1 files changed, 156 insertions, 0 deletions
diff --git a/files/src/android/goldfish/FileShareOpen.cpp b/files/src/android/goldfish/FileShareOpen.cpp
new file mode 100644
index 0000000..4efb155
--- /dev/null
+++ b/files/src/android/goldfish/FileShareOpen.cpp
@@ -0,0 +1,156 @@
+// Copyright 2018 The Android Open Source Project
+//
+// This software is licensed under the terms of the GNU General Public
+// License version 2, as published by the Free Software Foundation, and
+// may be copied, distributed, and modified under those terms.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+#include "aemu/base/files/FileShareOpen.h"
+
+#include <errno.h>
+
+#include <algorithm>
+#include <chrono>
+#include <cstdio>
+#include <thread>
+
+#include "absl//strings/str_format.h"
+#include "aemu/base/files/FileShareOpenImpl.h"
+#include "android/base/file/file_io.h"
+
+void android::base::createFileForShare(const char *filename) {
+  void *handle = internal::openFileForShare(filename);
+  if (handle) {
+    internal::closeFileForShare(handle);
+  }
+}
+
+FILE *android::base::fsopenWithTimeout(const char *filename, const char *mode,
+                                       android::base::FileShare fileshare,
+                                       int timeoutMs) {
+  if (timeoutMs <= 0) {
+    return fsopen(filename, mode, fileshare);
+  }
+  FILE *ret = nullptr;
+  int waited = 0;
+  while (!ret && waited < timeoutMs) {
+    ret = fsopen(filename, mode, fileshare);
+    if (ret) {
+      return ret;
+    }
+    int wait = std::min(timeoutMs - waited, 200);
+    std::this_thread::sleep_for(std::chrono::milliseconds(wait));
+    waited += wait;
+  }
+  return nullptr;
+}
+
+#ifdef _WIN32
+
+#include <share.h>
+#include <windows.h>
+
+#include "aemu/base/system/Win32UnicodeString.h"
+
+FILE *android::base::fsopen(const char *filename, const char *mode,
+                            android::base::FileShare fileshare) {
+  int shflag = _SH_DENYWR;
+  switch (fileshare) {
+  case FileShare::Read:
+    // Others cannot write
+    shflag = _SH_DENYWR;
+    break;
+  case FileShare::Write:
+    // Others cannot read nor write
+    shflag = _SH_DENYRW;
+    break;
+  }
+  const Win32UnicodeString filenameW(filename);
+  const Win32UnicodeString modeW(mode);
+  FILE *file = _wfsopen(filenameW.c_str(), modeW.c_str(), shflag);
+  return file;
+}
+
+bool android::base::updateFileShare(FILE *file, FileShare fileshare) {
+  // TODO: have windows support
+  // BUG: 112265408
+  derror("Error: updateFileShare not supported on windows");
+  return false;
+}
+
+void *android::base::internal::openFileForShare(const char *filename) {
+  const Win32UnicodeString filenameW(filename);
+  void *hndl =
+      CreateFileW(filenameW.c_str(), 0,
+                  FILE_SHARE_DELETE | FILE_SHARE_READ | FILE_SHARE_WRITE, NULL,
+                  CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL, nullptr);
+  if (hndl != INVALID_HANDLE_VALUE) {
+    return hndl;
+  } else {
+    return nullptr;
+  }
+}
+
+void android::base::internal::closeFileForShare(void *fileHandle) {
+  CloseHandle(fileHandle);
+}
+
+#else
+#include <sys/file.h>
+#ifndef _MSC_VER
+#include <unistd.h>
+#endif
+
+static int getFlockOperation(android::base::FileShare fileshare) {
+  switch (fileshare) {
+  case android::base::FileShare::Read:
+    return LOCK_SH;
+  case android::base::FileShare::Write:
+    return LOCK_EX;
+  default:
+    return LOCK_SH;
+  }
+}
+
+FILE *android::base::fsopen(const char *filename, const char *mode,
+                            android::base::FileShare fileshare) {
+  std::string tmp;
+  // "e" is a glibc extension from glibc 2.7, it open the file with
+  // O_CLOEXEC flag. It doesn't work for macOS/Windows actually but it
+  // also doesn't hurt.
+  if (!strchr(mode, 'e')) {
+    tmp = absl::StrFormat("%se", mode);
+    mode = tmp.c_str();
+  }
+  FILE *file = android_fopen(filename, mode);
+  if (!file) {
+    return nullptr;
+  }
+  int operation = getFlockOperation(fileshare);
+  int fd = fileno(file);
+  if (flock(fd, operation | LOCK_NB) == -1) {
+    fclose(file);
+    return nullptr;
+  }
+  return file;
+}
+
+bool android::base::updateFileShare(FILE *file, FileShare fileshare) {
+  int operation = getFlockOperation(fileshare);
+  int fd = fileno(file);
+  return -1 != flock(fd, operation | LOCK_NB);
+}
+
+void *android::base::internal::openFileForShare(const char *filename) {
+  return android_fopen(filename, "a");
+}
+
+void android::base::internal::closeFileForShare(void *fileHandle) {
+  fclose((FILE *)fileHandle);
+}
+
+#endif