cspawn revamp, part 1. Prepare for 2.14.0.0.

Signed-off-by: Laurent Bercot <ska@appnovation.com>

1 files changed, 18 insertions, 157 deletions

diff --git a/src/libstddjb/child_spawn3.c b/src/libstddjb/child_spawn3.c
index 6eb7519..932e5ab 100644
--- a/src/libstddjb/child_spawn3.c
+++ b/src/libstddjb/child_spawn3.c
@@ -1,185 +1,48 @@
 /* ISC license. */
 
-/* MT-unsafe */
-
-#include <skalibs/sysdeps.h>
-
 #include <unistd.h>
-#include <errno.h>
 
 #include <skalibs/types.h>
-#include <skalibs/djbunix.h>
-
-#ifdef SKALIBS_HASPOSIXSPAWN
-
-#include <signal.h>
-#include <stdlib.h>
-#include <spawn.h>
-
-#include <skalibs/config.h>
 #include <skalibs/env.h>
+#include <skalibs/djbunix.h>
+#include <skalibs/cspawn.h>
 
 pid_t child_spawn3 (char const *prog, char const *const *argv, char const *const *envp, int *fds)
 {
   pid_t pid ;
-  posix_spawn_file_actions_t actions ;
-  posix_spawnattr_t attr ;
-  sigset_t set ;
-  int e ;
   int p[3][2] ;
-  size_t m = sizeof(SKALIBS_CHILD_SPAWN_FDS_ENVVAR) ;
-  char modifs[sizeof(SKALIBS_CHILD_SPAWN_FDS_ENVVAR) + UINT_FMT] = SKALIBS_CHILD_SPAWN_FDS_ENVVAR "=" ;
-#ifdef SKALIBS_HASPOSIXSPAWNEARLYRETURN
-  int syncpipe[2] ;
-  if (pipecoe(syncpipe) == -1) return 0 ;
-#endif
 
-  if (pipe(p[0]) < 0 || ndelay_on(p[0][0]) < 0 || coe(p[0][0]) < 0) goto err ;
-  if (pipe(p[1]) < 0 || ndelay_on(p[1][1]) < 0 || coe(p[1][1]) < 0) goto errp0 ;
-  if (pipe(p[2]) < 0 || ndelay_on(p[2][0]) < 0 || coe(p[2][0]) < 0) goto errp1 ;
-  m += uint_fmt(modifs + sizeof(SKALIBS_CHILD_SPAWN_FDS_ENVVAR), p[2][1]) ;
-  modifs[m++] = 0 ;
+  if (pipe(p[0]) == -1) return 0 ;
+  if (ndelay_on(p[0][0]) == -1 || coe(p[0][0]) == -1 || pipe(p[1]) == -1) goto errp0 ;
+  if (ndelay_on(p[1][1]) == -1 || coe(p[1][1]) == -1 || pipe(p[2]) == -1) goto errp1 ;
+  if (ndelay_on(p[2][0]) == -1 || coe(p[2][0]) == -1) goto err ;
 
-  e = posix_spawnattr_init(&attr) ;
-  if (e) goto erre ;
-  sigemptyset(&set) ;
-  e = posix_spawnattr_setsigmask(&attr, &set) ;
-  if (e) goto errattr ;
-  e = posix_spawnattr_setflags(&attr, POSIX_SPAWN_SETSIGMASK) ;
-  if (e) goto errattr ;
-  e = posix_spawn_file_actions_init(&actions) ;
-  if (e) goto errattr ;
-  if (p[1][0] != fds[0])
   {
-    e = posix_spawn_file_actions_adddup2(&actions, p[1][0], fds[0]) ;
-    if (e) goto erractions ;
-    e = posix_spawn_file_actions_addclose(&actions, p[1][0]) ;
-    if (e) goto erractions ;
-  }
-  if (p[0][1] != fds[1])
-  {
-    e = posix_spawn_file_actions_adddup2(&actions, p[0][1], fds[1]) ;
-    if (e) goto erractions ;
-    e = posix_spawn_file_actions_addclose(&actions, p[0][1]) ;
-    if (e) goto erractions ;
-  }
-  { 
-    int nopath = !getenv("PATH") ;
+    cspawn_fileaction fa[2] =
+    {
+      [0] = { .type = CSPAWN_FA_MOVE, .x = { .fd2 = { [0] = fds[0], [1] = p[1][0] } } },
+      [1] = { .type = CSPAWN_FA_MOVE, .x = { .fd2 = { [0] = fds[1], [1] = p[0][1] } } }
+    } ;
     size_t envlen = env_len(envp) ;
+    size_t m = sizeof(SKALIBS_CHILD_SPAWN_FDS_ENVVAR) ;
+    char modifs[sizeof(SKALIBS_CHILD_SPAWN_FDS_ENVVAR) + UINT_FMT] = SKALIBS_CHILD_SPAWN_FDS_ENVVAR "=" ;
     char const *newenv[envlen + 2] ;
-    if (!env_mergen(newenv, envlen+2, envp, envlen, modifs, m, 1)) goto erractions ;
-    if (nopath && (setenv("PATH", SKALIBS_DEFAULTPATH, 0) < 0))
-    {
-      e = errno ; goto erractions ;
-    }
-    e = posix_spawnp(&pid, prog, &actions, &attr, (char *const *)argv, (char *const *)newenv) ;
-    if (nopath) unsetenv("PATH") ;
-    if (e) goto erractions ;
+    m += uint_fmt(modifs + sizeof(SKALIBS_CHILD_SPAWN_FDS_ENVVAR), p[2][1]) ;
+    modifs[m++] = 0 ;
+    if (!env_mergen(newenv, envlen + 2, envp, envlen, modifs, m, 1)) goto err ;
+    pid = cspawn(prog, argv, newenv, CSPAWN_FLAGS_SIGBLOCKNONE, fa, 2) ;
+    if (!pid) goto err ;
   }
 
