This document discusses deadlocks in operating systems. It defines deadlock and indefinite postponement. It describes the four conditions required for deadlock: mutual exclusion, hold and wait, no preemption, and circular wait. It discusses different approaches to handling deadlocks such as prevention, avoidance, detection, and recovery. It provides examples of resource allocation graphs and the banker's algorithm to illustrate deadlock avoidance techniques.
The document discusses deadlocks in operating systems. It defines deadlocks as a situation where a set of concurrent processes are prevented from completing tasks due to circular resource dependencies. The document outlines four conditions required for deadlock and presents methods for handling deadlocks, including prevention, avoidance, detection, and recovery. It provides examples using resource allocation graphs and the banker's algorithm to model processes and resources to ensure the system remains in a safe state to avoid deadlocks.
Deadlocks operating system To develop a description of deadlocks, which prevent sets of concurrent processes from completing their tasks
To present a number of different methods for preventing, avoiding, or detecting deadlocks in a computer system
e.t.c
This document discusses deadlocks in operating systems. It defines deadlock as when a set of processes are all waiting for resources held by each other in a cyclic manner, preventing any progress. Four conditions must hold for deadlock to occur: mutual exclusion, hold and wait, no preemption, and circular wait. Detection methods include using a resource allocation graph to model processes and resources. Prevention techniques enforce restrictions like requiring processes request resources in a predefined order to avoid circular waits. The banker's algorithm is also described, which uses matrices to model available resources and ensure the system remains in a safe state to avoid deadlocks.
Deadlock in Real Time operating Systempptxssuserca5764
This document discusses deadlocks in operating systems. It begins by defining a deadlock as a set of blocked processes each holding a resource and waiting for a resource held by another process. It then covers various methods for handling deadlocks including prevention, avoidance, detection, and recovery. Prevention methods restrain how processes can request resources to ensure deadlocks cannot occur. Avoidance methods allow requests but ensure the system never enters an unsafe state. Detection finds deadlocks after they occur, while recovery rolls back processes or preempts resources to break deadlock cycles.
This document discusses different methods for handling deadlocks in computer systems, including deadlock prevention, avoidance, detection, and recovery. It presents the four conditions required for deadlock, describes resource allocation graphs and how they can indicate deadlock situations. Prevention methods restrain how processes request resources to ensure deadlock cannot occur. Avoidance algorithms like the banker's algorithm dynamically assess the resource allocation state to guarantee a safe state where deadlock is not possible. Detection algorithms search allocation and wait graphs periodically to find any cycles indicating deadlock, and recovery aims to resolve deadlocks when they are detected.
The document discusses the deadlock problem in operating systems. It defines deadlock as a state where a set of blocked processes are each holding resources and waiting for additional resources held by other processes in the set, resulting in none of the processes being able to progress. Four conditions must hold simultaneously for deadlock to occur: mutual exclusion, hold and wait, no preemption, and circular wait. Methods for handling deadlocks include prevention, avoidance, and detection/recovery. The banker's algorithm is presented as a deadlock avoidance strategy that uses a resource allocation graph and ensures the system is always in a safe state where deadlocks cannot occur.
14th November - Deadlock Prevention, Avoidance.pptUnknown664473
This document discusses various techniques for handling deadlocks in operating systems. It begins by defining the deadlock problem and characterizing the conditions required for a deadlock to occur. It then presents different methods for preventing, avoiding, detecting, and recovering from deadlocks, including deadlock prevention, avoidance using safe states and the banker's algorithm, detection using wait-for graphs and the resource allocation graph, and recovery through process termination or resource preemption.
The document discusses deadlocks in operating systems. It defines deadlocks as a situation where a set of concurrent processes are prevented from completing tasks due to circular resource dependencies. The document outlines four conditions required for deadlock and presents methods for handling deadlocks, including prevention, avoidance, detection, and recovery. It provides examples using resource allocation graphs and the banker's algorithm to model processes and resources to ensure the system remains in a safe state to avoid deadlocks.
Deadlocks operating system To develop a description of deadlocks, which prevent sets of concurrent processes from completing their tasks
To present a number of different methods for preventing, avoiding, or detecting deadlocks in a computer system
e.t.c
This document discusses deadlocks in operating systems. It defines deadlock as when a set of processes are all waiting for resources held by each other in a cyclic manner, preventing any progress. Four conditions must hold for deadlock to occur: mutual exclusion, hold and wait, no preemption, and circular wait. Detection methods include using a resource allocation graph to model processes and resources. Prevention techniques enforce restrictions like requiring processes request resources in a predefined order to avoid circular waits. The banker's algorithm is also described, which uses matrices to model available resources and ensure the system remains in a safe state to avoid deadlocks.
Deadlock in Real Time operating Systempptxssuserca5764
This document discusses deadlocks in operating systems. It begins by defining a deadlock as a set of blocked processes each holding a resource and waiting for a resource held by another process. It then covers various methods for handling deadlocks including prevention, avoidance, detection, and recovery. Prevention methods restrain how processes can request resources to ensure deadlocks cannot occur. Avoidance methods allow requests but ensure the system never enters an unsafe state. Detection finds deadlocks after they occur, while recovery rolls back processes or preempts resources to break deadlock cycles.
