Security-57031.30.12.tar.gz

[apple/security.git] / Security / libsecurity_codesigning / lib / csutilities.cpp

diff --git a/Security/libsecurity_codesigning/lib/csutilities.cpp b/Security/libsecurity_codesigning/lib/csutilities.cpp
index 092ec1eddb60a8adb1a869c48de34686759c6cf3..dfa6e3a503002b2091085f7f3c61b93d0159a569 100644 (file)
--- a/Security/libsecurity_codesigning/lib/csutilities.cpp
+++ b/Security/libsecurity_codesigning/lib/csutilities.cpp
@@ -219,5 +219,50 @@ void MessageTrace::send(const char *format, ...)
 }
 
 
+
+// Resource limited async workers for doing work on nested bundles
+LimitedAsync::LimitedAsync(bool async)
+{
+       // validate multiple resources concurrently if bundle resides on solid-state media
+
+       // How many async workers to spin off. If zero, validating only happens synchronously.
+       long async_workers = 0;
+
+       long ncpu = sysconf(_SC_NPROCESSORS_ONLN);
+
+       if (async && ncpu > 0)
+               async_workers = ncpu - 1; // one less because this thread also validates
+
+       mResourceSemaphore = new Dispatch::Semaphore(async_workers);
+}
+
+LimitedAsync::LimitedAsync(LimitedAsync &limitedAsync)
+{
+       mResourceSemaphore = new Dispatch::Semaphore(*limitedAsync.mResourceSemaphore);
+}
+
+LimitedAsync::~LimitedAsync()
+{
+       delete mResourceSemaphore;
+}
+
+bool LimitedAsync::perform(Dispatch::Group &groupRef, void (^block)()) {
+       __block Dispatch::SemaphoreWait wait(*mResourceSemaphore, DISPATCH_TIME_NOW);
+
+       if (wait.acquired()) {
+               dispatch_queue_t defaultQueue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0);
+
+               groupRef.enqueue(defaultQueue, ^{
+                       // Hold the semaphore count until the worker is done validating.
+                       Dispatch::SemaphoreWait innerWait(wait);
+                       block();
+               });
+               return true;
+       } else {
+               block();
+               return false;
+       }
+}
+
 } // end namespace CodeSigning
 } // end namespace Security