-  posix_spawn_file_actions_destroy(&actions) ;
-  posix_spawnattr_destroy(&attr) ;
   fd_close(p[2][1]) ;
   fd_close(p[1][0]) ;
   fd_close(p[0][1]) ;
-
-#ifdef SKALIBS_HASPOSIXSPAWNEARLYRETURN
-  pid = child_spawn_workaround(pid, syncpipe) ;
-  if (!pid)
-  {
-    fd_close(p[2][0]) ;
-    fd_close(p[1][1]) ;
-    fd_close(p[0][0]) ;
-    return 0 ;
-  }
-#endif
   fds[0] = p[0][0] ;
   fds[1] = p[1][1] ;
   fds[2] = p[2][0] ;
   return pid ;
 
- erractions:
-  posix_spawn_file_actions_destroy(&actions) ;
- errattr:
-  posix_spawnattr_destroy(&attr) ;
- erre:
-  errno = e ;
-  fd_close(p[2][1]) ;
-  fd_close(p[2][0]) ;
- errp1:
-  fd_close(p[1][1]) ;
-  fd_close(p[1][0]) ;
- errp0:
-  fd_close(p[0][1]) ;
-  fd_close(p[0][0]) ;
  err:
-#ifdef SKALIBS_HASPOSIXSPAWNEARLYRETURN
-  fd_close(syncpipe[1]) ;
-  fd_close(syncpipe[0]) ;
-#endif
-  return 0 ;
-}
-
-#else
-
-#include <skalibs/allreadwrite.h>
-#include <skalibs/sig.h>
-#include <skalibs/exec.h>
-
-pid_t child_spawn3 (char const *prog, char const *const *argv, char const *const *envp, int *fds)
-{
-  pid_t pid ;
-  int syncpipe[2] ;
-  int p[3][2] ;
-  size_t m = sizeof(SKALIBS_CHILD_SPAWN_FDS_ENVVAR) ;
-  char modifs[sizeof(SKALIBS_CHILD_SPAWN_FDS_ENVVAR) + UINT_FMT] = SKALIBS_CHILD_SPAWN_FDS_ENVVAR "=" ;
-  char c ;
-
-  if (pipe(p[0]) == -1 || ndelay_on(p[0][0]) == -1 || coe(p[0][0]) == -1) return 0 ;
-  if (pipe(p[1]) == -1 || ndelay_on(p[1][1]) == -1 || coe(p[1][1]) == -1) goto errp0 ;
-  if (pipe(p[2]) == -1 || ndelay_on(p[2][0]) == -1 || coe(p[2][0]) == -1) goto errp1 ;
-  m += uint_fmt(modifs + sizeof(SKALIBS_CHILD_SPAWN_FDS_ENVVAR), p[2][1]) ;
-  modifs[m++] = 0 ;
-  if (pipecoe(syncpipe) < 0) goto errp2 ;
-
-  pid = fork() ;
-  if (pid < 0) goto errsp ;
-  else if (!pid)
-  {
-    if (fd_move2(fds[0], p[1][0], fds[1], p[0][1]) == -1) goto syncdie ;
-    sig_blocknone() ;
-    mexec_aen(prog, argv, envp, modifs, m, 1) ;
-   syncdie:
-    c = errno ;
-    fd_write(syncpipe[1], &c, 1) ;
-    _exit(127) ;
-  }
-
-  fd_close(syncpipe[1]) ;
-  syncpipe[1] = fd_read(syncpipe[0], &c, 1) ;
-  if (syncpipe[1])
-  {
-    int e = (unsigned char)c ;
-    if (syncpipe[1] == -1) e = errno ;
-    if (wait_pid(pid, &syncpipe[1]) == -1) e = errno ;
-    errno = e ;
-    goto errsp0 ;
-  }
-  fd_close(syncpipe[0]) ;
-
-  fd_close(p[2][1]) ;
-  fd_close(p[1][0]) ;
-  fd_close(p[0][1]) ;
-  fds[0] = p[0][0] ;
-  fds[1] = p[1][1] ;
-  fds[2] = p[2][0] ;
-  return pid ;
-
- errsp:
-  fd_close(syncpipe[1]) ;
- errsp0:
-  fd_close(syncpipe[0]) ;
- errp2:
   fd_close(p[2][1]) ;
   fd_close(p[2][0]) ;
  errp1:
@@ -190,5 +53,3 @@ pid_t child_spawn3 (char const *prog, char const *const *argv, char const *const
   fd_close(p[0][0]) ;
   return 0 ;
 }
-
-#endif