Bug 1828192 [Linux] Remove c style hacks to run glxtest and use FireTestProcess() for it r=emilio

- Migrate glxtest pid and pipe fd variables to static members of GfxInfo on Linux
- Implement GfxInfo::FireGLXTestProcess() to run glxtest process.

Differential Revision: https://phabricator.services.mozilla.com/D175867

toolkit/xre/nsAppRunner.cpp

@@ -3664,61 +3664,6 @@ static DWORD WINAPI InitDwriteBG(LPVOID lpdwThreadParam) {
 }
 #endif
 
-#ifdef USE_GLX_TEST
-namespace mozilla::widget {
-// the read end of the pipe, which will be used by GfxInfo
-extern int glxtest_pipe;
-// the PID of the glxtest process, to pass to waitpid()
-extern pid_t glxtest_pid;
-}  // namespace mozilla::widget
-
-void fire_glxtest_process() {
-  nsCOMPtr<nsIFile> appFile;
-  nsresult rv = XRE_GetBinaryPath(getter_AddRefs(appFile));
-  if (NS_FAILED(rv)) {
-    Output(true, "Couldn't find application file.\n");
-    return;
-  }
-  nsCOMPtr<nsIFile> exePath;
-  rv = appFile->GetParent(getter_AddRefs(exePath));
-  if (NS_FAILED(rv)) {
-    Output(true, "Couldn't get application directory.\n");
-    return;
-  }
-  exePath->Append(FILE_GLX_TEST);
-
-  int pfd[2];
-  if (pipe(pfd) == -1) {
-    Output(true, "Failed to create pipe\n");
-    return;
-  }
-
-  mozilla::widget::glxtest_pipe = pfd[0];
-
-  char* argv[] = {strdup(exePath->NativePath().get()), strdup("-f"),
-                  strdup(std::to_string(pfd[1]).c_str()),
-                  IsWaylandEnabled() ? strdup("-w") : nullptr, nullptr};
-  auto cleanup = mozilla::MakeScopeExit([&] {
-    for (auto& arg : argv) {
-      free(arg);
-    }
-    close(pfd[1]);
-  });
-
-  // Use G_SPAWN_LEAVE_DESCRIPTORS_OPEN | G_SPAWN_DO_NOT_REAP_CHILD flags
-  // to g_spawn_async_with_pipes() run posix_spawn() directly.
-  GUniquePtr<GError> err;
-  g_spawn_async_with_pipes(
-      nullptr, argv, nullptr,
-      GSpawnFlags(G_SPAWN_LEAVE_DESCRIPTORS_OPEN | G_SPAWN_DO_NOT_REAP_CHILD),
-      nullptr, nullptr, &mozilla::widget::glxtest_pid, nullptr, nullptr,
-      nullptr, getter_Transfers(err));
-  if (err) {
-    Output(true, "Failed to probe graphics hardware! %s\n", err->message);
-  }
-}
-#endif
-
 #include "GeckoProfiler.h"
 #include "ProfilerControl.h"
 
@@ -5164,7 +5109,7 @@ int XREMain::XRE_mainStartup(bool* aExitFlag) {
   mozilla::glean_pings::Pageload.Submit("startup"_ns);
 
 #ifdef USE_GLX_TEST
-  fire_glxtest_process();
+  GfxInfo::FireGLXTestProcess();
 #endif
 
   return 0;

widget/gtk/GfxInfo.cpp

@@ -40,21 +40,17 @@
 #define GFX_TEST_TIMEOUT 4000
 #define VAAPI_TEST_TIMEOUT 2000
 
+#define GLX_PROBE_BINARY u"glxtest"_ns
 #define VAAPI_PROBE_BINARY u"vaapitest"_ns
 
-#ifdef DEBUG
-bool fire_glxtest_process();
-#endif
-
 namespace mozilla::widget {
 
 #ifdef DEBUG
 NS_IMPL_ISUPPORTS_INHERITED(GfxInfo, GfxInfoBase, nsIGfxInfoDebug)
 #endif
 
