hotspot/src/share/vm/runtime/perfMemory.cpp
changeset 1 489c9b5090e2
child 1553 fc10c169d15d
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/src/share/vm/runtime/perfMemory.cpp	Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,248 @@
+/*
+ * Copyright 2001-2006 Sun Microsystems, Inc.  All Rights Reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ *
+ */
+
+# include "incls/_precompiled.incl"
+# include "incls/_perfMemory.cpp.incl"
+
+char*                    PerfMemory::_start = NULL;
+char*                    PerfMemory::_end = NULL;
+char*                    PerfMemory::_top = NULL;
+size_t                   PerfMemory::_capacity = 0;
+jint                     PerfMemory::_initialized = false;
+PerfDataPrologue*        PerfMemory::_prologue = NULL;
+
+void perfMemory_init() {
+
+  if (!UsePerfData) return;
+
+  PerfMemory::initialize();
+}
+
+void perfMemory_exit() {
+
+  if (!UsePerfData) return;
+  if (!PerfMemory::is_initialized()) return;
+
+  // if the StatSampler is active, then we don't want to remove
+  // resources it may be dependent on. Typically, the StatSampler
+  // is disengaged from the watcher thread when this method is called,
+  // but it is not disengaged if this method is invoked during a
+  // VM abort.
+  //
+  if (!StatSampler::is_active())
+    PerfDataManager::destroy();
+
+  // remove the persistent external resources, if any. this method
+  // does not unmap or invalidate any virtual memory allocated during
+  // initialization.
+  //
+  PerfMemory::destroy();
+}
+
+void PerfMemory::initialize() {
+
+  if (_prologue != NULL)
+    // initialization already performed
+    return;
+
+  size_t capacity = align_size_up(PerfDataMemorySize,
+                                  os::vm_allocation_granularity());
+
+  if (PerfTraceMemOps) {
+    tty->print("PerfDataMemorySize = " SIZE_FORMAT ","
+               " os::vm_allocation_granularity = " SIZE_FORMAT ","
+               " adjusted size = " SIZE_FORMAT "\n",
+               PerfDataMemorySize,
+               os::vm_allocation_granularity(),
+               capacity);
+  }
+
+  // allocate PerfData memory region
+  create_memory_region(capacity);
+
+  if (_start == NULL) {
+
+    // the PerfMemory region could not be created as desired. Rather
+    // than terminating the JVM, we revert to creating the instrumentation
+    // on the C heap. When running in this mode, external monitoring
+    // clients cannot attach to and monitor this JVM.
+    //
+    // the warning is issued only in debug mode in order to avoid
+    // additional output to the stdout or stderr output streams.
+    //
+    if (PrintMiscellaneous && Verbose) {
+      warning("Could not create PerfData Memory region, reverting to malloc");
+    }
+
+    _prologue = NEW_C_HEAP_OBJ(PerfDataPrologue);
+  }
+  else {
+
+    // the PerfMemory region was created as expected.
+
+    if (PerfTraceMemOps) {
+      tty->print("PerfMemory created: address = " INTPTR_FORMAT ","
+                 " size = " SIZE_FORMAT "\n",
+                 (void*)_start,
+                 _capacity);
+    }
+
+    _prologue = (PerfDataPrologue *)_start;
+    _end = _start + _capacity;
+    _top = _start + sizeof(PerfDataPrologue);
+  }
+
+  assert(_prologue != NULL, "prologue pointer must be initialized");
+
+#ifdef VM_LITTLE_ENDIAN
+  _prologue->magic = (jint)0xc0c0feca;
+  _prologue->byte_order = PERFDATA_LITTLE_ENDIAN;
+#else
+  _prologue->magic = (jint)0xcafec0c0;
+  _prologue->byte_order = PERFDATA_BIG_ENDIAN;
+#endif
+
+  _prologue->major_version = PERFDATA_MAJOR_VERSION;
+  _prologue->minor_version = PERFDATA_MINOR_VERSION;
+  _prologue->accessible = 0;
+
+  _prologue->entry_offset = sizeof(PerfDataPrologue);
+  _prologue->num_entries = 0;
+  _prologue->used = 0;
+  _prologue->overflow = 0;
+  _prologue->mod_time_stamp = 0;
+
+  OrderAccess::release_store(&_initialized, 1);
+}
+
+void PerfMemory::destroy() {
+
+  assert(_prologue != NULL, "prologue pointer must be initialized");
+
+  if (_start != NULL && _prologue->overflow != 0) {
+
+    // This state indicates that the contiguous memory region exists and
+    // that it wasn't large enough to hold all the counters. In this case,
+    // we output a warning message to the user on exit if the -XX:+Verbose
+    // flag is set (a debug only flag). External monitoring tools can detect
+    // this condition by monitoring the _prologue->overflow word.
