Use better JS engine defaults

This adds in preferences for all the SM 39 available options (as
retrieved from Gecko), and uses the same defaults as Gecko. A few
properties are not supported yet, and incremental GC is still always
disabled regardless of the preference setting.

This also adds back in the options that were accidentally deleted when
\#10342 was rebased, which moved things from script_thread.rs to
script_runtime.rs.

components/script/script_runtime.rs

@@ -13,6 +13,8 @@ use js::glue::CollectServoSizes;
 use js::jsapi::{DisableIncrementalGC, GCDescription, GCProgress};
 use js::jsapi::{JSContext, JS_GetRuntime, JSRuntime, JSTracer, SetDOMCallbacks, SetGCSliceCallback};
 use js::jsapi::{JSGCInvocationKind, JSGCStatus, JS_AddExtraGCRootsTracer, JS_SetGCCallback};
+use js::jsapi::{JSGCMode, JSGCParamKey, JS_SetGCParameter, JS_SetGlobalJitCompilerOption};
+use js::jsapi::{JSJitCompilerOption, JS_SetOffthreadIonCompilationEnabled, JS_SetParallelParsingEnabled};
 use js::jsapi::{JSObject, RuntimeOptionsRef, SetPreserveWrapperCallback};
 use js::rust::Runtime;
 use libc;
@@ -130,6 +132,181 @@ pub fn new_rt_and_cx() -> Runtime {
     if let Some(val) = get_pref("js.ion.enabled").as_boolean() {
         rt_opts.set_ion_(val);
     }
+    if let Some(val) = get_pref("js.asmjs.enabled").as_boolean() {
+        rt_opts.set_asmJS_(val);
+    }
+    if let Some(val) = get_pref("js.strict.enabled").as_boolean() {
+        rt_opts.set_extraWarnings_(val);
+    }
+    // TODO: handle js.strict.debug.enabled
+    // TODO: handle js.throw_on_asmjs_validation_failure (needs new Spidermonkey)
+    if let Some(val) = get_pref("js.native_regexp.enabled").as_boolean() {
+        rt_opts.set_nativeRegExp_(val);
+    }
+    if let Some(val) = get_pref("js.parallel_parsing.enabled").as_boolean() {
+        unsafe { JS_SetParallelParsingEnabled(runtime.rt(), val); }
+    }
+    if let Some(val) = get_pref("js.offthread_compilation_enabled").as_boolean() {
+        unsafe { JS_SetOffthreadIonCompilationEnabled(runtime.rt(), val); }
+    }
+    if let Some(val) = get_pref("js.baseline.unsafe_eager_compilation.enabled").as_boolean() {
+        let trigger: i32 = if val {
+            0
+        } else {
+            -1
+        };
+        unsafe {
+            JS_SetGlobalJitCompilerOption(runtime.rt(),
+                                          JSJitCompilerOption::JSJITCOMPILER_BASELINE_WARMUP_TRIGGER,
+                                          trigger as u32);
+        }
+    }
+    if let Some(val) = get_pref("js.ion.unsafe_eager_compilation.enabled").as_boolean() {
+        let trigger: i64 = if val {
+            0
+        } else {
+            -1
+        };
+        unsafe {
+            JS_SetGlobalJitCompilerOption(runtime.rt(),
+                                          JSJitCompilerOption::JSJITCOMPILER_ION_WARMUP_TRIGGER,
+                                          trigger as u32);
+        }
+    }
+    // TODO: handle js.discard_system_source.enabled
+    // TODO: handle js.asyncstack.enabled (needs new Spidermonkey)
+    // TODO: handle js.throw_on_debugee_would_run (needs new Spidermonkey)
+    // TODO: handle js.dump_stack_on_debugee_would_run (needs new Spidermonkey)
+    if let Some(val) = get_pref("js.werror.enabled").as_boolean() {
+        rt_opts.set_werror_(val);
+    }
+    // TODO: handle js.shared_memory.enabled
+    if let Some(val) = get_pref("js.mem.high_water_mark").as_i64() {
+        unsafe {
+            JS_SetGCParameter(runtime.rt(), JSGCParamKey::JSGC_MAX_MALLOC_BYTES, val as u32 * 1024 * 1024);
+        }
+    }
+    if let Some(val) = get_pref("js.mem.max").as_i64() {
+        let max = if val <= 0 || val >= 0x1000 {
+            -1
+        } else {
+            val * 1024 * 1024
+        };
+        unsafe {
+            JS_SetGCParameter(runtime.rt(), JSGCParamKey::JSGC_MAX_BYTES, max as u32);
+        }
+    }
+    // NOTE: This is disabled above, so enabling it here will do nothing for now.
+    if let Some(val) = get_pref("js.mem.gc.incremental.enabled").as_boolean() {
+        let compartment = if let Some(val) = get_pref("js.mem.gc.per_compartment.enabled").as_boolean() {
+            val