This document discusses different methods for handling deadlocks in computer systems, including deadlock prevention, avoidance, detection, and recovery. It presents the four conditions required for deadlock, describes resource allocation graphs and how they can indicate deadlock situations. Prevention methods restrain how processes request resources to ensure deadlock cannot occur. Avoidance algorithms like the banker's algorithm dynamically assess the resource allocation state to guarantee a safe state where deadlock is not possible. Detection algorithms search allocation and wait graphs periodically to find any cycles indicating deadlock, and recovery aims to resolve deadlocks when they are detected.
The document discusses the deadlock problem in operating systems. It defines deadlock as a state where a set of blocked processes are each holding resources and waiting for additional resources held by other processes in the set, resulting in none of the processes being able to progress. Four conditions must hold simultaneously for deadlock to occur: mutual exclusion, hold and wait, no preemption, and circular wait. Methods for handling deadlocks include prevention, avoidance, and detection/recovery. The banker's algorithm is presented as a deadlock avoidance strategy that uses a resource allocation graph and ensures the system is always in a safe state where deadlocks cannot occur.
14th November - Deadlock Prevention, Avoidance.pptUnknown664473
This document discusses various techniques for handling deadlocks in operating systems. It begins by defining the deadlock problem and characterizing the conditions required for a deadlock to occur. It then presents different methods for preventing, avoiding, detecting, and recovering from deadlocks, including deadlock prevention, avoidance using safe states and the banker's algorithm, detection using wait-for graphs and the resource allocation graph, and recovery through process termination or resource preemption.
This document discusses different approaches to handling deadlocks in operating systems. It begins by defining deadlocks and providing examples. It then describes four conditions required for deadlock to occur. Various methods for handling deadlocks are discussed, including prevention, avoidance, detection, and recovery. Prevention methods aim to restrict system states that could lead to deadlocks. Avoidance methods dynamically allocate resources to ensure the system cannot reach an unsafe state. Detection methods identify deadlocks after they occur, while recovery rolls back processes or terminates them. A combined approach uses elements of multiple methods.
The document discusses deadlocks in computer systems. It defines deadlocks as when a set of blocked processes each hold a resource and wait for a resource held by another process in the set, creating a circular wait. It presents methods for handling deadlocks including prevention, avoidance, detection, and recovery. Prevention methods restrict how processes can request resources to avoid deadlock conditions. Avoidance methods use additional information to ensure the system never enters an unsafe state allowing deadlocks. Detection finds cycles in a wait-for graph to detect existing deadlocks while recovery schemes deal with detected deadlocks.
The objectives of Deadlocks in Operating Systems are:
- To develop a description of deadlocks, which prevent sets of concurrent processes from completing their tasks
- To present a number of different methods for preventing or avoiding deadlocks in a computer system
This document discusses deadlocks in a multiprogramming system. It defines deadlock as a situation where a set of processes are waiting indefinitely for resources held by each other in a circular chain. Four necessary conditions for deadlock are explained: mutual exclusion, hold and wait, no preemption, and circular wait. Methods for handling deadlocks include prevention, avoidance, detection and recovery. Prevention methods aim to enforce restrictions to ensure at least one condition cannot be met, such as allocating all resources for a process upfront or not allowing processes to hold resources while waiting for others.
Process synchronization ensures systematic sharing of resources among concurrent processes. A race condition occurs when two processes access and modify shared resources without coordination. In a printer spooler example, two processes modify shared variables that point to files to print and available slots, which could result in files being skipped or printed multiple times. The critical section is the part of the program where shared memory is accessed; avoiding race conditions requires no two processes to be in their critical section simultaneously. Deadlocks occur when a set of processes are blocked waiting for resources held by other processes in the set, forming a circular wait. Methods to handle deadlocks include prevention, avoidance, detection, and recovery.
This document discusses various techniques for handling deadlocks in operating systems, including prevention, avoidance, detection, and recovery. Deadlock prevention methods ensure deadlock conditions cannot occur by restricting resource usage. Deadlock avoidance algorithms dynamically examine the resource allocation state to guarantee the system remains in a safe state. Detection algorithms search for resource allocation cycles to identify deadlocks. Recovery methods terminate or roll back processes involved in deadlocks. The document provides examples to illustrate these deadlock handling techniques.
This document discusses deadlocks in computer systems. It defines a deadlock as when two or more processes are waiting for resources held by each other in a circular chain. It describes the four conditions required for a deadlock to occur: mutual exclusion, hold and wait, no preemption, and circular wait. Methods to handle deadlocks include deadlock prevention, avoidance, detection, and recovery. Prevention ensures conditions don't hold, avoidance uses additional process information, detection uses graphs to find cycles indicating deadlocks, and recovery aborts processes or preempts resources.
The document discusses different methods for handling deadlocks in computer systems, including deadlock prevention, avoidance, detection, and recovery. It describes the four necessary conditions for deadlock, and models like the resource allocation graph and banker's algorithm that can be used to prevent or avoid deadlocks by ensuring the system remains in a safe state where deadlocks cannot occur. Detection methods allow the system to enter a deadlocked state before taking action to recover through rollback or preemption.
