Script that formats dvm_gc_info lines.

Simple (?) script that parses the dvm_gc_info lines out of the event log
and parses the contents.  Mostly useful for displaying the external
allocation "limit" and "allocated" values, which don't really show up
anywhere else.

1 files changed, 204 insertions, 0 deletions

diff --git a/tools/gclog.py b/tools/gclog.py
new file mode 100755
index 000000000..4696965ed
--- /dev/null
+++ b/tools/gclog.py
@@ -0,0 +1,204 @@
+#!/usr/bin/env python
+#
+# Copyright (C) 2009 The Android Open Source Project
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+#
+# Version 1.0, 29-Apr-2009
+#
+# Parse event log output, looking for GC events.  Format them for human
+# consumption.
+#
+# ALL OUTPUT VALUES ARE APPROXIMATE.  The event log data format uses a
+# 12-bit floating-point representation, which means there aren't enough
+# bits to accurately represent anything but small integers.  Larger
+# values will be rounded off.
+#
+# The data is generated by dalvik/vm/alloc/HeapDebug.c.
+#
+
+import os
+import re
+import time
+
+def unfloat12(f12):
+    """Unpack a float12 value"""
+    if f12 < 0:
+        raise DataParseError, "bad float12 value %s" % f12
+    return (f12 & 0x1ff) << ((f12 >> 9) * 4)
+
+
+def parseGlobalInfo(value):
+    """Parse event0 (global info)"""
+    value = int(value)
+
+    # Global information:
+    #
+    # [63   ] Must be zero
+    # [62-24] ASCII process identifier
+    # [23-12] GC time in ms
+    # [11- 0] Bytes freed
+    id = (value >> 24) & 0xffffffffff
+    gctime = unfloat12((value >> 12) & 0xfff)
+    bytes_freed = unfloat12(value & 0xfff)
+
+    idstr = "%c%c%c%c%c" % ( \
+            (id >> 32) & 0xff, \
+            (id >> 24) & 0xff, \
+            (id >> 16) & 0xff, \
+            (id >> 8) & 0xff, \
+            id & 0xff )
+
+    return ( idstr, gctime, bytes_freed )
+
+
+def parseAggHeapStats(value):
+    """Parse event1 (aggregated heap stats)"""
+    value = int(value)
+
+    # Aggregated heap stats:
+    #
+    # [63-62] 10
+    # [61-60] Reserved; must be zero
+    # [59-48] Objects freed
+    # [47-36] Actual size (current footprint)
+    # [35-24] Allowed size (current hard max)
+    # [23-12] Objects allocated
+    # [11- 0] Bytes allocated
+    freed = unfloat12((value >> 48) & 0xfff)
+    footprint = unfloat12((value >> 36) & 0xfff)
+    allowed = unfloat12((value >> 24) & 0xfff)
+    objs = unfloat12((value >> 12) & 0xfff)
+    bytes = unfloat12(value & 0xfff)
+
+    return ( freed, footprint, allowed, objs, bytes )
+
+
+def parseZygoteStats(value):
+    """Parse event2 (zygote heap stats)"""
+    value = int(value)
+
+    # Zygote heap stats (except for the soft limit, which belongs to the
+    # active heap):
+    #
+    # [63-62] 11
+    # [61-60] Reserved; must be zero
+    # [59-48] Soft Limit (for the active heap)
+    # [47-36] Actual size (current footprint)
+    # [35-24] Allowed size (current hard max)
+    # [23-12] Objects allocated
+    # [11- 0] Bytes allocated
+    soft_limit = unfloat12((value >> 48) & 0xfff)
+    actual = unfloat12((value >> 36) & 0xfff)
+    allowed = unfloat12((value >> 24) & 0xfff)
+    objs = unfloat12((value >> 12) & 0xfff)
+    bytes = unfloat12(value & 0xfff)
+
+    return ( soft_limit, actual, allowed, objs, bytes )
+
+
+def parseExternalStats(value):
+    """Parse event3 (external allocation stats)"""
+    value = int(value)
+
+    # Report the current external allocation stats and the native heap
+    # summary.
+    #
+    # [63-48] Reserved; must be zero (TODO: put new data in these slots)
+    # [47-36] dlmalloc_footprint
+    # [35-24] mallinfo: total allocated space
+    # [23-12] External byte limit
+    # [11- 0] External bytes allocated
+    footprint = unfloat12((value >> 36) & 0xfff)    # currently disabled
+    total = unfloat12((value >> 24) & 0xfff)        # currently disabled
+    limit = unfloat12((value >> 12) & 0xfff)
+    bytes = unfloat12(value & 0xfff)
+
+    return ( footprint, total, limit, bytes )
+
+
+def handleGcInfo(timestamp, pid, values):
+    """Handle a single dvm_gc_info event"""
+
+    pid = int(pid)
+
+    global_info = parseGlobalInfo(values[0])
+    heap_stats = parseAggHeapStats(values[1])
+    zygote = parseZygoteStats(values[2])
+    external = parseExternalStats(values[3])
+
+    debug = False
+    if debug:
+        print "RAW: %s %s (%s,%s,%s,%s)" % \
+                (timestamp, pid, values[0], values[1], values[2], values[3])
+
+        print "> id=\"%s\" time=%d freed=%d" % (global_info[0], global_info[1], global_info[2])
+        print ">  freed=%d foot=%d allow=%d objs=%d bytes=%d" % \
+                (heap_stats[0], heap_stats[1], heap_stats[2], heap_stats[3], heap_stats[4])
+        print ">  soft=%d act=%d allow=%d objs=%d bytes=%d" % \
+                (zygote[0], zygote[1], zygote[2], zygote[3], zygote[4])
+        print ">  foot=%d total=%d limit=%d alloc=%d" % \
+                (external[0], external[1], external[2], external[3])
+
+    print "%s %s(%d) softlim=%dKB, extlim=%dKB, extalloc=%dKB" % \
+            (timestamp, global_info[0], pid, zygote[0]/1024, external[2]/1024, external[3]/1024)
+    print "  freed %d objects / %d bytes in %dms" % \
+            (heap_stats[0], global_info[2], global_info[1])
+
+
+def filterInput(logPipe):
+    """Loop until EOF, pulling out GC events"""
+
+    # 04-29 20:31:00.334 I/dvm_gc_info(   69): [8320808730292729543,-8916699241518090181,-4006371297196337158,8165229]
+    gc_info_re = re.compile(r"""
+        (\d+-\d+\ \d+:\d+:\d+)\.\d+     # extract the date (#1), ignoring ms
+        .*                              # filler, usually " I/"
+        dvm_gc_info                     # only interested in GC info lines
+        \(\s*(\d+)\)                    # extract the pid (#2)
+        :\ \[                           # filler
+        ([0-9-]+),([0-9-]+),([0-9-]+),([0-9-]+) # four values, may be negative
+        \].*                            # junk to end of line
+        """, re.VERBOSE)
+
+    while True:
+        line = logPipe.readline()
+        if not line:
+            print "EOF hit"
+            return
+
+        match = gc_info_re.match(line)
+        if not match:
+            #print "no match on %s" % line.strip()
+            continue
+        else:
+            handleGcInfo(match.group(1), match.group(2), ( match.group(3), \
+                    match.group(4), match.group(5), match.group(6) ) )
+
+def start():
+    """Entry point"""
+
+    # launch a logcat and read from it
+    command = 'adb logcat -v time -b events'
+    logPipe = os.popen(command)
+
+    try:
+        filterInput(logPipe)
+    except KeyboardInterrupt, err:
+        print "Stopping on keyboard interrupt."
+
+    logPipe.close()
+
+
+start()
+