Allow EAGAIN failures
Certain devices are known to return EAGAIN failures when read
too frequently, so be tolerant of them.
On startup, the code will retry for up to a second to get a good
first reading, and then in the main loop the code will just stick
with the current value if it fails that way.
Resolves openbmc/openbmc#2038
Change-Id: I7621aa30429c43276239982a03ec3eef02ce9c6e
Signed-off-by: Matt Spinler <spinler@us.ibm.com>
diff --git a/sysfs.cpp b/sysfs.cpp
index b26c9ae..efdba92 100644
--- a/sysfs.cpp
+++ b/sysfs.cpp
@@ -153,7 +153,8 @@
const std::string& instance,
const std::string& type,
const std::string& id,
- const std::string& sensor)
+ const std::string& sensor,
+ bool throwDeviceBusy)
{
namespace fs = std::experimental::filesystem;
@@ -181,6 +182,11 @@
// or read system calls that got us here.
auto rc = errno;
+ if ((rc == EAGAIN) && throwDeviceBusy)
+ {
+ throw DeviceBusyException(fullPath);
+ }
+
// If the directory disappeared then this application should gracefully
// exit. There are race conditions between the unloading of a hwmon
// driver and the stopping of this service by systemd. To prevent