-// these global variables will be set when firing the glxtest process
-int glxtest_pipe = -2;
-pid_t glxtest_pid = 0;
+int GfxInfo::sGLXTestPipe = -1;
+pid_t GfxInfo::sGLXTestPID = 0;
 
 // bits to use decoding codec information returned from glxtest
 constexpr int CODEC_HW_H264 = 1 << 4;
@@ -109,6 +105,11 @@ static bool MakeFdNonBlocking(int fd) {
 
 static bool ManageChildProcess(int* aPID, int* aPipe, int aTimeout,
                                char** aData) {
+  // Don't try anything if we failed before
+  if (*aPID == -1) {
+    return false;
+  }
+
   GIOChannel* channel = nullptr;
   *aData = nullptr;
 
@@ -188,7 +189,7 @@ void GfxInfo::GetData() {
   char* glxData = nullptr;
   auto free = mozilla::MakeScopeExit([&] { g_free((void*)glxData); });
 
-  bool error = !ManageChildProcess(&glxtest_pid, &glxtest_pipe,
+  bool error = !ManageChildProcess(&sGLXTestPID, &sGLXTestPipe,
                                    GFX_TEST_TIMEOUT, &glxData);
   if (error) {
     gfxCriticalNote << "glxtest: ManageChildProcess failed\n";
@@ -584,6 +585,33 @@ int GfxInfo::FireTestProcess(const nsAString& aBinaryFile, int* aOutPipe,
   return pid;
 }
 
+bool GfxInfo::FireGLXTestProcess() {
+  // If the pid is zero, then we have never run the test process to query for
+  // driver information. This would normally be run on startup, but we need to
+  // manually invoke it for XPC shell tests.
+  if (sGLXTestPID > 0) {
+    return true;
+  }
+
+  int pfd[2];
+  if (pipe(pfd) == -1) {
+    gfxCriticalNote << "FireGLXTestProcess failed to create pipe\n";
+    return false;
+  }
+  sGLXTestPipe = pfd[0];
+
+  auto pipeID = std::to_string(pfd[1]);
+  const char* args[] = {"-f", pipeID.c_str(),
+                        IsWaylandEnabled() ? "-w" : nullptr, nullptr};
+  sGLXTestPID = FireTestProcess(GLX_PROBE_BINARY, nullptr, args);
+  // Set pid to -1 to avoid further test launch.
+  if (!sGLXTestPID) {
+    sGLXTestPID = -1;
+  }
+  close(pfd[1]);
+  return true;
+}
+
 #ifdef MOZ_WAYLAND
 void GfxInfo::GetDataVAAPI() {
   if (mIsVAAPISupported.isSome()) {
@@ -1293,9 +1321,7 @@ NS_IMETHODIMP GfxInfo::FireTestProcess() {
   // If the pid is zero, then we have never run the test process to query for
   // driver information. This would normally be run on startup, but we need to
   // manually invoke it for XPC shell tests.
-  if (glxtest_pid == 0) {
-    fire_glxtest_process();
-  }
+  FireGLXTestProcess();
   return NS_OK;
 }
 

widget/gtk/GfxInfo.h

@@ -55,6 +55,8 @@ class GfxInfo final : public GfxInfoBase {
 
   NS_IMETHOD_(void) GetData() override;
 
+  static bool FireGLXTestProcess();
+
 #ifdef DEBUG
   NS_DECL_ISUPPORTS_INHERITED
   NS_DECL_NSIGFXINFODEBUG
@@ -117,6 +119,9 @@ class GfxInfo final : public GfxInfoBase {
   bool mGlxTestError;
   mozilla::Maybe<bool> mIsVAAPISupported;
 
+  static int sGLXTestPipe;
+  static pid_t sGLXTestPID;
+
 #ifdef MOZ_WAYLAND
   void GetDataVAAPI();
 #endif