add change pipe size command

auto/modules

@@ -1454,6 +1454,7 @@ END
 have=T_NGX_DNS_RESOLVE_BACKUP . auto/have
 have=T_NGX_MASTER_ENV . auto/have
 have=T_PIPES . auto/have
+have=T_PIPE_SET_SIZE . auto/have
 have=T_NGX_INPUT_BODY_FILTER . auto/have
 have=T_NGX_GZIP_CLEAR_ETAG . auto/have
 have=T_NGX_RESOLVER_FILE . auto/have

src/core/nginx.c

@@ -166,6 +166,15 @@ static ngx_command_t  ngx_core_commands[] = {
 
 #endif
 
+#if (T_PIPE_SET_SIZE)
+    { ngx_string("pipe_set_size"),
+      NGX_MAIN_CONF|NGX_DIRECT_CONF|NGX_CONF_TAKE1,
+      ngx_conf_set_size_slot,
+      0,
+      offsetof(ngx_core_conf_t, pipe_size),
+      NULL },
+#endif
+
       ngx_null_command
 };
 
@@ -1148,6 +1157,10 @@ ngx_core_module_create_conf(ngx_cycle_t *cycle)
         return NULL;
     }
 
+#ifdef T_PIPE_SET_SIZE
+    ccf->pipe_size = NGX_CONF_UNSET_SIZE;
+#endif
+
     return ccf;
 }
 
@@ -1282,6 +1295,16 @@ ngx_core_module_init_conf(ngx_cycle_t *cycle, void *conf)
 
 #endif
 
+#ifdef T_PIPE_SET_SIZE
+    if (ccf->pipe_size != NGX_CONF_UNSET_SIZE) {
+        if (ccf->pipe_size < 64 * 1024) {
+            ngx_log_error(NGX_LOG_EMERG, cycle->log, 0,
+                          "\"pipe_size\" must be at least 64K, ignored");
+            return NGX_CONF_ERROR;
+        }
+    }
+#endif
+
     return NGX_CONF_OK;
 }
 

src/core/ngx_cycle.h

@@ -133,6 +133,11 @@ typedef struct {
     char                    **environment;
 
     ngx_uint_t                transparent;  /* unsigned  transparent:1; */
+
+#if (T_PIPE_SET_SIZE)
+    size_t pipe_size;
+#endif
+
 } ngx_core_conf_t;
 
 

src/os/unix/ngx_pipe.c

@@ -428,7 +428,7 @@ ngx_open_pipe(ngx_cycle_t *cycle, ngx_open_pipe_t *op)
     u_char          **argv;
     ngx_pid_t         pid;
     sigset_t          set;
-#ifdef T_PIPE_USE_USER
+#if defined(T_PIPE_USE_USER) || defined(T_PIPE_SET_SIZE)
     ngx_core_conf_t  *ccf;
 
     ccf = (ngx_core_conf_t *) ngx_get_conf(cycle->conf_ctx, ngx_core_module);
@@ -438,6 +438,16 @@ ngx_open_pipe(ngx_cycle_t *cycle, ngx_open_pipe_t *op)
         return NGX_ERROR;
     }
 
+#ifdef T_PIPE_SET_SIZE
+    if (ccf->pipe_size != NGX_CONF_UNSET_SIZE && ccf->pipe_size != 0) {
+        if (fcntl(op->pfd[1], F_SETPIPE_SZ, ccf->pipe_size) == -1) {
+            ngx_log_error(NGX_LOG_EMERG, cycle->log, ngx_errno,
+                          "set pipe size (%d) failed", ccf->pipe_size);
+            goto err;
+        }
+    }
+#endif
+
     argv = op->argv->elts;
 
     if ((pid = fork()) < 0) {