commit f1ff65dfad800ed89e5b01c1c5b4b77c10a438b8
Author: Steven Murdoch <Steven.Murdoch(a)cl.cam.ac.uk>
Date: Mon Aug 29 00:30:18 2011 +0100
Replace two magic tristates with #define'd names
- process_handle_t.status
- return value of tor_get_exit_code()
---
src/common/util.c | 64 ++++++++++++++++++++++++-------------------------
src/common/util.h | 13 +++++++++-
src/test/test_util.c | 18 ++++++++------
3 files changed, 53 insertions(+), 42 deletions(-)
diff --git a/src/common/util.c b/src/common/util.c
index 91b83db..371e09b 100644
--- a/src/common/util.c
+++ b/src/common/util.c
@@ -3082,7 +3082,7 @@ tor_spawn_background(const char *const filename, const char **argv,
/* Assume failure to start process */
memset(process_handle, 0, sizeof(process_handle_t));
- process_handle->status = -1;
+ process_handle->status = PROCESS_STATUS_ERROR;
/* Set up pipe for stdout */
if (!CreatePipe(&stdout_pipe_read, &stdout_pipe_write, &saAttr, 0)) {
@@ -3157,7 +3157,7 @@ tor_spawn_background(const char *const filename, const char **argv,
/* TODO: Close hProcess and hThread in process_handle->pid? */
process_handle->stdout_pipe = stdout_pipe_read;
process_handle->stderr_pipe = stderr_pipe_read;
- process_handle->status = 1;
+ process_handle->status = PROCESS_STATUS_RUNNING;
}
/* TODO: Close pipes on exit */
@@ -3183,7 +3183,7 @@ tor_spawn_background(const char *const filename, const char **argv,
/* Assume failure to start */
memset(process_handle, 0, sizeof(process_handle_t));
- process_handle->status = -1;
+ process_handle->status = PROCESS_STATUS_ERROR;
/* We do the strlen here because strlen() is not signal handler safe,
and we are not allowed to use unsafe functions between fork and exec */
@@ -3329,7 +3329,7 @@ tor_spawn_background(const char *const filename, const char **argv,
strerror(errno));
}
- process_handle->status = 1;
+ process_handle->status = PROCESS_STATUS_RUNNING;
/* Set stdout/stderr pipes to be non-blocking */
fcntl(process_handle->stdout_pipe, F_SETFL, O_NONBLOCK);
fcntl(process_handle->stderr_pipe, F_SETFL, O_NONBLOCK);
@@ -3341,16 +3341,16 @@ tor_spawn_background(const char *const filename, const char **argv,
#endif // MS_WINDOWS
}
-/* Get the exit code of a process specified by <b>process_handle</b> and
- * store it in <b>exit_code</b>, if set to a non-NULL value. If
- * <b>block</b> is set to true, the call will block until the process has
- * exited. Otherwise if the process is still running, the function will
- * return -2, and exit_code will be left unchanged. Returns 0 if the
- * process did exit. If there is a failure, -1 will be returned and the
- * contents of exit_code (if non-NULL) will be undefined. N.B. Under *nix
- * operating systems, this will probably not work in Tor, because
- * waitpid() is called in main.c to reap any terminated child
- * processes.*/
+/* Get the exit code of a process specified by <b>process_handle</b> and store
+ * it in <b>exit_code</b>, if set to a non-NULL value. If <b>block</b> is set
+ * to true, the call will block until the process has exited. Otherwise if
+ * the process is still running, the function will return
+ * PROCESS_EXIT_RUNNING, and exit_code will be left unchanged. Returns
+ * PROCESS_EXIT_EXITED if the process did exit. If there is a failure,
+ * PROCESS_EXIT_ERROR will be returned and the contents of exit_code (if
+ * non-NULL) will be undefined. N.B. Under *nix operating systems, this will
+ * probably not work in Tor, because waitpid() is called in main.c to reap any
+ * terminated child processes.*/
int
tor_get_exit_code(const process_handle_t process_handle,
int block, int *exit_code)
@@ -3365,17 +3365,17 @@ tor_get_exit_code(const process_handle_t process_handle,
if (retval != WAIT_OBJECT_0) {
log_warn(LD_GENERAL, "WaitForSingleObject() failed (%d): %s",
