diff --git a/libc/Android.mk b/libc/Android.mk
index 590afbe..0271f10 100644
--- a/libc/Android.mk
+++ b/libc/Android.mk
@@ -322,6 +322,7 @@
 # up any thumb code.
 libc_common_src_files += \
 	bionic/pthread.c.arm \
+	bionic/pthread-rwlocks.c.arm \
 	bionic/pthread-timers.c.arm \
 	bionic/ptrace.c.arm
 
@@ -356,6 +357,7 @@
 	arch-x86/string/strncmp_wrapper.S \
 	arch-x86/string/strlen.S \
 	bionic/pthread.c \
+	bionic/pthread-rwlocks.c \
 	bionic/pthread-timers.c \
 	bionic/ptrace.c
 
@@ -393,6 +395,7 @@
 	string/strlen.c \
 	bionic/eabi.c \
 	bionic/pthread.c \
+	bionic/pthread-rwlocks.c \
 	bionic/pthread-timers.c \
 	bionic/ptrace.c \
 	unistd/socketcalls.c
diff --git a/libc/arch-arm/bionic/_setjmp.S b/libc/arch-arm/bionic/_setjmp.S
index 6a27af2..5626219 100644
--- a/libc/arch-arm/bionic/_setjmp.S
+++ b/libc/arch-arm/bionic/_setjmp.S
@@ -3,6 +3,7 @@
 
 /*
  * Copyright (c) 1997 Mark Brinicombe
+ * Copyright (c) 2010 Android Open Source Project.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -35,6 +36,7 @@
 
 #include <machine/asm.h>
 #include <machine/setjmp.h>
+#include <machine/cpu-features.h>
 
 /*
  * C library -- _setjmp, _longjmp
@@ -51,18 +53,20 @@
 
 ENTRY(_setjmp)
 	ldr	r1, .L_setjmp_magic
-	str	r1, [r0], #4
-#ifdef SOFTFLOAT
-	add	r0, r0, #52
-#else
-	/* Store fp registers */
-	sfm	f4, 4, [r0], #48
-	/* Store fpsr */
-	rfs	r1
-	str	r1, [r0], #0x0004
-#endif	/* SOFTFLOAT */
-	/* Store integer registers */
-        stmia	r0, {r4-r14}
+	str	r1, [r0, #(_JB_MAGIC * 4)]
+
+	/* Store core registers */
+	add     r1, r0, #(_JB_CORE_BASE * 4)
+	stmia   r1, {r4-r14}
+
+#ifdef __ARM_HAVE_VFP
+	/* Store floating-point registers */
+	add     r1, r0, #(_JB_FLOAT_BASE * 4)
+	vstmia  r1, {d8-d15}
+	/* Store floating-point state */
+	fmrx    r1, fpscr
+	str     r1, [r0, #(_JB_FLOAT_STATE * 4)]
+#endif  /* __ARM_HAVE_VFP */
 
         mov	r0, #0x00000000
         bx      lr
@@ -72,21 +76,22 @@
 
 ENTRY(_longjmp)
 	ldr	r2, .L_setjmp_magic
-	ldr	r3, [r0], #4
+	ldr	r3, [r0, #(_JB_MAGIC * 4)]
 	teq	r2, r3
 	bne	botch
 
-#ifdef SOFTFLOAT
-	add	r0, r0, #52
-#else
-	/* Restore fp registers */
-	lfm	f4, 4, [r0], #48
-	/* Restore fpsr */
-	ldr	r4, [r0], #0x0004
-	wfs	r4
-#endif	/* SOFTFLOAT */
-       	/* Restore integer registers */
-        ldmia	r0, {r4-r14}
+#ifdef __ARM_HAVE_VFP
+	/* Restore floating-point registers */
+	add     r2, r0, #(_JB_FLOAT_BASE * 4)
+	vldmia  r2, {d8-d15}
+	/* Restore floating-point state */
+	ldr     r2, [r0, #(_JB_FLOAT_STATE * 4)]
+	fmxr    fpscr, r2
+#endif /* __ARM_HAVE_VFP */
+
+	/* Restore core registers */
+	add     r2, r0, #(_JB_CORE_BASE * 4)
+	ldmia   r2, {r4-r14}
 
 	/* Validate sp and r14 */
 	teq	sp, #0
diff --git a/libc/arch-arm/bionic/setjmp.S b/libc/arch-arm/bionic/setjmp.S
index a9f6ea4..59aff66 100644
--- a/libc/arch-arm/bionic/setjmp.S
+++ b/libc/arch-arm/bionic/setjmp.S
@@ -3,6 +3,7 @@
 
