multithreading

问题 This question already has an answer here : Flask Gunicorn app can't get __name__ to equal '__main__' (1 answer) Closed 3 months ago . I have the following code for testing running two threads with flask on heroku. app.py from flask import Flask, render_template import threading import time import sys app = Flask(__name__, static_url_path='') test_result = 'failed' @app.route('/') def index(): return 'Hello! Server is running' @app.route('/thread-test') def thread_test(): global test_result

问题 This question already has an answer here : Flask Gunicorn app can't get __name__ to equal '__main__' (1 answer) Closed 3 months ago . I have the following code for testing running two threads with flask on heroku. app.py from flask import Flask, render_template import threading import time import sys app = Flask(__name__, static_url_path='') test_result = 'failed' @app.route('/') def index(): return 'Hello! Server is running' @app.route('/thread-test') def thread_test(): global test_result

问题 I am looking for a good way to implement read/write lock in Perl. This is needed to synchronize file access from different Perl threads and/or processes on Windows and Unix. Tried Fcntl::flock which would be perfect for me if it worked as expected. Unfortunately it looks like under stress flock allows to set lock on already locked file in another thread. Looked into some CPAN modules, but most are implemented with flock. Next I am planning to evaluate fcntl for Unix and Win32::Mutex for

问题 I am looking for a good way to implement read/write lock in Perl. This is needed to synchronize file access from different Perl threads and/or processes on Windows and Unix. Tried Fcntl::flock which would be perfect for me if it worked as expected. Unfortunately it looks like under stress flock allows to set lock on already locked file in another thread. Looked into some CPAN modules, but most are implemented with flock. Next I am planning to evaluate fcntl for Unix and Win32::Mutex for

问题 How can I model two parallel threads that perform operations on an object in a sequence diagram? 回答1: In a sequence diagram, a lifeline represents an individual participant in the interaction. So your object that is shared between the threads should appear once and only once in the diagram. You would also represent with a lifeline each threaded object that interact with your shared object. It could be thread instantiations directly, or it could be several objects that are created in the

问题 Suppose the architecture is x86. And the OS is Linux based. Given a multithreaded process in which a single thread executes an int 3 instruction, does the interrupt handler stop from executing the entire process or just the thread that executed the int 3 instruction? 回答1: Since the question is Linux specific, let's dive into kernel sources! We know int 3 will generate a SIGTRAP, as we can see in do_int3. The default behaviour of SIGTRAP is to terminate the process and dump core. do_int3 calls

问题 Suppose the architecture is x86. And the OS is Linux based. Given a multithreaded process in which a single thread executes an int 3 instruction, does the interrupt handler stop from executing the entire process or just the thread that executed the int 3 instruction? 回答1: Since the question is Linux specific, let's dive into kernel sources! We know int 3 will generate a SIGTRAP, as we can see in do_int3. The default behaviour of SIGTRAP is to terminate the process and dump core. do_int3 calls

问题 I did some search on the question, but it seems like people only emphasize on Non-blocking IO. Let's say if I just have a very simple application to respond "Hello World" text to the client, it still needs time to finish the execution, no matter how quick it is. What if there are two request coming in at exactly the same time, how does Node.js make sure both requests will be processed with one thread? I read the blog Understanding the node.js event loop which says "Of course, on the backend,

问题 I did some search on the question, but it seems like people only emphasize on Non-blocking IO. Let's say if I just have a very simple application to respond "Hello World" text to the client, it still needs time to finish the execution, no matter how quick it is. What if there are two request coming in at exactly the same time, how does Node.js make sure both requests will be processed with one thread? I read the blog Understanding the node.js event loop which says "Of course, on the backend,

问题 My question refers specifically to why it was designed that way, due to the unnecessary performance implication. When thread T1 has this code: cv.acquire() cv.wait() cv.release() and thread T2 has this code: cv.acquire() cv.notify() # requires that lock be held cv.release() what happens is that T1 waits and releases the lock, then T2 acquires it, notifies cv which wakes up T1. Now, there is a race-condition between T2's release and T1's reacquiring after returning from wait() . If T1 tries to