lua: subprocess: move to osdep/subprocess-{win,posix}.c

The subprocess code was already split into fairly general functions,
separate from the Lua code. It's getting pretty big though, especially
the Windows-specific parts, so move it into its own files.

1 files changed, 3 insertions, 478 deletions

diff --git a/player/lua.c b/player/lua.c
index ba60826778..cdcd2a2443 100644
--- a/player/lua.c
+++ b/player/lua.c
@@ -15,11 +15,6 @@
  * with mpv.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#ifdef __MINGW32__
-#define _WIN32_WINNT 0x0600
-#include <windows.h>
-#endif
-
 #include <assert.h>
 #include <string.h>
 #include <strings.h>
@@ -47,6 +42,7 @@
 #include "options/path.h"
 #include "misc/bstr.h"
 #include "misc/json.h"
+#include "osdep/subprocess.h"
 #include "osdep/timer.h"
 #include "osdep/threads.h"
 #include "stream/stream.h"
@@ -1177,477 +1173,6 @@ static int script_join_path(lua_State *L)
     return 1;
 }
 
-typedef void (*read_cb)(void *ctx, char *data, size_t size);
-
-#ifdef __MINGW32__
-static void write_arg(bstr *cmdline, char *arg)
-{
-    // If the string doesn't have characters that need to be escaped, it's best
-    // to leave it alone for the sake of Windows programs that don't process
-    // quoted args correctly.
-    if (!strpbrk(arg, " \t\"")) {
-        bstr_xappend(NULL, cmdline, bstr0(arg));
-        return;
-    }
-
-    // If there are characters that need to be escaped, write a quoted string
-    bstr_xappend(NULL, cmdline, bstr0("\""));
-
-    // Escape the argument. To match the behavior of CommandLineToArgvW,
-    // backslashes are only escaped if they appear before a quote or the end of
-    // the string.
-    int num_slashes = 0;
-    for (int pos = 0; arg[pos]; pos++) {
-        switch (arg[pos]) {
-        case '\\':
-            // Count backslashes that appear in a row
-            num_slashes++;
-            break;
-        case '"':
-            bstr_xappend(NULL, cmdline, (struct bstr){arg, pos});
-
-            // Double preceding slashes
-            for (int i = 0; i < num_slashes; i++)
-                bstr_xappend(NULL, cmdline, bstr0("\\"));
-
-            // Escape the following quote
-            bstr_xappend(NULL, cmdline, bstr0("\\"));
-
-            arg += pos;
-            pos = 0;
-            num_slashes = 0;
-            break;
-        default:
-            num_slashes = 0;
-        }
-    }
-
-    // Write the rest of the argument
-    bstr_xappend(NULL, cmdline, bstr0(arg));
-
-    // Double slashes that appear at the end of the string
-    for (int i = 0; i < num_slashes; i++)
-        bstr_xappend(NULL, cmdline, bstr0("\\"));
-
-    bstr_xappend(NULL, cmdline, bstr0("\""));
-}
-
-// Convert an array of arguments to a properly escaped command-line string
-static wchar_t *write_cmdline(void *ctx, char **argv)
-{
-    bstr cmdline = {0};
-
-    for (int i = 0; argv[i]; i++) {
-        write_arg(&cmdline, argv[i]);
-        if (argv[i + 1])
-            bstr_xappend(NULL, &cmdline, bstr0(" "));
-    }
-
-    wchar_t *wcmdline = mp_from_utf8(ctx, cmdline.start);
-    talloc_free(cmdline.start);
-    return wcmdline;
-}
-
-static int create_overlapped_pipe(HANDLE *read, HANDLE *write)
-{
-    static atomic_ulong counter = ATOMIC_VAR_INIT(0);
-
-    // Generate pipe name
-    unsigned long id = atomic_fetch_add(&counter, 1);