 /*
  * Copyright (c) 1997 Mark Brinicombe
+ * Copyright (c) 2010 Android Open Source Project.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -35,6 +36,7 @@
 
 #include <machine/asm.h>
 #include <machine/setjmp.h>
+#include <machine/cpu-features.h>
 
 /*
  * C library -- setjmp, longjmp
@@ -57,24 +59,26 @@
 	ldmfd	sp!, {r0, r14}
 
 	/* Store signal mask */
-	str	r1, [r0, #(25 * 4)]
+	str	r1, [r0, #(_JB_SIGMASK * 4)]
 
 	ldr	r1, .Lsetjmp_magic
-	str	r1, [r0], #4
+	str	r1, [r0, #(_JB_MAGIC * 4)]
 
-#ifdef SOFTFLOAT
-	add	r0, r0, #52
-#else
-	/* Store fp registers */
-	sfm	f4, 4, [r0], #48
-	/* Store fpsr */
-	rfs	r1
-	str	r1, [r0], #0x0004
-#endif	/*SOFTFLOAT*/
-	/* Store integer registers */
-        stmia	r0, {r4-r14}
-        mov	r0, #0x00000000
-        bx      lr
+	/* Store core registers */
+	add     r1, r0, #(_JB_CORE_BASE * 4)
+	stmia   r1, {r4-r14}
+
+#ifdef __ARM_HAVE_VFP
+	/* Store floating-point registers */
+	add     r1, r0, #(_JB_FLOAT_BASE * 4)
+	vstmia  r1, {d8-d15}
+	/* Store floating-point state */
+	fmrx    r1, fpscr
+	str     r1, [r0, #(_JB_FLOAT_STATE * 4)]
+#endif  /* __ARM_HAVE_VFP */
+
+	mov	r0, #0x00000000
+	bx      lr
 
 .Lsetjmp_magic:
 	.word	_JB_MAGIC_SETJMP
@@ -82,12 +86,12 @@
 
 ENTRY(longjmp)
 	ldr	r2, .Lsetjmp_magic
-	ldr	r3, [r0]
+	ldr	r3, [r0, #(_JB_MAGIC * 4)]
 	teq	r2, r3
 	bne	botch
 
 	/* Fetch signal mask */
-	ldr	r2, [r0, #(25 * 4)]
+	ldr	r2, [r0, #(_JB_SIGMASK * 4)]
 
 	/* Set signal mask */
 	stmfd	sp!, {r0, r1, r14}
@@ -99,18 +103,18 @@
 	add	sp, sp, #4	/* unalign the stack */
 	ldmfd	sp!, {r0, r1, r14} 
 
-	add	r0, r0, #4
-#ifdef SOFTFLOAT
-	add	r0, r0, #52
-#else
-	/* Restore fp registers */
-	lfm	f4, 4, [r0], #48
-	/* Restore FPSR */
-	ldr	r4, [r0], #0x0004
-	wfs	r4
-#endif	/* SOFTFLOAT */
-	/* Restore integer registers */
-        ldmia	r0, {r4-r14}
+#ifdef __ARM_HAVE_VFP
+	/* Restore floating-point registers */
+	add     r2, r0, #(_JB_FLOAT_BASE * 4)
+	vldmia  r2, {d8-d15}
+	/* Restore floating-point state */
+	ldr     r2, [r0, #(_JB_FLOAT_STATE * 4)]
+	fmxr    fpscr, r2
+#endif /* __ARM_HAVE_VFP */
+
+	/* Restore core registers */
+	add     r2, r0, #(_JB_CORE_BASE * 4)
+	ldmia   r2, {r4-r14}
 
 	/* Validate sp and r14 */
 	teq	sp, #0
diff --git a/libc/arch-arm/include/machine/cpu-features.h b/libc/arch-arm/include/machine/cpu-features.h
index ecf6ff6..abf226a 100644
--- a/libc/arch-arm/include/machine/cpu-features.h
+++ b/libc/arch-arm/include/machine/cpu-features.h
@@ -156,6 +156,19 @@
 #  define _ARM_HAVE_LDREX_STREX
 #endif
 
