Prototype implementation of zygotes.

Limitations that need addressing still:
- Doesn't forcibly terminate children that should have exited but haven't

Enable with env var ENABLE_ZYGOTE_MANAGER=1.

BUG=11841
TEST=
start the browser, then make chrome and all .pak files unreadable; or alternately, start an installed browser, and uninstall the browser while it's running.  Then create a new tab and browse to two new sites. 

Here's an example script to hide and unhide the .pak files (note: do not move the directory they're in, that doesn't work):

#!/bin/sh
chmod_all() {
   chmod $1 sconsbuild/Debug/chrome
   for path in . locales obj/chrome/app/intermediate/repack obj/global_intermediate/* themes
   do
     chmod $1 sconsbuild/Debug/$path/*.pak
   done
}
case $1 in
hide) chmod_all 000 ;;
show) chmod_all 755 ;;
esac


Review URL: http://codereview.chromium.org/115773

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@17840 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 266 insertions, 0 deletions

diff --git a/base/zygote_manager_unittest.cc b/base/zygote_manager_unittest.cc
new file mode 100644
index 0000000..d879d1a
--- /dev/null
+++ b/base/zygote_manager_unittest.cc
@@ -0,0 +1,266 @@
+// Copyright (c) 2009 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "base/zygote_manager.h"
+
+#include <errno.h>
+#include <fcntl.h>
+#include <stdlib.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+
+#include "base/eintr_wrapper.h"
+#include "base/file_path.h"
+#include "base/file_util.h"
+#include "base/process_util.h"
+#include "base/scoped_ptr.h"
+#include "base/string_util.h"
+
+#include "testing/gtest/include/gtest/gtest.h"
+
+using file_util::Delete;
+using file_util::WriteFile;
+using file_util::ReadFileToString;
+using file_util::GetCurrentDirectory;
+
+#if defined(OS_LINUX)
+// ZygoteManager is only used on Linux at the moment
+
+typedef testing::Test ZygoteManagerTest;
+
+TEST_F(ZygoteManagerTest, Ping) {
+  base::ZygoteManager zm;
+
+  scoped_ptr< std::vector<std::string> > new_argv;
+  new_argv.reset(zm.Start());
+  EXPECT_TRUE(new_argv.get() == NULL);
+  // Measure round trip time
+  base::TimeDelta delta;
+  EXPECT_EQ(zm.Ping(&delta), true);
+  EXPECT_LT(delta.InMilliseconds(), 5000);
+}
+
+TEST_F(ZygoteManagerTest, SpawnChild) {
+  base::ZygoteManager zm;
+  const int kDummyChildExitCode = 39;
+
+  scoped_ptr< std::vector<std::string> > new_argv;
+  new_argv.reset(zm.Start());
+  if (new_argv.get() == NULL) {
+    // original process
+    // Launch a child process
+    std::vector<std::string> myargs;
+    myargs.push_back(std::string("0thArg"));
+    myargs.push_back(std::string("1stArg"));
+    base::file_handle_mapping_vector no_files;
+    pid_t child = zm.LongFork(myargs, no_files);
+    EXPECT_NE(child, -1);
+    EXPECT_NE(child, 0);
+    LOG(INFO) << "child pid " << child;
+
+    // ZygoteManager doesn't support waiting for exit status
+    int status;
+    int err = HANDLE_EINTR(waitpid(child, &status, 0));
+    EXPECT_EQ(-1, err);
+    EXPECT_EQ(ECHILD, errno);
+  } else {
+    LOG(INFO) << "Hello from child!";
+    // child process
+    std::string arg0(new_argv.get()->at(0));
+    std::string arg1(new_argv.get()->at(1));
+    EXPECT_EQ(arg0, std::string("0thArg"));
+    EXPECT_EQ(arg1, std::string("1stArg"));
+    exit(kDummyChildExitCode);
+  }
+}
+
+TEST_F(ZygoteManagerTest, MapFile) {
+  base::ZygoteManager zm;
+  const int kDummyChildExitCode = 39;
