Browse Source

test: Add unit test for LockDirectory

Add a unit test for LockDirectory, introduced in #11281.

Github-Pull: #12422
Rebased-From: 1d4cbd26e4
Tree-SHA512: 8186f4b22c65153e30ec1e0b68be20fd59d34e1fe565d99f3b5a302780125953b867fb14c37144de3fd7baf5751df94bf3901eebbb7b820491ca452706d4e205
tags/v0.16.1
Wladimir J. van der Laan 3 years ago
parent
commit
4d54e7ad41
No account linked to committer's email address
3 changed files with 154 additions and 9 deletions
  1. 130
    0
      src/test/util_tests.cpp
  2. 18
    9
      src/util.cpp
  3. 6
    0
      src/util.h

+ 130
- 0
src/test/util_tests.cpp View File

@@ -13,6 +13,10 @@

#include <stdint.h>
#include <vector>
#ifndef WIN32
#include <sys/types.h>
#include <sys/wait.h>
#endif

#include <boost/test/unit_test.hpp>

@@ -603,4 +607,130 @@ BOOST_AUTO_TEST_CASE(test_ParseFixedPoint)
BOOST_CHECK(!ParseFixedPoint("1.", 8, &amount));
}

static void TestOtherThread(fs::path dirname, std::string lockname, bool *result)
{
*result = LockDirectory(dirname, lockname);
}

#ifndef WIN32 // Cannot do this test on WIN32 due to lack of fork()
static constexpr char LockCommand = 'L';
static constexpr char UnlockCommand = 'U';
static constexpr char ExitCommand = 'X';

static void TestOtherProcess(fs::path dirname, std::string lockname, int fd)
{
char ch;
int rv;
while (true) {
rv = read(fd, &ch, 1); // Wait for command
assert(rv == 1);
switch(ch) {
case LockCommand:
ch = LockDirectory(dirname, lockname);
rv = write(fd, &ch, 1);
assert(rv == 1);
break;
case UnlockCommand:
ReleaseDirectoryLocks();
ch = true; // Always succeeds
rv = write(fd, &ch, 1);
break;
case ExitCommand:
close(fd);
exit(0);
default:
assert(0);
}
}
}
#endif

BOOST_AUTO_TEST_CASE(test_LockDirectory)
{
fs::path dirname = fs::temp_directory_path() / fs::unique_path();
const std::string lockname = ".lock";
#ifndef WIN32
// Revert SIGCHLD to default, otherwise boost.test will catch and fail on
// it: there is BOOST_TEST_IGNORE_SIGCHLD but that only works when defined
// at build-time of the boost library
void (*old_handler)(int) = signal(SIGCHLD, SIG_DFL);

// Fork another process for testing before creating the lock, so that we
// won't fork while holding the lock (which might be undefined, and is not
// relevant as test case as that is avoided with -daemonize).
int fd[2];
BOOST_CHECK_EQUAL(socketpair(AF_UNIX, SOCK_STREAM, 0, fd), 0);
pid_t pid = fork();
if (!pid) {
BOOST_CHECK_EQUAL(close(fd[1]), 0); // Child: close parent end
TestOtherProcess(dirname, lockname, fd[0]);
}
BOOST_CHECK_EQUAL(close(fd[0]), 0); // Parent: close child end
#endif
// Lock on non-existent directory should fail
BOOST_CHECK_EQUAL(LockDirectory(dirname, lockname), false);

fs::create_directories(dirname);

// Probing lock on new directory should succeed
BOOST_CHECK_EQUAL(LockDirectory(dirname, lockname, true), true);

// Persistent lock on new directory should succeed
BOOST_CHECK_EQUAL(LockDirectory(dirname, lockname), true);

// Another lock on the directory from the same thread should succeed
BOOST_CHECK_EQUAL(LockDirectory(dirname, lockname), true);

// Another lock on the directory from a different thread within the same process should succeed
bool threadresult;
std::thread thr(TestOtherThread, dirname, lockname, &threadresult);
thr.join();
BOOST_CHECK_EQUAL(threadresult, true);
#ifndef WIN32
// Try to aquire lock in child process while we're holding it, this should fail.
char ch;
BOOST_CHECK_EQUAL(write(fd[1], &LockCommand, 1), 1);
BOOST_CHECK_EQUAL(read(fd[1], &ch, 1), 1);
BOOST_CHECK_EQUAL((bool)ch, false);

// Give up our lock
ReleaseDirectoryLocks();
// Probing lock from our side now should succeed, but not hold on to the lock.
BOOST_CHECK_EQUAL(LockDirectory(dirname, lockname, true), true);