+/* define _ARM_HAVE_VFP if we have VFPv3
+ */
+#if __ARM_ARCH__ >= 7 && defined __VFP_FP__
+#  define __ARM_HAVE_VFP
+#endif
+
+/* define _ARM_HAVE_NEON for ARMv7 architecture if we support the
+ * Neon SIMD instruction set extensions. This also implies
+ * that VFPv3-D32 is supported.
+ */
+#if __ARM_ARCH__ >= 7 && defined __ARM_NEON__
+#  define __ARM_HAVE_NEON
+#endif
 
 /* Assembly-only macros */
 
diff --git a/libc/arch-arm/include/machine/setjmp.h b/libc/arch-arm/include/machine/setjmp.h
index f20cab2..0941202 100644
--- a/libc/arch-arm/include/machine/setjmp.h
+++ b/libc/arch-arm/include/machine/setjmp.h
@@ -1,87 +1,82 @@
-/*	$OpenBSD: setjmp.h,v 1.1 2004/02/01 05:09:49 drahn Exp $	*/
-/*	$NetBSD: setjmp.h,v 1.2 2001/08/25 14:45:59 bjh21 Exp $	*/
+/*
+ * Copyright (C) 2010 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
 
 /*
  * machine/setjmp.h: machine dependent setjmp-related information.
  */
 
-#ifdef __ELF__
-#define	_JBLEN	64		/* size, in longs, of a jmp_buf */
-#else
-#define	_JBLEN	29		/* size, in longs, of a jmp_buf */
-#endif
-
-/*
- * NOTE: The internal structure of a jmp_buf is *PRIVATE*
- *       This information is provided as there is software
- *       that fiddles with this with obtain the stack pointer
- *	 (yes really ! and its commercial !).
+/* _JBLEN is the size of a jmp_buf in longs.
+ * Do not modify this value or you will break the ABI !
  *
- * Description of the setjmp buffer
- *
- * word  0	magic number	(dependant on creator)
- *       1 -  3	f4		fp register 4
- *	 4 -  6	f5		fp register 5
- *	 7 -  9 f6		fp register 6
- *	10 - 12	f7		fp register 7
- *	13	fpsr		fp status register
- *	14	r4		register 4
- *	15	r5		register 5
- *	16	r6		register 6
- *	17	r7		register 7
- *	18	r8		register 8
- *	19	r9		register 9
- *	20	r10		register 10 (sl)
- *	21	r11		register 11 (fp)
- *	22	r12		register 12 (ip)
- *	23	r13		register 13 (sp)
- *	24	r14		register 14 (lr)
- *	25	signal mask	(dependant on magic)
- *	26	(con't)
- *	27	(con't)
- *	28	(con't)
- *
- * The magic number number identifies the jmp_buf and
- * how the buffer was created as well as providing
- * a sanity check
- *
- * A side note I should mention - Please do not tamper
- * with the floating point fields. While they are
- * always saved and restored at the moment this cannot
- * be garenteed especially if the compiler happens
- * to be generating soft-float code so no fp
- * registers will be used.
- *
- * Whilst this can be seen an encouraging people to
- * use the setjmp buffer in this way I think that it
- * is for the best then if changes occur compiles will
- * break rather than just having new builds falling over
- * mysteriously.
+ * This value comes from the original OpenBSD ARM-specific header
+ * that was replaced by this one.
  */
+#define _JBLEN  64
+
+/* According to the ARM AAPCS document, we only need to save
+ * the following registers:
+ *
+ *  Core   r4-r14
+ *
+ *  VFP    d8-d15  (see section 5.1.2.1)
+ *
+ *      Registers s16-s31 (d8-d15, q4-q7) must be preserved across subroutine
+ *      calls; registers s0-s15 (d0-d7, q0-q3) do not need to be preserved
+ *      (and can be used for passing arguments or returning results in standard
+ *      procedure-call variants). Registers d16-d31 (q8-q15), if present, do
+ *      not need to be preserved.
+ *
+ *  FPSCR  saved because GLibc does saves it too.
+ *
+ */
+
+/* The internal structure of a jmp_buf is totally private.
+ * Current layout (may change in the future):
+ *
+ * word   name         description
+ * 0      magic        magic number
+ * 1      sigmask      signal mask (not used with _setjmp / _longjmp)
+ * 2      float_base   base of float registers (d8 to d15)
+ * 18     float_state  floating-point status and control register
+ * 19     core_base    base of core registers (r4 to r14)
+ * 30     reserved     reserved entries (room to grow)
+ * 64
+ *
+ * NOTE: float_base must be at an even word index, since the
+ *       FP registers will be loaded/stored with instructions
+ *       that expect 8-byte alignment.
+ */
+
+#define _JB_MAGIC       0
+#define _JB_SIGMASK     (_JB_MAGIC+1)
+#define _JB_FLOAT_BASE  (_JB_SIGMASK+1)
+#define _JB_FLOAT_STATE (_JB_FLOAT_BASE + (15-8+1)*2)
+#define _JB_CORE_BASE   (_JB_FLOAT_STATE+1)
 
