* Fix pthread_once extern declarations (willchan)

* Add missing closing brace that resulted in compile failure (willchan)
	* Handle closed stdin/out/err properly when forking (glider)


git-svn-id: http://gperftools.googlecode.com/svn/trunk@93 6b5cf1ce-ec42-a296-1ba9-69fdba395a50

src/maybe_threads.cc

@@ -63,7 +63,7 @@ extern "C" {
   int pthread_setspecific(pthread_key_t, const void*)
       __THROW ATTRIBUTE_WEAK;
   int pthread_once(pthread_once_t *, void (*)(void))
-      __THROW ATTRIBUTE_WEAK;
+      ATTRIBUTE_WEAK;
 }
 
 #define MAX_PERTHREAD_VALS 16

src/profile-handler.cc

@@ -215,11 +215,8 @@ const int32 ProfileHandler::kDefaultFrequency;
 // pthread_once won't be defined.  We declare it here, for that
 // case (with weak linkage) which will cause the non-definition to
 // resolve to NULL.  We can then check for NULL or not in Instance.
-#ifndef __THROW    // I guess we're not on a glibc system
-# define __THROW   // __THROW is just an optimization, so ok to make it ""
-#endif
 extern "C" int pthread_once(pthread_once_t *, void (*)(void))
-    __THROW ATTRIBUTE_WEAK;
+    ATTRIBUTE_WEAK;
 
 void ProfileHandler::Init() {
   instance_ = new ProfileHandler();

src/symbolize.cc

@@ -87,16 +87,40 @@ int SymbolTable::Symbolize() {
 #else
   // All this work is to do two-way communication.  ugh.
   extern char* program_invocation_name;  // gcc provides this
-  int child_in[2];   // file descriptors
-  int child_out[2];  // for now, we don't worry about child_err
-  if (socketpair(AF_UNIX, SOCK_STREAM, 0, child_in) == -1) {
-    return 0;
-  }
-  if (socketpair(AF_UNIX, SOCK_STREAM, 0, child_out) == -1) {
-    close(child_in[0]);
-    close(child_in[1]);
-    return 0;
+  int *child_in = NULL;   // file descriptors
+  int *child_out = NULL;  // for now, we don't worry about child_err
+  int child_fds[5][2];    // socketpair may be called up to five times below
+
+  // The client program may close its stdin and/or stdout and/or stderr
+  // thus allowing socketpair to reuse file descriptors 0, 1 or 2.
+  // In this case the communication between the forked processes may be broken
+  // if either the parent or the child tries to close or duplicate these
+  // descriptors. The loop below produces two pairs of file descriptors, each
+  // greater than 2 (stderr).
+  for (int i = 0; i < 5; i++) {
+    if (socketpair(AF_UNIX, SOCK_STREAM, 0, child_fds[i]) == -1) {
+      for (int j = 0; j < i; j++) {
+        close(child_fds[j][0]);
+        close(child_fds[j][1]);
+        return 0;
+      }
+    } else {
+      if ((child_fds[i][0] > 2) && (child_fds[i][1] > 2)) {
+        if (child_in == NULL) {
+          child_in = child_fds[i];
+        } else {
+          child_out = child_fds[i];
+          for (int j = 0; j < i; j++) {
+            if (child_fds[j] == child_in) continue;
+            close(child_fds[j][0]);
+            close(child_fds[j][1]);
+          }
+          break;
+        }
+      }
+    }
   }
+
   switch (fork()) {
     case -1: {  // error
       close(child_in[0]);

src/tcmalloc.cc

@@ -898,6 +898,7 @@ inline bool should_report_large(Length num_pages) {
     return true;
   }
   return false;
+}
 
 // Helper for do_malloc().
 inline void* do_malloc_pages(ThreadCache* heap, size_t size) {