Fix php-cgi process hanging after PHP script was served (#221).

Copy license and readme files to the bin/ directory during build.

Implement waitpid() on Windows. Better handling of php-cgi processes
hanging should also be used on Windows. Use the latest mongoose.c
from the Linux branch in the next Windows release.

Makefile

@@ -2,12 +2,12 @@ TARGET=build/bin/phpdesktop
 
 INCLUDES = -Isrc -Lbuild/lib -Lbuild/bin
 
-CCFLAGS = -g -Wall -Werror -std=gnu++11 $(INCLUDES)
+CCFLAGS = -g -Wall -Werror -std=gnu++11 -pthread $(INCLUDES)
 CCFLAGS += $(shell pkg-config --cflags glib-2.0 gtk+-3.0)
 
 CFLAGS_OPTIMIZE = -O3 -fvisibility=hidden
 
-LDFLAGS = -Wl,-rpath,. -Wl,-rpath,"\$$ORIGIN" -lX11 -lcef -lcef_dll_wrapper -Wl,--as-needed -ldl
+LDFLAGS = -Wl,-rpath,. -Wl,-rpath,"\$$ORIGIN" -lX11 -lcef -lcef_dll_wrapper -Wl,--as-needed -ldl -lpthread
 LDFLAGS += $(shell pkg-config --libs glib-2.0 gtk+-3.0)
 
 OBJS=\

build-php.sh

@@ -14,6 +14,7 @@ set -e
 root_dir=$(dirname $0)
 cd ${root_dir}/build/php*/
 php_dir=$(pwd)
+echo "Found PHP: ${php_dir}"
 echo "Configure PHP..."
 ./configure \
     --prefix=${php_dir}/dist-install \

build.sh

@@ -25,6 +25,9 @@ rc=$?;
 if [[ ${rc} = 0 ]]; then
     echo "OK phpdesktop was built";
     cp src/php.ini build/bin/
+    cp CEF.License.txt build/bin/
+    cp CEF.Readme.txt build/bin/
+    cp License.txt build/bin/
     if [[ -d build/bin/www ]]; then
         rm -r build/bin/www
     fi

src/mongoose.c

@@ -1,5 +1,5 @@
 // Forked from Mongoose MIT licensed revision 04fc209. 
-// Bug fixes and minor changes were made for PHP Desktop.
+// This is a custom edition of Mongoose web server for PHP Desktop.
 // Copyright (c) 2012 PHP Desktop.
 // Copyright (c) 2004 Sergey Lyubka.
 //
@@ -1294,6 +1294,19 @@ static int kill(pid_t pid, int sig_num) {
   return 0;
 }
 
+#define WNOHANG 1 /* do not wait for child to exit */
+static pid_t waitpid(pid_t pid, int *status, int flags) {
+  (void)status;
+  DWORD waitres = WaitForSingleObject((HANDLE)pid, 0);
+  if (waitres == WAIT_OBJECT_0) {
+    return pid;
+  }
+  if (waitres == WAIT_TIMEOUT) {
+    return 0;
+  }
+  return (pid_t)-1;
+}
+
 static void trim_trailing_whitespaces(char *s) {
   char *e = s + strlen(s) - 1;
   while (e > s && isspace(* (unsigned char *) e)) {
@@ -1466,14 +1479,25 @@ static pid_t spawn_process(struct mg_connection *conn, const char *prog,
       // if it was set to be ignored. Restore it to default action.
       signal(SIGCHLD, SIG_DFL);
 
+      // It is recommended to use sigaction() instead of signal()
+      // as it is more reliable. However this does not fix issue
+      // with php-cgi zombie processes hanging after PHP script
+      // was served. (Linux issue).
+      // struct sigaction sa;
+      // memset(&sa, 0, sizeof(sa));
+      // sa.sa_handler = SIG_DFL;
+      // sigaction(SIGCHLD, &sa, NULL);
+
       interp = conn->ctx->config[CGI_INTERPRETER];
       if (interp == NULL) {
         (void) execle(prog, prog, NULL, envp);
         cry(conn, "%s: execle(%s): %s", __func__, prog, strerror(ERRNO));
       } else {
         // char prog_abspath[PATH_MAX];
         // strcpy(prog_abspath, dir);
+        // strcat(prog_abspath, "/");
         // strcat(prog_abspath, prog);
+        // conn->ctx->callbacks.log_message(conn, interp);
         (void) execle(interp, interp, prog, NULL, envp);
         cry(conn, "%s: execle(%s %s): %s", __func__, interp, prog,
             strerror(ERRNO));
@@ -3666,7 +3690,14 @@ static void handle_cgi_request(struct mg_connection *conn, const char *prog) {
 
 done:
   if (pid != (pid_t) -1) {
-    kill(pid, SIGKILL);
+    // Use SIGABRT so that CGI process has an opportunity to
+    // handle event and exit gracefully.
+    kill(pid, SIGABRT);
+    // Wait until process is terminated, otherwise CGI process will be
+    // hanging forever on Linux. This code should also be used on Windows.
+    // Do not use the "status" param that can be returned by waitpid().
+    // These statuses are buggy and CGI process will still be hanging.
+    while (waitpid(pid, NULL, 0) != (pid_t) -1);
   }
   if (fdin[0] != -1) {
     close(fdin[0]);
@@ -5616,7 +5647,7 @@ struct mg_context *mg_start(const struct mg_callbacks *callbacks,
   // won't kill the whole process.
   (void) signal(SIGPIPE, SIG_IGN);
   // Also ignoring SIGCHLD to let the OS to reap zombies properly.
-  (void) signal(SIGCHLD, SIG_IGN);
+  // (void) signal(SIGCHLD, SIG_IGN);
 #endif // !_WIN32
 
   (void) pthread_mutex_init(&ctx->mutex, NULL);

src/mongoose_server.cpp

@@ -14,11 +14,12 @@ std::string g_mongoose_url = "";
 struct mg_context* g_mongoose_context = 0;
 extern std::string g_cgi_env_from_argv;
 
-static int mongoose_log_message(const struct mg_connection* conn,
+static int mongoose_error_message(const struct mg_connection* conn,
                                 const char *message) {
-    // Called when mongoose is about to log a message. If callback returns
-    // non-zero, mongoose does not log anything.
-    LOG(WARNING) << message;
+    // Called when mongoose is about to log an error message.
+    // If callback returns non-zero, mongoose does not log anything
+    // to a file ("error_log_file" option).
+    LOG(ERROR) << message;
     return 0;
 }
 
@@ -109,7 +110,7 @@ bool MongooseStart() {
 
     // Start mongoose
     mg_callbacks callbacks = {0};
-    callbacks.log_message = &mongoose_log_message;
+    callbacks.log_message = &mongoose_error_message;
     callbacks.end_request = &mongoose_end_request;
     g_mongoose_context = mg_start(&callbacks, NULL, options);
     if (g_mongoose_context == NULL) {

src/utils.cpp

@@ -3,12 +3,12 @@
 // Project website: https://github.com/cztomczak/phpdesktop
 
 #include "utils.h"
+#include <limits.h>
 #include <unistd.h>
 
-
 std::string executable_dir() {
     // Directory in which executable resides.
-    char app_path[1024] = {};
+    char app_path[PATH_MAX] = {};
     ssize_t pplen = readlink("/proc/self/exe", app_path, sizeof(app_path)-1);
     if (pplen != -1) {
         app_path[pplen] = '\0';