The Deadlock Problem
System Model
Deadlock Characterization
Methods for Handling Deadlocks
Deadlock Prevention
Deadlock Avoidance
Deadlock Detection
Recovery from Deadlock
The objectives of Deadlocks in Operating Systems are:
- To develop a description of deadlocks, which prevent sets of concurrent processes from completing their tasks
- To present a number of different methods for preventing or avoiding deadlocks in a computer system
This document discusses deadlock prevention and recovery in computer systems. It defines deadlock as when a set of blocked processes each hold a resource and wait for a resource held by another process. The document outlines the system model involving resources and processes. It describes deadlock characterization including conditions like mutual exclusion, hold and wait, no preemption, and circular wait. Methods to handle deadlocks include prevention techniques like avoiding one of the four conditions, detection of deadlocks in a resource allocation graph, and recovery methods like process termination or resource preemption.
This document discusses deadlock prevention and recovery in computer systems. It begins by defining deadlock and describing the conditions required for deadlock to occur. It then presents a system model and characterizes deadlocks using resource allocation graphs. The document outlines four main methods for handling deadlocks: prevention, avoidance, detection, and recovery. It focuses on prevention, describing four different approaches to ensure at least one deadlock condition does not hold: eliminating mutual exclusion, hold and wait, no preemption, or circular wait. The document also briefly discusses deadlock detection and two recovery methods: process termination and resource preemption.
This document discusses deadlocks in computer systems. It begins by defining a deadlock as a state where a set of blocked processes are each holding resources and waiting for resources held by others in a cyclic manner. It then presents methods for handling deadlocks, including prevention, avoidance, and detection and recovery. For avoidance, it describes using a resource allocation graph to model processes and resources, and the banker's algorithm to ensure the system is always in a safe state where deadlocks cannot occur.
OS - Unit 3 Deadlock (Bankers Algorithm).pptxGovindJha93
Here is the solution to the Bankers Algorithm example 3:
A) The content of the Need matrix will be:
Process | A | B | C
P0 | 3 | 1 | 3
P1 | 2 | 4 | 2
P2 | 7 | 4 | 5
P3 | 8 | 4 | 6
P4 | 8 | 5 | 5
B) The system is not in a safe state. The available resources (3, 3, 2) are not sufficient to fulfill the need of process P2 (7, 4, 5).
C) If process P1 requests one more instance of resource A and two instances of resource C, the request can be granted as
This document summarizes principles of deadlock and concurrency mechanisms in operating systems. It discusses deadlock prevention, avoidance, detection and integrated strategies. The dining philosophers problem is presented as an example. Concurrency mechanisms in UNIX, Linux, Solaris and Windows are also summarized, including pipes, messages, shared memory, semaphores, signals, atomic operations, spinlocks, mutex locks, condition variables, and wait functions.
Deadlock occurs when multiple processes are waiting for resources held by other processes in the set, resulting in a cyclic wait. There are three main approaches to dealing with deadlock: prevention, avoidance, and detection/recovery. Prevention methods deny one of the necessary conditions for deadlock. Avoidance methods allocate resources in a way that guarantees safe allocation. Detection methods allow deadlock to occur but use resource graphs and reducibility to detect cycles and recover by killing processes or preempting resources. The Banker's Algorithm uses resource allocation tables to determine safe states for avoidance.
The document discusses different methods for handling deadlocks in a system. It describes deadlock characterization including the necessary conditions for deadlock, using a resource-allocation graph to model deadlocks, and examples of such graphs. It also explains several methods for handling deadlocks including deadlock prevention, avoidance, and detection and recovery. Deadlock prevention methods aim to enforce constraints to ensure the necessary conditions for deadlock cannot occur. Deadlock avoidance uses additional information to dynamically monitor the system state and ensure it remains in a safe state where deadlocks cannot happen.
The objectives of Deadlocks in Operating Systems are:
- To develop a description of deadlocks, which prevent sets of concurrent processes from completing their tasks
- To present a number of different methods for preventing or avoiding deadlocks in a computer system
Batteries -Introduction – Types of Batteries – discharging and charging of battery - characteristics of battery –battery rating- various tests on battery- – Primary battery: silver button cell- Secondary battery :Ni-Cd battery-modern battery: lithium ion battery-maintenance of batteries-choices of batteries for electric vehicle applications.
Fuel Cells: Introduction- importance and classification of fuel cells - description, principle, components, applications of fuel cells: H2-O2 fuel cell, alkaline fuel cell, molten carbonate fuel cell and direct methanol fuel cells.
This document discusses different approaches to handling deadlocks in operating systems. It begins by defining deadlocks and providing examples. It then describes four conditions required for deadlock to occur. Various methods for handling deadlocks are discussed, including prevention, avoidance, detection, and recovery. Prevention methods aim to restrict system states that could lead to deadlocks. Avoidance methods dynamically allocate resources to ensure the system cannot reach an unsafe state. Detection methods identify deadlocks after they occur, while recovery rolls back processes or terminates them. A combined approach uses elements of multiple methods.
