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#include "fslock.h"
#include <fcntl.h>
#include <semaphore.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>
#include "3rd-party/catch.hpp"
#include "test_helpers/tempdir.h"
#include "test_helpers/tempfile.h"
using namespace newsboat;
// Forks and calls FsLock::try_lock() in the child process.
class LockProcess {
public:
explicit LockProcess(const std::string& lock_location)
{
sem_start = sem_open(sem_start_name, O_CREAT, 0644, 0);
sem_stop = sem_open(sem_stop_name, O_CREAT, 0644, 0);
pid = ::fork();
if (pid == -1) {
FAIL("LockProcess: fork() failed");
} else if (pid > 0) {
// Parent process: Wait until child process has finished calling try_lock
sem_wait(sem_start);
} else {
// Child process: Call try_lock, signal parent to continue, wait for parent process signal to stop
pid_t ignore_pid;
FsLock lock;
std::string error_message;
lock.try_lock(lock_location, ignore_pid, error_message);
sem_post(sem_start);
sem_wait(sem_stop);
// Exit directly without running destructors (making sure we don't interfere with the original process)
_exit(0);
}
}
pid_t get_child_pid()
{
return pid;
}
~LockProcess()
{
if (pid > 0) {
// Parent process: Signal child process to exit and wait for it to finish
sem_post(sem_stop);
::waitpid(pid, nullptr, 0);
REQUIRE(sem_unlink(sem_start_name) == 0);
REQUIRE(sem_unlink(sem_stop_name) == 0);
REQUIRE(sem_close(sem_start) == 0);
REQUIRE(sem_close(sem_stop) == 0);
}
}
private:
const char* sem_start_name = "/newsboat-test-fslock-start";
const char* sem_stop_name = "/newsboat-test-fslock-stop";
pid_t pid;
sem_t* sem_start;
sem_t* sem_stop;
};
TEST_CASE("try_lock() returns an error if lock-file permissions or location are invalid",
"[FsLock]")
{
GIVEN("An invalid lock location") {
const test_helpers::TempDir test_directory;
const std::string non_existing_dir = test_directory.get_path() +
"does-not-exist/";
const std::string lock_location = non_existing_dir + "lockfile";
THEN("try_lock() will fail and return pid == 0") {
FsLock lock;
pid_t pid = -1;
// try_lock() is expected to fail as the relevant directory does not exist
std::string error_message;
REQUIRE_FALSE(lock.try_lock(lock_location, pid, error_message));
REQUIRE(pid == 0);
REQUIRE(error_message.length() > 0);
}
}
GIVEN("A lock file which does not grant write access") {
const test_helpers::TempFile lock_location;
const int fd = ::open(lock_location.get_path().c_str(), O_RDWR | O_CREAT, 0400);
::close(fd);
THEN("try_lock() will fail and return pid == 0") {
FsLock lock;
pid_t pid = -1;
std::string error_message;
REQUIRE_FALSE(lock.try_lock(lock_location.get_path(), pid, error_message));
REQUIRE(pid == 0);
REQUIRE(error_message.length() > 0);
}
}
}
TEST_CASE("try_lock() fails if lock was already created", "[FsLock]")
{
const test_helpers::TempFile lock_location;
WHEN("A different process has called try_lock()") {
LockProcess lock_process(lock_location.get_path());
FsLock lock;
pid_t pid = 0;
THEN("Calling try_lock() for the same lock location will fail") {
std::string error_message;
REQUIRE_FALSE(lock.try_lock(lock_location.get_path(), pid, error_message));
}
THEN("try_lock() returns the pid of the process holding the lock") {
std::string error_message;
REQUIRE_FALSE(lock.try_lock(lock_location.get_path(), pid, error_message));
REQUIRE(pid == lock_process.get_child_pid());
}
}
}
TEST_CASE("try_lock() succeeds if lock file location is valid and not locked by a different process",
"[FsLock]")
{
const test_helpers::TempFile lock_location;
FsLock lock;
pid_t pid = 0;
std::string error_message;
REQUIRE(lock.try_lock(lock_location.get_path(), pid, error_message));
SECTION("The lock file exists after a call to try_lock()") {
REQUIRE(0 == ::access(lock_location.get_path().c_str(), F_OK));
}
SECTION("Calling try_lock() a second time for the same location succeeds") {
REQUIRE(lock.try_lock(lock_location.get_path(), pid, error_message));
}
SECTION("Calling try_lock() a second time with a different location succeeds and cleans up old lock file") {
const test_helpers::TempFile new_lock_location;
REQUIRE(0 == ::access(lock_location.get_path().c_str(), F_OK));
REQUIRE(lock.try_lock(new_lock_location.get_path(), pid, error_message));
REQUIRE(0 != ::access(lock_location.get_path().c_str(), F_OK));
REQUIRE(0 == ::access(new_lock_location.get_path().c_str(), F_OK));
}
}
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