[Tarantool-patches] [PATCH 01/13] popen: require popen handle to be non-NULL
Alexander Turenko
alexander.turenko at tarantool.org
Fri Apr 10 05:50:39 MSK 2020
Further commits will add proper entries into the diagnostics area for
failures inside popen functions. We should either report handle == NULL
case via the diagnostics area or ensure that the NULL handle case is not
possible.
The latter approach is implemented in this commit. There are two
reasons for this:
* This way simplifies function contracts (one less kind of failure).
* The popen Lua module (that will be implemented in the further commits)
will not construct any logic using NULL as a handle. When 'NULL
handle' error is not possible in the C API, it will be easier to
verify that this failure is not possible the Lua API.
A user of the C API should take care to don't call those functions with
NULL handle.
Part of #4031
---
src/lib/core/popen.c | 33 +++++++++++++--------------------
1 file changed, 13 insertions(+), 20 deletions(-)
diff --git a/src/lib/core/popen.c b/src/lib/core/popen.c
index 6b6062215..5f74bc3ce 100644
--- a/src/lib/core/popen.c
+++ b/src/lib/core/popen.c
@@ -163,13 +163,13 @@ popen_may_io(struct popen_handle *handle, unsigned int idx,
}
/**
- * Test if the handle is not nil and still have
- * a living child process.
+ * Test if the handle still have a living child process.
*/
static inline bool
popen_may_pidop(struct popen_handle *handle)
{
- if (!handle || handle->pid == -1) {
+ assert(handle != NULL);
+ if (handle->pid == -1) {
errno = ESRCH;
return false;
}
@@ -182,10 +182,7 @@ popen_may_pidop(struct popen_handle *handle)
int
popen_stat(struct popen_handle *handle, struct popen_stat *st)
{
- if (!handle) {
- errno = ESRCH;
- return -1;
- }
+ assert(handle != NULL);
st->pid = handle->pid;
st->flags = handle->flags;
@@ -204,11 +201,7 @@ popen_stat(struct popen_handle *handle, struct popen_stat *st)
const char *
popen_command(struct popen_handle *handle)
{
- if (!handle) {
- errno = ESRCH;
- return NULL;
- }
-
+ assert(handle != NULL);
return (const char *)handle->command;
}
@@ -236,6 +229,8 @@ popen_write_timeout(struct popen_handle *handle, void *buf,
size_t count, unsigned int flags,
ev_tstamp timeout)
{
+ assert(handle != NULL);
+
int idx = STDIN_FILENO;
if (!(flags & POPEN_FLAG_FD_STDIN)) {
@@ -268,6 +263,8 @@ popen_read_timeout(struct popen_handle *handle, void *buf,
size_t count, unsigned int flags,
ev_tstamp timeout)
{
+ assert(handle != NULL);
+
int idx = flags & POPEN_FLAG_FD_STDOUT ?
STDOUT_FILENO : STDERR_FILENO;
@@ -380,10 +377,7 @@ popen_sigchld_handler(EV_P_ ev_child *w, int revents)
int
popen_state(struct popen_handle *handle, int *state, int *exit_code)
{
- if (!handle) {
- errno = ESRCH;
- return -1;
- }
+ assert(handle != NULL);
if (handle->pid != -1) {
*state = POPEN_STATE_ALIVE;
@@ -437,6 +431,8 @@ popen_send_signal(struct popen_handle *handle, int signo)
{
int ret;
+ assert(handle != NULL);
+
/*
* A child may be killed or exited already.
*/
@@ -464,10 +460,7 @@ popen_delete(struct popen_handle *handle)
{
size_t i;
- if (!handle) {
- errno = ESRCH;
- return -1;
- }
+ assert(handle != NULL);
if (popen_send_signal(handle, SIGKILL) && errno != ESRCH)
return -1;
--
2.25.0
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