 #define _JB_MAGIC__SETJMP	0x4278f500
 #define _JB_MAGIC_SETJMP	0x4278f501
-
-/* Valid for all jmp_buf's */
-
-#define _JB_MAGIC		 0
-#define _JB_REG_F4		 1
-#define _JB_REG_F5		 4
-#define _JB_REG_F6		 7
-#define _JB_REG_F7		10
-#define _JB_REG_FPSR		13
-#define _JB_REG_R4		14
-#define _JB_REG_R5		15
-#define _JB_REG_R6		16
-#define _JB_REG_R7		17
-#define _JB_REG_R8		18
-#define _JB_REG_R9		19
-#define _JB_REG_R10		20
-#define _JB_REG_R11		21
-#define _JB_REG_R12		22
-#define _JB_REG_R13		23
-#define _JB_REG_R14		24
-
-/* Only valid with the _JB_MAGIC_SETJMP magic */
-
-#define _JB_SIGMASK		25
diff --git a/libc/bionic/pthread-rwlocks.c b/libc/bionic/pthread-rwlocks.c
new file mode 100644
index 0000000..ca3e95c
--- /dev/null
+++ b/libc/bionic/pthread-rwlocks.c
@@ -0,0 +1,347 @@
+/*
+ * Copyright (C) 2010 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include "pthread_internal.h"
+#include <errno.h>
+
+/* Technical note:
+ *
+ * Possible states of a read/write lock:
+ *
+ *  - no readers and no writer (unlocked)
+ *  - one or more readers sharing the lock at the same time (read-locked)
+ *  - one writer holding the lock (write-lock)
+ *
+ * Additionally:
+ *  - trying to get the write-lock while there are any readers blocks
+ *  - trying to get the read-lock while there is a writer blocks
+ *  - a single thread can acquire the lock multiple times in the same mode
+ *
+ *  - Posix states that behaviour is undefined it a thread tries to acquire
+ *    the lock in two distinct modes (e.g. write after read, or read after write).
+ *
+ *  - This implementation tries to avoid writer starvation by making the readers
+ *    block as soon as there is a waiting writer on the lock. However, it cannot
+ *    completely eliminate it: each time the lock is unlocked, all waiting threads
+ *    are woken and battle for it, which one gets it depends on the kernel scheduler
+ *    and is semi-random.
+ *
+ */
+
+#define  __likely(cond)    __builtin_expect(!!(cond), 1)
+#define  __unlikely(cond)  __builtin_expect(!!(cond), 0)
+
+#define  RWLOCKATTR_DEFAULT     0
+#define  RWLOCKATTR_SHARED_MASK 0x0010
+
+extern pthread_internal_t* __get_thread(void);
+
+/* Return a global kernel ID for the current thread */
+static int __get_thread_id(void)
+{
+    return __get_thread()->kernel_id;
+}
+
+int pthread_rwlockattr_init(pthread_rwlockattr_t *attr)
+{
+    if (!attr)
+        return EINVAL;
+
+    *attr = PTHREAD_PROCESS_PRIVATE;
+    return 0;
+}
+
+int pthread_rwlockattr_destroy(pthread_rwlockattr_t *attr)
+{
+    if (!attr)
+        return EINVAL;
+
+    *attr = -1;
+    return 0;
+}
+
+int pthread_rwlockattr_setpshared(pthread_rwlockattr_t *attr, int  pshared)
+{
+    if (!attr)
+        return EINVAL;
+
+    switch (pshared) {
+    case PTHREAD_PROCESS_PRIVATE:
+    case PTHREAD_PROCESS_SHARED:
+        *attr = pshared;
+        return 0;
+    default:
+        return EINVAL;
+    }
+}
+
+int pthread_rwlockattr_getpshared(pthread_rwlockattr_t *attr, int *pshared)
+{
+    if (!attr || !pshared)
+        return EINVAL;
+
+    *pshared = *attr;
+    return 0;
+}
+
+int pthread_rwlock_init(pthread_rwlock_t *rwlock, const pthread_rwlockattr_t *attr)
+{
+    pthread_mutexattr_t*  lock_attr = NULL;
