Some fixes to ease debugging of the renderer process on OS X.

Review URL: http://codereview.chromium.org/21084

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@9225 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 21 insertions, 3 deletions

diff --git a/base/debug_util.h b/base/debug_util.h
index b7b5180..b61cb1e 100644
--- a/base/debug_util.h
+++ b/base/debug_util.h
@@ -43,6 +43,10 @@ class DebugUtil {
   static bool WaitForDebugger(int wait_seconds, bool silent);
 
   // Are we running under a debugger?
+  // On OS X, the underlying mechanism doesn't work when the sandbox is enabled.
+  // To get around this, this function caches it's value.
+  // WARNING: Because of this, on OS X, a call MUST be made to this function
+  // BEFORE the sandbox is enabled.
   static bool BeingDebugged();
 
   // Break into the debugger, assumes a debugger is present.
diff --git a/base/debug_util_posix.cc b/base/debug_util_posix.cc
index 3a25017..60e2ff5 100644
--- a/base/debug_util_posix.cc
+++ b/base/debug_util_posix.cc
@@ -29,6 +29,15 @@ bool DebugUtil::SpawnDebuggerOnProcess(unsigned /* process_id */) {
 // http://developer.apple.com/qa/qa2004/qa1361.html
 // static
 bool DebugUtil::BeingDebugged() {
+  // If the process is sandboxed then we can't use the sysctl, so cache the
+  // value.
+  static bool is_set = false;
+  static bool being_debugged = false;
+
+  if (is_set) {
+    return being_debugged;
+  }
+
   // Initialize mib, which tells sysctl what info we want.  In this case,
   // we're looking for information about a specific process ID.
   int mib[] = {
@@ -45,11 +54,16 @@ bool DebugUtil::BeingDebugged() {
 
   int sysctl_result = sysctl(mib, arraysize(mib), &info, &info_size, NULL, 0);
   DCHECK(sysctl_result == 0);
-  if (sysctl_result != 0)
-    return false;
+  if (sysctl_result != 0) {
+    is_set = true;
+    being_debugged = false;
+    return being_debugged;
+  }
 
   // This process is being debugged if the P_TRACED flag is set.
-  return (info.kp_proc.p_flag & P_TRACED) != 0;
+  is_set = true;
+  being_debugged = (info.kp_proc.p_flag & P_TRACED) != 0;
+  return being_debugged;
 }
 
 #elif defined(OS_LINUX)