Asynchronous process reaping (#1412)

* refactor(process): introduce process_stream_handle separate from process_handle

* feat(process): introduce process_handle helper functions

* feat(process): add asynchronous process reaping

* feat(process): wait for shorter period if possible

* style(process): remove unecessary brackets

* style(process): fix parentheses

* refactor(process): remove useless setvbuf call

* style(process): remove unecessary value

* refactor(process): add size field into kill_list

* refactor(process): use SDL_Delay for sleeping

* style(process): remove trailing whitespace

* fix(main): destroy window before closing lua

* fix(process): check for timeout correctly

* refactor(process): remove unecessary if check

* refactor(process): remove size from the list

* fix(process): fix invalid delay calculation

Co-authored-by: Guldoman <giulio.lettieri@gmail.com>

---------

Co-authored-by: Guldoman <giulio.lettieri@gmail.com>
This commit is contained in:
Takase 2023-03-22 20:36:05 +08:00 committed by takase1121
parent 89864ee88c
commit 84c7bb9de6
No known key found for this signature in database
GPG Key ID: 60EEFFC68EB3031B
2 changed files with 262 additions and 54 deletions

View File

@ -5,6 +5,7 @@
#include <stdint.h> #include <stdint.h>
#include <stdlib.h> #include <stdlib.h>
#include <SDL.h> #include <SDL.h>
#include <SDL_thread.h>
#include <assert.h> #include <assert.h>
#if _WIN32 #if _WIN32
@ -21,11 +22,15 @@
#endif #endif
#define READ_BUF_SIZE 2048 #define READ_BUF_SIZE 2048
#define PROCESS_TERM_TRIES 3
#define PROCESS_TERM_DELAY 50
#if _WIN32 #if _WIN32
typedef HANDLE process_stream_handle;
typedef HANDLE process_handle; typedef HANDLE process_handle;
#else #else
typedef int process_handle; typedef int process_stream_handle;
typedef pid_t process_handle;
#endif #endif
typedef struct { typedef struct {
@ -38,9 +43,24 @@ typedef struct {
bool reading[2]; bool reading[2];
char buffer[2][READ_BUF_SIZE]; char buffer[2][READ_BUF_SIZE];
#endif #endif
process_handle child_pipes[3][2]; process_stream_handle child_pipes[3][2];
} process_t; } process_t;
typedef struct process_kill_s {
int tries;
uint32_t start_time;
process_handle handle;
struct process_kill_s *next;
} process_kill_t;
typedef struct {
bool stop;
SDL_mutex *mutex;
SDL_cond *has_work, *work_done;
process_kill_t *head;
process_kill_t *tail;
} process_kill_list_t;
typedef enum { typedef enum {
SIGNAL_KILL, SIGNAL_KILL,
SIGNAL_TERM, SIGNAL_TERM,
@ -63,60 +83,201 @@ typedef enum {
REDIRECT_PARENT = -3, REDIRECT_PARENT = -3,
} filed_e; } filed_e;
static process_kill_list_t kill_list = { 0 };
static SDL_Thread *kill_list_thread = NULL;
#ifdef _WIN32 #ifdef _WIN32
static volatile long PipeSerialNumber; static volatile long PipeSerialNumber;
static void close_fd(HANDLE* handle) { if (*handle) CloseHandle(*handle); *handle = INVALID_HANDLE_VALUE; } static void close_fd(HANDLE* handle) { if (*handle) CloseHandle(*handle); *handle = INVALID_HANDLE_VALUE; }
#define PROCESS_GET_HANDLE(P) ((P)->process_information.hProcess)
#else #else
static void close_fd(int* fd) { if (*fd) close(*fd); *fd = 0; } static void close_fd(int* fd) { if (*fd) close(*fd); *fd = 0; }
#define PROCESS_GET_HANDLE(P) ((P)->pid)
#endif #endif
static void kill_list_free(process_kill_list_t *list) {
