123955 2013-11-06 22:19:05 -0800 Avoid calling fastRealloc when it returns the same address 2013-11-06 22:19:05 -0800 1 1 1 Unclassified WebKit Web Template Framework 528+ (Nightly build) Mac OS X 10.8 NEW P5 Enhancement --- 1 hbono webkit-unassigned oldest_to_newest 948072 0 216259 hbono 2013-11-06 22:19:05 -0800 Created attachment 216259 A patch that uses fastMallocGoodSize Greetings, On OS X, malloc() rounds up the specified size to a multiple of malloc_good_size(). (For example, malloc(1) returns a 16-byte block on OS X.) Also, as listed in the source code <http://www.opensource.apple.com/source/Libc/Libc-594.1.4/gen/malloc.c>, realloc() returns the same address when the specified new size is less than the block size of the given memory, i.e. |p0| is equal to |p1| in the following code snippet. int main(int argc, char* argv[]) { void* p0 = malloc(1); void* p1 = realloc(p0, 10); printf("p0=%p, p1=%p\n", p0, p1); return 0; } To consider this fact, it may be good for the StringBuilder class to use fastMallocGoodSize(length) instead of length to check if it needs to call StringBuilder<T>::reallocateBuffer() as listed in the attached diff. (For your information, the StringBUilder class tried reallocating memory to the same block size >13000 times when I ran 'run-webkit-tests --no-http' on my Mac.) Regards, Hironori Bono 216259 2013-11-06 22:19:05 -0800 2013-11-06 22:19:05 -0800 A patch that uses fastMallocGoodSize stringbuilder.diff text/plain 2788 hbono SW5kZXg6IFNvdXJjZS9XVEYvd3RmL3RleHQvU3RyaW5nQnVpbGRlci5jcHAKPT09PT09PT09PT09 PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PQot LS0gU291cmNlL1dURi93dGYvdGV4dC9TdHJpbmdCdWlsZGVyLmNwcCAgICAgICAocmV2aXNpb24g MTU4ODA4KQorKysgU291cmNlL1dURi93dGYvdGV4dC9TdHJpbmdCdWlsZGVyLmNwcCAgICAgICAo d29ya2luZyBjb3B5KQpAQCAtMzMsNiArMzMsMTIgQEAKCiBuYW1lc3BhY2UgV1RGIHsKCitzdGF0 aWMgYm9vbCBuZWVkUmVhbGxvY2F0aW9uKHNpemVfdCBuZXdMZW5ndGgsIHNpemVfdCBvbGRMZW5n dGgsIGJvb2wgaXM4Qml0KQoreworICAgIGNvbnN0IHNpemVfdCBrQ2hhclNpemUgPSBpczhCaXQg PyBzaXplb2YoTENoYXIpIDogc2l6ZW9mKFVDaGFyKTsKKyAgICByZXR1cm4gZmFzdE1hbGxvY0dv b2RTaXplKHNpemVvZihTdHJpbmdJbXBsKSArIG5ld0xlbmd0aCAqIGtDaGFyU2l6ZSkgPiBmYXN0 TWFsbG9jR29vZFNpemUoc2l6ZW9mKFN0cmluZ0ltcGwpICsgb2xkTGVuZ3RoICoga0NoYXJTaXpl KTsKK30KKwogc3RhdGljIHNpemVfdCBleHBhbmRlZENhcGFjaXR5KHNpemVfdCBjYXBhY2l0eSwg c2l6ZV90IG5ld0xlbmd0aCkKIHsKICAgICBzdGF0aWMgY29uc3Qgc2l6ZV90IG1pbmltdW1DYXBh Y2l0eSA9IDE2OwpAQCAtMTc1LDcgKzE4MSw3IEBAIHZvaWQgU3RyaW5nQnVpbGRlcjo6cmVzZXJ2 ZUNhcGFjaXR5KHVuc2kKIHsKICAgICBpZiAobV9idWZmZXIpIHsKICAgICAgICAgLy8gSWYgdGhl cmUgaXMgYWxyZWFkeSBhIGJ1ZmZlciwgdGhlbiBncm93IGlmIG5lY2Vzc2FyeS4KLSAgICAgICAg