Use FUTEX_WAIT_BITSET to avoid converting timeouts.

Add unittests for pthread APIs with timeout parameter.

Bug: 17569991

Change-Id: I6b3b9b2feae03680654cd64c3112ce7644632c87
diff --git a/libc/private/bionic_futex.h b/libc/private/bionic_futex.h
index 401577a..946d9dd 100644
--- a/libc/private/bionic_futex.h
+++ b/libc/private/bionic_futex.h
@@ -40,10 +40,12 @@
 
 struct timespec;
 
-static inline __always_inline int __futex(volatile void* ftx, int op, int value, const struct timespec* timeout) {
+static inline __always_inline int __futex(volatile void* ftx, int op, int value,
+                                          const struct timespec* timeout,
+                                          int bitset) {
   // Our generated syscall assembler sets errno, but our callers (pthread functions) don't want to.
   int saved_errno = errno;
-  int result = syscall(__NR_futex, ftx, op, value, timeout);
+  int result = syscall(__NR_futex, ftx, op, value, timeout, NULL, bitset);
   if (__predict_false(result == -1)) {
     result = -errno;
     errno = saved_errno;
@@ -52,19 +54,22 @@
 }
 
 static inline int __futex_wake(volatile void* ftx, int count) {
-  return __futex(ftx, FUTEX_WAKE, count, NULL);
+  return __futex(ftx, FUTEX_WAKE, count, NULL, 0);
 }
 
 static inline int __futex_wake_ex(volatile void* ftx, bool shared, int count) {
-  return __futex(ftx, shared ? FUTEX_WAKE : FUTEX_WAKE_PRIVATE, count, NULL);
+  return __futex(ftx, shared ? FUTEX_WAKE : FUTEX_WAKE_PRIVATE, count, NULL, 0);
 }
 
 static inline int __futex_wait(volatile void* ftx, int value, const struct timespec* timeout) {
-  return __futex(ftx, FUTEX_WAIT, value, timeout);
+  return __futex(ftx, FUTEX_WAIT, value, timeout, 0);
 }
 
-static inline int __futex_wait_ex(volatile void* ftx, bool shared, int value, const struct timespec* timeout) {
-  return __futex(ftx, shared ? FUTEX_WAIT : FUTEX_WAIT_PRIVATE, value, timeout);
+static inline int __futex_wait_ex(volatile void* ftx, bool shared, int value,
+                                  bool use_realtime_clock, const struct timespec* abs_timeout) {
+  return __futex(ftx, (shared ? FUTEX_WAIT_BITSET : FUTEX_WAIT_BITSET_PRIVATE) |
+                 (use_realtime_clock ? FUTEX_CLOCK_REALTIME : 0), value, abs_timeout,
+                 FUTEX_BITSET_MATCH_ANY);
 }
 
 __END_DECLS
diff --git a/libc/private/bionic_lock.h b/libc/private/bionic_lock.h
index a36d1ed..eb73274 100644
--- a/libc/private/bionic_lock.h
+++ b/libc/private/bionic_lock.h
@@ -57,7 +57,7 @@
     }
     while (atomic_exchange_explicit(&state, LockedWithWaiter, memory_order_acquire) != Unlocked) {
       // TODO: As the critical section is brief, it is a better choice to spin a few times befor sleeping.
-      __futex_wait_ex(&state, process_shared, LockedWithWaiter, NULL);
+      __futex_wait_ex(&state, process_shared, LockedWithWaiter, false, nullptr);
     }
     return;
   }
diff --git a/libc/private/bionic_time_conversions.h b/libc/private/bionic_time_conversions.h
index cf0046a..294c29a 100644
--- a/libc/private/bionic_time_conversions.h
+++ b/libc/private/bionic_time_conversions.h
@@ -29,9 +29,12 @@
 #ifndef _BIONIC_TIME_CONVERSIONS_H
 #define _BIONIC_TIME_CONVERSIONS_H
 
+#include <errno.h>
 #include <time.h>
 #include <sys/cdefs.h>
 
+#include "private/bionic_constants.h"
+
 __BEGIN_DECLS
 
 __LIBC_HIDDEN__ bool timespec_from_timeval(timespec& ts, const timeval& tv);
@@ -39,8 +42,21 @@
 
 __LIBC_HIDDEN__ void timeval_from_timespec(timeval& tv, const timespec& ts);
 
-__LIBC_HIDDEN__ bool timespec_from_absolute_timespec(timespec& ts, const timespec& abs_ts, clockid_t clock);
+__LIBC_HIDDEN__ void absolute_timespec_from_timespec(timespec& abs_ts, const timespec& ts,
+                                                     clockid_t clock);
 
 __END_DECLS
 
+static inline int check_timespec(const timespec* ts) {
+  if (ts != nullptr) {
+    if (ts->tv_nsec < 0 || ts->tv_nsec >= NS_PER_S) {
+      return EINVAL;
+    }
+    if (ts->tv_sec < 0) {
+      return ETIMEDOUT;
+    }
+  }
+  return 0;
+}
+
 #endif