From 46b8665ea49afebea3161dbad80f81b4d81fd83f Mon Sep 17 00:00:00 2001
From: Alexey Samsonov <samsonov@google.com>
Date: Fri, 5 Apr 2013 07:41:21 +0000
Subject: [PATCH] Remove InternalAlloc/InternalFree calls from StopTheWorld.
 Patch by Sergey Matveev.

llvm-svn: 178855
---
 compiler-rt/lib/sanitizer_common/sanitizer_linux.cc |  9 +++++----
 compiler-rt/lib/sanitizer_common/sanitizer_linux.h  |  3 ++-
 .../sanitizer_stoptheworld_linux.cc                 | 13 +++++--------
 3 files changed, 12 insertions(+), 13 deletions(-)

diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_linux.cc b/compiler-rt/lib/sanitizer_common/sanitizer_linux.cc
index 1c1a3fbc34ab..ef185571ada1 100644
--- a/compiler-rt/lib/sanitizer_common/sanitizer_linux.cc
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_linux.cc
@@ -651,8 +651,9 @@ int internal_sigaltstack(const struct sigaltstack *ss,
 ThreadLister::ThreadLister(int pid)
   : pid_(pid),
     descriptor_(-1),
+    buffer_(4096),
     error_(true),
-    entry_((linux_dirent *)buffer_),
+    entry_((struct linux_dirent *)buffer_.data()),
     bytes_read_(0) {
   char task_directory_path[80];
   internal_snprintf(task_directory_path, sizeof(task_directory_path),
@@ -700,8 +701,8 @@ bool ThreadLister::GetDirectoryEntries() {
   CHECK_GE(descriptor_, 0);
   CHECK_NE(error_, true);
   bytes_read_ = internal_getdents(descriptor_,
-                                  (struct linux_dirent *)buffer_,
-                                  sizeof(buffer_));
+                                  (struct linux_dirent *)buffer_.data(),
+                                  buffer_.size());
   if (bytes_read_ < 0) {
     Report("Can't read directory entries from /proc/%d/task.\n", pid_);
     error_ = true;
@@ -709,7 +710,7 @@ bool ThreadLister::GetDirectoryEntries() {
   } else if (bytes_read_ == 0) {
     return false;
   }
-  entry_ = (struct linux_dirent *)buffer_;
+  entry_ = (struct linux_dirent *)buffer_.data();
   return true;
 }
 
diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_linux.h b/compiler-rt/lib/sanitizer_common/sanitizer_linux.h
index 33d39bf50c19..13b60fa91bc0 100644
--- a/compiler-rt/lib/sanitizer_common/sanitizer_linux.h
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_linux.h
@@ -13,6 +13,7 @@
 #ifndef SANITIZER_LINUX_H
 #define SANITIZER_LINUX_H
 
+#include "sanitizer_common.h"
 #include "sanitizer_internal_defs.h"
 
 struct sigaltstack;
@@ -43,7 +44,7 @@ class ThreadLister {
 
   int pid_;
   int descriptor_;
-  char buffer_[4096];
+  InternalScopedBuffer<char> buffer_;
   bool error_;
   struct linux_dirent* entry_;
   int bytes_read_;
diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_stoptheworld_linux.cc b/compiler-rt/lib/sanitizer_common/sanitizer_stoptheworld_linux.cc
index 05da7fb0ebd1..8bb155588cdc 100644
--- a/compiler-rt/lib/sanitizer_common/sanitizer_stoptheworld_linux.cc
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_stoptheworld_linux.cc
@@ -148,27 +148,24 @@ void ThreadSuspender::KillAllThreads() {
 }
 
 bool ThreadSuspender::SuspendAllThreads() {
-  void *mem = InternalAlloc(sizeof(ThreadLister));
-  ThreadLister *thread_lister = new(mem) ThreadLister(pid_);
+  ThreadLister thread_lister(pid_);
   bool added_threads;
   do {
     // Run through the directory entries once.
     added_threads = false;
-    pid_t tid = thread_lister->GetNextTID();
+    pid_t tid = thread_lister.GetNextTID();
     while (tid >= 0) {
       if (SuspendThread(tid))
         added_threads = true;
-      tid = thread_lister->GetNextTID();
+      tid = thread_lister.GetNextTID();
     }
-    if (thread_lister->error()) {
+    if (thread_lister.error()) {
       // Detach threads and fail.
       ResumeAllThreads();
-      InternalFree(mem);
       return false;
     }
-    thread_lister->Reset();
+    thread_lister.Reset();
   } while (added_threads);
-  InternalFree(mem);
   return true;
 }