+        } else {
+            false
+        };
+        let mode = if val {
+            JSGCMode::JSGC_MODE_INCREMENTAL
+        } else if compartment {
+            JSGCMode::JSGC_MODE_COMPARTMENT
+        } else {
+            JSGCMode::JSGC_MODE_GLOBAL
+        };
+        unsafe {
+            JS_SetGCParameter(runtime.rt(), JSGCParamKey::JSGC_MODE, mode as u32);
+        }
+    }
+    if let Some(val) = get_pref("js.mem.gc.incremental.slice_ms").as_i64() {
+        if val >= 0 && val < 100000 {
+            unsafe {
+                JS_SetGCParameter(runtime.rt(), JSGCParamKey::JSGC_SLICE_TIME_BUDGET, val as u32);
+            }
+        }
+    }
+    if let Some(val) = get_pref("js.mem.gc.compacting.enabled").as_boolean() {
+        unsafe {
+            JS_SetGCParameter(runtime.rt(), JSGCParamKey::JSGC_COMPACTING_ENABLED, val as u32);
+        }
+    }
+    if let Some(val) = get_pref("js.mem.gc.high_frequency_time_limit_ms").as_i64() {
+        if val >= 0 && val < 10000 {
+            unsafe {
+                JS_SetGCParameter(runtime.rt(), JSGCParamKey::JSGC_HIGH_FREQUENCY_TIME_LIMIT, val as u32);
+            }
+        }
+    }
+    if let Some(val) = get_pref("js.mem.gc.dynamic_mark_slice.enabled").as_boolean() {
+        unsafe {
+            JS_SetGCParameter(runtime.rt(), JSGCParamKey::JSGC_DYNAMIC_MARK_SLICE, val as u32);
+        }
+    }
+    // TODO: handle js.mem.gc.refresh_frame_slices.enabled
+    if let Some(val) = get_pref("js.mem.gc.dynamic_heap_growth.enabled").as_boolean() {
+        unsafe {
+            JS_SetGCParameter(runtime.rt(), JSGCParamKey::JSGC_DYNAMIC_HEAP_GROWTH, val as u32);
+        }
+    }
+    if let Some(val) = get_pref("js.mem.gc.low_frequency_heap_growth").as_i64() {
+        if val >= 0 && val < 10000 {
+            unsafe {
+                JS_SetGCParameter(runtime.rt(), JSGCParamKey::JSGC_LOW_FREQUENCY_HEAP_GROWTH, val as u32);
+            }
+        }
+    }
+    if let Some(val) = get_pref("js.mem.gc.high_frequency_heap_growth_min").as_i64() {
+        if val >= 0 && val < 10000 {
+            unsafe {
+                JS_SetGCParameter(runtime.rt(), JSGCParamKey::JSGC_HIGH_FREQUENCY_HEAP_GROWTH_MIN, val as u32);
+            }
+        }
+    }
+    if let Some(val) = get_pref("js.mem.gc.high_frequency_heap_growth_max").as_i64() {
+        if val >= 0 && val < 10000 {
+            unsafe {
+                JS_SetGCParameter(runtime.rt(), JSGCParamKey::JSGC_HIGH_FREQUENCY_HEAP_GROWTH_MAX, val as u32);
+            }
+        }
+    }
+    if let Some(val) = get_pref("js.mem.gc.high_frequency_low_limit_mb").as_i64() {
+        if val >= 0 && val < 10000 {
+            unsafe {
+                JS_SetGCParameter(runtime.rt(), JSGCParamKey::JSGC_HIGH_FREQUENCY_LOW_LIMIT, val as u32);
+            }
+        }
+    }
+    if let Some(val) = get_pref("js.mem.gc.high_frequency_high_limit_mb").as_i64() {
+        if val >= 0 && val < 10000 {
+            unsafe {
+                JS_SetGCParameter(runtime.rt(), JSGCParamKey::JSGC_HIGH_FREQUENCY_HIGH_LIMIT, val as u32);
+            }
+        }
+    }
+    if let Some(val) = get_pref("js.mem.gc.allocation_threshold_mb").as_i64() {
+        if val >= 0 && val < 10000 {
+            unsafe {
+                JS_SetGCParameter(runtime.rt(), JSGCParamKey::JSGC_ALLOCATION_THRESHOLD, val as u32);
+            }
+        }
+    }
+    if let Some(val) = get_pref("js.mem.gc.decommit_threshold_mb").as_i64() {
+        if val >= 0 && val < 10000 {
+            unsafe {
+                JS_SetGCParameter(runtime.rt(), JSGCParamKey::JSGC_DECOMMIT_THRESHOLD, val as u32);
+            }
+        }
+    }
+    if let Some(val) = get_pref("js.mem.gc.empty_chunk_count_min").as_i64() {
+        if val >= 0 && val < 10000 {
+            unsafe {
+                JS_SetGCParameter(runtime.rt(), JSGCParamKey::JSGC_MIN_EMPTY_CHUNK_COUNT, val as u32);
+            }
+        }
+    }
+    if let Some(val) = get_pref("js.mem.gc.empty_chunk_count_max").as_i64() {
+        if val >= 0 && val < 10000 {
+            unsafe {
+                JS_SetGCParameter(runtime.rt(), JSGCParamKey::JSGC_MAX_EMPTY_CHUNK_COUNT, val as u32);
+            }
+        }
+    }
 