+  const int kSpecialFDSlot = 5;
+
+  scoped_ptr< std::vector<std::string> > new_argv;
+  new_argv.reset(zm.Start());
+  if (new_argv.get() == NULL) {
+    // original process
+    // Launch a child process
+    std::vector<std::string> myargs;
+    myargs.push_back(std::string("0thArg"));
+    myargs.push_back(std::string("1stArg"));
+    base::file_handle_mapping_vector fds_to_map;
+    int fd = open("/tmp/zygote_manager_unittest.tmp", O_CREAT|O_RDWR|O_TRUNC, 0644);
+    fds_to_map.push_back(std::pair<int, int>(fd, kSpecialFDSlot));
+    pid_t child = zm.LongFork(myargs, fds_to_map);
+    EXPECT_NE(child, -1);
+    EXPECT_NE(child, 0);
+    // FIXME: really wait for child
+    sleep(3);
+    char buf[100];
+
+    // Expect fd to be seeked to end, so reading without seeking should fail
+    off_t loc = lseek(fd, 0L, SEEK_CUR);
+    EXPECT_EQ(3, loc);
+
+    memset(buf, 0, sizeof(buf));
+    int nread = read(fd, buf, 5);
+    EXPECT_EQ(0, nread);
+
+    // Try again from beginning
+    lseek(fd, 0L, SEEK_SET);
+    memset(buf, 0, sizeof(buf));
+    nread = read(fd, buf, 2);
+    EXPECT_EQ(2, nread);
+    EXPECT_EQ(strncmp(buf, "hi", 2), 0);
+    close(fd);
+  } else {
+    // child process
+    // Write three bytes; this happens to seek the file descriptor to the end.
+    int nwritten = write(kSpecialFDSlot, "hi\n", 3);
+    EXPECT_EQ(3, nwritten);
+    exit(kDummyChildExitCode);
+  }
+}
+
+TEST_F(ZygoteManagerTest, OpenFile) {
+  base::ZygoteManager zm;
+
+  scoped_ptr< std::vector<std::string> > new_argv;
+  new_argv.reset(zm.Start());
+  EXPECT_EQ(NULL, new_argv.get());
+
+  const char kSomeText[] = "foobar\n";
+
+  // Verify that we disallow nonabsolute paths.
+  FilePath badfilepath(FilePath::kCurrentDirectory);
+  badfilepath = badfilepath.AppendASCII("zygote_manager_test.pak");
+  ASSERT_FALSE(badfilepath.IsAbsolute());
+  EXPECT_NE(-1, WriteFile(badfilepath, kSomeText, strlen(kSomeText)));
+  std::string badfilename = WideToASCII(badfilepath.ToWStringHack());
+  int fd = zm.OpenFile(badfilename);
+  EXPECT_EQ(-1, fd);
+  EXPECT_TRUE(Delete(badfilepath, false));
+
+  // Verify that we disallow non-plain files.
+  ASSERT_TRUE(GetCurrentDirectory(&badfilepath));
+  badfilepath = badfilepath.AppendASCII("zygote_manager_test.pak");
+  std::string badfilenameA = WideToASCII(badfilepath.ToWStringHack());
+  EXPECT_EQ(0, mkfifo(badfilenameA.c_str(), 0644));
+  badfilename = WideToASCII(badfilepath.ToWStringHack());
+  fd = zm.OpenFile(badfilename);
+  ASSERT_EQ(-1, fd);
+  EXPECT_TRUE(Delete(badfilepath, false));
+
+  // Verify that we disallow files not ending in .pak.
+  ASSERT_TRUE(GetCurrentDirectory(&badfilepath));
+  badfilepath = badfilepath.AppendASCII("zygote_manager_test.tmp");
+  ASSERT_NE(-1, WriteFile(badfilepath, kSomeText, strlen(kSomeText)));
+  badfilename = WideToASCII(badfilepath.ToWStringHack());
+  fd = zm.OpenFile(badfilename);
+  ASSERT_EQ(-1, fd);
+  EXPECT_TRUE(Delete(badfilepath, false));
+
+  // Verify that we disallow files in /etc
+  badfilepath = FilePath(FILE_PATH_LITERAL("/"));
+  badfilepath = badfilepath.AppendASCII("etc");
+  badfilepath = badfilepath.AppendASCII("hosts");
+  EXPECT_TRUE(badfilepath.IsAbsolute());
+  badfilename = WideToASCII(badfilepath.ToWStringHack());
+  fd = zm.OpenFile(badfilename);
+  ASSERT_EQ(-1, fd);
+
+  // Verify that we disallow files in /dev
+  badfilepath = FilePath(FILE_PATH_LITERAL("/"));