+    pthread_condattr_t*   cond_attr = NULL;
+    pthread_mutexattr_t   lock_attr0;
+    pthread_condattr_t    cond_attr0;
+    int                   ret;
+
+    if (rwlock == NULL)
+        return EINVAL;
+
+    if (attr && *attr == PTHREAD_PROCESS_SHARED) {
+        lock_attr = &lock_attr0;
+        pthread_mutexattr_init(lock_attr);
+        pthread_mutexattr_setpshared(lock_attr, PTHREAD_PROCESS_SHARED);
+
+        cond_attr = &cond_attr0;
+        pthread_condattr_init(cond_attr);
+        pthread_condattr_setpshared(cond_attr, PTHREAD_PROCESS_SHARED);
+    }
+
+    ret = pthread_mutex_init(&rwlock->lock, lock_attr);
+    if (ret != 0)
+        return ret;
+
+    ret = pthread_cond_init(&rwlock->cond, cond_attr);
+    if (ret != 0) {
+        pthread_mutex_destroy(&rwlock->lock);
+        return ret;
+    }
+
+    rwlock->numLocks = 0;
+    rwlock->pendingReaders = 0;
+    rwlock->pendingWriters = 0;
+    rwlock->writerThreadId = 0;
+
+    return 0;
+}
+
+int pthread_rwlock_destroy(pthread_rwlock_t *rwlock)
+{
+    int  ret;
+
+    if (rwlock == NULL)
+        return EINVAL;
+
+    if (rwlock->numLocks > 0)
+        return EBUSY;
+
+    pthread_cond_destroy(&rwlock->cond);
+    pthread_mutex_destroy(&rwlock->lock);
+    return 0;
+}
+
+/* Returns TRUE iff we can acquire a read lock. */
+static __inline__ int read_precondition(pthread_rwlock_t *rwlock, int  thread_id)
+{
+    /* We can't have the lock if any writer is waiting for it (writer bias).
+     * This tries to avoid starvation when there are multiple readers racing.
+     */
+    if (rwlock->pendingWriters > 0)
+        return 0;
+
+    /* We can have the lock if there is no writer, or if we write-own it */
+    /* The second test avoids a self-dead lock in case of buggy code. */
+    if (rwlock->writerThreadId == 0 || rwlock->writerThreadId == thread_id)
+        return 1;
+
+    /* Otherwise, we can't have it */
+    return 0;
+}
+
+/* returns TRUE iff we can acquire a write lock. */
+static __inline__ int write_precondition(pthread_rwlock_t *rwlock, int  thread_id)
+{
+    /* We can get the lock if nobody has it */
+    if (rwlock->numLocks == 0)
+        return 1;
+
+    /* Or if we already own it */
+    if (rwlock->writerThreadId == thread_id)
+        return 1;
+
+    /* Otherwise, not */
+    return 0;
+}
+
+/* This function is used to waken any waiting thread contending
+ * for the lock. One of them should be able to grab it after
+ * that.
+ */
+static void _pthread_rwlock_pulse(pthread_rwlock_t *rwlock)
+{
+    if (rwlock->pendingReaders > 0 || rwlock->pendingWriters > 0)
+        pthread_cond_broadcast(&rwlock->cond);
+}
+
+
+int pthread_rwlock_rdlock(pthread_rwlock_t *rwlock)
+{
+    return pthread_rwlock_timedrdlock(rwlock, NULL);
+}
+
+int pthread_rwlock_tryrdlock(pthread_rwlock_t *rwlock)
+{
+    int ret = 0;
+
+    if (rwlock == NULL)
+        return EINVAL;
+
+    pthread_mutex_lock(&rwlock->lock);
+    if (__unlikely(!read_precondition(rwlock, __get_thread_id())))
+        ret = EBUSY;
+    else
+        rwlock->numLocks ++;
+    pthread_mutex_unlock(&rwlock->lock);
+
+    return ret;
+}
+
+int pthread_rwlock_timedrdlock(pthread_rwlock_t *rwlock, const struct timespec *abs_timeout)
+{
+    int thread_id, ret = 0;
