Cleans up POSIX/C bits in H5private.h (#804)

* Cleans up POSIX/C bits in H5private.h

* Assume difftime exists (C89)
* Reorg AC_CHECK_HEADERS so headers are in alphabetical order
* Split off networking-related AC_CHECK_HEADERS
* Remove unused UNAME_CYGWIN from configure.ac
* Remove checks for unused sys/timeb.h
* Tidying pass over H5private.h HD prefix macros
* Tidy H5win32defs.h
* Add HD prefix to various scanf calls

* Committing clang-format changes

* Fixes to the alarm(2) code used in the tests to make Windows happy

Co-authored-by: github-actions <41898282+github-actions[bot]@users.noreply.github.com>

1 files changed, 18 insertions, 4 deletions

diff --git a/test/testframe.c b/test/testframe.c
index f805997..d3f0211 100644
--- a/test/testframe.c
+++ b/test/testframe.c
@@ -320,9 +320,9 @@ PerformTests(void)
             MESSAGE(5, ("===============================================\n"));
             Test[Loop].NumErrors = num_errs;
             Test_parameters      = Test[Loop].Parameters;
-            ALARM_ON;
+            TestAlarmOn();
             Test[Loop].Call();
-            ALARM_OFF;
+            TestAlarmOff();
             Test[Loop].NumErrors = num_errs - Test[Loop].NumErrors;
             MESSAGE(5, ("===============================================\n"));
             MESSAGE(5, ("There were %d errors detected.\n\n", (int)Test[Loop].NumErrors));
@@ -620,12 +620,15 @@ SetTest(const char *testname, int action)
     }
 }
 
-/*
- * Enable alarm on test execution, configurable by environment variable
+/* Enable a test timer that will kill long-running tests, the time is configurable
+ * via an environment variable.
+ *
+ * Only useful on POSIX systems where alarm(2) is present.
  */
 void
 TestAlarmOn(void)
 {
+#ifdef H5_HAVE_ALARM
     char *        env_val   = HDgetenv("HDF5_ALARM_SECONDS"); /* Alarm environment */
     unsigned long alarm_sec = H5_ALARM_SEC;                   /* Number of seconds before alarm goes off */
 
@@ -635,4 +638,15 @@ TestAlarmOn(void)
 
     /* Set the number of seconds before alarm goes off */
     HDalarm((unsigned)alarm_sec);
+#endif
+}
+
+/* Disable the test timer */
+void
+TestAlarmOff(void)
+{
+#ifdef H5_HAVE_ALARM
+    /* Set the number of seconds to zero */
+    HDalarm(0);
+#endif
 }