win32: ash: reimplement waitpid(-1)

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>

1 files changed, 53 insertions, 0 deletions

diff --git a/shell/ash.c b/shell/ash.c
index a54284155..40b4c421d 100644
--- a/shell/ash.c
+++ b/shell/ash.c
@@ -3889,6 +3889,53 @@ sprint_status(char *s, int status, int sigonly)
         return col;
 }
 
+#if ENABLE_PLATFORM_MINGW32
+/*
+ * Windows does not know about parent-child relationship
+ * They don't support waitpid(-1)
+ */
+static pid_t
+waitpid_child(int *status)
+{
+        HANDLE *pidlist, *pidp;
+        int pid_nr = 0;
+        pid_t pid;
+        DWORD win_status, idx;
+        struct job *jb;
+
+        #define LOOP(stmt) \
+        for (jb = curjob; jb; jb = jb->prev_job) { \
+                struct procstat *ps, *psend; \
+                if (jb->state == JOBDONE) \
+                        continue; \
+                ps = jb->ps; \
+                psend = ps + jb->nprocs; \
+                while (ps < psend) { \
+                        if (ps->ps_pid != -1) { \
+                                stmt; \
+                        } \
+                        ps++; \
+                } \
+        }
+
+        LOOP(pid_nr++);
+        pidp = pidlist = ckmalloc(sizeof(*pidlist)*pid_nr);
+        LOOP(*pidp++ = (HANDLE)ps->ps_pid);
+        #undef LOOP
+
+        idx = WaitForMultipleObjects(pid_nr, pidlist, FALSE, INFINITE);
+        if (idx >= pid_nr) {
+                free(pidlist);
+                return -1;
+        }
+        GetExitCodeProcess(pidlist[idx], &win_status);
+        pid = (int)pidlist[idx];
+        free(pidlist);
+        *status = (int)win_status;
+        return pid;
+}
+#endif
+
 static int
 dowait(int wait_flags, struct job *job)
 {
@@ -3905,7 +3952,11 @@ dowait(int wait_flags, struct job *job)
          * NB: _not_ safe_waitpid, we need to detect EINTR */
         if (doing_jobctl)
                 wait_flags |= WUNTRACED;
+#if ENABLE_PLATFORM_MINGW32
+        pid = waitpid_child(&status);
+#else
         pid = waitpid(-1, &status, wait_flags);
+#endif
         TRACE(("wait returns pid=%d, status=0x%x, errno=%d(%s)\n",
                                 pid, status, errno, strerror(errno)));
         if (pid <= 0)
@@ -3928,6 +3979,8 @@ dowait(int wait_flags, struct job *job)
                                         jobno(jp), pid, ps->ps_status, status));
                                 ps->ps_status = status;
                                 thisjob = jp;
+                                if (ENABLE_PLATFORM_MINGW32)
+                                        ps->ps_pid = -1;
                         }
                         if (ps->ps_status == -1)
                                 state = JOBRUNNING;