ncfdplane: on non-following planes, break out on 0 read

doc/man/man3/notcurses_fds.3.md

@@ -21,7 +21,7 @@ typedef struct ncfdplane_options {
 } ncfdplane_options;
 
 typedef struct ncsubproc_options {
-  ncfdplane_options popts;
+  void* curry; // parameter provided to callbacks
   uint64_t restart_period;  // restart after exit
 } ncsubproc_options;
 ```

include/notcurses/notcurses.h

@@ -2685,7 +2685,7 @@ API struct ncplane* ncfdplane_plane(struct ncfdplane* n);
 API int ncfdplane_destroy(struct ncfdplane* n);
 
 typedef struct ncsubproc_options {
-  ncfdplane_options popts;
+  void* curry;
   uint64_t restart_period;  // restart this many seconds after an exit (watch)
 } ncsubproc_options;
 

python/src/notcurses/build_notcurses.py

@@ -460,7 +460,7 @@ struct ncfdplane* ncfdplane_create(struct ncplane* n, const ncfdplane_options* o
 struct ncplane* ncfdplane_plane(struct ncfdplane* n);
 int ncfdplane_destroy(struct ncfdplane* n);
 typedef struct ncsubproc_options {
-  ncfdplane_options popts;
+  void* curry;
   uint64_t restart_period;  // restart this many seconds after an exit (watch)
 } ncsubproc_options;
 struct ncsubproc* ncsubproc_createv(struct ncplane* n, const ncsubproc_options* opts, const char* bin, char* const arg[], ncfdplane_callback cbfxn, ncfdplane_done_cb donecbfxn);

src/lib/fd.c

@@ -45,6 +45,10 @@ fdthread(ncfdplane* ncfp, int pidfd){
           break;
         }
       }
+      // if we're not doing follow, break out on a zero-byte read
+      if(r == 0 && !ncfp->follow){
+        break;
+      }
     }
     if(fdcount > 1 && pfds[1].revents & POLLIN){
       r = 0;
@@ -63,6 +67,22 @@ ncfdplane_thread(void* vncfp){
   return NULL;
 }
 
+static int
+set_fd_nonblocking(int fd){
+  int flags = fcntl(fd, F_GETFL, 0);
+  if(flags < 0){
+    return -1;
+  }
+  if(flags & O_NONBLOCK){
+    return 0;
+  }
+  flags |= O_NONBLOCK;
+  if(fcntl(fd, F_SETFL, flags)){
+    return -1;
+  }
+  return 0;
+}
+
 static ncfdplane*
 ncfdplane_create_internal(ncplane* n, const ncfdplane_options* opts, int fd,
                           ncfdplane_callback cbfxn, ncfdplane_done_cb donecbfxn,
@@ -146,14 +166,7 @@ launch_pipe_process(int* pipe, int* pidfd){
     }
   }else if(p > 0){ // parent
     *pipe = pipes[0];
-    int flags = fcntl(*pipe, F_GETFL, 0);
-    if(flags < 0){
-      // FIXME
-    }
-    flags |= O_NONBLOCK;
-    if(fcntl(*pipe, F_SETFL, flags)){
-      // FIXME
-    }
+    set_fd_nonblocking(*pipe);
   }
   return p;
 }
@@ -184,7 +197,11 @@ ncsubproc_thread(void* vncsp){
 static ncfdplane*
 ncsubproc_launch(ncplane* n, ncsubproc* ret, const ncsubproc_options* opts, int fd,
                  ncfdplane_callback cbfxn, ncfdplane_done_cb donecbfxn){
-  ret->nfp = ncfdplane_create_internal(n, &opts->popts, fd, cbfxn, donecbfxn, false);
+  ncfdplane_options popts = {
+    .curry = opts->curry,
+    .follow = true,
+  };
+  ret->nfp = ncfdplane_create_internal(n, &popts, fd, cbfxn, donecbfxn, false);
   if(ret->nfp == NULL){
     return NULL;
   }

tests/fds.cpp

@@ -103,7 +103,7 @@ TEST_CASE("FdsAndSubprocs") {
     char * const argv[] = { strdup("/dev/nope"), NULL, };
     bool outofline_cancelled = false;
     ncsubproc_options opts{};
-    opts.popts.curry = &outofline_cancelled;
+    opts.curry = &outofline_cancelled;
     auto ncsubp = ncsubproc_createvp(n_, &opts, argv[0], argv, testfdcb, testfdeof);
     REQUIRE(ncsubp);
     std::unique_lock<std::mutex> lck(lock);
@@ -123,7 +123,7 @@ TEST_CASE("FdsAndSubprocs") {
     char * const argv[] = { strdup("/bin/cat"), strdup("/dev/null"), NULL, };
     bool outofline_cancelled = false;
     ncsubproc_options opts{};
-    opts.popts.curry = &outofline_cancelled;
+    opts.curry = &outofline_cancelled;
     auto ncsubp = ncsubproc_createvp(n_, &opts, argv[0], argv, testfdcb, testfdeof);
     REQUIRE(ncsubp);
     std::unique_lock<std::mutex> lck(lock);
@@ -140,7 +140,7 @@ TEST_CASE("FdsAndSubprocs") {
     char * const argv[] = { strdup("/bin/cat"), strdup("/dev/nope"), NULL, };
     bool outofline_cancelled = false;
     ncsubproc_options opts{};
-    opts.popts.curry = &outofline_cancelled;
+    opts.curry = &outofline_cancelled;
     auto ncsubp = ncsubproc_createvp(n_, &opts, argv[0], argv, testfdcb, testfdeof);
     REQUIRE(ncsubp);
     std::unique_lock<std::mutex> lck(lock);
@@ -157,7 +157,7 @@ TEST_CASE("FdsAndSubprocs") {
     char * const argv[] = { strdup("/bin/cat"), NULL, };
     bool outofline_cancelled = false;
     ncsubproc_options opts{};
-    opts.popts.curry = &outofline_cancelled;
+    opts.curry = &outofline_cancelled;
     auto ncsubp = ncsubproc_createvp(n_, &opts, argv[0], argv, testfdcb, testfdeof);
     REQUIRE(ncsubp);
     CHECK(0 == ncsubproc_destroy(ncsubp));