The document discusses deadlocks in computer systems. It defines deadlocks as when a set of blocked processes each hold a resource and wait for a resource held by another process in the set, creating a circular wait. It presents methods for handling deadlocks including prevention, avoidance, detection, and recovery. Prevention methods restrict how processes can request resources to avoid deadlock conditions. Avoidance methods use additional information to ensure the system never enters an unsafe state allowing deadlocks. Detection finds cycles in a wait-for graph to detect existing deadlocks while recovery schemes deal with detected deadlocks.
The objectives of Deadlocks in Operating Systems are:
- To develop a description of deadlocks, which prevent sets of concurrent processes from completing their tasks
- To present a number of different methods for preventing or avoiding deadlocks in a computer system
This document discusses deadlocks in a multiprogramming system. It defines deadlock as a situation where a set of processes are waiting indefinitely for resources held by each other in a circular chain. Four necessary conditions for deadlock are explained: mutual exclusion, hold and wait, no preemption, and circular wait. Methods for handling deadlocks include prevention, avoidance, detection and recovery. Prevention methods aim to enforce restrictions to ensure at least one condition cannot be met, such as allocating all resources for a process upfront or not allowing processes to hold resources while waiting for others.
Process synchronization ensures systematic sharing of resources among concurrent processes. A race condition occurs when two processes access and modify shared resources without coordination. In a printer spooler example, two processes modify shared variables that point to files to print and available slots, which could result in files being skipped or printed multiple times. The critical section is the part of the program where shared memory is accessed; avoiding race conditions requires no two processes to be in their critical section simultaneously. Deadlocks occur when a set of processes are blocked waiting for resources held by other processes in the set, forming a circular wait. Methods to handle deadlocks include prevention, avoidance, detection, and recovery.
This document discusses various techniques for handling deadlocks in operating systems, including prevention, avoidance, detection, and recovery. Deadlock prevention methods ensure deadlock conditions cannot occur by restricting resource usage. Deadlock avoidance algorithms dynamically examine the resource allocation state to guarantee the system remains in a safe state. Detection algorithms search for resource allocation cycles to identify deadlocks. Recovery methods terminate or roll back processes involved in deadlocks. The document provides examples to illustrate these deadlock handling techniques.
This document discusses deadlocks in computer systems. It defines a deadlock as when two or more processes are waiting for resources held by each other in a circular chain. It describes the four conditions required for a deadlock to occur: mutual exclusion, hold and wait, no preemption, and circular wait. Methods to handle deadlocks include deadlock prevention, avoidance, detection, and recovery. Prevention ensures conditions don't hold, avoidance uses additional process information, detection uses graphs to find cycles indicating deadlocks, and recovery aborts processes or preempts resources.
The document discusses different methods for handling deadlocks in computer systems, including deadlock prevention, avoidance, detection, and recovery. It describes the four necessary conditions for deadlock, and models like the resource allocation graph and banker's algorithm that can be used to prevent or avoid deadlocks by ensuring the system remains in a safe state where deadlocks cannot occur. Detection methods allow the system to enter a deadlocked state before taking action to recover through rollback or preemption.
The Deadlock Problem
System Model
Deadlock Characterization
Methods for Handling Deadlocks
Deadlock Prevention
Deadlock Avoidance
Deadlock Detection
Recovery from Deadlock
The objectives of Deadlocks in Operating Systems are:
- To develop a description of deadlocks, which prevent sets of concurrent processes from completing their tasks
- To present a number of different methods for preventing or avoiding deadlocks in a computer system
This document discusses deadlock prevention and recovery in computer systems. It defines deadlock as when a set of blocked processes each hold a resource and wait for a resource held by another process. The document outlines the system model involving resources and processes. It describes deadlock characterization including conditions like mutual exclusion, hold and wait, no preemption, and circular wait. Methods to handle deadlocks include prevention techniques like avoiding one of the four conditions, detection of deadlocks in a resource allocation graph, and recovery methods like process termination or resource preemption.
This document discusses deadlock prevention and recovery in computer systems. It begins by defining deadlock and describing the conditions required for deadlock to occur. It then presents a system model and characterizes deadlocks using resource allocation graphs. The document outlines four main methods for handling deadlocks: prevention, avoidance, detection, and recovery. It focuses on prevention, describing four different approaches to ensure at least one deadlock condition does not hold: eliminating mutual exclusion, hold and wait, no preemption, or circular wait. The document also briefly discusses deadlock detection and two recovery methods: process termination and resource preemption.
This document discusses deadlocks in computer systems. It begins by defining a deadlock as a state where a set of blocked processes are each holding resources and waiting for resources held by others in a cyclic manner. It then presents methods for handling deadlocks, including prevention, avoidance, and detection and recovery. For avoidance, it describes using a resource allocation graph to model processes and resources, and the banker's algorithm to ensure the system is always in a safe state where deadlocks cannot occur.
OS - Unit 3 Deadlock (Bankers Algorithm).pptxGovindJha93
Here is the solution to the Bankers Algorithm example 3:
A) The content of the Need matrix will be:
Process | A | B | C
P0 | 3 | 1 | 3
P1 | 2 | 4 | 2
P2 | 7 | 4 | 5
P3 | 8 | 4 | 6
P4 | 8 | 5 | 5
B) The system is not in a safe state. The available resources (3, 3, 2) are not sufficient to fulfill the need of process P2 (7, 4, 5).
