Implementation of single-module-per-logon-session-per-profile implementation for Chrome Frame.

BUG=61383
TEST=Run IE with version X of CF loaded. Register version Y of CF. Run a second IE process, notice that version Y when loaded defers to version X.


Review URL: http://codereview.chromium.org/4144008

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@65236 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 31 insertions, 2 deletions

diff --git a/base/shared_memory.h b/base/shared_memory.h
index 79ea8fd..719eb69 100644
--- a/base/shared_memory.h
+++ b/base/shared_memory.h
@@ -43,6 +43,13 @@ class SharedMemory {
  public:
   SharedMemory();
 
+#if defined(OS_WIN)
+  // Similar to the default constructor, except that this allows for
+  // calling Lock() to acquire the named mutex before either Create or Open
+  // are called on Windows.
+  explicit SharedMemory(const std::wstring& name);
+#endif
+
   // Create a new SharedMemory object from an existing, open
   // shared memory file.
   SharedMemory(SharedMemoryHandle handle, bool read_only);
@@ -165,6 +172,12 @@ class SharedMemory {
   // across Mac and Linux.
   void Lock();
 
+#if defined(OS_WIN)
+  // A Lock() implementation with a timeout. Returns true if the Lock() has
+  // been acquired, false if the timeout was reached.
+  bool Lock(uint32 timeout_ms);
+#endif
+
   // Releases the shared memory lock.
   void Unlock();
 
diff --git a/base/shared_memory_win.cc b/base/shared_memory_win.cc
index a0b2a5a..5f293fc 100644
--- a/base/shared_memory_win.cc
+++ b/base/shared_memory_win.cc
@@ -17,6 +17,15 @@ SharedMemory::SharedMemory()
       lock_(NULL) {
 }
 
+SharedMemory::SharedMemory(const std::wstring& name)
+    : mapped_file_(NULL),
+      memory_(NULL),
+      read_only_(false),
+      created_size_(0),
+      lock_(NULL),
+      name_(name) {
+}
+
 SharedMemory::SharedMemory(SharedMemoryHandle handle, bool read_only)
     : mapped_file_(handle),
       memory_(NULL),
@@ -188,6 +197,10 @@ void SharedMemory::Close() {
 }
 
 void SharedMemory::Lock() {
+  Lock(INFINITE);
+}
+
+bool SharedMemory::Lock(uint32 timeout_ms) {
   if (lock_ == NULL) {
     std::wstring name = name_;
     name.append(L"lock");
@@ -195,10 +208,13 @@ void SharedMemory::Lock() {
     DCHECK(lock_ != NULL);
     if (lock_ == NULL) {
       DLOG(ERROR) << "Could not create mutex" << GetLastError();
-      return;  // there is nothing good we can do here.
+      return false;  // there is nothing good we can do here.
     }
   }
-  WaitForSingleObject(lock_, INFINITE);
+  DWORD result = WaitForSingleObject(lock_, timeout_ms);
+
+  // Return false for WAIT_ABANDONED, WAIT_TIMEOUT or WAIT_FAILED.
+  return (result == WAIT_OBJECT_0);
 }
 
 void SharedMemory::Unlock() {