1 /*
   2  * Copyright (c) 2006, 2018, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #ifndef _JVM_DTRACE_H_
  26 #define _JVM_DTRACE_H_
  27 
  28 /*
  29  * Interface to dynamically turn on probes in Hotspot JVM. Currently,
  30  * this interface can be used to dynamically enable certain DTrace
  31  * probe points that are costly to have "always on".
  32  */
  33 
  34 #ifdef __cplusplus
  35 extern "C" {
  36 #endif
  37 
  38 #include <sys/types.h>
  39 #include "jni.h"
  40 
  41 struct _jvm_t;
  42 typedef struct _jvm_t jvm_t;
  43 
  44 
  45 /* Attach to the given JVM process. Returns NULL on failure.
  46    jvm_get_last_error() returns last error message. */
  47 JNIEXPORT jvm_t* jvm_attach(pid_t pid);
  48 
  49 /* Returns the last error message from this library or NULL if none. */
  50 JNIEXPORT const char* jvm_get_last_error();
  51 
  52 /* few well-known probe type constants for 'probe_types' param below */
  53 
  54 #define JVM_DTPROBE_METHOD_ENTRY         "method-entry"
  55 #define JVM_DTPROBE_METHOD_RETURN        "method-return"
  56 #define JVM_DTPROBE_MONITOR_ENTER        "monitor-contended-enter"
  57 #define JVM_DTPROBE_MONITOR_ENTERED      "monitor-contended-entered"
  58 #define JVM_DTPROBE_MONITOR_EXIT         "monitor-contended-exit"
  59 #define JVM_DTPROBE_MONITOR_WAIT         "monitor-wait"
  60 #define JVM_DTPROBE_MONITOR_WAITED       "monitor-waited"
  61 #define JVM_DTPROBE_MONITOR_NOTIFY       "monitor-notify"
  62 #define JVM_DTPROBE_MONITOR_NOTIFYALL    "monitor-notifyall"
  63 #define JVM_DTPROBE_OBJECT_ALLOC         "object-alloc"
  64 #define JVM_DTPROBE_ALL                  "*"
  65 
  66 /* Enable the specified DTrace probes of given probe types on
  67  * the specified JVM. Returns >= 0 on success, -1 on failure.
  68  * On success, this returns number of probe_types enabled.
  69  * On failure, jvm_get_last_error() returns the last error message.
  70  */
  71 JNIEXPORT int jvm_enable_dtprobes(jvm_t* jvm, int num_probe_types, const char** probe_types);
  72 
  73 /* Note: There is no jvm_disable_dtprobes function. Probes are automatically
  74  * disabled when there are no more clients requiring those probes.
  75  */
  76 
  77 /* Detach the given JVM. Returns 0 on success, -1 on failure.
  78  * jvm_get_last_error() returns the last error message.
  79  */
  80 JNIEXPORT int jvm_detach(jvm_t* jvm);
  81 
  82 #ifdef __cplusplus
  83 }
  84 #endif
  85 
  86 #endif /* _JVM_DTRACE_H_ */