C) If process P1 requests one more instance of resource A and two instances of resource C, the request can be granted as
This document summarizes principles of deadlock and concurrency mechanisms in operating systems. It discusses deadlock prevention, avoidance, detection and integrated strategies. The dining philosophers problem is presented as an example. Concurrency mechanisms in UNIX, Linux, Solaris and Windows are also summarized, including pipes, messages, shared memory, semaphores, signals, atomic operations, spinlocks, mutex locks, condition variables, and wait functions.
Deadlock occurs when multiple processes are waiting for resources held by other processes in the set, resulting in a cyclic wait. There are three main approaches to dealing with deadlock: prevention, avoidance, and detection/recovery. Prevention methods deny one of the necessary conditions for deadlock. Avoidance methods allocate resources in a way that guarantees safe allocation. Detection methods allow deadlock to occur but use resource graphs and reducibility to detect cycles and recover by killing processes or preempting resources. The Banker's Algorithm uses resource allocation tables to determine safe states for avoidance.
The document discusses different methods for handling deadlocks in a system. It describes deadlock characterization including the necessary conditions for deadlock, using a resource-allocation graph to model deadlocks, and examples of such graphs. It also explains several methods for handling deadlocks including deadlock prevention, avoidance, and detection and recovery. Deadlock prevention methods aim to enforce constraints to ensure the necessary conditions for deadlock cannot occur. Deadlock avoidance uses additional information to dynamically monitor the system state and ensure it remains in a safe state where deadlocks cannot happen.
The objectives of Deadlocks in Operating Systems are:
- To develop a description of deadlocks, which prevent sets of concurrent processes from completing their tasks
- To present a number of different methods for preventing or avoiding deadlocks in a computer system
Batteries -Introduction – Types of Batteries – discharging and charging of battery - characteristics of battery –battery rating- various tests on battery- – Primary battery: silver button cell- Secondary battery :Ni-Cd battery-modern battery: lithium ion battery-maintenance of batteries-choices of batteries for electric vehicle applications.
Fuel Cells: Introduction- importance and classification of fuel cells - description, principle, components, applications of fuel cells: H2-O2 fuel cell, alkaline fuel cell, molten carbonate fuel cell and direct methanol fuel cells.
Optimizing Gradle Builds - Gradle DPE Tour Berlin 2024Sinan KOZAK
Sinan from the Delivery Hero mobile infrastructure engineering team shares a deep dive into performance acceleration with Gradle build cache optimizations. Sinan shares their journey into solving complex build-cache problems that affect Gradle builds. By understanding the challenges and solutions found in our journey, we aim to demonstrate the possibilities for faster builds. The case study reveals how overlapping outputs and cache misconfigurations led to significant increases in build times, especially as the project scaled up with numerous modules using Paparazzi tests. The journey from diagnosing to defeating cache issues offers invaluable lessons on maintaining cache integrity without sacrificing functionality.
Redefining brain tumor segmentation: a cutting-edge convolutional neural netw...IJECEIAES
Medical image analysis has witnessed significant advancements with deep learning techniques. In the domain of brain tumor segmentation, the ability to
precisely delineate tumor boundaries from magnetic resonance imaging (MRI)
scans holds profound implications for diagnosis. This study presents an ensemble convolutional neural network (CNN) with transfer learning, integrating
the state-of-the-art Deeplabv3+ architecture with the ResNet18 backbone. The
model is rigorously trained and evaluated, exhibiting remarkable performance
metrics, including an impressive global accuracy of 99.286%, a high-class accuracy of 82.191%, a mean intersection over union (IoU) of 79.900%, a weighted
IoU of 98.620%, and a Boundary F1 (BF) score of 83.303%. Notably, a detailed comparative analysis with existing methods showcases the superiority of
our proposed model. These findings underscore the model’s competence in precise brain tumor localization, underscoring its potential to revolutionize medical
image analysis and enhance healthcare outcomes. This research paves the way
for future exploration and optimization of advanced CNN models in medical
imaging, emphasizing addressing false positives and resource efficiency.
CHINA’S GEO-ECONOMIC OUTREACH IN CENTRAL ASIAN COUNTRIES AND FUTURE PROSPECTjpsjournal1
The rivalry between prominent international actors for dominance over Central Asia's hydrocarbon
reserves and the ancient silk trade route, along with China's diplomatic endeavours in the area, has been
referred to as the "New Great Game." This research centres on the power struggle, considering
geopolitical, geostrategic, and geoeconomic variables. Topics including trade, political hegemony, oil
politics, and conventional and nontraditional security are all explored and explained by the researcher.
Using Mackinder's Heartland, Spykman Rimland, and Hegemonic Stability theories, examines China's role
in Central Asia. This study adheres to the empirical epistemological method and has taken care of
objectivity. This study analyze primary and secondary research documents critically to elaborate role of
china’s geo economic outreach in central Asian countries and its future prospect. China is thriving in trade,
pipeline politics, and winning states, according to this study, thanks to important instruments like the
Shanghai Cooperation Organisation and the Belt and Road Economic Initiative. According to this study,
China is seeing significant success in commerce, pipeline politics, and gaining influence on other
governments. This success may be attributed to the effective utilisation of key tools such as the Shanghai
Cooperation Organisation and the Belt and Road Economic Initiative.
