Linux: create a library loader code generator for dlopen and use it for libpci.

content/gpu/gpu_info_collector_linux.cc

Index: content/gpu/gpu_info_collector_linux.cc
diff --git a/content/gpu/gpu_info_collector_linux.cc b/content/gpu/gpu_info_collector_linux.cc
index c6f2c2bcd7a97e32db76975f388cf934b819ebd5..d849cab7f25b6873d3cf512a9037aed056856fdf 100644
--- a/content/gpu/gpu_info_collector_linux.cc
+++ b/content/gpu/gpu_info_collector_linux.cc
@@ -4,15 +4,9 @@
 
 #include "content/gpu/gpu_info_collector.h"
 
-#include <dlfcn.h>
 #include <X11/Xlib.h>
 #include <vector>
 
-// TODO(phajdan.jr): Report problem upstream and make pci.h handle this.
-extern "C" {
-#include <pci/pci.h>
-}
-
 #include "base/command_line.h"
 #include "base/debug/trace_event.h"
 #include "base/file_util.h"
@@ -23,6 +17,7 @@ extern "C" {
 #include "base/string_split.h"
 #include "base/string_tokenizer.h"
 #include "base/string_util.h"
+#include "library_loaders/libpci.h"
 #include "third_party/libXNVCtrl/NVCtrl.h"
 #include "third_party/libXNVCtrl/NVCtrlLib.h"
 #include "ui/gl/gl_bindings.h"
@@ -33,28 +28,6 @@ extern "C" {
 
 namespace {
 
-// Define function types.
-typedef pci_access* (*FT_pci_alloc)();
-typedef void (*FT_pci_init)(pci_access*);
-typedef void (*FT_pci_cleanup)(pci_access*);
-typedef void (*FT_pci_scan_bus)(pci_access*);
-typedef void (*FT_pci_scan_bus)(pci_access*);
-typedef int (*FT_pci_fill_info)(pci_dev*, int);
-typedef char* (*FT_pci_lookup_name)(pci_access*, char*, int, int, ...);
-
-// This includes dynamically linked library handle and functions pointers from
-// libpci.
-struct PciInterface {
-  void* lib_handle;
-
-  FT_pci_alloc pci_alloc;
-  FT_pci_init pci_init;
-  FT_pci_cleanup pci_cleanup;
-  FT_pci_scan_bus pci_scan_bus;
-  FT_pci_fill_info pci_fill_info;
-  FT_pci_lookup_name pci_lookup_name;
-};
-
 // This checks if a system supports PCI bus.
 // We check the existence of /sys/bus/pci or /sys/bug/pci_express.
 bool IsPciSupported() {
@@ -64,68 +37,6 @@ bool IsPciSupported() {
           file_util::PathExists(pcie_path));
 }
 
-// This dynamically opens libpci and get function pointers we need.  Return
-// NULL if library fails to open or any functions can not be located.
-// Returned interface (if not NULL) should be deleted in FinalizeLibPci.
-PciInterface* InitializeLibPci(const char* lib_name) {
-  scoped_ptr<PciInterface> interface(new PciInterface);
-#if defined(DLOPEN_LIBPCI)
-  void* handle = dlopen(lib_name, RTLD_LAZY);
-  if (handle == NULL) {
-    VLOG(1) << "Failed to dlopen " << lib_name;
-    return NULL;
-  }
-  interface->lib_handle = handle;
-  interface->pci_alloc = reinterpret_cast<FT_pci_alloc>(
-      dlsym(handle, "pci_alloc"));
-  interface->pci_init = reinterpret_cast<FT_pci_init>(
-      dlsym(handle, "pci_init"));
-  interface->pci_cleanup = reinterpret_cast<FT_pci_cleanup>(
-      dlsym(handle, "pci_cleanup"));
-  interface->pci_scan_bus = reinterpret_cast<FT_pci_scan_bus>(
-      dlsym(handle, "pci_scan_bus"));
-  interface->pci_fill_info = reinterpret_cast<FT_pci_fill_info>(
-      dlsym(handle, "pci_fill_info"));
-  interface->pci_lookup_name = reinterpret_cast<FT_pci_lookup_name>(
-      dlsym(handle, "pci_lookup_name"));
-  if (interface->pci_alloc == NULL ||
-      interface->pci_init == NULL ||
-      interface->pci_cleanup == NULL ||
-      interface->pci_scan_bus == NULL ||
-      interface->pci_fill_info == NULL ||
-      interface->pci_lookup_name == NULL) {
-    VLOG(1) << "Missing required function(s) from " << lib_name;
-    dlclose(handle);
-    return NULL;
-  }
-#else  // !defined(DLOPEN_LIBPCI)
-  interface->lib_handle = NULL;
-  interface->pci_alloc = reinterpret_cast<FT_pci_alloc>(
-      &pci_alloc);
-  interface->pci_init = reinterpret_cast<FT_pci_init>(
-      &pci_init);
-  interface->pci_cleanup = reinterpret_cast<FT_pci_cleanup>(
-      &pci_cleanup);
-  interface->pci_scan_bus = reinterpret_cast<FT_pci_scan_bus>(
-      &pci_scan_bus);
-  interface->pci_fill_info = reinterpret_cast<FT_pci_fill_info>(
-      &pci_fill_info);
-  interface->pci_lookup_name = reinterpret_cast<FT_pci_lookup_name>(
-      &pci_lookup_name);
-#endif  // !defined(DLOPEN_LIBPCI)
-  return interface.release();
-}
-
-// This close the dynamically opened libpci and delete the interface.
-void FinalizeLibPci(PciInterface** interface) {
-#if defined(DLOPEN_LIBPCI)
-  DCHECK(interface && *interface && (*interface)->lib_handle);
-  dlclose((*interface)->lib_handle);
-#endif  // defined(DLOPEN_LIBPCI)
-  delete (*interface);
-  *interface = NULL;
-}
-
 // Scan /etc/ati/amdpcsdb.default for "ReleaseVersion".
 // Return empty string on failing.
 std::string CollectDriverVersionATI() {
@@ -263,22 +174,22 @@ bool CollectVideoCardInfo(content::GPUInfo* gpu_info) {
   }
 