process_kill_t *node, *temp;
SDL_DestroyMutex(list->mutex);
SDL_DestroyCond(list->has_work);
SDL_DestroyCond(list->work_done);
node = list->head;
while (node) {
temp = node;
node = node->next;
free(temp);
}
}
static bool kill_list_init(process_kill_list_t *list) {
list->mutex = SDL_CreateMutex();
list->has_work = SDL_CreateCond();
list->work_done = SDL_CreateCond();
list->head = list->tail = NULL;
list->stop = false;
if (!list->mutex || !list->has_work || !list->work_done) {
kill_list_free(list);
return false;
}
return true;
}
static void kill_list_push(process_kill_list_t *list, process_kill_t *task) {
if (!list) return;
task->next = NULL;
if (list->tail) {
list->tail->next = task;
list->tail = task;
} else {
list->head = list->tail = task;
}
}
static void kill_list_pop(process_kill_list_t *list) {
if (!list || !list->head) return;
process_kill_t *head = list->head;
list->head = list->head->next;
if (!list->head) list->tail = NULL;
head->next = NULL;
}
static void kill_list_wait_all(process_kill_list_t *list) {
SDL_LockMutex(list->mutex);
// wait until list is empty
while (list->head)
SDL_CondWait(list->work_done, list->mutex);
// tell the worker to stop
list->stop = true;
SDL_CondSignal(list->has_work);
SDL_UnlockMutex(list->mutex);
}
static void process_handle_close(process_handle *handle) {
#ifdef _WIN32
if (*handle) {
CloseHandle(*handle);
*handle = NULL;
}
#endif
(void) 0;
}
static bool process_handle_is_running(process_handle handle, int *status) {
#ifdef _WIN32
DWORD s;
if (GetExitCodeProcess(handle, &s) && s != STILL_ACTIVE) {
if (status != NULL)
*status = s;
return false;
}
#else
int s;
if (waitpid(handle, &s, WNOHANG) != 0) {
if (status != NULL)
*status = WEXITSTATUS(s);
return false;
}
#endif
return true;
}
static bool process_handle_signal(process_handle handle, signal_e sig) {
#if _WIN32
switch(sig) {
case SIGNAL_TERM: return GenerateConsoleCtrlEvent(CTRL_BREAK_EVENT, GetProcessId(handle));
case SIGNAL_KILL: return TerminateProcess(handle, -1);
case SIGNAL_INTERRUPT: return DebugBreakProcess(handle);
}
#else
switch (sig) {
case SIGNAL_TERM: return kill(-handle, SIGTERM) == 0; break;
case SIGNAL_KILL: return kill(-handle, SIGKILL) == 0; break;
case SIGNAL_INTERRUPT: return kill(-handle, SIGINT) == 0; break;
}
#endif
return false;
}
static int kill_list_worker(void *ud) {
process_kill_list_t *list = (process_kill_list_t *) ud;
process_kill_t *current_task;
uint32_t delay;
while (true) {
SDL_LockMutex(list->mutex);
// wait until we have work to do
while (!list->head && !list->stop)
SDL_CondWait(list->has_work, list->mutex); // LOCK MUTEX
if (list->stop) break;
while ((current_task = list->head)) {
if ((SDL_GetTicks() - current_task->start_time) < PROCESS_TERM_DELAY)
break;
kill_list_pop(list);
if (process_handle_is_running(current_task->handle, NULL)) {
if (current_task->tries < PROCESS_TERM_TRIES)
process_handle_signal(current_task->handle, SIGNAL_TERM);
else if (current_task->tries == PROCESS_TERM_TRIES)
process_handle_signal(current_task->handle, SIGNAL_KILL);
else
goto free_task;
// add the task back into the queue
current_task->tries++;
current_task->start_time = SDL_GetTicks();
kill_list_push(list, current_task);
} else {
free_task:
SDL_CondSignal(list->work_done);
process_handle_close(&current_task->handle);
