Merge pull request #48475 from robert-kalmar:shmem-unlink-for-non-adroid

PiperOrigin-RevId: 374851010
Change-Id: I10191ea32762a257136f6b8eee2062c29677ca8f

tensorflow/lite/delegates/nnapi/nnapi_delegate.cc

@@ -670,7 +670,22 @@ NNMemory::NNMemory(const NnApi* nnapi, const char* name, size_t size) {
   if (name && size > 0) {
     nnapi_ = nnapi;
     byte_size_ = size;
+#ifdef __ANDROID__
     fd_ = nnapi_->ASharedMemory_create(name, size);
+#else
+    // For non-Android platforms ASharedMemory_create needs unique name to
+    // create a shared memory object (see nnapi_implementation.cc).
+    char shm_name_buffer[L_tmpnam];
+    if (tmpnam(shm_name_buffer) == nullptr) {
+      shm_name_buffer[0] = '\0';
+    }
+    // tmpnam will produce a string containing with slashes, but shm_open
+    // won't like that.
+    shm_region_name_ = std::string(name) + std::string(shm_name_buffer);
+    std::replace(shm_region_name_.begin(), shm_region_name_.end(), '/', '-');
+    fd_ = nnapi_->ASharedMemory_create(shm_region_name_.c_str(), size);
+#endif
+
     data_ptr_ = reinterpret_cast<uint8_t*>(
         mmap(nullptr, size, PROT_READ | PROT_WRITE, MAP_SHARED, fd_, 0));
     nnapi_->ANeuralNetworksMemory_createFromFd(size, PROT_READ | PROT_WRITE,
@@ -691,7 +706,11 @@ NNMemory::~NNMemory() {
   if (nn_memory_handle_) {
     nnapi_->ANeuralNetworksMemory_free(nn_memory_handle_);
   }
+#ifdef __ANDROID__
   if (fd_ >= 0) close(fd_);
+#else
+  if (!shm_region_name_.empty()) shm_unlink(shm_region_name_.c_str());
+#endif
 #endif
 }
 

tensorflow/lite/delegates/nnapi/nnapi_delegate_kernel.h

@@ -188,6 +188,9 @@ class NNMemory {
   size_t byte_size_ = 0;
   uint8_t* data_ptr_ = nullptr;
   ANeuralNetworksMemory* nn_memory_handle_ = nullptr;
+#ifndef __ANDROID__
+  std::string shm_region_name_;
+#endif
 };
 
 // LINT.IfChange

tensorflow/lite/nnapi/nnapi_implementation.cc

@@ -65,21 +65,15 @@ void* LoadFunction(void* handle, const char* name, bool optional) {
 
 #ifndef __ANDROID__
 // Add /dev/shm implementation of shared memory for non-Android platforms
-int ASharedMemory_create(const char* /* name */, size_t size) {
+int ASharedMemory_create(const char* name, size_t size) {
   // Each call to ASharedMemory_create produces a unique memory space, hence
-  // name should not be used to create the shared memory file, otherwise
-  // two calls to create memory regions using the same 'name', will collide.
-  char shm_name_buffer[L_tmpnam];
-  if (tmpnam(shm_name_buffer) == nullptr) {
-    return -1;
-  }
-
-  // tmpnam will produce a string containing with slashes, but shm_open
-  // won't like that.
-  std::string shm_region_name = std::string(shm_name_buffer);
-  std::replace(shm_region_name.begin(), shm_region_name.end(), '/', '-');
+  // name should be unique, otherwise two calls to create memory regions using
+  // the same 'name', will collide.
+  // Caller is responsible to provide a unique name.
 
-  int fd = shm_open(shm_region_name.c_str(), O_RDWR | O_CREAT, 0644);
+  // Make sure new shared memory region is created: shm_open return an error if
+  // shm object with given name already exists (O_CREAT | O_EXCL)
+  int fd = shm_open(name, O_RDWR | O_CREAT | O_EXCL, 0644);
   if (fd < 0) {
     return fd;
   }