   // TODO(zmo): be more flexible about library name.
-  PciInterface* interface = InitializeLibPci("libpci.so.3");
-  if (interface == NULL)
-    interface = InitializeLibPci("libpci.so");
-  if (interface == NULL) {
+  LibPciLoader libpci_loader;
+  if (!libpci_loader.Load("libpci.so.3") &&
+      !libpci_loader.Load("libpci.so")) {
     VLOG(1) << "Failed to locate libpci";
     return false;
   }
 
-  pci_access* access = (interface->pci_alloc)();
+  pci_access* access = (libpci_loader.pci_alloc)();
   DCHECK(access != NULL);
-  (interface->pci_init)(access);
-  (interface->pci_scan_bus)(access);
+  (libpci_loader.pci_init)(access);
+  (libpci_loader.pci_scan_bus)(access);
   bool primary_gpu_identified = false;
   for (pci_dev* device = access->devices;
        device != NULL; device = device->next) {
-    (interface->pci_fill_info)(device, 33);  // Fill the IDs and class fields.
+    // Fill the IDs and class fields.
+    (libpci_loader.pci_fill_info)(device, 33);
     // TODO(zmo): there might be other classes that qualify as display devices.
     if (device->device_class != 0x0300)  // Device class is DISPLAY_VGA.
       continue;
@@ -292,19 +203,19 @@ bool CollectVideoCardInfo(content::GPUInfo* gpu_info) {
     // The current implementation of pci_lookup_name returns the same pointer
     // as the passed in upon success, and a different one (NULL or a pointer
     // to an error message) upon failure.
-    if ((interface->pci_lookup_name)(access,
-                                     buffer.get(),
-                                     buffer_size,
-                                     1,
-                                     device->vendor_id) == buffer.get()) {
+    if ((libpci_loader.pci_lookup_name)(access,
+                                        buffer.get(),
+                                        buffer_size,
+                                        1,
+                                        device->vendor_id) == buffer.get()) {
       gpu.vendor_string = buffer.get();
     }
-    if ((interface->pci_lookup_name)(access,
-                                     buffer.get(),
-                                     buffer_size,
-                                     2,
-                                     device->vendor_id,
-                                     device->device_id) == buffer.get()) {
+    if ((libpci_loader.pci_lookup_name)(access,
+                                        buffer.get(),
+                                        buffer_size,
+                                        2,
+                                        device->vendor_id,
+                                        device->device_id) == buffer.get()) {
       std::string device_string = buffer.get();
       size_t begin = device_string.find_first_of('[');
       size_t end = device_string.find_last_of(']');
@@ -341,8 +252,7 @@ bool CollectVideoCardInfo(content::GPUInfo* gpu_info) {
       gpu_info->amd_switchable = true;
   }
 
-  (interface->pci_cleanup)(access);
-  FinalizeLibPci(&interface);
+  (libpci_loader.pci_cleanup)(access);
   return (primary_gpu_identified);
 }