-    unsigned pid = GetCurrentProcessId();
-    wchar_t buf[36];
-    swprintf(buf, sizeof(buf), L"\\\\?\\pipe\\mpv-anon-%08x-%08lx", pid, id);
-
-    // The function for creating anonymous pipes (CreatePipe) can't create
-    // overlapped pipes, so instead, use a named pipe with a unique name
-    *read = CreateNamedPipeW(buf, PIPE_ACCESS_INBOUND |
-        FILE_FLAG_FIRST_PIPE_INSTANCE | FILE_FLAG_OVERLAPPED,
-        PIPE_TYPE_BYTE | PIPE_WAIT | PIPE_REJECT_REMOTE_CLIENTS,
-        1, 0, 4096, 0, NULL);
-    if (!*read)
-        goto error;
-
-    // Open the write end of the pipe as a synchronous handle
-    *write = CreateFileW(buf, GENERIC_WRITE, 0, NULL, OPEN_EXISTING,
-        FILE_ATTRIBUTE_NORMAL, NULL);
-    if (*write == INVALID_HANDLE_VALUE)
-        goto error;
-
-    return 0;
-error:
-    *read = *write = INVALID_HANDLE_VALUE;
-    return -1;
-}
-
-static void delete_handle_list(void *p)
-{
-    LPPROC_THREAD_ATTRIBUTE_LIST list = p;
-    VOID (WINAPI *pDeleteProcThreadAttributeList)(LPPROC_THREAD_ATTRIBUTE_LIST);
-
-    HMODULE kernel32 = GetModuleHandleW(L"kernel32.dll");
-    pDeleteProcThreadAttributeList =
-        (VOID (WINAPI*)(LPPROC_THREAD_ATTRIBUTE_LIST))
-        GetProcAddress(kernel32, "DeleteProcThreadAttributeList");
-
-    if (pDeleteProcThreadAttributeList)
-        pDeleteProcThreadAttributeList(list);
-}
-
-// Create a PROC_THREAD_ATTRIBUTE_LIST that specifies exactly which handles are
-// inherited by the subprocess
-static LPPROC_THREAD_ATTRIBUTE_LIST create_handle_list(void *ctx,
-                                                       HANDLE *handles, int num)
-{
-    WINBOOL (WINAPI *pInitializeProcThreadAttributeList)(
-            LPPROC_THREAD_ATTRIBUTE_LIST, DWORD, DWORD, PSIZE_T);
-    WINBOOL (WINAPI *pUpdateProcThreadAttribute)(LPPROC_THREAD_ATTRIBUTE_LIST,
-            DWORD, DWORD_PTR, PVOID, SIZE_T, PVOID, PSIZE_T);
-
-    // Load Windows Vista functions, if available
-    HMODULE kernel32 = GetModuleHandleW(L"kernel32.dll");
-    pInitializeProcThreadAttributeList =
-        (WINBOOL (WINAPI*)(LPPROC_THREAD_ATTRIBUTE_LIST, DWORD, DWORD, PSIZE_T))
-        GetProcAddress(kernel32, "InitializeProcThreadAttributeList");
-    pUpdateProcThreadAttribute =
-        (WINBOOL (WINAPI*)(LPPROC_THREAD_ATTRIBUTE_LIST, DWORD, DWORD_PTR,
-                           PVOID, SIZE_T, PVOID, PSIZE_T))
-        GetProcAddress(kernel32, "UpdateProcThreadAttribute");
-    if (!pInitializeProcThreadAttributeList || !pUpdateProcThreadAttribute)
-        return NULL;
-
-    // Get required attribute list size
-    SIZE_T size = 0;
-    if (!pInitializeProcThreadAttributeList(NULL, 1, 0, &size)) {
-        if (GetLastError() != ERROR_INSUFFICIENT_BUFFER)
-            return NULL;
-    }
-
-    // Allocate attribute list
-    LPPROC_THREAD_ATTRIBUTE_LIST list = talloc_size(ctx, size);
-    if (!pInitializeProcThreadAttributeList(list, 1, 0, &size))
-        goto error;
-    talloc_set_destructor(list, delete_handle_list);
-
-    if (!pUpdateProcThreadAttribute(list, 0, PROC_THREAD_ATTRIBUTE_HANDLE_LIST,
-                                    handles, num * sizeof(HANDLE), NULL, NULL))
-        goto error;
-
-    return list;
-error:
-    talloc_free(list);
-    return NULL;
-}
-
-// Helper method similar to sparse_poll, skips NULL handles
