michael@0: // Copyright (c) 2006-2008 The Chromium Authors. All rights reserved.
michael@0: // Use of this source code is governed by a BSD-style license that can be
michael@0: // found in the LICENSE file.
michael@0: 
michael@0: #include "base/platform_thread.h"
michael@0: 
michael@0: #import <Foundation/Foundation.h>
michael@0: #include <dlfcn.h>
michael@0: 
michael@0: #include "base/logging.h"
michael@0: #include "base/scoped_nsautorelease_pool.h"
michael@0: 
michael@0: // A simple class that demonstrates our impressive ability to do nothing.
michael@0: @interface NoOp : NSObject
michael@0: 
michael@0: // Does the deed.  Or does it?
michael@0: + (void)noOp;
michael@0: 
michael@0: @end
michael@0: 
michael@0: @implementation NoOp
michael@0: 
michael@0: + (void)noOp {
michael@0: }
michael@0: 
michael@0: @end
michael@0: 
michael@0: namespace base {
michael@0: 
michael@0: // If Cocoa is to be used on more than one thread, it must know that the
michael@0: // application is multithreaded.  Since it's possible to enter Cocoa code
michael@0: // from threads created by pthread_thread_create, Cocoa won't necessarily
michael@0: // be aware that the application is multithreaded.  Spawning an NSThread is
michael@0: // enough to get Cocoa to set up for multithreaded operation, so this is done
michael@0: // if necessary before pthread_thread_create spawns any threads.
michael@0: //
michael@0: // http://developer.apple.com/documentation/Cocoa/Conceptual/Multithreading/CreatingThreads/chapter_4_section_4.html
michael@0: void InitThreading() {
michael@0:   // this is called early in startup, before the event loop, so provide
michael@0:   // an autorelease pool to prevent leaks here
michael@0:   ScopedNSAutoreleasePool pool;
michael@0: 
michael@0:   static BOOL multithreaded = [NSThread isMultiThreaded];
michael@0:   if (!multithreaded) {
michael@0:     [NSThread detachNewThreadSelector:@selector(noOp)
michael@0:                              toTarget:[NoOp class]
michael@0:                            withObject:nil];
michael@0:     multithreaded = YES;
michael@0: 
michael@0:     DCHECK([NSThread isMultiThreaded]);
michael@0:   }
michael@0: }
michael@0: 
michael@0: }  // namespace base
michael@0: 
michael@0: // static
michael@0: void PlatformThread::SetName(const char* name) {
michael@0:   // pthread_setname_np is only available in 10.6 or later, so test
michael@0:   // for it at runtime.
michael@0:   int (*dynamic_pthread_setname_np)(const char*);
michael@0:   *reinterpret_cast<void**>(&dynamic_pthread_setname_np) =
michael@0:       dlsym(RTLD_DEFAULT, "pthread_setname_np");
michael@0:   if (!dynamic_pthread_setname_np)
michael@0:     return;
michael@0: 
michael@0:   // Mac OS X does not expose the length limit of the name, so
michael@0:   // hardcode it.
michael@0:   const int kMaxNameLength = 63;
michael@0:   std::string shortened_name = std::string(name).substr(0, kMaxNameLength);
michael@0:   // pthread_setname() fails (harmlessly) in the sandbox, ignore when it does.
michael@0:   // See http://crbug.com/47058
michael@0: 
michael@0:   // The name parameter is copied thus it's safe to release it after calling.
michael@0:   // Checked against the bionic implementation in bionic/libc/bionic/pthread.c
michael@0:   dynamic_pthread_setname_np(shortened_name.c_str());
michael@0: }
michael@0: