switch writen() to blocking_write() to avoid spinning

src/lib/direct.c

@@ -38,7 +38,7 @@ int ncdirect_putstr(ncdirect* nc, uint64_t channels, const char* utf8){
 
 static int
 cursor_yx_get(int ttyfd, int* y, int* x){
-  if(writen(ttyfd, "\033[6n", 4) != 4){
+  if(blocking_write(ttyfd, "\033[6n", 4)){
     return -1;
   }
   bool done = false;

src/lib/internal.h

@@ -8,6 +8,7 @@ extern "C" {
 #include "version.h"
 #include "builddef.h"
 
+#include <poll.h>
 #include <term.h>
 #include <time.h>
 #include <stdio.h>
@@ -741,21 +742,31 @@ rgb_greyscale(int r, int g, int b){
   return fg * 255;
 }
 
-// write(2) with retry on partial write or interrupted write
-static inline ssize_t
-writen(int fd, const void* buf, size_t len){
-  ssize_t r;
-  size_t w = 0;
-  while(w < len){
-    if((r = write(fd, (const char*)buf + w, len - w)) < 0){
-      if(errno == EAGAIN || errno == EBUSY || errno == EINTR){
-        continue;
+// write(2) until we've written it all. uses poll(2) to avoid spinning on
+// EAGAIN, at the possible cost of some small latency.
+static inline int
+blocking_write(int fd, const char* buf, size_t buflen){
+//fprintf(stderr, "writing %zu to %d...\n", buflen, fd);
+  size_t written = 0;
+  while(written < buflen){
+    ssize_t w = write(fd, buf + written, buflen - written);
+    if(w < 0){
+      if(errno != EAGAIN && errno != EWOULDBLOCK && errno != EINTR){
+        return -1;
       }
-      return -1;
+    }else{
+      written += w;
+    }
+    if(written < buflen){
+      struct pollfd pfd = {
+        .fd = fd,
+        .events = POLLOUT,
+        .revents = 0,
+      };
+      poll(&pfd, 1, -1);
     }
-    w += r;
   }
-  return w;
+  return 0;
 }
 
 static inline int
@@ -764,7 +775,7 @@ tty_emit(const char* seq, int fd){
     return -1;
   }
   size_t slen = strlen(seq);
-  if(writen(fd, seq, slen) < 0){
+  if(blocking_write(fd, seq, slen)){
     return -1;
   }
   return 0;

src/lib/render.c

@@ -1,4 +1,3 @@
-#include <poll.h>
 #include <ctype.h>
 #include <limits.h>
 #include <unistd.h>
@@ -74,33 +73,6 @@ notcurses_resize(notcurses* n, int* restrict rows, int* restrict cols){
   return ret;
 }
 
-// write(2) until we've written it all. Uses poll(2) to avoid spinning on
-// EAGAIN, at a small cost of latency.
-static int
-blocking_write(int fd, const char* buf, size_t buflen){
-//fprintf(stderr, "writing %zu to %d...\n", buflen, fd);
-  size_t written = 0;
-  while(written < buflen){
-    ssize_t w = write(fd, buf + written, buflen - written);
-    if(w < 0){
-      if(errno != EAGAIN && errno != EWOULDBLOCK && errno != EINTR){
-        return -1;
-      }
-    }else{
-      written += w;
-    }
-    if(written < buflen){
-      struct pollfd pfd = {
-        .fd = fd,
-        .events = POLLOUT,
-        .revents = 0,
-      };
-      poll(&pfd, 1, -1);
-    }
-  }
-  return 0;
-}
-
 void nccell_release(ncplane* n, nccell* c){
   pool_release(&n->pool, c);
 }

src/lib/termdesc.c

@@ -458,8 +458,7 @@ read_xtsmgraphics_reply(int fd, int* val2){
 
 static int
 query_xtsmgraphics(int fd, const char* seq, int* val, int* val2){
-  ssize_t w = writen(fd, seq, strlen(seq));
-  if(w < 0 || (size_t)w != strlen(seq)){
+  if(blocking_write(fd, seq, strlen(seq))){
     return -1;
   }
   int r = read_xtsmgraphics_reply(fd, val2);