Bug 1202706 - Part 1: Add telemetry histograms for worker use counters; r=chutten,bzbarsky

This patch uses similar architecture of use counters of main thread for workers.

Which introduces the following format histograms for use counters of workers

USE_COUNTER2_*_DEDICATED_WORKER
USE_COUNTER2_*_SHARED_WORKER
USE_COUNTER2_*_SERVICE_WORKER

And add the following histograms used in conjunction with above use counter histograms

DEDICATED_WORKER_DESTROYED
SHARED_WORKER_DESTROYED
SERVICE_WORKER_DESTROYED

Differential Revision: https://phabricator.services.mozilla.com/D53221

--HG--
rename : dom/base/UseCounters.conf => dom/base/UseCountersWorker.conf
extra : moz-landing-system : lando

dom/base/UseCountersWorker.conf

@@ -0,0 +1,67 @@
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this
+// file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+// This file defines a list of use counters, which are things that can
+// record usage of Web platform features and then report this information
+// through Telemetry.
+//
+// The format of this file is very strict.  Each line can be:
+//
+//   (a) a blank line
+//
+//   (b) a comment, which is a line that begins with "//"
+//
+//   (c) one of four possible use counter declarations:
+//
+//         method <IDL interface name>.<IDL operation name>
+//         attribute <IDL interface name>.<IDL attribute name>
+//         custom <any valid identifier> <description>
+//
+// The <description> for custom counters will be appended to "Whether a
+// dedicated worker " or "Whether a shared worker" or "Whether a service worker
+//  ", so phrase it appropriately.  For instance, "constructs a
+// Foo object" or "calls Bar.baz('some value')". It may contain any character
+// (including whitespace).
+//
+// To actually cause use counters to be incremented, DOM methods
+// and attributes must have a [UseCounter] extended attribute and be exposed to
+// workers in the Web IDL file.
+// Custom counters are incremented when
+// SetUseCounter(UseCounterWoker::Custom_MyName) is called on a WorkerPrivate
+// object.
+//
+// You might reasonably ask why we have this file and we require
+// annotating things with [UseCounter] in the relevant WebIDL file as
+// well.  Generating things from bindings codegen and ensuring all the
+// dependencies were correct would have been rather difficult.
+
+// Push API
+method PushManager.subscribe
+method PushSubscription.unsubscribe
+
+// Console API
+method console.assert
+method console.clear
+method console.count
+method console.countReset
+method console.debug
+method console.error
+method console.info
+method console.log
+method console.table
+method console.trace
+method console.warn
+method console.dir
+method console.dirxml
+method console.group
+method console.groupCollapsed
+method console.groupEnd
+method console.time
+method console.timeLog
+method console.timeEnd
+method console.exception
+method console.timeStamp
+method console.profile
+method console.profileEnd
+

dom/base/usecounters.py

@@ -43,9 +43,14 @@ def read_conf(conf_filename):
 
     return parse_counters(stream)
 
-def generate_histograms(filename):
+def generate_histograms(filename, is_for_worker=False):
     # The mapping for use counters to telemetry histograms depends on the
     # ordering of items in the dictionary.
+
+    # The ordering of the ending for workers depends on the WorkerType defined
+    # in WorkerPrivate.h.
+    endings = ["DEDICATED_WORKER", "SHARED_WORKER", "SERVICE_WORKER"] if is_for_worker else ["DOCUMENT", "PAGE"]
+
     items = collections.OrderedDict()
     for counter in read_conf(filename):
         def append_counter(name, desc):
@@ -54,8 +59,9 @@ def generate_histograms(filename):
                             'description': desc }
 
         def append_counters(name, desc):
-            append_counter('USE_COUNTER2_%s_DOCUMENT' % name, 'Whether a document %s' % desc)
-            append_counter('USE_COUNTER2_%s_PAGE' % name, 'Whether a page %s' % desc)
+            for ending in endings:
+                append_counter('USE_COUNTER2_%s_%s' % (name, ending),
+                               'Whether a %s %s' % (ending.replace('_', ' ').lower(), desc))
 
         if counter['type'] == 'method':
             method = '%s.%s' % (counter['interface_name'], counter['method_name'])

toolkit/components/telemetry/Histograms.json

@@ -11987,6 +11987,16 @@
     "description": "Time (in ms) measured between when the fetch handler finished executing and when we reset the network channel."
   },
 
