commit 2227bd52c5bb8d62dcfe33b58d65515d21e9be17
author William A. Kennington III <wak@google.com> Wed Jun 19 11:32:22 2019 -0700
committer William A. Kennington III <wak@google.com> Fri Jul 26 12:39:53 2019 -0700
tree e555d50cc5f3aaf7f603cc3826bb6ce29de7376b
parent 501ade24fb8eaa8112fb2c267727888fd5ac685c

sensor: Replace GpioLock with stdplus RAII helper

The old RAII helper was not move safe, although it was never moved in
the current code so it didn't have any effect on runtime safety.

Change-Id: Ica19ed7e60d699d86d0166b356cedb82e4a28b61
Signed-off-by: William A. Kennington III <wak@google.com>

sensor.cpp

diff --git a/sensor.cpp b/sensor.cpp
index 6e5e841..145ba6c 100644
--- a/sensor.cpp
+++ b/sensor.cpp
@@ -9,6 +9,7 @@
 #include "sysfs.hpp"
 
 #include <cassert>
+#include <chrono>
 #include <cmath>
 #include <cstring>
 #include <filesystem>
@@ -151,7 +152,7 @@
 #endif
         {
             // RAII object for GPIO unlock / lock
-            GpioLock gpioLock(getGpio());
+            auto locker = gpioUnlock(getGpio());
 
             // Retry for up to a second if device is busy
             // or has a transient error.
@@ -259,31 +260,22 @@
     return iface;
 }
 
-GpioLock::GpioLock(const gpioplus::HandleInterface* handle) : _handle(handle)
+void gpioLock(const gpioplus::HandleInterface*&& handle)
 {
-    unlockGpio();
+    handle->setValues({0});
 }
 
-GpioLock::~GpioLock()
+std::optional<GpioLocker> gpioUnlock(const gpioplus::HandleInterface* handle)
 {
-    lockGpio();
-}
-
-void GpioLock::unlockGpio()
-{
-    if (_handle)
+    if (handle == nullptr)
     {
-        _handle->setValues({1});
-        std::this_thread::sleep_for(_pause);
+        return std::nullopt;
     }
-}
 
-void GpioLock::lockGpio()
-{
-    if (_handle)
-    {
-        _handle->setValues({0});
-    }
+    handle->setValues({1});
+    // Default pause needed to guarantee sensors are ready
+    std::this_thread::sleep_for(std::chrono::milliseconds(500));
+    return GpioLocker(std::move(handle));
 }
 
 } // namespace sensor