From d9ac3741922a58b17aec730ba113f44efb8b6600 Mon Sep 17 00:00:00 2001
From: Fyodor Kupolov <fkupolov@google.com>
Date: Mon, 13 Nov 2017 15:51:03 -0800
Subject: Provide remote stack trace information

The stack is truncated up to 5 lines at parcel time. When unparceling,
a separate RemoteException will be created and set as a cause of the
exception being thrown.

Performance results(in nanoseconds):
timeWriteExceptionWithStackTraceParceling  82175
timeWriteException                          6616
timeReadException                          22529
timeReadExceptionWithStackTraceParceling   34151

Test: manual + ParcelPerfTest
Bug: 36561158
Change-Id: I9c0a54a86cd82cff92d8e1a15ec19dfed58ef856
---
 libs/binder/Status.cpp | 10 ++++++++++
 1 file changed, 10 insertions(+)

(limited to 'libs/binder/Status.cpp')

diff --git a/libs/binder/Status.cpp b/libs/binder/Status.cpp
index 006f7f94e9..a9d5055549 100644
--- a/libs/binder/Status.cpp
+++ b/libs/binder/Status.cpp
@@ -102,6 +102,15 @@ status_t Status::readFromParcel(const Parcel& parcel) {
     }
     mMessage = String8(message);
 
+    // Skip over the remote stack trace data
+    int32_t remote_stack_trace_header_size;
+    status = parcel.readInt32(&remote_stack_trace_header_size);
+    if (status != OK) {
+        setFromStatusT(status);
+        return status;
+    }
+    parcel.setDataPosition(parcel.dataPosition() + remote_stack_trace_header_size);
+
     if (mException == EX_SERVICE_SPECIFIC) {
         status = parcel.readInt32(&mErrorCode);
     } else if (mException == EX_PARCELABLE) {
@@ -137,6 +146,7 @@ status_t Status::writeToParcel(Parcel* parcel) const {
         return status;
     }
     status = parcel->writeString16(String16(mMessage));
+    status = parcel->writeInt32(0); // Empty remote stack trace header
     if (mException == EX_SERVICE_SPECIFIC) {
         status = parcel->writeInt32(mErrorCode);
     } else if (mException == EX_PARCELABLE) {
-- 
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