+
+    if (rwlock == NULL)
+        return EINVAL;
+
+    pthread_mutex_lock(&rwlock->lock);
+    thread_id = __get_thread_id();
+    if (__unlikely(!read_precondition(rwlock, thread_id))) {
+        rwlock->pendingReaders += 1;
+        do {
+            ret = pthread_cond_timedwait(&rwlock->cond, &rwlock->lock, abs_timeout);
+        } while (ret == 0 && !read_precondition(rwlock, thread_id));
+        rwlock->pendingReaders -= 1;
+        if (ret != 0)
+            goto EXIT;
+    }
+    rwlock->numLocks ++;
+EXIT:
+    pthread_mutex_unlock(&rwlock->lock);
+    return ret;
+}
+
+
+int pthread_rwlock_wrlock(pthread_rwlock_t *rwlock)
+{
+    return pthread_rwlock_timedwrlock(rwlock, NULL);
+}
+
+int pthread_rwlock_trywrlock(pthread_rwlock_t *rwlock)
+{
+    int thread_id, ret = 0;
+
+    if (rwlock == NULL)
+        return EINVAL;
+
+    pthread_mutex_lock(&rwlock->lock);
+    thread_id = __get_thread_id();
+    if (__unlikely(!write_precondition(rwlock, thread_id))) {
+        ret = EBUSY;
+    } else {
+        rwlock->numLocks ++;
+        rwlock->writerThreadId = thread_id;
+    }
+    pthread_mutex_unlock(&rwlock->lock);
+    return ret;
+}
+
+int pthread_rwlock_timedwrlock(pthread_rwlock_t *rwlock, const struct timespec *abs_timeout)
+{
+    int thread_id, ret = 0;
+
+    if (rwlock == NULL)
+        return EINVAL;
+
+    pthread_mutex_lock(&rwlock->lock);
+    thread_id = __get_thread_id();
+    if (__unlikely(!write_precondition(rwlock, thread_id))) {
+        /* If we can't read yet, wait until the rwlock is unlocked
+         * and try again. Increment pendingReaders to get the
+         * cond broadcast when that happens.
+         */
+        rwlock->pendingWriters += 1;
+        do {
+            ret = pthread_cond_timedwait(&rwlock->cond, &rwlock->lock, abs_timeout);
+        } while (ret == 0 && !write_precondition(rwlock, thread_id));
+        rwlock->pendingWriters -= 1;
+        if (ret != 0)
+            goto EXIT;
+    }
+    rwlock->numLocks ++;
+    rwlock->writerThreadId = thread_id;
+EXIT:
+    pthread_mutex_unlock(&rwlock->lock);
+    return ret;
+}
+
+
+int pthread_rwlock_unlock(pthread_rwlock_t *rwlock)
+{
+    int  ret = 0;
+
+    if (rwlock == NULL)
+        return EINVAL;
+
+    pthread_mutex_lock(&rwlock->lock);
+
+    /* The lock must be held */
+    if (rwlock->numLocks == 0) {
+        ret = EPERM;
+        goto EXIT;
+    }
+
+    /* If it has only readers, writerThreadId is 0 */
+    if (rwlock->writerThreadId == 0) {
+        if (--rwlock->numLocks == 0)
+            _pthread_rwlock_pulse(rwlock);
+    }
+    /* Otherwise, it has only a single writer, which
+     * must be ourselves.
+     */
+    else {
+        if (rwlock->writerThreadId != __get_thread_id()) {
+            ret = EPERM;
+            goto EXIT;
+        }
+        if (--rwlock->numLocks == 0) {
+            rwlock->writerThreadId = 0;
+            _pthread_rwlock_pulse(rwlock);
+        }
+    }
+EXIT:
+    pthread_mutex_unlock(&rwlock->lock);
+    return ret;
+}
diff --git a/libc/docs/CHANGES.TXT b/libc/docs/CHANGES.TXT
index 9080685..e72b422 100644
--- a/libc/docs/CHANGES.TXT
+++ b/libc/docs/CHANGES.TXT
@@ -1,7 +1,14 @@
 Bionic ChangeLog:
 -----------------
 
