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8043770: File leak in MemNotifyThread::start() in hotspot.src.os.linux.vm.os_linux.cpp

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Fixed by removing all code related to LowMemoryProtection, which removed offending code.

Reviewed-by: dholmes, minqi
This commit is contained in:
Chris Plummer 2014-11-05 13:00:59 -08:00
parent f048251de8
commit 7a414a2c7d
8 changed files with 0 additions and 139 deletions
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116
hotspot/src/os/linux/vm/os_linux.cpp
View file

@ -163,35 +163,6 @@ static pthread_mutex_t dl_mutex;
// Declarations
static void unpackTime(timespec* absTime, bool isAbsolute, jlong time);
#ifdef JAVASE_EMBEDDED
class MemNotifyThread: public Thread {
friend class VMStructs;
public:
virtual void run();
private:
static MemNotifyThread* _memnotify_thread;
int _fd;
public:
// Constructor
MemNotifyThread(int fd);
// Tester
bool is_memnotify_thread() const { return true; }
// Printing
char* name() const { return (char*)"Linux MemNotify Thread"; }
// Returns the single instance of the MemNotifyThread
static MemNotifyThread* memnotify_thread() { return _memnotify_thread; }
// Create and start the single instance of MemNotifyThread
static void start();
};
#endif // JAVASE_EMBEDDED
// utility functions
static int SR_initialize();
@ -4866,17 +4837,6 @@ jint os::init_2(void) {
return JNI_OK;
}
// this is called at the end of vm_initialization
void os::init_3(void) {
#ifdef JAVASE_EMBEDDED
// Start the MemNotifyThread
if (LowMemoryProtection) {
MemNotifyThread::start();
}
return;
#endif
}
// Mark the polling page as unreadable
void os::make_polling_page_unreadable(void) {
if (!guard_memory((char*)_polling_page, Linux::page_size())) {
@ -6033,82 +5993,6 @@ int os::get_core_path(char* buffer, size_t bufferSize) {
return strlen(buffer);
}
#ifdef JAVASE_EMBEDDED
//
// A thread to watch the '/dev/mem_notify' device, which will tell us when the OS is running low on memory.
//
MemNotifyThread* MemNotifyThread::_memnotify_thread = NULL;
// ctor
//
MemNotifyThread::MemNotifyThread(int fd): Thread() {
assert(memnotify_thread() == NULL, "we can only allocate one MemNotifyThread");
_fd = fd;
if (os::create_thread(this, os::os_thread)) {
_memnotify_thread = this;
os::set_priority(this, NearMaxPriority);
os::start_thread(this);
}
}
// Where all the work gets done
//
void MemNotifyThread::run() {
assert(this == memnotify_thread(), "expected the singleton MemNotifyThread");
// Set up the select arguments
fd_set rfds;
if (_fd != -1) {
FD_ZERO(&rfds);
FD_SET(_fd, &rfds);
}
// Now wait for the mem_notify device to wake up
while (1) {
// Wait for the mem_notify device to signal us..
int rc = select(_fd+1, _fd != -1 ? &rfds : NULL, NULL, NULL, NULL);
if (rc == -1) {
perror("select!\n");
break;
} else if (rc) {
//ssize_t free_before = os::available_memory();
//tty->print ("Notified: Free: %dK \n",os::available_memory()/1024);
// The kernel is telling us there is not much memory left...
// try to do something about that
// If we are not already in a GC, try one.
if (!Universe::heap()->is_gc_active()) {
Universe::heap()->collect(GCCause::_allocation_failure);
//ssize_t free_after = os::available_memory();
//tty->print ("Post-Notify: Free: %dK\n",free_after/1024);
//tty->print ("GC freed: %dK\n", (free_after - free_before)/1024);
}
// We might want to do something like the following if we find the GC's are not helping...
// Universe::heap()->size_policy()->set_gc_time_limit_exceeded(true);
}
}
}
// See if the /dev/mem_notify device exists, and if so, start a thread to monitor it.
//
void MemNotifyThread::start() {
int fd;
fd = open("/dev/mem_notify", O_RDONLY, 0);
if (fd < 0) {
return;
}
if (memnotify_thread() == NULL) {
new MemNotifyThread(fd);
}
}
#endif // JAVASE_EMBEDDED
/////////////// Unit tests ///////////////
#ifndef PRODUCT