Literature Review Basics and Understanding Reference Management.pptxDr Ramhari Poudyal
Three-day training on academic research focuses on analytical tools at United Technical College, supported by the University Grant Commission, Nepal. 24-26 May 2024
Use PyCharm for remote debugging of WSL on a Windo cf5c162d672e4e58b4dde5d797...shadow0702a
This document serves as a comprehensive step-by-step guide on how to effectively use PyCharm for remote debugging of the Windows Subsystem for Linux (WSL) on a local Windows machine. It meticulously outlines several critical steps in the process, starting with the crucial task of enabling permissions, followed by the installation and configuration of WSL.
The guide then proceeds to explain how to set up the SSH service within the WSL environment, an integral part of the process. Alongside this, it also provides detailed instructions on how to modify the inbound rules of the Windows firewall to facilitate the process, ensuring that there are no connectivity issues that could potentially hinder the debugging process.
The document further emphasizes on the importance of checking the connection between the Windows and WSL environments, providing instructions on how to ensure that the connection is optimal and ready for remote debugging.
It also offers an in-depth guide on how to configure the WSL interpreter and files within the PyCharm environment. This is essential for ensuring that the debugging process is set up correctly and that the program can be run effectively within the WSL terminal.
Additionally, the document provides guidance on how to set up breakpoints for debugging, a fundamental aspect of the debugging process which allows the developer to stop the execution of their code at certain points and inspect their program at those stages.
Finally, the document concludes by providing a link to a reference blog. This blog offers additional information and guidance on configuring the remote Python interpreter in PyCharm, providing the reader with a well-rounded understanding of the process.
KuberTENes Birthday Bash Guadalajara - K8sGPT first impressionsVictor Morales
K8sGPT is a tool that analyzes and diagnoses Kubernetes clusters. This presentation was used to share the requirements and dependencies to deploy K8sGPT in a local environment.
Advanced control scheme of doubly fed induction generator for wind turbine us...IJECEIAES
This paper describes a speed control device for generating electrical energy on an electricity network based on the doubly fed induction generator (DFIG) used for wind power conversion systems. At first, a double-fed induction generator model was constructed. A control law is formulated to govern the flow of energy between the stator of a DFIG and the energy network using three types of controllers: proportional integral (PI), sliding mode controller (SMC) and second order sliding mode controller (SOSMC). Their different results in terms of power reference tracking, reaction to unexpected speed fluctuations, sensitivity to perturbations, and resilience against machine parameter alterations are compared. MATLAB/Simulink was used to conduct the simulations for the preceding study. Multiple simulations have shown very satisfying results, and the investigations demonstrate the efficacy and power-enhancing capabilities of the suggested control system.
Embedded machine learning-based road conditions and driving behavior monitoringIJECEIAES
Car accident rates have increased in recent years, resulting in losses in human lives, properties, and other financial costs. An embedded machine learning-based system is developed to address this critical issue. The system can monitor road conditions, detect driving patterns, and identify aggressive driving behaviors. The system is based on neural networks trained on a comprehensive dataset of driving events, driving styles, and road conditions. The system effectively detects potential risks and helps mitigate the frequency and impact of accidents. The primary goal is to ensure the safety of drivers and vehicles. Collecting data involved gathering information on three key road events: normal street and normal drive, speed bumps, circular yellow speed bumps, and three aggressive driving actions: sudden start, sudden stop, and sudden entry. The gathered data is processed and analyzed using a machine learning system designed for limited power and memory devices. The developed system resulted in 91.9% accuracy, 93.6% precision, and 92% recall. The achieved inference time on an Arduino Nano 33 BLE Sense with a 32-bit CPU running at 64 MHz is 34 ms and requires 2.6 kB peak RAM and 139.9 kB program flash memory, making it suitable for resource-constrained embedded systems.
2. Definitions
• A process is deadlocked if it is waiting for an
event that will never occur.
Typically, more than one process will be involved in a
deadlock (the deadly embrace).
• A process is indefinitely postponed if it is
delayed repeatedly over a long period of time
while the attention of the system is given to
other processes,
• i.e. the process is ready to proceed but never gets the
CPU.
