This adds support for cross-compartment WeakMaps and changes js::Debug::objects to be one. It eliminates the vexing JSMSG_DEBUG_STREAMS_CROSSED error messsage.
The GC interaction between jsgc and jsdbg is a little more complex now; like the cross-compartment wrapper maps, Debug::objects must be marked (just once) during per-compartment GC. In other ways this is a simplification.
This allows most of the tests to run without the -d command-line flag.
Now a compartment is in debug mode if
* JSD1 wants debug mode on, thanks to a JS_SetDebugMode* call; OR
* JSD2 wants debug mode on, because a live Debug object has a debuggee
global in that compartment.
Since this patch only adds the second half of the rule, JSD1 should be
unaffected.
The new rule has three issues:
1. When removeDebuggee is called, it can cause debug mode to be turned
off for a compartment. If any scripts from that compartment are on
the stack, and the methodjit is enabled, returning to those stack
frames will crash.
2. When a Debug object is GC'd, it can cause debug mode to be turned off
for one or more compartments. This causes the same problem with
returning to deleted methodjit code, but the fix is different: such
Debug objects simply should not be GC'd.
3. Setting .enabled to false still does not turn off debug mode
anywhere, so it does not reduce overhead as much as it should.
A possible fix for issue #1 would be to make such removeDebuggee calls
throw; a different possibility is to turn off debug mode but leave all
the scripts alone, accepting the performance loss (as we do for JSD1 in
JSCompartment::setDebugModeFromC). The fix to issues #2 and #3 is to
tweak the rule--and to tweak the rule for Debug object GC-reachability.
--HG--
rename : js/src/jit-test/tests/debug/Debug-ctor.js => js/src/jit-test/tests/debug/Debug-ctor-01.js
Remove WeakMap class; implement the JavaScript object using functions static to jsweakmap.cpp.
Define a new WeakMap class template, parameterized by Key and Value types,
and accepting a MarkPolicy argument saying how to mark them.
Add assertions to check that we check and set the right mark bits, and
tests that trip them in the presence of mistakes in earlier revisions of
this patch.
This allows most of the tests to run without the -d command-line flag.
Now a compartment is in debug mode if
* JSD1 wants debug mode on, thanks to a JS_SetDebugMode* call; OR
* JSD2 wants debug mode on, because a live Debug object has a debuggee
global in that compartment.
Since this patch only adds the second half of the rule, JSD1 should be
unaffected.
The new rule has three issues:
1. When removeDebuggee is called, it can cause debug mode to be turned
off for a compartment. If any scripts from that compartment are on
the stack, and the methodjit is enabled, returning to those stack
frames will crash.
2. When a Debug object is GC'd, it can cause debug mode to be turned off
for one or more compartments. This causes the same problem with
returning to deleted methodjit code, but the fix is different: such
Debug objects simply should not be GC'd.
3. Setting .enabled to false still does not turn off debug mode
anywhere, so it does not reduce overhead as much as it should.
A possible fix for issue #1 would be to make such removeDebuggee calls
throw. The fix to issues #2 and #3 is to tweak the rule--and to tweak
the rule for Debug object GC-reachability.
--HG--
rename : js/src/jit-test/tests/debug/Debug-ctor.js => js/src/jit-test/tests/debug/Debug-ctor-01.js