free(current_task);
}
}
delay = list->head ? (list->head->start_time + PROCESS_TERM_DELAY) - SDL_GetTicks() : 0;
SDL_UnlockMutex(list->mutex);
SDL_Delay(delay);
}
SDL_UnlockMutex(list->mutex);
return 0;
}
static bool poll_process(process_t* proc, int timeout) { static bool poll_process(process_t* proc, int timeout) {
uint32_t ticks;
if (!proc->running) if (!proc->running)
return false; return false;
uint32_t ticks = SDL_GetTicks();
if (timeout == WAIT_DEADLINE) if (timeout == WAIT_DEADLINE)
timeout = proc->deadline; timeout = proc->deadline;
ticks = SDL_GetTicks();
do { do {
#ifdef _WIN32 int status;
DWORD exit_code = -1; if (!process_handle_is_running(PROCESS_GET_HANDLE(proc), &status)) {
if (!GetExitCodeProcess( proc->process_information.hProcess, &exit_code ) || exit_code != STILL_ACTIVE) { proc->running = false;
proc->returncode = exit_code; proc->returncode = status;
proc->running = false; break;
break; }
}
#else
int status;
pid_t wait_response = waitpid(proc->pid, &status, WNOHANG);
if (wait_response != 0) {
proc->running = false;
proc->returncode = WEXITSTATUS(status);
break;
}
#endif
if (timeout) if (timeout)
SDL_Delay(5); SDL_Delay(timeout >= 5 ? 5 : 0);
} while (timeout == WAIT_INFINITE || (int)SDL_GetTicks() - ticks < timeout); } while (timeout == WAIT_INFINITE || (int)SDL_GetTicks() - ticks < timeout);
return proc->running; return proc->running;
} }
static bool signal_process(process_t* proc, signal_e sig) { static bool signal_process(process_t* proc, signal_e sig) {
bool terminate = false; if (process_handle_signal(PROCESS_GET_HANDLE(proc), sig))
#if _WIN32
switch(sig) {
case SIGNAL_TERM: terminate = GenerateConsoleCtrlEvent(CTRL_BREAK_EVENT, GetProcessId(proc->process_information.hProcess)); break;
case SIGNAL_KILL: terminate = TerminateProcess(proc->process_information.hProcess, -1); break;
case SIGNAL_INTERRUPT: DebugBreakProcess(proc->process_information.hProcess); break;
}
#else
switch (sig) {
case SIGNAL_TERM: terminate = kill(-proc->pid, SIGTERM) == 1; break;
case SIGNAL_KILL: terminate = kill(-proc->pid, SIGKILL) == 1; break;
case SIGNAL_INTERRUPT: kill(-proc->pid, SIGINT); break;
}
#endif
if (terminate)
poll_process(proc, WAIT_NONE); poll_process(proc, WAIT_NONE);
return true; return true;
} }
@ -372,7 +533,7 @@ static int process_start(lua_State* L) {
free((char*)env_values[i]); free((char*)env_values[i]);
} }
for (int stream = 0; stream < 3; ++stream) { for (int stream = 0; stream < 3; ++stream) {
process_handle* pipe = &self->child_pipes[stream][stream == STDIN_FD ? 0 : 1]; process_stream_handle* pipe = &self->child_pipes[stream][stream == STDIN_FD ? 0 : 1];
if (*pipe) { if (*pipe) {
close_fd(pipe); close_fd(pipe);
} }
@ -525,14 +686,37 @@ static int self_signal(lua_State* L, signal_e sig) {
static int f_terminate(lua_State* L) { return self_signal(L, SIGNAL_TERM); } static int f_terminate(lua_State* L) { return self_signal(L, SIGNAL_TERM); }
static int f_kill(lua_State* L) { return self_signal(L, SIGNAL_KILL); } static int f_kill(lua_State* L) { return self_signal(L, SIGNAL_KILL); }
static int f_interrupt(lua_State* L) { return self_signal(L, SIGNAL_INTERRUPT); } static int f_interrupt(lua_State* L) { return self_signal(L, SIGNAL_INTERRUPT); }
static int f_gc(lua_State* L) { static int f_gc(lua_State* L) {