-Differences between current and Android 2.1:
+Differences between current and Android 2.2:
+
+- <pthread.h>: Add reader/writer locks implementation.
+
+-------------------------------------------------------------------------------
+Differences between Android 2.2. and Android 2.1:
+
+- Support FP register save/load in setjmp()/longjmp() on ARMv7 builds.
 
 - Add support for SH-4 CPU architecture !
 
diff --git a/libc/include/pthread.h b/libc/include/pthread.h
index eb2d169..33039b9 100644
--- a/libc/include/pthread.h
+++ b/libc/include/pthread.h
@@ -219,6 +219,41 @@
  */
 int pthread_mutex_lock_timeout_np(pthread_mutex_t *mutex, unsigned msecs);
 
+/* read-write lock support */
+
+typedef int pthread_rwlockattr_t;
+
+typedef struct {
+    pthread_mutex_t  lock;
+    pthread_cond_t   cond;
+    int              numLocks;
+    int              writerThreadId;
+    int              pendingReaders;
+    int              pendingWriters;
+    void*            reserved[4];  /* for future extensibility */
+} pthread_rwlock_t;
+
+#define PTHREAD_RWLOCK_INITIALIZER  { PTHREAD_MUTEX_INITIALIZER, 0, NULL, 0, 0 }
+
+int pthread_rwlockattr_init(pthread_rwlockattr_t *attr);
+int pthread_rwlockattr_destroy(pthread_rwlockattr_t *attr);
+int pthread_rwlockattr_setpshared(pthread_rwlockattr_t *attr, int  pshared);
+int pthread_rwlockattr_getpshared(pthread_rwlockattr_t *attr, int *pshared);
+
+int pthread_rwlock_init(pthread_rwlock_t *rwlock, const pthread_rwlockattr_t *attr);
+int pthread_rwlock_destroy(pthread_rwlock_t *rwlock);
+
+int pthread_rwlock_rdlock(pthread_rwlock_t *rwlock);
+int pthread_rwlock_tryrdlock(pthread_rwlock_t *rwlock);
+int pthread_rwlock_timedrdlock(pthread_rwlock_t *rwlock, const struct timespec *abs_timeout);
+
+int pthread_rwlock_wrlock(pthread_rwlock_t *rwlock);
+int pthread_rwlock_trywrlock(pthread_rwlock_t *rwlock);
+int pthread_rwlock_timedwrlock(pthread_rwlock_t *rwlock, const struct timespec *abs_timeout);
+
+int pthread_rwlock_unlock(pthread_rwlock_t *rwlock);
+
+
 int pthread_key_create(pthread_key_t *key, void (*destructor_function)(void *));
 int pthread_key_delete (pthread_key_t);
 int pthread_setspecific(pthread_key_t key, const void *value);
diff --git a/libthread_db/include/thread_db.h b/libthread_db/include/thread_db.h
index 9c76d40..1b36cb2 100644
--- a/libthread_db/include/thread_db.h
+++ b/libthread_db/include/thread_db.h
@@ -10,6 +10,8 @@
 #include <stdint.h>
 #include <sys/types.h>
 
+typedef void *psaddr_t;
+typedef pid_t lwpid_t;
 
 #define TD_THR_ANY_USER_FLAGS       0xffffffff
 #define TD_THR_LOWEST_PRIORITY      -20
@@ -67,6 +69,7 @@
 typedef struct
 {
     pid_t pid;
+    struct ps_prochandle *ph;
 } td_thragent_t;
 
 typedef struct
@@ -123,19 +126,37 @@
 extern "C"{
 #endif
 
-extern td_err_e td_ta_new(struct ps_prochandle const * proc_handle, td_thragent_t ** thread_agent);
+extern td_err_e td_ta_new(struct ps_prochandle * proc_handle, td_thragent_t ** thread_agent);
+
+extern td_err_e td_ta_delete(td_thragent_t * ta);
 
 extern td_err_e td_ta_set_event(td_thragent_t const * agent, td_thr_events_t * event);
 
 extern td_err_e td_ta_event_addr(td_thragent_t const * agent, td_event_e event, td_notify_t * notify);
 
+extern td_err_e td_ta_clear_event(const td_thragent_t * ta_arg,
+				  td_thr_events_t * event);
+
 extern td_err_e td_ta_event_getmsg(td_thragent_t const * agent, td_event_msg_t * event);
 
+extern td_err_e td_ta_map_lwp2thr(td_thragent_t const * agent, lwpid_t lwpid,
+				  td_thrhandle_t *th);
+
+extern td_err_e td_thr_get_info(td_thrhandle_t const * handle,
+				td_thrinfo_t * info);
+
+extern td_err_e td_thr_event_enable(td_thrhandle_t const * handle,
+				    td_event_e event);
+
 extern td_err_e td_ta_thr_iter(td_thragent_t const * agent, td_thr_iter_f * func, void * cookie,
                                td_thr_state_e state, int32_t prio, sigset_t * sigmask, uint32_t user_flags);
 
 extern char const ** td_symbol_list(void);
 
