From e0a72c8d7522a99294d7f65225e0979d62f4a73d Mon Sep 17 00:00:00 2001
From: "brendan%mozilla.org" <brendan%mozilla.org>
Date: Wed, 22 Feb 2006 05:52:13 +0000
Subject: [PATCH] Separate gcMaxBytes from gcMaxMallocBytes and unconstrain the
 former for Mozilla code (317865, r/sr=mrbkap/shaver).

---
 js/src/jsapi.c                         | 13 +++++++++++++
 js/src/jsapi.h                         |  8 ++++++++
 js/src/jscntxt.h                       |  1 +
 js/src/jsgc.c                          |  9 +++++++--
 js/src/xpconnect/src/xpcruntimesvc.cpp |  8 ++++++++
 5 files changed, 37 insertions(+), 2 deletions(-)

diff --git a/js/src/jsapi.c b/js/src/jsapi.c
index bbfd35f65298..1c52f9d08855 100644
--- a/js/src/jsapi.c
+++ b/js/src/jsapi.c
@@ -1889,6 +1889,19 @@ JS_IsAboutToBeFinalized(JSContext *cx, void *thing)
     return js_IsAboutToBeFinalized(cx, thing);
 }
 
+JS_PUBLIC_API(void)
+JS_SetGCParameter(JSRuntime *rt, JSGCParamKey key, uint32 value)
+{
+    switch (key) {
+      case JSGC_MAX_BYTES:
+        rt->gcMaxBytes = value;
+        break;
+      case JSGC_MAX_MALLOC_BYTES:
+        rt->gcMaxMallocBytes = value;
+        break;
+    }
+}
+
 JS_PUBLIC_API(intN)
 JS_AddExternalStringFinalizer(JSStringFinalizeOp finalizer)
 {
diff --git a/js/src/jsapi.h b/js/src/jsapi.h
index 90785bb6b5ea..ed80a2da807f 100644
--- a/js/src/jsapi.h
+++ b/js/src/jsapi.h
@@ -814,6 +814,14 @@ JS_SetGCCallbackRT(JSRuntime *rt, JSGCCallback cb);
 extern JS_PUBLIC_API(JSBool)
 JS_IsAboutToBeFinalized(JSContext *cx, void *thing);
 
+typedef enum JSGCParamKey {
+    JSGC_MAX_BYTES        = 0,  /* maximum nominal heap before last ditch GC */
+    JSGC_MAX_MALLOC_BYTES = 1   /* # of JS_malloc bytes before last ditch GC */
+} JSGCParamKey;
+
+extern JS_PUBLIC_API(void)
+JS_SetGCParameter(JSRuntime *rt, JSGCParamKey key, uint32 value);
+
 /*
  * Add a finalizer for external strings created by JS_NewExternalString (see
  * below) using a type-code returned from this function, and that understands
diff --git a/js/src/jscntxt.h b/js/src/jscntxt.h
index 2db203b3ec33..17b0a0c452cd 100644
--- a/js/src/jscntxt.h
+++ b/js/src/jscntxt.h
@@ -83,6 +83,7 @@ struct JSRuntime {
     uint32              gcBytes;
     uint32              gcLastBytes;
     uint32              gcMaxBytes;
+    uint32              gcMaxMallocBytes;
     uint32              gcLevel;
     uint32              gcNumber;
     JSPackedBool        gcPoke;
diff --git a/js/src/jsgc.c b/js/src/jsgc.c
index 6d415a0fe9cc..bd4779800e1b 100644
--- a/js/src/jsgc.c
+++ b/js/src/jsgc.c
@@ -378,7 +378,12 @@ js_InitGC(JSRuntime *rt, uint32 maxbytes)
         return JS_FALSE;
     }
     rt->gcLocksHash = NULL;     /* create lazily */
-    rt->gcMaxBytes = maxbytes;
+
+    /*
+     * Separate gcMaxMallocBytes from gcMaxBytes but initialize to maxbytes
+     * for default backward API compatibility.
+     */
+    rt->gcMaxBytes = rt->gcMaxMallocBytes = maxbytes;
     return JS_TRUE;
 }
 
@@ -649,7 +654,7 @@ js_NewGCThing(JSContext *cx, uintN flags, size_t nbytes)
          * arenaList.
          */
         if (rt->gcBytes < rt->gcMaxBytes &&
-            (tried_gc || rt->gcMallocBytes < rt->gcMaxBytes)) {
+            (tried_gc || rt->gcMallocBytes < rt->gcMaxMallocBytes)) {
             if (!arenaList->last || arenaList->lastLimit == GC_THINGS_SIZE) {
                 /*
                  * The last arena (and the whole arenaList) is full, time
diff --git a/js/src/xpconnect/src/xpcruntimesvc.cpp b/js/src/xpconnect/src/xpcruntimesvc.cpp
index 01336097a7ab..fe8a68a6ad06 100644
--- a/js/src/xpconnect/src/xpcruntimesvc.cpp
+++ b/js/src/xpconnect/src/xpcruntimesvc.cpp
@@ -140,6 +140,14 @@ nsJSRuntimeServiceImpl::GetRuntime(JSRuntime **runtime)
         mRuntime = JS_NewRuntime(gGCSize);
         if(!mRuntime)
             return NS_ERROR_OUT_OF_MEMORY;
+
+        // Unconstrain the runtime's threshold on nominal heap size, to avoid
+        // triggering GC too often if operating continuously near an arbitrary
+        // finite threshold (0xffffffff is infinity for uint32 parameters).
+        // This leaves the maximum-JS_malloc-bytes threshold still in effect
+        // to cause period, and we hope hygienic, last-ditch GCs from within
+        // the GC's allocator.
+        JS_SetGCParameter(mRuntime, JSGC_MAX_BYTES, 0xffffffff);
     }
     *runtime = mRuntime;
     return NS_OK;