<AWT Dev> Proposal: Memory leak issue on awt_InputMethod.c

[Phil Race]

On 06/27/2018 06:45 AM, Ichiroh Takiguchi wrote:
> Hello,
>
> I should post this mail before starting JDK11 RDP1.

Already too too late for that, but although this looks like a bug - and 
the correct fix -
the bug has been there forever .. since JDK 1.2  in 1998 !
That makes it a 20 year old bug, so I don't think we need to treat it as 
urgent
for JDK 11.

-phil.

>
> I found memory leak issue on awt_InputMethod.c.
>
> See src/java.desktop/unix/native/libawt_xawt/awt/awt_InputMethod.c.
> On line 1117, memory area was allocated by malloc(), but free() is 
> missing
> ===========================================
>   1099          if (text->feedback != NULL) {
>   1100              int cnt;
>   1101              jint *tmpstyle;
>   1102
>   1103              style = (*env)->NewIntArray(env, text->length);
>   1104              if (JNU_IsNull(env, style)) {
>   1105                  (*env)->ExceptionClear(env);
>   1106                  THROW_OUT_OF_MEMORY_ERROR();
>   1107                  goto finally;
>   1108              }
>   1109
>   1110              if (sizeof(XIMFeedback) == sizeof(jint)) {
>   1111                  /*
>   1112                   * Optimization to avoid copying the array
>   1113                   */
>   1114                  (*env)->SetIntArrayRegion(env, style, 0,
>   1115                                            text->length, (jint 
> *)text->feedback);
>   1116              } else {
>   1117                  tmpstyle  = (jint 
> *)malloc(sizeof(jint)*(text->length));
>   1118                  if (tmpstyle == (jint *) NULL) {
>   1119                      THROW_OUT_OF_MEMORY_ERROR();
>   1120                      goto finally;
>   1121                  }
>   1122                  for (cnt = 0; cnt < (int)text->length; cnt++)
>   1123                          tmpstyle[cnt] = text->feedback[cnt];
>   1124                  (*env)->SetIntArrayRegion(env, style, 0,
>   1125                                            text->length, (jint 
> *)tmpstyle);
>   1126              }
>   1127          }
> ===========================================
> In my investigation, malloc() was called on RHEL7 x86_64 with Japanese 
> Input Method.
>
> I'd like to obtain a sponsor for this patch.
> --------
> --- old/src/java.desktop/aix/native/libawt_xawt/awt/awt_InputMethod.c 
> 2018-06-27 02:03:48.134991703 +0900
> +++ new/src/java.desktop/aix/native/libawt_xawt/awt/awt_InputMethod.c 
> 2018-06-27 02:03:47.493005265 +0900
> @@ -1148,6 +1148,7 @@
>                          tmpstyle[cnt] = text->feedback[cnt];
>                  (*env)->SetIntArrayRegion(env, style, 0,
>                                            text->length, (jint 
> *)tmpstyle);
> +                free(tmpstyle);
>              }
>          }
>      }
> --- old/src/java.desktop/unix/native/libawt_xawt/awt/awt_InputMethod.c 
>  2018-06-27 02:03:49.040972563 +0900
> +++ new/src/java.desktop/unix/native/libawt_xawt/awt/awt_InputMethod.c 
>  2018-06-27 02:03:48.391986274 +0900
> @@ -1123,6 +1123,7 @@
>                          tmpstyle[cnt] = text->feedback[cnt];
>                  (*env)->SetIntArrayRegion(env, style, 0,
>                                            text->length, (jint 
> *)tmpstyle);
> +                free(tmpstyle);
>              }
>          }
>      }
> --------
>
> Thanks,
> Ichiroh Takiguchi
> IBM Japan, Ltd.
>