aWYgKG5ld0NhcGFjaXR5ID4gbV9idWZmZXItPmxlbmd0aCgpKSB7CisgICAgICAgIGlmIChuZWVk UmVhbGxvY2F0aW9uKG5ld0NhcGFjaXR5LCBtX2J1ZmZlci0+bGVuZ3RoKCksIG1fYnVmZmVyLT5p czhCaXQoKSkpIHsKICAgICAgICAgICAgIGlmIChtX2J1ZmZlci0+aXM4Qml0KCkpCiAgICAgICAg ICAgICAgICAgcmVhbGxvY2F0ZUJ1ZmZlcjxMQ2hhcj4obmV3Q2FwYWNpdHkpOwogICAgICAgICAg ICAgZWxzZQpAQCAtMzUxLDcgKzM1Nyw3IEBAIHZvaWQgU3RyaW5nQnVpbGRlcjo6YXBwZW5kRml4 ZWRXaWR0aE51bWIKIGJvb2wgU3RyaW5nQnVpbGRlcjo6Y2FuU2hyaW5rKCkgY29uc3QKIHsKICAg ICAvLyBPbmx5IHNocmluayB0aGUgYnVmZmVyIGlmIGl0J3MgbGVzcyB0aGFuIDgwJSBmdWxsLiBO ZWVkIHRvIHR1bmUgdGhpcyBoZXVyaXN0aWMhCi0gICAgcmV0dXJuIG1fYnVmZmVyICYmIG1fYnVm ZmVyLT5sZW5ndGgoKSA+IChtX2xlbmd0aCArIChtX2xlbmd0aCA+PiAyKSk7CisgICAgcmV0dXJu IG1fYnVmZmVyICYmIG1fYnVmZmVyLT5sZW5ndGgoKSA+IChtX2xlbmd0aCArIChtX2xlbmd0aCA+ PiAyKSkgJiYgbmVlZFJlYWxsb2NhdGlvbihtX2J1ZmZlci0+bGVuZ3RoKCksIG1fbGVuZ3RoLCBt X2lzOEJpdCk7CiB9Cgogdm9pZCBTdHJpbmdCdWlsZGVyOjpzaHJpbmtUb0ZpdCgpCkluZGV4OiBT b3VyY2UvV1RGL3d0Zi90ZXh0L1N0cmluZ0ltcGwuY3BwCj09PT09PT09PT09PT09PT09PT09PT09 PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT0KLS0tIFNvdXJjZS9X VEYvd3RmL3RleHQvU3RyaW5nSW1wbC5jcHAgIChyZXZpc2lvbiAxNTg4MDgpCisrKyBTb3VyY2Uv V1RGL3d0Zi90ZXh0L1N0cmluZ0ltcGwuY3BwICAod29ya2luZyBjb3B5KQpAQCAtMTk3LDcgKzE5 Nyw3IEBAIGlubGluZSBQYXNzUmVmPFN0cmluZ0ltcGw+IFN0cmluZ0ltcGw6OmMKICAgICAvLyBo ZWFwIGFsbG9jYXRpb24gZnJvbSB0aGlzIGNhbGwuCiAgICAgaWYgKGxlbmd0aCA+ICgoc3RkOjpu dW1lcmljX2xpbWl0czx1bnNpZ25lZD46Om1heCgpIC0gc2l6ZW9mKFN0cmluZ0ltcGwpKSAvIHNp emVvZihDaGFyVHlwZSkpKQogICAgICAgICBDUkFTSCgpOwotICAgIHNpemVfdCBzaXplID0gc2l6 ZW9mKFN0cmluZ0ltcGwpICsgbGVuZ3RoICogc2l6ZW9mKENoYXJUeXBlKTsKKyAgICBzaXplX3Qg c2l6ZSA9IGZhc3RNYWxsb2NHb29kU2l6ZShzaXplb2YoU3RyaW5nSW1wbCkgKyBsZW5ndGggKiBz aXplb2YoQ2hhclR5cGUpKTsKICAgICBTdHJpbmdJbXBsKiBzdHJpbmcgPSBzdGF0aWNfY2FzdDxT dHJpbmdJbXBsKj4oZmFzdE1hbGxvYyhzaXplKSk7CgogICAgIGRhdGEgPSByZWludGVycHJldF9j YXN0PENoYXJUeXBlKj4oc3RyaW5nICsgMSk7CkBAIC0yMjgsNyArMjI4LDcgQEAgaW5saW5lIFBh c3NSZWY8U3RyaW5nSW1wbD4gU3RyaW5nSW1wbDo6cgogICAgIC8vIFNhbWUgYXMgY3JlYXRlVW5p bml0aWFsaXplZCgpIGV4Y2VwdCBoZXJlIHdlIHVzZSBmYXN0UmVhbGxvYy4KICAgICBpZiAobGVu Z3RoID4gKChzdGQ6Om51bWVyaWNfbGltaXRzPHVuc2lnbmVkPjo6bWF4KCkgLSBzaXplb2YoU3Ry aW5nSW1wbCkpIC8gc2l6ZW9mKENoYXJUeXBlKSkpCiAgICAgICAgIENSQVNIKCk7Ci0gICAgc2l6 ZV90IHNpemUgPSBzaXplb2YoU3RyaW5nSW1wbCkgKyBsZW5ndGggKiBzaXplb2YoQ2hhclR5cGUp OworICAgIHNpemVfdCBzaXplID0gZmFzdE1hbGxvY0dvb2RTaXplKHNpemVvZihTdHJpbmdJbXBs KSArIGxlbmd0aCAqIHNpemVvZihDaGFyVHlwZSkpOwogICAgIG9yaWdpbmFsU3RyaW5nLT5+U3Ry aW5nSW1wbCgpOwogICAgIFN0cmluZ0ltcGwqIHN0cmluZyA9IHN0YXRpY19jYXN0PFN0cmluZ0lt cGwqPihmYXN0UmVhbGxvYyhvcmlnaW5hbFN0cmluZy5sZWFrUmVmKCksIHNpemUpKTsKCg==