-static int sparse_wait(HANDLE *handles, unsigned num_handles)
-{
-    unsigned w_num_handles = 0;
-    HANDLE w_handles[num_handles];
-    int map[num_handles];
-
-    for (unsigned i = 0; i < num_handles; i++) {
-        if (!handles[i])
-            continue;
-
-        w_handles[w_num_handles] = handles[i];
-        map[w_num_handles] = i;
-        w_num_handles++;
-    }
-
-    if (w_num_handles == 0)
-        return -1;
-    DWORD i = WaitForMultipleObjects(w_num_handles, w_handles, FALSE, INFINITE);
-    i -= WAIT_OBJECT_0;
-
-    if (i >= w_num_handles)
-        return -1;
-    return map[i];
-}
-
-// Wrapper for ReadFile that treats ERROR_IO_PENDING as success
-static int async_read(HANDLE file, void *buf, unsigned size, OVERLAPPED* ol)
-{
-    if (!ReadFile(file, buf, size, NULL, ol))
-        return (GetLastError() == ERROR_IO_PENDING) ? 0 : -1;
-    return 0;
-}
-
-static int subprocess(char **args, struct mp_cancel *cancel, void *ctx,
-                      read_cb on_stdout, read_cb on_stderr, char **error)
-{
-    wchar_t *tmp = talloc_new(NULL);
-    int status = -1;
-    struct {
-        HANDLE read;
-        HANDLE write;
-        OVERLAPPED ol;
-        char buf[4096];
-        read_cb read_cb;
-    } pipes[2] = {
-        { .read_cb = on_stdout },
-        { .read_cb = on_stderr },
-    };
-
-    // If the function exits before CreateProcess, there was an init error
-    *error = "init";
-
-    for (int i = 0; i < 2; i++) {
-        pipes[i].ol.hEvent = CreateEventW(NULL, TRUE, FALSE, NULL);
-        if (!pipes[i].ol.hEvent)
-            goto done;
-        if (create_overlapped_pipe(&pipes[i].read, &pipes[i].write))
-            goto done;
-        if (!SetHandleInformation(pipes[i].write, HANDLE_FLAG_INHERIT,
-                                                  HANDLE_FLAG_INHERIT))
-            goto done;
-    }
-
-    // Convert the args array to a UTF-16 Windows command-line string
-    wchar_t *cmdline = write_cmdline(tmp, args);
-
-    DWORD flags = CREATE_UNICODE_ENVIRONMENT;
-    PROCESS_INFORMATION pi = {0};
-    STARTUPINFOEXW si = {
-        .StartupInfo = {
-            .cb = sizeof(si),
-            .dwFlags = STARTF_USESTDHANDLES,
-            .hStdInput = NULL,
-            .hStdOutput = pipes[0].write,
-            .hStdError = pipes[1].write,
-        },
-
-        // Specify which handles are inherited by the subprocess. If this isn't
-        // specified, the subprocess inherits all inheritable handles, which
-        // could include handles created by other threads. See:
-        // http://blogs.msdn.com/b/oldnewthing/archive/2011/12/16/10248328.aspx
-        .lpAttributeList = create_handle_list(tmp,
-                (HANDLE[]){ pipes[0].write, pipes[1].write }, 2),
-    };
-
-    // PROC_THREAD_ATTRIBUTE_LISTs are only supported in Vista and up. If not
-    // supported, create_handle_list will return NULL.
-    if (si.lpAttributeList)
-        flags |= EXTENDED_STARTUPINFO_PRESENT;
-
-    // If we have a console, the subprocess will automatically attach to it so
-    // it can receive Ctrl+C events. If we don't have a console, prevent the
-    // subprocess from creating its own console window by specifying
-    // CREATE_NO_WINDOW. GetConsoleCP() can be used to reliably determine if we
-    // have a console or not (Cygwin uses it too.)