+  "SERVICE_WORKER_DESTROYED": {
+    "record_in_processes": ["main", "content"],
+    "products": ["firefox", "fennec", "geckoview"],
+    "expires_in_version": "never",
+    "kind": "count",
+    "releaseChannelCollection": "opt-out",
+    "bug_numbers": [1202706],
+    "alert_emails": ["tdsmith@mozilla.com", "compatibility@lists.mozilla.org"],
+    "description": "Number of service workers destroyed; used in conjunction with use counter histograms"
+  },
   "ONBEFOREUNLOAD_PROMPT_ACTION" : {
     "record_in_processes": ["main", "content"],
     "products": ["firefox", "fennec", "geckoview"],
@@ -12542,6 +12552,16 @@
     "kind": "count",
     "description": "Tracking whether a SharedWorker spawn gets queued due to hitting max workers per domain limit. File bugs in Core::DOM in case of a Telemetry regression."
   },
+  "SHARED_WORKER_DESTROYED": {
+    "record_in_processes": ["main", "content"],
+    "products": ["firefox", "fennec", "geckoview"],
+    "expires_in_version": "never",
+    "kind": "count",
+    "releaseChannelCollection": "opt-out",
+    "bug_numbers": [1202706],
+    "alert_emails": ["tdsmith@mozilla.com", "compatibility@lists.mozilla.org"],
+    "description": "Number of shared workers destroyed; used in conjunction with use counter histograms"
+  },
   "DEDICATED_WORKER_SPAWN_GETS_QUEUED": {
     "record_in_processes": ["main", "content"],
     "products": ["firefox", "fennec", "geckoview"],
@@ -12551,6 +12571,16 @@
     "kind": "count",
     "description": "Tracking whether a DedicatedWorker spawn gets queued due to hitting max workers per domain limit. File bugs in Core::DOM in case of a Telemetry regression."
   },
+  "DEDICATED_WORKER_DESTROYED": {
+    "record_in_processes": ["main", "content"],
+    "products": ["firefox", "fennec", "geckoview"],
+    "expires_in_version": "never",
+    "kind": "count",
+    "releaseChannelCollection": "opt-out",
+    "bug_numbers": [1202706],
+    "alert_emails": ["tdsmith@mozilla.com", "compatibility@lists.mozilla.org"],
+    "description": "Number of dedicated workers destroyed; used in conjunction with use counter histograms"
+  },
   "SERVICE_WORKER_REGISTRATIONS": {
     "record_in_processes": ["main", "content"],
     "products": ["firefox", "fennec", "geckoview"],

toolkit/components/telemetry/build_scripts/gen_histogram_enum.py

@@ -40,6 +40,13 @@ footer = """
 #endif // mozilla_TelemetryHistogramEnums_h"""
 
 
+def get_histogram_typename(histogram):
+    name = histogram.name()
+    if name.startswith("USE_COUNTER2_"):
+        return "UseCounterWorker" if name.endswith("_WORKER") else "UseCounter"
+    return None
+
+
 def main(output, *filenames):
     # Print header.
     print(banner, file=output)
@@ -52,42 +59,46 @@ def main(output, *filenames):
         print("\nError processing histograms:\n" + str(ex) + "\n")
         sys.exit(1)
 
-    groups = itertools.groupby(all_histograms,
-                               lambda h: h.name().startswith("USE_COUNTER2_"))
+    groups = itertools.groupby(all_histograms, get_histogram_typename)
 