process_t* self = (process_t*) luaL_checkudata(L, 1, API_TYPE_PROCESS); process_t* self = (process_t*) luaL_checkudata(L, 1, API_TYPE_PROCESS);
if (!self->detached)
if (poll_process(self, 0) && !self->detached) {
// attempt to kill the process if not detached
process_kill_t *p;
signal_process(self, SIGNAL_TERM); signal_process(self, SIGNAL_TERM);
p = malloc(sizeof(process_kill_t));
if (!p || !kill_list_thread) {
// if we can't allocate, we'll use the old method
poll_process(self, PROCESS_TERM_DELAY);
if (self->running) {
signal_process(self, SIGNAL_KILL);
poll_process(self, PROCESS_TERM_DELAY);
}
} else {
// send the handle to a queue for asynchronous waiting
p->handle = PROCESS_GET_HANDLE(self);
p->start_time = SDL_GetTicks();
p->tries = 1;
SDL_LockMutex(kill_list.mutex);
kill_list_push(&kill_list, p);
SDL_CondSignal(kill_list.has_work);
SDL_UnlockMutex(kill_list.mutex);
}
}
close_fd(&self->child_pipes[STDIN_FD ][1]); close_fd(&self->child_pipes[STDIN_FD ][1]);
close_fd(&self->child_pipes[STDOUT_FD][0]); close_fd(&self->child_pipes[STDOUT_FD][0]);
close_fd(&self->child_pipes[STDERR_FD][0]); close_fd(&self->child_pipes[STDERR_FD][0]);
poll_process(self, 10);
return 0; return 0;
} }
@ -542,11 +726,16 @@ static int f_running(lua_State* L) {
return 1; return 1;
} }
static const struct luaL_Reg lib[] = { static int process_gc(lua_State *L) {
kill_list_wait_all(&kill_list);
SDL_WaitThread(kill_list_thread, NULL);
kill_list_free(&kill_list);
return 0;
}
static const struct luaL_Reg process_metatable[] = {
{"__gc", f_gc}, {"__gc", f_gc},
{"__tostring", f_tostring}, {"__tostring", f_tostring},
{"start", process_start},
{"strerror", process_strerror},
{"pid", f_pid}, {"pid", f_pid},
{"returncode", f_returncode}, {"returncode", f_returncode},
{"read", f_read}, {"read", f_read},
@ -562,12 +751,29 @@ static const struct luaL_Reg lib[] = {
{NULL, NULL} {NULL, NULL}
}; };
static const struct luaL_Reg lib[] = {
{ "start", process_start },
{ "strerror", process_strerror },
{ NULL, NULL }
};
int luaopen_process(lua_State *L) { int luaopen_process(lua_State *L) {
if (kill_list_init(&kill_list))
kill_list_thread = SDL_CreateThread(kill_list_worker, "process_kill", &kill_list);
// create the process metatable
luaL_newmetatable(L, API_TYPE_PROCESS); luaL_newmetatable(L, API_TYPE_PROCESS);
luaL_setfuncs(L, lib, 0); luaL_setfuncs(L, process_metatable, 0);
lua_pushvalue(L, -1); lua_pushvalue(L, -1);
lua_setfield(L, -2, "__index"); lua_setfield(L, -2, "__index");
// create the process library
luaL_newlib(L, lib);
lua_newtable(L);
lua_pushcfunction(L, process_gc);
lua_setfield(L, -2, "__gc");
lua_setmetatable(L, -2);
API_CONSTANT_DEFINE(L, -1, "WAIT_INFINITE", WAIT_INFINITE); API_CONSTANT_DEFINE(L, -1, "WAIT_INFINITE", WAIT_INFINITE);
API_CONSTANT_DEFINE(L, -1, "WAIT_DEADLINE", WAIT_DEADLINE); API_CONSTANT_DEFINE(L, -1, "WAIT_DEADLINE", WAIT_DEADLINE);

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@ -255,8 +255,10 @@ init_lua:
goto init_lua; goto init_lua;
} }
lua_close(L); // This allows the window to be destroyed before lite-xl is done with
// reaping child processes
ren_free_window_resources(&window_renderer); ren_free_window_resources(&window_renderer);
lua_close(L);
return EXIT_SUCCESS; return EXIT_SUCCESS;
} }