(int)retval, format_win32_error(GetLastError()));
- return -1;
+ return PROCESS_EXIT_ERROR;
}
} else {
retval = WaitForSingleObject(process_handle.pid.hProcess, 0);
if (WAIT_TIMEOUT == retval) {
/* Process has not exited */
- return -2;
+ return PROCESS_EXIT_RUNNING;
} else if (retval != WAIT_OBJECT_0) {
log_warn(LD_GENERAL, "WaitForSingleObject() failed (%d): %s",
(int)retval, format_win32_error(GetLastError()));
- return -1;
+ return PROCESS_EXIT_ERROR;
}
}
@@ -3385,7 +3385,7 @@ tor_get_exit_code(const process_handle_t process_handle,
if (!success) {
log_warn(LD_GENERAL, "GetExitCodeProcess() failed: %s",
format_win32_error(GetLastError()));
- return -1;
+ return PROCESS_EXIT_ERROR;
}
}
#else
@@ -3395,24 +3395,24 @@ tor_get_exit_code(const process_handle_t process_handle,
retval = waitpid(process_handle.pid, &stat_loc, block?0:WNOHANG);
if (!block && 0 == retval) {
/* Process has not exited */
- return -2;
+ return PROCESS_EXIT_RUNNING;
} else if (retval != process_handle.pid) {
log_warn(LD_GENERAL, "waitpid() failed for PID %d: %s", process_handle.pid,
strerror(errno));
- return -1;
+ return PROCESS_EXIT_ERROR;
}
if (!WIFEXITED(stat_loc)) {
log_warn(LD_GENERAL, "Process %d did not exit normally",
process_handle.pid);
- return -1;
+ return PROCESS_EXIT_ERROR;
}
if (exit_code != NULL)
*exit_code = WEXITSTATUS(stat_loc);
#endif // MS_WINDOWS
- return 0;
+ return PROCESS_EXIT_EXITED;
}
#ifdef MS_WINDOWS
@@ -3648,11 +3648,7 @@ tor_check_port_forwarding(const char *filename, int dir_port, int or_port,
/* Static variables are initialized to zero, so child_handle.status=0
* which corresponds to it not running on startup */
-#ifdef MS_WINDOWS
static process_handle_t child_handle;
-#else
- static process_handle_t child_handle;
-#endif
static time_t time_to_run_helper = 0;
int stdout_status, stderr_status, retval;
@@ -3678,7 +3674,8 @@ tor_check_port_forwarding(const char *filename, int dir_port, int or_port,
argv[9] = NULL;
/* Start the child, if it is not already running */
- if (child_handle.status <= 0 && time_to_run_helper < now) {
+ if (child_handle.status != PROCESS_STATUS_RUNNING &&
+ time_to_run_helper < now) {
/* Assume tor-fw-helper will succeed, start it later*/
time_to_run_helper = now + TIME_TO_EXEC_FWHELPER_SUCCESS;
@@ -3688,7 +3685,7 @@ tor_check_port_forwarding(const char *filename, int dir_port, int or_port,
#else
tor_spawn_background(filename, argv, &child_handle);
#endif
- if (child_handle.status < 0) {
+ if (PROCESS_STATUS_ERROR == child_handle.status) {
log_warn(LD_GENERAL, "Failed to start port forwarding helper %s",
filename);
time_to_run_helper = now + TIME_TO_EXEC_FWHELPER_FAIL;
@@ -3705,7 +3702,7 @@ tor_check_port_forwarding(const char *filename, int dir_port, int or_port,
}
/* If child is running, read from its stdout and stderr) */
- if (child_handle.status > 0) {
+ if (PROCESS_STATUS_RUNNING == child_handle.status) {
/* Read from stdout/stderr and log result */
retval = 0;
#ifdef MS_WINDOWS
@@ -3729,8 +3726,9 @@ tor_check_port_forwarding(const char *filename, int dir_port, int or_port,
/* There was a failure */
retval = -1;
#ifdef MS_WINDOWS
- else if (tor_get_exit_code(child_handle, 0, NULL) >= 0) {
- /* process has exited */
+ else if (tor_get_exit_code(child_handle, 0, NULL) !=
+ PROCESS_EXIT_RUNNING) {
+ /* process has exited or there was an error */
/* TODO: Do something with the process return value */
/* TODO: What if the process output something since
* between log_from_handle and tor_get_exit_code? */
@@ -3751,10 +3749,10 @@ tor_check_port_forwarding(const char *filename, int dir_port, int or_port,
if (0 != retval) {
if (1 == retval) {
log_info(LD_GENERAL, "Port forwarding helper terminated");
- child_handle.status = 0;
+ child_handle.status = PROCESS_STATUS_NOTRUNNING;
} else {
log_warn(LD_GENERAL, "Failed to read from port forwarding helper");