-    if (!GetConsoleCP())
-        flags |= CREATE_NO_WINDOW;
-
-    if (!CreateProcessW(NULL, cmdline, NULL, NULL, TRUE, flags, NULL, NULL,
-                        &si.StartupInfo, &pi))
-        goto done;
-    talloc_free(cmdline);
-    talloc_free(si.lpAttributeList);
-    CloseHandle(pi.hThread);
-
-    // Init is finished
-    *error = NULL;
-
-    // List of handles to watch with sparse_wait
-    HANDLE handles[] = { pipes[0].ol.hEvent, pipes[1].ol.hEvent, pi.hProcess,
-                         cancel ? mp_cancel_get_event(cancel) : NULL };
-
-    for (int i = 0; i < 2; i++) {
-        // Close our copy of the write end of the pipes
-        CloseHandle(pipes[i].write);
-        pipes[i].write = NULL;
-
-        // Do the first read operation on each pipe
-        if (async_read(pipes[i].read, pipes[i].buf, 4096, &pipes[i].ol)) {
-            CloseHandle(pipes[i].read);
-            handles[i] = pipes[i].read = NULL;
-        }
-    }
-
-    DWORD r;
-    DWORD exit_code;
-    while (pipes[0].read || pipes[1].read || pi.hProcess) {
-        int i = sparse_wait(handles, MP_ARRAY_SIZE(handles));
-        switch (i) {
-        case 0:
-        case 1:
-            // Complete the read operation on the pipe
-            if (!GetOverlappedResult(pipes[i].read, &pipes[i].ol, &r, TRUE)) {
-                CloseHandle(pipes[i].read);
-                handles[i] = pipes[i].read = NULL;
-                break;
-            }
-
-            pipes[i].read_cb(ctx, pipes[i].buf, r);
-
-            // Begin the next read operation on the pipe
-            if (async_read(pipes[i].read, pipes[i].buf, 4096, &pipes[i].ol)) {
-                CloseHandle(pipes[i].read);
-                handles[i] = pipes[i].read = NULL;
-            }
-
-            break;
-        case 2:
-            GetExitCodeProcess(pi.hProcess, &exit_code);
-            status = exit_code;
-
-            CloseHandle(pi.hProcess);
-            handles[i] = pi.hProcess = NULL;
-            break;
-        case 3:
-            if (pi.hProcess) {
-                TerminateProcess(pi.hProcess, 1);
-                *error = "killed";
-                goto done;
-            }
-            break;
-        default:
-            goto done;
-        }
-    }
-
-done:
-    for (int i = 0; i < 2; i++) {
-        if (pipes[i].read) {
-            // Cancel any pending I/O (if the process was killed)
-            CancelIo(pipes[i].read);
-            GetOverlappedResult(pipes[i].read, &pipes[i].ol, &r, TRUE);
-            CloseHandle(pipes[i].read);
-        }
-        if (pipes[i].write) CloseHandle(pipes[i].write);
-        if (pipes[i].ol.hEvent) CloseHandle(pipes[i].ol.hEvent);
-    }
-    if (pi.hProcess) CloseHandle(pi.hProcess);
-    talloc_free(tmp);
-    return status;
-}
-#endif
-
-#if HAVE_POSIX_SPAWN
-#include <spawn.h>
-#include <poll.h>
-#include <unistd.h>
-#include <sys/types.h>
-#include <sys/wait.h>
-#include <errno.h>
-#include <signal.h>
-
-// Normally, this must be declared manually, but glibc is retarded.