+  badfilepath = badfilepath.AppendASCII("dev");
+  badfilepath = badfilepath.AppendASCII("tty");
+  EXPECT_TRUE(badfilepath.IsAbsolute());
+  badfilename = WideToASCII(badfilepath.ToWStringHack());
+  fd = zm.OpenFile(badfilename);
+  ASSERT_EQ(-1, fd);
+
+  // Verify that we allow absolute paths with filename ending in .pak,
+  // and that we can open them a second time even if they were
+  // deleted after we opened them the first time.
+  // Because of our restrictive filename checks, can't put
+  // test file in /tmp, so put it in current directory.
+  FilePath goodfilepath;
+  ASSERT_TRUE(GetCurrentDirectory(&goodfilepath));
+  goodfilepath = goodfilepath.AppendASCII("zygote_manager_test.pak");
+  ASSERT_NE(-1, WriteFile(goodfilepath, kSomeText, strlen(kSomeText)));
+  std::string goodfilename = WideToASCII(goodfilepath.ToWStringHack());
+  for (int i = 0; i < 2; i++) {
+    fd = zm.OpenFile(goodfilename);
+    ASSERT_NE(-1, fd);
+    char buf[sizeof(kSomeText)];
+    // Can't use read because it depends on file position.
+    // (In practice these files are mmapped.)
+    int nread = pread(fd, buf, strlen(kSomeText), 0);
+    ASSERT_EQ(strlen(kSomeText), static_cast<size_t>(nread));
+    EXPECT_EQ(0, strncmp(buf, kSomeText, strlen(kSomeText)));
+    EXPECT_EQ(0, close(fd));
+
+    // oddly, our Delete returns true for nonexistant files.
+    EXPECT_EQ(true, Delete(goodfilepath, false));
+  }
+}
+
+TEST_F(ZygoteManagerTest, ChildOpenFile) {
+  base::ZygoteManager zm;
+  const int kDummyChildExitCode = 39;
+
+  const char kSomeText[] = "foobar\n";
+
+  FilePath resultfilepath(FILE_PATH_LITERAL("/tmp"));
+  resultfilepath = resultfilepath.AppendASCII("zygote_manager_test_result.tmp");
+  EXPECT_EQ(true, Delete(resultfilepath, false));
+
+  scoped_ptr< std::vector<std::string> > new_argv;
+  new_argv.reset(zm.Start());
+  if (new_argv.get() == NULL) {
+    // original process
+    // Launch a child process
+    std::vector<std::string> myargs;
+    base::file_handle_mapping_vector no_files;
+    pid_t child = zm.LongFork(myargs, no_files);
+    EXPECT_NE(child, -1);
+    EXPECT_NE(child, 0);
+    LOG(INFO) << "child pid " << child;
+
+    // Wait for resultfile to be created
+    std::string result;
+    int nloops = 0;
+    while (!ReadFileToString(resultfilepath, &result)) {
+      sleep(1);
+      ++nloops;
+      ASSERT_NE(10, nloops);
+    }
+    ASSERT_EQ(result, std::string(kSomeText));
+
+    EXPECT_EQ(true, Delete(resultfilepath, false));
+
+  } else {
+    LOG(INFO) << "Hello from child!";
+
+    FilePath goodfilepath;
+    ASSERT_TRUE(GetCurrentDirectory(&goodfilepath));
+    goodfilepath = goodfilepath.AppendASCII("zygote_manager_test.pak");
+    ASSERT_NE(-1, WriteFile(goodfilepath, kSomeText, strlen(kSomeText)));
+    std::string goodfilename = WideToASCII(goodfilepath.ToWStringHack());
+    int fd = zm.OpenFile(goodfilename);
+    EXPECT_EQ(true, Delete(goodfilepath, false));
+    ASSERT_NE(-1, fd);
+    char buf[sizeof(kSomeText)];
+    // Can't use read because it depends on file position.
+    // (In practice these files are mmapped.)
+    int nread = pread(fd, buf, strlen(kSomeText), 0);
+    ASSERT_EQ(strlen(kSomeText), static_cast<size_t>(nread));
+    EXPECT_EQ(0, strncmp(buf, kSomeText, strlen(kSomeText)));
+    EXPECT_EQ(0, close(fd));
+
+    ASSERT_NE(-1, WriteFile(resultfilepath, kSomeText, strlen(kSomeText)));
+
+    exit(kDummyChildExitCode);
+  }
+}
+
+#endif