RFR 8202835: jfr/event/os/TestSystemProcess.java fails on missing events

[B. Blaser]

On 17 May 2018 at 22:10, B. Blaser <bsrbnd at gmail.com> wrote:
> Hi,
>
> A recent change in 'os::readdir()' to use 'readdir' instead of the
> deprecated 'readdir_r' implies to copy the returned 'dirent' if
> necessary because 'readdir' uses its own buffer and not the one
> provided by the caller as it was done before with 'readdir_r'.
> The following fix is only intended to correct 'ProcessIterator',
> further improvements will be addressed as part of:
> https://bugs.openjdk.java.net/browse/JDK-8202353
>
> Tier1 is OK.

Looking closer at 'ProcessIterator', I note that copying 'dirent' is
unnecessary. Here is the updated fix.
Any comment or review is welcome.

Thanks,
Bernard


diff -r 8e4fcfb4cfe4 src/hotspot/os/linux/os_perf_linux.cpp
--- a/src/hotspot/os/linux/os_perf_linux.cpp    Thu May 17 10:32:26 2018 +0200
+++ b/src/hotspot/os/linux/os_perf_linux.cpp    Sat May 19 17:22:18 2018 +0200
@@ -903,21 +903,14 @@
 }

 int SystemProcessInterface::SystemProcesses::ProcessIterator::next_process() {
-  struct dirent* entry;
-
   if (!is_valid()) {
     return OS_ERR;
   }

   do {
-      entry = os::readdir(_dir, _entry);
-    if (entry == NULL) {
-      // error
-      _valid = false;
-      return OS_ERR;
-    }
+    _entry = os::readdir(_dir, NULL);
     if (_entry == NULL) {
-      // reached end
+      // reached end or error
       _valid = false;
       return OS_ERR;
     }
@@ -935,10 +928,6 @@

 bool SystemProcessInterface::SystemProcesses::ProcessIterator::initialize() {
   _dir = opendir("/proc");
-  _entry = (struct dirent*)NEW_C_HEAP_ARRAY(char, sizeof(struct
dirent) + NAME_MAX + 1, mtInternal);
-  if (NULL == _entry) {
-    return false;
-  }
   _valid = true;
   next_process();

@@ -946,9 +935,6 @@
 }

 SystemProcessInterface::SystemProcesses::ProcessIterator::~ProcessIterator() {
-  if (_entry != NULL) {
-    FREE_C_HEAP_ARRAY(char, _entry);
-  }
   if (_dir != NULL) {
     closedir(_dir);
   }
diff -r 8e4fcfb4cfe4 test/jdk/ProblemList.txt
--- a/test/jdk/ProblemList.txt    Thu May 17 10:32:26 2018 +0200
+++ b/test/jdk/ProblemList.txt    Sat May 19 17:22:18 2018 +0200
@@ -829,5 +829,4 @@

 jdk/jfr/event/io/TestInstrumentation.java
8202142    generic-all
 jdk/jfr/event/sampling/TestNative.java
8202142    generic-all
-jdk/jfr/event/os/TestSystemProcess.java
8202835    linux-all
-jdk/jfr/event/runtime/TestBiasedLockRevocationEvents.java
8203237    generic-all
\ No newline at end of file
+jdk/jfr/event/runtime/TestBiasedLockRevocationEvents.java
8203237    generic-all
diff -r 8e4fcfb4cfe4 test/jdk/TEST.groups
--- a/test/jdk/TEST.groups    Thu May 17 10:32:26 2018 +0200
+++ b/test/jdk/TEST.groups    Sat May 19 17:22:18 2018 +0200
@@ -465,6 +465,7 @@
     jdk/jfr/api/recording/event/TestLoadEventAfterStart.java \
     jdk/jfr/api/recording/state/TestState.java \
     jdk/jfr/event/os/TestCPULoad.java \
+    jdk/jfr/event/os/TestSystemProcess.java \
     jdk/jfr/event/compiler/TestAllocInNewTLAB.java \
     jdk/jfr/jcmd/TestJcmdStartStopDefault.java \
     jdk/jfr/event/io/TestFileStreamEvents.java \