+    //
+    // There are two tunables that can help resolve this issue:
+    //   - increase the size of the PerfMemory with -XX:PerfDataMemorySize=<n>
+    //   - decrease the maximum string constant length with
+    //     -XX:PerfMaxStringConstLength=<n>
+    //
+    if (PrintMiscellaneous && Verbose) {
+      warning("PerfMemory Overflow Occurred.\n"
+              "\tCapacity = " SIZE_FORMAT " bytes"
+              "  Used = " SIZE_FORMAT " bytes"
+              "  Overflow = " INT32_FORMAT " bytes"
+              "\n\tUse -XX:PerfDataMemorySize=<size> to specify larger size.",
+              PerfMemory::capacity(),
+              PerfMemory::used(),
+              _prologue->overflow);
+    }
+  }
+
+  if (_start != NULL) {
+
+    // this state indicates that the contiguous memory region was successfully
+    // and that persistent resources may need to be cleaned up. This is
+    // expected to be the typical condition.
+    //
+    delete_memory_region();
+  }
+
+  _start = NULL;
+  _end = NULL;
+  _top = NULL;
+  _prologue = NULL;
+  _capacity = 0;
+}
+
+// allocate an aligned block of memory from the PerfData memory
+// region. This method assumes that the PerfData memory region
+// was aligned on a double word boundary when created.
+//
+char* PerfMemory::alloc(size_t size) {
+
+  if (!UsePerfData) return NULL;
+
+  MutexLocker ml(PerfDataMemAlloc_lock);
+
+  assert(_prologue != NULL, "called before initialization");
+
+  // check that there is enough memory for this request
+  if ((_top + size) >= _end) {
+
+    _prologue->overflow += (jint)size;
+
+    return NULL;
+  }
+
+  char* result = _top;
+
+  _top += size;
+
+  assert(contains(result), "PerfData memory pointer out of range");
+
+  _prologue->used = (jint)used();
+  _prologue->num_entries = _prologue->num_entries + 1;
+
+  return result;
+}
+
+void PerfMemory::mark_updated() {
+  if (!UsePerfData) return;
+
+  _prologue->mod_time_stamp = os::elapsed_counter();
+}
+
+// Returns the complete path including the file name of performance data file.
+// Caller is expected to release the allocated memory.
+char* PerfMemory::get_perfdata_file_path() {
+  char* dest_file = NULL;
+
+  if (PerfDataSaveFile != NULL) {
+    // dest_file_name stores the validated file name if file_name
+    // contains %p which will be replaced by pid.
+    dest_file = NEW_C_HEAP_ARRAY(char, JVM_MAXPATHLEN);
+    if(!Arguments::copy_expand_pid(PerfDataSaveFile, strlen(PerfDataSaveFile),
+                                   dest_file, JVM_MAXPATHLEN)) {
+      FREE_C_HEAP_ARRAY(char, dest_file);
+      if (PrintMiscellaneous && Verbose) {
+        warning("Invalid performance data file path name specified, "\
+                "fall back to a default name");
+      }
+    } else {
+      return dest_file;
+    }
+  }
+  // create the name of the file for retaining the instrumentation memory.
+  dest_file = NEW_C_HEAP_ARRAY(char, PERFDATA_FILENAME_LEN);
+  jio_snprintf(dest_file, PERFDATA_FILENAME_LEN,
+               "%s_%d", PERFDATA_NAME, os::current_process_id());
+
+  return dest_file;
+}