unix: use uv__hrtime() internally

This commit renames the various uv_hrtime() implementations to uv__hrtime().

Libuv uses the high-res timer internally in performance-critical code paths.
Calling the non-public version avoids going through the PLT when libuv is
compiled as a shared object.

The exported uv_hrtime() now has a single definition in src/unix/core.c that
calls uv__hrtime().

A future optimization is to lift the uv__hrtime() declarations into header
files so they can be inlined at the call sites. Then again, linking with -flto
should accomplish the same thing.

src/unix/aix.c

@@ -45,7 +45,7 @@
 #include <sys/proc.h>
 #include <sys/procfs.h>
 
-uint64_t uv_hrtime() {
+uint64_t uv__hrtime(void) {
   uint64_t G = 1000000000;
   timebasestruct_t t;
   read_wall_time(&t, TIMEBASE_SZ);

src/unix/core.c

@@ -66,6 +66,11 @@ static uv_loop_t default_loop_struct;
 static uv_loop_t* default_loop_ptr;
 
 
+uint64_t uv_hrtime(void) {
+  return uv__hrtime();
+}
+
+
 void uv_close(uv_handle_t* handle, uv_close_cb close_cb) {
   assert(!(handle->flags & (UV_CLOSING | UV_CLOSED)));
 
@@ -302,7 +307,7 @@ int uv_run(uv_loop_t* loop) {
 
 
 void uv_update_time(uv_loop_t* loop) {
-  loop->time = uv_hrtime() / 1000000;
+  loop->time = uv__hrtime() / 1000000;
 }
 
 

src/unix/cygwin.c

@@ -41,12 +41,13 @@ void uv__platform_loop_delete(uv_loop_t* loop) {
 }
 
 
-uint64_t uv_hrtime() {
+uint64_t uv__hrtime(void) {
   struct timespec ts;
   clock_gettime(CLOCK_MONOTONIC, &ts);
   return (((uint64_t) ts.tv_sec) * NANOSEC + ts.tv_nsec);
 }
 
+
 void uv_loadavg(double avg[3]) {
   /* Unsupported as of cygwin 1.7.7 */
   avg[0] = avg[1] = avg[2] = 0;

src/unix/darwin.c

@@ -176,7 +176,7 @@ void uv__cf_loop_signal(uv_loop_t* loop, cf_loop_signal_cb cb, void* arg) {
 }
 
 
-uint64_t uv_hrtime(void) {
+uint64_t uv__hrtime(void) {
     mach_timebase_info_data_t info;
 
     if (mach_timebase_info(&info) != KERN_SUCCESS)

src/unix/freebsd.c

@@ -63,7 +63,7 @@ void uv__platform_loop_delete(uv_loop_t* loop) {
 }
 
 
-uint64_t uv_hrtime(void) {
+uint64_t uv__hrtime(void) {
   struct timespec ts;
   clock_gettime(CLOCK_MONOTONIC, &ts);
   return (((uint64_t) ts.tv_sec) * NANOSEC + ts.tv_nsec);

src/unix/internal.h

@@ -174,6 +174,7 @@ void uv__work_submit(uv_loop_t* loop,
 void uv__work_done(uv_async_t* handle, int status);
 
 /* platform specific */
+uint64_t uv__hrtime(void);
 int uv__kqueue_init(uv_loop_t* loop);
 int uv__platform_loop_init(uv_loop_t* loop, int default_loop);
 void uv__platform_loop_delete(uv_loop_t* loop);

src/unix/kqueue.c

@@ -244,7 +244,7 @@ void uv__io_poll(uv_loop_t* loop, int timeout) {
 update_timeout:
     assert(timeout > 0);
 
-    diff = uv_hrtime() / 1000000;
+    diff = uv__hrtime() / 1000000;
     assert(diff >= base);
     diff -= base;
 

src/unix/linux/linux-core.c

@@ -243,7 +243,7 @@ void uv__io_poll(uv_loop_t* loop, int timeout) {
 update_timeout:
     assert(timeout > 0);
 
-    diff = uv_hrtime() / 1000000;
+    diff = uv__hrtime() / 1000000;
     assert(diff >= base);
     diff -= base;
 
@@ -255,7 +255,7 @@ update_timeout:
 }
 
 
-uint64_t uv_hrtime() {
+uint64_t uv__hrtime(void) {
   struct timespec ts;
   clock_gettime(CLOCK_MONOTONIC, &ts);
   return (((uint64_t) ts.tv_sec) * NANOSEC + ts.tv_nsec);

src/unix/loop.c

@@ -49,7 +49,7 @@ int uv__loop_init(uv_loop_t* loop, int default_loop) {
   ngx_queue_init(&loop->watcher_queue);
 
   loop->closing_handles = NULL;
-  loop->time = uv_hrtime() / 1000000;
+  loop->time = uv__hrtime() / 1000000;
   loop->async_pipefd[0] = -1;
   loop->async_pipefd[1] = -1;
   loop->signal_pipefd[0] = -1;

src/unix/netbsd.c

@@ -56,7 +56,7 @@ void uv__platform_loop_delete(uv_loop_t* loop) {
 }
 
 
-uint64_t uv_hrtime(void) {
+uint64_t uv__hrtime(void) {
   struct timespec ts;
   clock_gettime(CLOCK_MONOTONIC, &ts);
   return (((uint64_t) ts.tv_sec) * NANOSEC + ts.tv_nsec);

src/unix/openbsd.c

@@ -52,7 +52,7 @@ void uv__platform_loop_delete(uv_loop_t* loop) {
 }
 
 
-uint64_t uv_hrtime(void) {
+uint64_t uv__hrtime(void) {
   struct timespec ts;
   clock_gettime(CLOCK_MONOTONIC, &ts);
   return (((uint64_t) ts.tv_sec) * NANOSEC + ts.tv_nsec);

src/unix/sunos.c

@@ -211,7 +211,7 @@ void uv__io_poll(uv_loop_t* loop, int timeout) {
 update_timeout:
     assert(timeout > 0);
 
-    diff = uv_hrtime() / 1000000;
+    diff = uv__hrtime() / 1000000;
     assert(diff >= base);
     diff -= base;
 
@@ -223,8 +223,8 @@ update_timeout:
 }
 
 
-uint64_t uv_hrtime() {
-  return (gethrtime());
+uint64_t uv__hrtime(void) {
+  return gethrtime();
 }
 
 

src/unix/thread.c

@@ -354,7 +354,7 @@ int uv_cond_timedwait(uv_cond_t* cond, uv_mutex_t* mutex, uint64_t timeout) {
   struct timespec ts;
   uint64_t abstime;
 
-  abstime = uv_hrtime() + timeout;
+  abstime = uv__hrtime() + timeout;
   ts.tv_sec = abstime / NANOSEC;
   ts.tv_nsec = abstime % NANOSEC;
   r = pthread_cond_timedwait(cond, mutex, &ts);