     # Print the histogram enums.
-    # Note that parse_histograms.py guarantees that all of the USE_COUNTER2_*
-    # histograms are defined in a contiguous block.  We therefore assume
-    # that there's at most one group for which use_counter_group is true.
+    # Note that parse_histograms.py guarantees that all of the
+    # USE_COUNTER2_*_WORKER and USE_COUNTER2_* histograms are both defined in a
+    # contiguous block.
     print("enum HistogramID : uint32_t {", file=output)
-    seen_use_counters = False
-    for (use_counter_group, histograms) in groups:
-        if use_counter_group:
-            seen_use_counters = True
-
-        # The HistogramDUMMY* enum variables are used to make the computation
-        # of Histogram{First,Last}UseCounter easier.  Otherwise, we'd have to
-        # special case the first and last histogram in the group.
-        if use_counter_group:
-            print("  HistogramFirstUseCounter,", file=output)
-            print("  HistogramDUMMY1 = HistogramFirstUseCounter - 1,", file=output)
+    seen_group_types = {"UseCounter": False, "UseCounterWorker": False}
+    for (group_type, histograms) in groups:
+        if group_type is not None:
+            assert isinstance(group_type, basestring)
+            assert group_type in seen_group_types.keys()
+            assert not seen_group_types[group_type]
+            seen_group_types[group_type] = True
+            # The Histogram*DUMMY enum variables are used to make the computation
+            # of Histogram{First,Last}* easier.  Otherwise, we'd have to special
+            # case the first and last histogram in the group.
+            print("  HistogramFirst%s," % group_type, file=output)
+            print("  Histogram{0}DUMMY1 = HistogramFirst{0} - 1,".format(group_type), file=output)
 
         for histogram in histograms:
             if histogram.record_on_os(buildconfig.substs["OS_TARGET"]):
                 print("  %s," % histogram.name(), file=output)
 
-        if use_counter_group:
-            print("  HistogramDUMMY2,", file=output)
-            print("  HistogramLastUseCounter = HistogramDUMMY2 - 1,", file=output)
+        if group_type is not None:
+            assert isinstance(group_type, basestring)
+            print("  Histogram%sDUMMY2," % group_type, file=output)
+            print("  HistogramLast{0} = Histogram{0}DUMMY2 - 1,".format(group_type), file=output)
 
     print("  HistogramCount,", file=output)
-    if seen_use_counters:
-        print("  HistogramUseCounterCount = HistogramLastUseCounter -"
-              " HistogramFirstUseCounter + 1", file=output)
-    else:
-        print("  HistogramFirstUseCounter = 0,", file=output)
-        print("  HistogramLastUseCounter = 0,", file=output)
-        print("  HistogramUseCounterCount = 0", file=output)
+
+    for (key, value) in seen_group_types.items():
+        if value:
+            print("  Histogram{0}Count = HistogramLast{0} - HistogramFirst{0} + 1,"
+                  .format(key), file=output)
+        else:
+            print("  HistogramFirst%s = 0," % key, file=output)
+            print("  HistogramLast%s = 0," % key, file=output)
+            print("  Histogram%sCount = 0," % key, file=output)
+
     print("};", file=output)
 
     # Write categorical label enums.

toolkit/components/telemetry/build_scripts/mozparsers/parse_histograms.py

@@ -725,6 +725,10 @@ def from_UseCounters_conf(filename, strict_type_checks):
     return usecounters.generate_histograms(filename)
 
 
+def from_UseCountersWorker_conf(filename, strict_type_checks):
+    return usecounters.generate_histograms(filename, True)
+
+
 def from_nsDeprecatedOperationList(filename, strict_type_checks):
     operation_regex = re.compile('^DEPRECATED_OPERATION\\(([^)]+)\\)')
     histograms = collections.OrderedDict()
@@ -828,6 +832,8 @@ try:
     import usecounters
 