-#ifndef __GLIBC__
-extern char **environ;
-#endif
-
-// A silly helper: automatically skips entries with negative FDs
-static int sparse_poll(struct pollfd *fds, int num_fds, int timeout)
-{
-    struct pollfd p_fds[10];
-    int map[10];
-    if (num_fds > MP_ARRAY_SIZE(p_fds))
-        return -1;
-    int p_num_fds = 0;
-    for (int n = 0; n < num_fds; n++) {
-        map[n] = -1;
-        if (fds[n].fd < 0)
-            continue;
-        map[n] = p_num_fds;
-        p_fds[p_num_fds++] = fds[n];
-    }
-    int r = poll(p_fds, p_num_fds, timeout);
-    for (int n = 0; n < num_fds; n++)
-        fds[n].revents = (map[n] < 0 && r >= 0) ? 0 : p_fds[map[n]].revents;
-    return r;
-}
-
-static int subprocess(char **args, struct mp_cancel *cancel, void *ctx,
-                      read_cb on_stdout, read_cb on_stderr, char **error)
-{
-    posix_spawn_file_actions_t fa;
-    bool fa_destroy = false;
-    int status = -1;
-    int p_stdout[2] = {-1, -1};
-    int p_stderr[2] = {-1, -1};
-    pid_t pid = -1;
-
-    if (mp_make_cloexec_pipe(p_stdout) < 0)
-        goto done;
-    if (mp_make_cloexec_pipe(p_stderr) < 0)
-        goto done;
-
-    if (posix_spawn_file_actions_init(&fa))
-        goto done;
-    fa_destroy = true;
-    // redirect stdout and stderr
-    if (posix_spawn_file_actions_adddup2(&fa, p_stdout[1], 1))
-        goto done;
-    if (posix_spawn_file_actions_adddup2(&fa, p_stderr[1], 2))
-        goto done;
-
-    if (posix_spawnp(&pid, args[0], &fa, NULL, args, environ)) {
-        pid = -1;
-        goto done;
-    }
-
-    close(p_stdout[1]);
-    p_stdout[1] = -1;
-    close(p_stderr[1]);
-    p_stderr[1] = -1;
-
-    int *read_fds[2] = {&p_stdout[0], &p_stderr[0]};
-    read_cb read_cbs[2] = {on_stdout, on_stderr};
-
-    while (p_stdout[0] >= 0 || p_stderr[0] >= 0) {
-        struct pollfd fds[] = {
-            {.events = POLLIN, .fd = *read_fds[0]},
-            {.events = POLLIN, .fd = *read_fds[1]},
-            {.events = POLLIN, .fd = cancel ? mp_cancel_get_fd(cancel) : -1},
-        };
-        if (sparse_poll(fds, MP_ARRAY_SIZE(fds), -1) < 0 && errno != EINTR)
-            break;
-        for (int n = 0; n < 2; n++) {
-            if (fds[n].revents) {
-                char buf[4096];
-                ssize_t r = read(*read_fds[n], buf, sizeof(buf));
-                if (r < 0 && errno == EINTR)
-                    continue;
-                if (r > 0 && read_cbs[n])
-                    read_cbs[n](ctx, buf, r);
-                if (r <= 0) {
-                    close(*read_fds[n]);
-                    *read_fds[n] = -1;
-                }
-            }
-        }
-        if (fds[2].revents) {
-            kill(pid, SIGKILL);
-            break;
-        }
-    }
-
-    // Note: it can happen that a child process closes the pipe, but does not
-    //       terminate yet. In this case, we would have to run waitpid() in
-    //       a separate thread and use pthread_cancel(), or use other weird
-    //       and laborious tricks. So this isn't handled yet.
-    while (waitpid(pid, &status, 0) < 0 && errno == EINTR) {}
-
-done:
-    if (fa_destroy)
-        posix_spawn_file_actions_destroy(&fa);
-    close(p_stdout[0]);
-    close(p_stdout[1]);
-    close(p_stderr[0]);
-    close(p_stderr[1]);
-
-    if (WIFEXITED(status) && WEXITSTATUS(status) != 127) {
-        *error = NULL;
-        status = WEXITSTATUS(status);
-    } else {
-        *error = WEXITSTATUS(status) == 127 ? "init" : "killed";
-        status = -1;
-    }
-
-    return status;
-}
-#endif
-
 #if HAVE_POSIX_SPAWN || defined(__MINGW32__)
 struct subprocess_cb_ctx {
     struct mp_log *log;
@@ -1711,8 +1236,8 @@ static int script_subprocess(lua_State *L)
     };
 
     char *error = NULL;
-    int status = subprocess(args, cancel, &cb_ctx, subprocess_stdout,
-                            subprocess_stderr, &error);
+    int status = mp_subprocess(args, cancel, &cb_ctx, subprocess_stdout,
+                               subprocess_stderr, &error);
 
     lua_newtable(L); // res
     if (error) {