- child_handle.status = -1;
+ child_handle.status = PROCESS_STATUS_ERROR;
}
/* TODO: The child might not actually be finished (maybe it failed or
diff --git a/src/common/util.h b/src/common/util.h
index e025265..d8c7370 100644
--- a/src/common/util.h
+++ b/src/common/util.h
@@ -355,8 +355,14 @@ HANDLE load_windows_system_library(const TCHAR *library_name);
#ifdef UTIL_PRIVATE
/* Prototypes for private functions only used by util.c (and unit tests) */
+/* Values of process_handle_t.status. PROCESS_STATUS_NOTRUNNING must be
+ * 0 because tor_check_port_forwarding depends on this being the initial
+ * statue of the static instance of process_handle_t */
+#define PROCESS_STATUS_NOTRUNNING 0
+#define PROCESS_STATUS_RUNNING 1
+#define PROCESS_STATUS_ERROR -1
typedef struct process_handle_s {
- int status; // 0: not running; 1: running; -1: error
+ int status;
#ifdef MS_WINDOWS
HANDLE stdout_pipe;
HANDLE stderr_pipe;
@@ -372,6 +378,11 @@ typedef struct process_handle_s {
int tor_spawn_background(const char *const filename, const char **argv,
process_handle_t *process_handle);
+
+/* Return values of tor_get_exit_code() */
+#define PROCESS_EXIT_RUNNING 1
+#define PROCESS_EXIT_EXITED 0
+#define PROCESS_EXIT_ERROR -1
int tor_get_exit_code(const process_handle_t process_handle,
int block, int *exit_code);
#ifdef MS_WINDOWS
diff --git a/src/test/test_util.c b/src/test/test_util.c
index 40ab098..4568fde 100644
--- a/src/test/test_util.c
+++ b/src/test/test_util.c
@@ -1397,7 +1397,7 @@ run_util_spawn_background(const char *argv[], const char *expected_out,
tt_int_op(process_handle.status, ==, expected_status);
/* If the process failed to start, don't bother continuing */
- if (process_handle.status == -1)
+ if (process_handle.status == PROCESS_STATUS_ERROR)
return;
tt_int_op(process_handle.stdout_pipe, >, 0);
@@ -1413,7 +1413,7 @@ run_util_spawn_background(const char *argv[], const char *expected_out,
/* Check it terminated correctly */
retval = tor_get_exit_code(process_handle, 1, &exit_code);
- tt_int_op(retval, ==, 0);
+ tt_int_op(retval, ==, PROCESS_EXIT_EXITED);
tt_int_op(exit_code, ==, expected_exit);
// TODO: Make test-child exit with something other than 0
@@ -1445,7 +1445,8 @@ test_util_spawn_background_ok(void *ptr)
(void)ptr;
- run_util_spawn_background(argv, expected_out, expected_err, 0, 1);
+ run_util_spawn_background(argv, expected_out, expected_err, 0,
+ PROCESS_STATUS_RUNNING);
}
/** Check that failing to find the executable works as expected */
@@ -1457,14 +1458,15 @@ test_util_spawn_background_fail(void *ptr)
const char *expected_out = "ERR: Failed to spawn background process "
"- code 9/2\n";
const char *expected_err = "";
- const int expected_status = -1;
+ const int expected_status = PROCESS_STATUS_ERROR;
#else
const char *argv[] = {BUILDDIR "/src/test/no-such-file", "--test", NULL};
const char *expected_out = "ERR: Failed to spawn background process "
"- code 9/2\n";
const char *expected_err = "";
- // TODO: Once we can signal failure to exec, set this to be -1;
- const int expected_status = 1;
+ /* TODO: Once we can signal failure to exec, set this to be
+ * PROCESS_STATUS_ERROR */
+ const int expected_status = PROCESS_STATUS_RUNNING;
#endif
(void)ptr;
@@ -1479,7 +1481,7 @@ static void
test_util_spawn_background_partial_read(void *ptr)
{
const int expected_exit = 0;
- const int expected_status = 1;
+ const int expected_status = PROCESS_STATUS_RUNNING;
int retval, exit_code;
ssize_t pos;
@@ -1536,7 +1538,7 @@ test_util_spawn_background_partial_read(void *ptr)
/* Check it terminated correctly */
retval = tor_get_exit_code(process_handle, 1, &exit_code);
- tt_int_op(retval, ==, 0);
+ tt_int_op(retval, ==, PROCESS_EXIT_EXITED);
tt_int_op(exit_code, ==, expected_exit);
// TODO: Make test-child exit with something other than 0