     FILENAME_PARSERS.append(lambda x: from_UseCounters_conf if x == 'UseCounters.conf' else None)
+    FILENAME_PARSERS.append(
+        lambda x: from_UseCountersWorker_conf if x == 'UseCountersWorker.conf' else None)
 except ImportError:
     pass
 
@@ -864,17 +870,26 @@ the histograms defined in filenames.
                 ParserError('Duplicate histogram name "%s".' % name).handle_later()
             all_histograms[name] = definition
 
-    # We require that all USE_COUNTER2_* histograms be defined in a contiguous
+    def check_continuity(iterable, filter_function, name):
+        indices = filter(filter_function, enumerate(iterable.iterkeys()))
+        if indices:
+            lower_bound = indices[0][0]
+            upper_bound = indices[-1][0]
+            n_counters = upper_bound - lower_bound + 1
+            if n_counters != len(indices):
+                ParserError("Histograms %s must be defined in a contiguous block." %
+                            name).handle_later()
+
+    # We require that all USE_COUNTER2_*_WORKER histograms be defined in a contiguous
     # block.
-    use_counter_indices = filter(lambda x: x[1].startswith("USE_COUNTER2_"),
-                                 enumerate(all_histograms.iterkeys()))
-    if use_counter_indices:
-        lower_bound = use_counter_indices[0][0]
-        upper_bound = use_counter_indices[-1][0]
-        n_counters = upper_bound - lower_bound + 1
-        if n_counters != len(use_counter_indices):
-            ParserError("Use counter histograms must be defined in a contiguous block."
-                        ).handle_later()
+    check_continuity(all_histograms,
+                     lambda x: x[1].startswith("USE_COUNTER2_") and x[1].endswith("_WORKER"),
+                     "use counter worker")
+    # And all other USE_COUNTER2_* histograms be defined in a contiguous
+    # block.
+    check_continuity(all_histograms,
+                     lambda x: x[1].startswith("USE_COUNTER2_") and not x[1].endswith("_WORKER"),
+                     "use counter")
 
     # Check that histograms that were removed from Histograms.json etc.
     # are also removed from the allowlists.

toolkit/components/telemetry/histogram-allowlists.json

@@ -1188,6 +1188,7 @@
     "D3D11_COMPOSITING_FAILURE_ID",
     "D3D11_SYNC_HANDLE_FAILURE",
     "DEDICATED_WORKER_SPAWN_GETS_QUEUED",
+    "DEDICATED_WORKER_DESTROYED",
     "DEFECTIVE_PERMISSIONS_SQL_REMOVED",
     "DENIED_TRANSLATION_OFFERS",
     "DEVTOOLS_ABOUTDEBUGGING_OPENED_COUNT",
@@ -1259,7 +1260,9 @@
     "SERVICE_WORKER_SPAWN_GETS_QUEUED",
     "SERVICE_WORKER_UPDATED",
     "SERVICE_WORKER_WAS_SPAWNED",
+    "SERVICE_WORKER_DESTROYED",
     "SHARED_WORKER_SPAWN_GETS_QUEUED",
+    "SHARED_WORKER_DESTROYED",
     "SHOULD_AUTO_DETECT_LANGUAGE",
     "SHOULD_TRANSLATION_UI_APPEAR",
     "SLOW_SCRIPT_NOTICE_COUNT",

toolkit/components/telemetry/moz.build

@@ -143,6 +143,7 @@ histogram_files = [
     '/dom/base/nsDeprecatedOperationList.h',
     '!/layout/style/ServoCSSPropList.py',
     '/servo/components/style/properties/counted_unknown_properties.py',
+    '/dom/base/UseCountersWorker.conf',
 ]
 if CONFIG['MOZ_TELEMETRY_EXTRA_HISTOGRAM_FILES']:
     histogram_files.extend(CONFIG['MOZ_TELEMETRY_EXTRA_HISTOGRAM_FILES'])