// Try to acquire the lock in the child process, this should be succesful.
BOOST_CHECK_EQUAL(write(fd[1], &LockCommand, 1), 1);
BOOST_CHECK_EQUAL(read(fd[1], &ch, 1), 1);
BOOST_CHECK_EQUAL((bool)ch, true);

// When we try to probe the lock now, it should fail.
BOOST_CHECK_EQUAL(LockDirectory(dirname, lockname, true), false);

// Unlock the lock in the child process
BOOST_CHECK_EQUAL(write(fd[1], &UnlockCommand, 1), 1);
BOOST_CHECK_EQUAL(read(fd[1], &ch, 1), 1);
BOOST_CHECK_EQUAL((bool)ch, true);

// When we try to probe the lock now, it should succeed.
BOOST_CHECK_EQUAL(LockDirectory(dirname, lockname, true), true);

// Re-lock the lock in the child process, then wait for it to exit, check
// successful return. After that, we check that exiting the process
// has released the lock as we would expect by probing it.
int processstatus;
BOOST_CHECK_EQUAL(write(fd[1], &LockCommand, 1), 1);
BOOST_CHECK_EQUAL(write(fd[1], &ExitCommand, 1), 1);
BOOST_CHECK_EQUAL(waitpid(pid, &processstatus, 0), pid);
BOOST_CHECK_EQUAL(processstatus, 0);
BOOST_CHECK_EQUAL(LockDirectory(dirname, lockname, true), true);

// Restore SIGCHLD
signal(SIGCHLD, old_handler);
BOOST_CHECK_EQUAL(close(fd[1]), 0); // Close our side of the socketpair
#endif
// Clean up
ReleaseDirectoryLocks();
fs::remove_all(dirname);
}

BOOST_AUTO_TEST_SUITE_END()

+ 18
- 9
src/util.cpp View File

@@ -376,19 +376,22 @@ int LogPrintStr(const std::string &str)
return ret;
}

/** A map that contains all the currently held directory locks. After
* successful locking, these will be held here until the global destructor
* cleans them up and thus automatically unlocks them, or ReleaseDirectoryLocks
* is called.
*/
static std::map<std::string, std::unique_ptr<boost::interprocess::file_lock>> dir_locks;
/** Mutex to protect dir_locks. */
static std::mutex cs_dir_locks;

bool LockDirectory(const fs::path& directory, const std::string lockfile_name, bool probe_only)
{
// A map that contains all the currently held directory locks. After
// successful locking, these will be held here until the global
// destructor cleans them up and thus automatically unlocks them.
static std::map<std::string, std::unique_ptr<boost::interprocess::file_lock>> locks;
// Protect the map with a mutex
static std::mutex cs;
std::lock_guard<std::mutex> ulock(cs);
std::lock_guard<std::mutex> ulock(cs_dir_locks);
fs::path pathLockFile = directory / lockfile_name;

// If a lock for this directory already exists in the map, don't try to re-lock it
if (locks.count(pathLockFile.string())) {
if (dir_locks.count(pathLockFile.string())) {
return true;
}

@@ -403,7 +406,7 @@ bool LockDirectory(const fs::path& directory, const std::string lockfile_name, b
}
if (!probe_only) {
// Lock successful and we're not just probing, put it into the map
locks.emplace(pathLockFile.string(), std::move(lock));
dir_locks.emplace(pathLockFile.string(), std::move(lock));
}
} catch (const boost::interprocess::interprocess_exception& e) {
return error("Error while attempting to lock directory %s: %s", directory.string(), e.what());
@@ -411,6 +414,12 @@ bool LockDirectory(const fs::path& directory, const std::string lockfile_name, b
return true;
}

void ReleaseDirectoryLocks()
{
std::lock_guard<std::mutex> ulock(cs_dir_locks);
dir_locks.clear();
}

/** Interpret string as boolean, for argument parsing */
static bool InterpretBool(const std::string& strValue)
{

+ 6
- 0
src/util.h View File

@@ -174,6 +174,12 @@ int RaiseFileDescriptorLimit(int nMinFD);
void AllocateFileRange(FILE *file, unsigned int offset, unsigned int length);
bool RenameOver(fs::path src, fs::path dest);
bool LockDirectory(const fs::path& directory, const std::string lockfile_name, bool probe_only=false);

/** Release all directory locks. This is used for unit testing only, at runtime
* the global destructor will take care of the locks.
*/
void ReleaseDirectoryLocks();

bool TryCreateDirectories(const fs::path& p);
fs::path GetDefaultDataDir();
const fs::path &GetDataDir(bool fNetSpecific = true);

Loading…
Cancel
Save