3. The Deadlock Problem
• A set of blocked processes each holding a
resource and waiting to acquire a resource
held by another process in the set
• Example
– System has 2 disk drives
– P1 and P2 each hold one disk drive and each
needs another one
4. Bridge Crossing Example
• Traffic only in one direction
• Each section of a bridge can be viewed as a resource
• If a deadlock occurs, it can be resolved if one car backs up
(preempt resources and rollback)
• Several cars may have to be backed up if a deadlock
occurs
• Starvation is possible
• Note – Most OSes do not prevent or deal with deadlocks
5. Resources
• Resource
• commodity required by a process to execute
• Resources can be of several types
• Serially Reusable Resources
– CPU cycles, memory space, I/O devices, files
– acquire -> use -> release
• Consumable Resources
– Produced by a process, needed by a process - e.g. Messages,
buffers of information, interrupts
– create ->acquire ->use
• Resource ceases to exist after it has been used
• Each process utilizes a resource as follows:
– request
– use
– release
6. Deadlock Characterization
• Mutual exclusion: only one process at a time can use a
resource
• Hold and wait: a process holding at least one resource is
waiting to acquire additional resources held by other
processes
• No preemption: a resource can be released only
voluntarily by the process holding it, after that process has
completed its task
• Circular wait: there exists a set {P0, P1, …, Pn} of waiting
processes such that P0 is waiting for a resource that is held
by P1, P1 is waiting for a resource that is held by
P2, …, Pn–1 is waiting for a resource that is held by Pn, and
Pn is waiting for a resource that is held by P0.
Deadlock can arise if four conditions hold simultaneously.
7. Resource-Allocation Graph
• V is partitioned into two types:
– P = {P1, P2, …, Pn}, the set consisting of all
the processes in the system
– R = {R1, R2, …, Rm}, the set consisting of all
resource types in the system
• request edge – directed edge Pi Rj
• assignment edge – directed edge Rj Pi
A set of vertices V and a set of edges E.
8. Resource-Allocation Graph (Cont.)
• Process
• Resource Type with 4 instances
• Pi requests instance of Rj
• Pi is holding an instance of Rj Pi
Pi
Rj
Rj
11. Basic Facts
• If graph contains no cycles no deadlock
• If graph contains a cycle
– if only one instance per resource type, then
deadlock
– if several instances per resource type,
possibility of deadlock
12. Methods for Handling Deadlocks
• Ensure that the system will never enter a deadlock
state
• Allow the system to enter a deadlock state and
then recover
• Ignore the problem and pretend that deadlocks
never occur in the system; used by most operating
systems, including UNIX
13. Deadlock Management
– Prevention
– Design the system in such a way that deadlocks can never occur
– Avoidance
– Impose less stringent conditions than for prevention, allowing the
possibility of deadlock but sidestepping it as it occurs.
– Detection
– Allow possibility of deadlock, determine if deadlock has occurred and
which processes and resources are involved.
– Recovery
– After detection, clear the problem, allow processes to complete and
resources to be reused. May involve destroying and restarting
processes.
14. Deadlock Prevention
• Mutual Exclusion – not required for sharable
resources; must hold for nonsharable resources
• Hold and Wait – must guarantee that whenever
a process requests a resource, it does not hold
any other resources
– Require process to request and be allocated all its
resources before it begins execution, or allow
process to request resources only when the
process has none
– Low resource utilization; starvation possible
Restrain the ways request can be made
15. Deadlock Prevention (Cont.)
• No Preemption –
– If a process that is holding some resources
requests another resource that cannot be
immediately allocated to it, then all resources
currently being held are released
– Preempted resources are added to the list of
resources for which the process is waiting
– Process will be restarted only when it can regain
its old resources, as well as the new ones that it is
requesting
Circular Wait – impose a total ordering of all
resource types, and require that each process
requests resources in an increasing order of
enumeration
16. Deadlock Avoidance
• Simplest and most useful model requires that each
process declare the maximum number of resources
of each type that it may need
• The deadlock-avoidance algorithm dynamically
examines the resource-allocation state to ensure that
there can never be a circular-wait condition
• Resource-allocation state is defined by the number
of available and allocated resources, and the
maximum demands of the processes
Requires that the system has some additional a priori information
available
17. Safe State
• When a process requests an available resource, system must
decide if immediate allocation leaves the system in a safe state
• System is in safe state if there exists a sequence <P1, P2, …, Pn>
of ALL the processes in the systems such that for each Pi, the
resources that Pi can still request can be satisfied by currently
available resources + resources held by all the Pj, with j < I
• That is:
– If Pi resource needs are not immediately available, then Pi can
wait until all Pj have finished
– When Pj is finished, Pi can obtain needed resources, execute,
return allocated resources, and terminate
– When Pi terminates, Pi +1 can obtain its needed resources, and so
on
18. Basic Facts
• If a system is in safe state no deadlocks
• If a system is in unsafe state possibility
of deadlock
• Avoidance ensure that a system will
never enter an unsafe state.
21. Recovery from Deadlock:
Process Termination
• Abort all deadlocked processes
• Abort one process at a time until the deadlock cycle is
eliminated
• In which order should we choose to abort?
– Priority of the process
– How long process has computed, and how much longer to
completion
– Resources the process has used
– Resources process needs to complete
– How many processes will need to be terminated
– Is process interactive or batch?
