Reputation: 6891

Python Threads: only one thread gets launched

thread.start_new_thread(target=self.socketFunctionRead1())
print "Thread 1"
thread.start_new_thread(target=self.socketFunctionWrite1())
print "Thread 2"
thread.start_new_thread(target=self.socketFunctionRead2())
print "Thread 3"
thread.start_new_thread(target=self.socketFunctionWrite2())
print "Thread 4"

I am trying to start multiple threads, but only one thread is started, how can I make the program go further by starting the other threads?

Upvotes: 1

Answers (3)

Martin

Reputation: 6032

Instead of thread.start_new_thread(target=self.socketFunctionRead1()),

try thread.start_new_thread(target=self.socketFunctionRead1)

Because of the parenthese, the function is called and the return value of the function is assigned to target. Since thread.start_new_thread(target=self.socketFunctionRead1()) is probably a blocking call, only this function gets called.

In thread.start_new_thread, target should be a callable (An object that behaves like a function).

Edit:

From the Python documentation:

thread.start_new_thread(function, args[, kwargs])

Start a new thread and return its identifier. The thread executes the function function with the argument list args (which must be a tuple). The optional kwargs argument specifies a dictionary of keyword arguments. When the function returns, the thread silently exits. When the function terminates with an unhandled exception, a stack trace is printed and then the thread exits (but other threads continue to run).

This means that you should call thread.start_new_thread(self.socketFunctionRead1).

If you pass keyword arguments to start_new_thread, they will get passed to self.socketFunctionRead1.

The target for your thread is required and not a keyword argument.

Upvotes: 2