From 63fd7f747915e38a5553bbcb55939d5e483445c7 Mon Sep 17 00:00:00 2001
From: deischen <deischen@FreeBSD.org>
Date: Wed, 30 Apr 2003 15:05:17 +0000
Subject: Move the mailbox to the beginning of the thread and align the thread
 so that the context (SSE FPU state) is also aligned.

---
 lib/libpthread/arch/i386/include/pthread_md.h |  3 +++
 lib/libpthread/thread/thr_create.c            |  3 +++
 lib/libpthread/thread/thr_init.c              |  3 +++
 lib/libpthread/thread/thr_kern.c              | 12 +++++++++---
 lib/libpthread/thread/thr_private.h           | 10 ++++++----
 5 files changed, 24 insertions(+), 7 deletions(-)

(limited to 'lib/libpthread')

diff --git a/lib/libpthread/arch/i386/include/pthread_md.h b/lib/libpthread/arch/i386/include/pthread_md.h
index 2611101..cb5a344 100644
--- a/lib/libpthread/arch/i386/include/pthread_md.h
+++ b/lib/libpthread/arch/i386/include/pthread_md.h
@@ -48,4 +48,7 @@ extern int _thr_getcontext(ucontext_t *);
 
 #define	THR_GETCONTEXT(ucp)	_thr_getcontext(ucp)
 #define	THR_SETCONTEXT(ucp)	_thr_setcontext(ucp)
+
+#define	THR_ALIGNBYTES	15
+#define	THR_ALIGN(td)	(((unsigned)(td) + THR_ALIGNBYTES) & ~THR_ALIGNBYTES)
 #endif
diff --git a/lib/libpthread/thread/thr_create.c b/lib/libpthread/thread/thr_create.c
index 4c65d3c..0c9edbd 100644
--- a/lib/libpthread/thread/thr_create.c
+++ b/lib/libpthread/thread/thr_create.c
@@ -97,6 +97,7 @@ _pthread_create(pthread_t * thread, const pthread_attr_t * attr,
 	struct pthread *curthread, *new_thread;
 	struct kse *kse = NULL;
 	struct kse_group *kseg = NULL;
+	void *p;
 	kse_critical_t crit;
 	int i;
 	int ret = 0;
@@ -123,7 +124,9 @@ _pthread_create(pthread_t * thread, const pthread_attr_t * attr,
 		ret = EAGAIN;
 	} else {
 		/* Initialize the thread structure: */
+		p = new_thread->alloc_addr;
 		memset(new_thread, 0, sizeof(struct pthread));
+		new_thread->alloc_addr = p;
 
 		/* Check if default thread attributes are required: */
 		if (attr == NULL || *attr == NULL)
diff --git a/lib/libpthread/thread/thr_init.c b/lib/libpthread/thread/thr_init.c
index d43adf5..f06df6c 100644
--- a/lib/libpthread/thread/thr_init.c
+++ b/lib/libpthread/thread/thr_init.c
@@ -311,10 +311,13 @@ _libpthread_init(struct pthread *curthread)
 static void
 init_main_thread(struct pthread *thread)
 {
+	void *p;
 	int i;
 
 	/* Zero the initial thread structure. */
+	p = thread->alloc_addr;
 	memset(thread, 0, sizeof(struct pthread));
+	thread->alloc_addr = p;
 
 	/* Setup the thread attributes. */
 	thread->attr = _pthread_attr_default;
diff --git a/lib/libpthread/thread/thr_kern.c b/lib/libpthread/thread/thr_kern.c
index a153a4d..54d9dd7 100644
--- a/lib/libpthread/thread/thr_kern.c
+++ b/lib/libpthread/thread/thr_kern.c
@@ -2019,6 +2019,7 @@ struct pthread *
 _thr_alloc(struct pthread *curthread)
 {
 	kse_critical_t crit;
+	void *p;
 	struct pthread *thread = NULL;
 
 	if (curthread != NULL) {
@@ -2035,8 +2036,13 @@ _thr_alloc(struct pthread *curthread)
 			_kse_critical_leave(crit);
 		}
 	}
-	if (thread == NULL)
-		thread = (struct pthread *)malloc(sizeof(struct pthread));
+	if (thread == NULL) {
+		p = malloc(sizeof(struct pthread) + THR_ALIGNBYTES);
+		if (p != NULL) {
+			thread = (struct pthread *)THR_ALIGN(p);
+			thread->alloc_addr = p;
+		}
+	}
 	return (thread);
 }
 
@@ -2052,7 +2058,7 @@ _thr_free(struct pthread *curthread, struct pthread *thread)
 			_lockuser_destroy(&thread->lockusers[i]);
 		}
 		_lock_destroy(&thread->lock);
-		free(thread);
+		free(thread->alloc_addr);
 	}
 	else {
 		crit = _kse_critical_enter();
diff --git a/lib/libpthread/thread/thr_private.h b/lib/libpthread/thread/thr_private.h
index 4d43242..22d2445 100644
--- a/lib/libpthread/thread/thr_private.h
+++ b/lib/libpthread/thread/thr_private.h
@@ -593,6 +593,12 @@ struct pthread_specific_elem {
  */
 struct pthread {
 	/*
+	 * Thread mailbox is first so it cal be aligned properly.
+	 */
+	struct kse_thr_mailbox	tmbx;
+	void			*alloc_addr;	/* real address (unaligned) */
+
+	/*
 	 * Magic value to help recognize a valid thread structure
 	 * from an invalid one:
 	 */
@@ -626,10 +632,6 @@ struct pthread {
 	void			*arg;
 	struct pthread_attr	attr;
 
-	/*
-	 * Thread mailbox.
-	 */
-	struct kse_thr_mailbox	tmbx;
 	int			active;		/* thread running */
 	int			blocked;	/* thread blocked in kernel */
 	int			need_switchout;
-- 
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