthread.c
+++ b/lib/libthr/arch/sparc64/sparc64/_setcurthread.c
@@ -48,9 +48,9 @@ _retire_thread(void *v)
 }
 
 void *
-_set_curthread(ucontext_t *uc, struct pthread *thread)
+_set_curthread(ucontext_t *uc, struct pthread *thread, int *err)
 {
-
+	*err = 0;
 	if (uc != NULL)
 		uc->uc_mcontext.mc_global[6] = (uint64_t)thread;
 	else
diff --git a/lib/libthr/thread/thr_create.c b/lib/libthr/thread/thr_create.c
index 3033421..5b0158d 100644
--- a/lib/libthr/thread/thr_create.c
+++ b/lib/libthr/thread/thr_create.c
@@ -116,7 +116,18 @@ _pthread_create(pthread_t * thread, const pthread_attr_t * attr,
 	new_thread->ctx.uc_stack.ss_sp = new_thread->stack;
 	new_thread->ctx.uc_stack.ss_size = pattr->stacksize_attr;
 	makecontext(&new_thread->ctx, _thread_start, 0);
-	new_thread->arch_id = _set_curthread(&new_thread->ctx, new_thread);
+	new_thread->arch_id = _set_curthread(&new_thread->ctx, new_thread, &ret);
+	if (ret != 0) {
+		if (pattr->stackaddr_attr == NULL) {
+			/* XXX - We really need to decouple from this lock */
+			DEAD_LIST_LOCK;
+			_thread_stack_free(new_thread->stack,
+			    pattr->stacksize_attr, pattr->guardsize_attr);
+			DEAD_LIST_UNLOCK;
+		}
+		free(new_thread);
+		return (ret);
+	}
 
 	/* Copy the thread attributes: */
 	memcpy(&new_thread->attr, pattr, sizeof(struct pthread_attr));
diff --git a/lib/libthr/thread/thr_init.c b/lib/libthr/thread/thr_init.c
index 98b0eef..9c334da 100644
--- a/lib/libthr/thread/thr_init.c
+++ b/lib/libthr/thread/thr_init.c
@@ -162,6 +162,7 @@ _thread_init(void)
 	size_t		len;
 	int		mib[2];
 	sigset_t	set;
+	int		error;
 
 	struct clockinfo clockinfo;
 	struct sigaction act;
@@ -221,7 +222,7 @@ _thread_init(void)
 	memset(pthread, 0, sizeof(struct pthread));
 
 	_thread_initial = pthread;
-	pthread->arch_id = _set_curthread(NULL, pthread);
+	pthread->arch_id = _set_curthread(NULL, pthread, &error);
 
 	/* Get our thread id. */
 	thr_self(&pthread->thr_id);
diff --git a/lib/libthr/thread/thr_private.h b/lib/libthr/thread/thr_private.h
index db2bab2..d8e37b4 100644
--- a/lib/libthr/thread/thr_private.h
+++ b/lib/libthr/thread/thr_private.h
@@ -711,7 +711,7 @@ char    *ttyname_r(int, char *, size_t);
 void	_cond_wait_backout(pthread_t);
 int     _find_thread(pthread_t);
 pthread_t _get_curthread(void);
-void	*_set_curthread(ucontext_t *, struct pthread *);
+void	*_set_curthread(ucontext_t *, struct pthread *, int *);
 void	_retire_thread(void *arch_id);
 void	*_thread_stack_alloc(size_t, size_t);
 void	_thread_stack_free(void *, size_t, size_t);