+extern td_err_e td_thr_tls_get_addr(const td_thrhandle_t * th,
+				    psaddr_t map_address, size_t offset,
+				    psaddr_t * address);
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/libthread_db/libthread_db.c b/libthread_db/libthread_db.c
index f1a78ac..2cf4d38 100644
--- a/libthread_db/libthread_db.c
+++ b/libthread_db/libthread_db.c
@@ -10,12 +10,7 @@
 #include <stdio.h>
 
 extern int ps_pglobal_lookup (void *, const char *obj, const char *name, void **sym_addr);
-
-struct ps_prochandle
-{
-    pid_t pid;
-};
-
+extern pid_t ps_getpid(struct ps_prochandle *ph);
 
 /*
  * This is the list of "special" symbols we care about whose addresses are
@@ -41,7 +36,7 @@
 
 
 td_err_e
-td_ta_new(struct ps_prochandle const * proc_handle, td_thragent_t ** agent_out)
+td_ta_new(struct ps_prochandle * proc_handle, td_thragent_t ** agent_out)
 {
     td_thragent_t * agent;
 
@@ -50,7 +45,8 @@
         return TD_MALLOC;
     }
 
-    agent->pid = proc_handle->pid;
+    agent->pid = ps_getpid(proc_handle);
+    agent->ph = proc_handle;
     *agent_out = agent;
 
     return TD_OK;
@@ -58,14 +54,28 @@
 
 
 td_err_e
+td_ta_delete(td_thragent_t * ta)
+{
+    free(ta);
+    // FIXME: anything else to do?
+    return TD_OK;
+}
+
+
+/* NOTE: not used by gdb 7.0 */
+
+td_err_e
 td_ta_set_event(td_thragent_t const * agent, td_thr_events_t * events)
 {
     return TD_OK;
 }
 
 
+/* NOTE: not used by gdb 7.0 */
 static td_thrhandle_t gEventMsgHandle;
 
+/* NOTE: not used by gdb 7.0 */
+
 static int
 _event_getmsg_helper(td_thrhandle_t const * handle, void * bkpt_addr)
 {
@@ -83,6 +93,8 @@
     return 0;
 }
 
+/* NOTE: not used by gdb 7.0 */
+
 td_err_e
 td_ta_event_getmsg(td_thragent_t const * agent, td_event_msg_t * event)
 {
@@ -107,6 +119,16 @@
 
 
 td_err_e
+td_ta_map_lwp2thr(td_thragent_t const * agent, lwpid_t lwpid,
+		  td_thrhandle_t *th)
+{
+    th->pid = ps_getpid(agent->ph);
+    th->tid = lwpid;
+    return TD_OK;
+}
+
+
+td_err_e
 td_thr_get_info(td_thrhandle_t const * handle, td_thrinfo_t * info)
 {
     info->ti_tid = handle->tid;
@@ -117,6 +139,8 @@
 }
 
 
+/* NOTE: not used by gdb 7.0 */
+
 td_err_e
 td_thr_event_enable(td_thrhandle_t const * handle, td_event_e event)
 {
@@ -125,6 +149,8 @@
 }
 
 
+/* NOTE: not used by gdb 7.0 */
+
 td_err_e
 td_ta_event_addr(td_thragent_t const * agent, td_event_e event, td_notify_t * notify_out)
 {
@@ -149,6 +175,15 @@
 
 
 td_err_e
+td_ta_clear_event(const td_thragent_t * ta_arg, td_thr_events_t * event)
+{
+    /* Given that gdb 7.0 doesn't use thread events,
+       there's nothing we need to do here.  */
+    return TD_OK;
+}
+
+
+td_err_e
 td_ta_thr_iter(td_thragent_t const * agent, td_thr_iter_f * func, void * cookie,
                td_thr_state_e state, int32_t prio, sigset_t * sigmask, uint32_t user_flags)
 {
@@ -170,8 +205,8 @@
             continue;
         }
         handle.tid = atoi(entry->d_name);
-        err = func(&handle, cookie);
-        if (err) {
+        if (func(&handle, cookie) != 0) {
+	    err = TD_DBERR;
             break;
         }
     }
@@ -181,3 +216,9 @@
     return err;
 }
 
+td_err_e
+td_thr_tls_get_addr(const td_thrhandle_t * th,
+		    psaddr_t map_address, size_t offset, psaddr_t * address)
+{
+    return TD_NOAPLIC; // FIXME: TODO
+}