Resource tracking done right.

src/shared/ppapi_proxy/ppb_core.srpc

Index: src/shared/ppapi_proxy/ppb_core.srpc
diff --git a/src/shared/ppapi_proxy/ppb_core.srpc b/src/shared/ppapi_proxy/ppb_core.srpc
index a8ff9e3ec0722f4528172e587973b6c98be34c64..f994a4fe5f6881a9c31872900efb2f451b859be4 100755
--- a/src/shared/ppapi_proxy/ppb_core.srpc
+++ b/src/shared/ppapi_proxy/ppb_core.srpc
@@ -19,6 +19,15 @@
                      ],
            'outputs': []
           },
+          # Implements calls to decrement more than one reference count on a
+          # resource. This does not exist in PPB_Core, we implement it as an

[sehr (please use chromium), 2010/12/10 01:09:18]

Why would we ever need more than one reference to a resource from untrusted
code?  The previous version only sent RPCs for 0 --> 1 and 1 --> 0 transitions.

[neb, 2010/12/10 20:43:31]

When the PPAPI layer returns Resources from function calls, it always gives the
caller one reference to it. If, for instance, we did:

Resource r1 = audio.config();
Resource r2 = audio.config();

we would consume two browser-side references to the same AudioConfig Resource
object. We could issue a RPC to decrease the refcount the very same moment we
see that we get a refcount to an object that we already track, I chose to block
less and just release them all at the end.

+          # optimization.
+          {'name': 'ReleaseResourceMultipleTimes',
+           'inputs': [['resource', 'int64_t'],
+                      ['count', 'int32_t']
+                     ],
+           'outputs': []
+          },
           # MemAlloc and MemFree do not require RPCs to the browser.
           # Implements calls to get the time.
           {'name': 'PPB_Core_GetTime',