     runtime
 }

components/script/script_thread.rs

@@ -52,7 +52,8 @@ use hyper::mime::{Mime, SubLevel, TopLevel};
 use ipc_channel::ipc::{self, IpcSender};
 use ipc_channel::router::ROUTER;
 use js::jsapi::{DOMProxyShadowsResult, HandleId, HandleObject, RootedValue};
-use js::jsapi::{JSAutoRequest, JSContext, JS_SetWrapObjectCallbacks, JSTracer};
+use js::jsapi::{JSAutoRequest, JS_SetWrapObjectCallbacks};
+use js::jsapi::{JSContext, JSTracer};
 use js::jsval::UndefinedValue;
 use js::rust::Runtime;
 use layout_interface::{ReflowQueryType};

components/util/prefs.rs

@@ -23,6 +23,7 @@ lazy_static! {
 pub enum PrefValue {
     Boolean(bool),
     String(String),
+    Number(f64),
     Missing
 }
 
@@ -31,6 +32,9 @@ impl PrefValue {
         let value = match data {
             Json::Boolean(x) => PrefValue::Boolean(x),
             Json::String(x) => PrefValue::String(x),
+            Json::F64(x) => PrefValue::Number(x),
+            Json::I64(x) => PrefValue::Number(x as f64),
+            Json::U64(x) => PrefValue::Number(x as f64),
             _ => return Err(())
         };
         Ok(value)
@@ -53,6 +57,13 @@ impl PrefValue {
             _ => None
         }
     }
+
+    pub fn as_i64(&self) -> Option<i64> {
+        match *self {
+            PrefValue::Number(x) => Some(x as i64),
+            _ => None,
+        }
+    }
 }
 
 impl ToJson for PrefValue {
@@ -63,7 +74,10 @@ impl ToJson for PrefValue {
             },
             PrefValue::String(ref x) => {
                 Json::String(x.clone())
-            }
+            },
+            PrefValue::Number(x) => {
+                Json::F64(x)
+            },
             PrefValue::Missing => Json::Null
         }
     }
@@ -136,7 +150,7 @@ pub fn read_prefs_from_file<T>(mut file: T)
                 Ok(x) => {
                     prefs.insert(name, x);
                 },
-                Err(_) => println!("Ignoring non-boolean/string preference value for {:?}", name)
+                Err(_) => println!("Ignoring non-boolean/string/i64 preference value for {:?}", name),
             }
         }
     }

resources/prefs.json

@@ -5,6 +5,41 @@
   "gfx.webrender.enabled": false,
   "js.baseline.enabled": true,
   "js.ion.enabled": true,
+  "js.asmjs.enabled": true,
+  "js.strict.enabled": false,
+  "js.strict.debug.enabled": false,
+  "js.throw_on_asmjs_validation_failure.enabled": false,
+  "js.native_regexp.enabled": true,
+  "js.parallel_parsing.enabled": true,
+  "js.ion.offthread_compilation.enabled": true,
+  "js.baseline.unsafe_eager_compilation.enabled": false,
+  "js.ion.unsafe_eager_compilation.enabled": false,
+  "js.discard_system_source.enabled": false,
+  "js.asyncstack.enabled": false,
+  "js.throw_on_debuggee_would_run.enabled": false,
+  "js.dump_stack_on_debuggee_would_run.enabled": false,
+  "js.werror.enabled": false,
+  "js.strict.enabled": false,
+  "js.shared_memory.enabled": true,
+  "js.mem.high_water_mark": 128,
+  "js.mem.max": -1,
+  "js.mem.gc.per_compartment.enabled": true,
+  "js.mem.gc.incremental.enabled": true,
+  "js.mem.gc.incremental.slice_ms": 10,
+  "js.mem.gc.compacting.enabled": true,
+  "js.mem.gc.high_frequency_time_limit_ms": 1000,
+  "js.mem.gc.dynamic_mark_slice.enabled": true,
+  "js.mem.gc.refresh_frame_slices.enabled": true,
+  "js.mem.gc.dynamic_heap_growth.enabled": true,
+  "js.mem.gc.low_frequency_heap_growth": 150,
+  "js.mem.gc.high_frequency_heap_growth_min": 150,
+  "js.mem.gc.high_frequency_heap_growth_max": 300,
+  "js.mem.gc.high_frequency_low_limit_mb": 100,
+  "js.mem.gc.high_frequency_high_limit_mb": 500,
+  "js.mem.gc.allocation_threshold_mb": 30,
+  "js.mem.gc.decommit_threshold_mb": 32,
+  "js.mem.gc.empty_chunk_count_min": 1,
+  "js.mem.gc.empty_chunk_count_max": 30,
   "layout.columns.enabled": false,
   "layout.column-width.enabled": false,
   "layout.column-count.enabled": false,