22. Recovery from Deadlock:
Resource Preemption
• Selecting a victim – minimize cost
• Rollback – return to some safe state,
restart process for that state
• Starvation – same process may always
be picked as victim, include number of
rollback in cost factor
23. Avoidance algorithms
• Single instance of a resource type
– Use a resource-allocation graph
• Multiple instances of a resource type
– Use the banker’s algorithm
24. Resource-Allocation Graph Scheme
• Claim edge Pi Rj indicated that process Pj may
request resource Rj; represented by a dashed line
• Claim edge converts to request edge when a process
requests a resource
• Request edge converted to an assignment edge when
the resource is allocated to the process
• When a resource is released by a process, assignment
edge reconverts to a claim edge
• Resources must be claimed a priori in the system
27. Resource-Allocation Graph
Algorithm
• Suppose that process Pi requests a
resource Rj
• The request can be granted only if
converting the request edge to an
assignment edge does not result in the
formation of a cycle in the resource
allocation graph
28. Banker’s Algorithm
• Multiple instances
• Each process must a priori claim maximum
use
• When a process requests a resource it may
have to wait
• When a process gets all its resources it must
return them in a finite amount of time
29. Data Structures for the Banker’s Algorithm
• Available: Vector of length m. If available [j] = k,
there are k instances of resource type Rj available
• Max: n x m matrix. If Max [i,j] = k, then process Pi
may request at most k instances of resource type Rj
• Allocation: n x m matrix. If Allocation[i,j] = k then Pi
is currently allocated k instances of Rj
• Need: n x m matrix. If Need[i,j] = k, then Pi may need
k more instances of Rj to complete its task
Need [i,j] = Max[i,j] – Allocation [i,j]
Let n = number of processes, and m = number of resources types.
30. Safety Algorithm
1.Let Work and Finish be vectors of length m
and n, respectively. Initialize:
Work = Available
Finish [i] = false for i = 0, 1, …, n- 1
2.Find an i such that both:
(a) Finish [i] = false
(b) Needi Work
If no such i exists, go to step 4
3. Work = Work + Allocationi
Finish[i] = true
go to step 2
4.If Finish [i] == true for all i, then the system
is in a safe state
31. Resource-Request Algorithm for Process Pi
Request = request vector for process Pi. If Requesti
[j] = k then process Pi wants k instances of resource
type Rj
1. If Requesti Needi go to step 2. Otherwise, raise error
condition, since process has exceeded its maximum
claim
2. If Requesti Available, go to step 3. Otherwise Pi
must wait, since resources are not available
3. Pretend to allocate requested resources to Pi by
modifying the state as follows:
Available = Available – Request;
Allocationi = Allocationi + Requesti;
Needi = Needi – Requesti;
If safe the resources are allocated to Pi
If unsafe Pi must wait, and the old resource-allocation
state is restored
32. Example of Banker’s Algorithm
• 5 processes P0 through P4;
3 resource types:
A (10 instances), B (5instances), and C (7 instances)
Snapshot at time T0:
Allocation Max Available
A B C A B C A B C
P0 0 1 0 7 5 3 3 3 2
P1 2 0 0 3 2 2
P2 3 0 2 9 0 2
P3 2 1 1 2 2 2
P4 0 0 2 4 3 3
33. Example (Cont.)
• The content of the matrix Need is defined to be Max –
Allocation
Need
A B C
P0 7 4 3
P1 1 2 2
P2 6 0 0
P3 0 1 1
P4 4 3 1
• The system is in a safe state since the sequence < P1, P3, P4, P2,
P0> satisfies safety criteria
34. Example: P1 Request (1,0,2)
• Check that Request Available (that is, (1,0,2) (3,3,2)
true
Allocation Need Available
A B C A B C A B C
P0 0 1 0 7 4 3 2 3 0
P1 3 0 2 0 2 0
P2 3 0 2 6 0 0
P3 2 1 1 0 1 1
P4 0 0 2 4 3 1
• Executing safety algorithm shows that sequence < P1,
P3, P4, P0, P2> satisfies safety requirement
• Can request for (3,3,0) by P4 be granted?
• Can request for (0,2,0) by P0 be granted?
35. Single Instance of Each Resource
Type
• Maintain wait-for graph
– Nodes are processes
– Pi Pj if Pi is waiting for Pj
• Periodically invoke an algorithm that
searches for a cycle in the graph. If there is a
cycle, there exists a deadlock
• An algorithm to detect a cycle in a graph
requires an order of n2 operations, where n is
the number of vertices in the graph
37. Several Instances of a Resource Type
• Available: A vector of length m indicates the number
of available resources of each type.
• Allocation: An n x m matrix defines the number of
resources of each type currently allocated to each
process.
• Request: An n x m matrix indicates the current
request of each process. If Request [i][j] = k, then
process Pi is requesting k more instances of resource
type.Rj.
38. Detection Algorithm
1.Let Work and Finish be vectors of length m and
n, respectively Initialize:
(a) Work = Available
(b)For i = 1,2, …, n, if Allocationi 0, then
Finish[i] = false; otherwise, Finish[i] = true
2.Find an index i such that both:
(a)Finish[i] == false
(b)Requesti Work
If no such i exists, go to step 4
39. Detection Algorithm (Cont.)
3. Work = Work + Allocationi
Finish[i] = true
go to step 2
4. If Finish[i] == false, for some i, 1 i n, then the system is in
deadlock state. Moreover, if Finish[i] == false, then Pi is
deadlocked
Algorithm requires an order of O(m x n2) operations to detect
whether the system is in deadlocked state
40. Example of Detection Algorithm
• Five processes P0 through P4; three resource types
A (7 instances), B (2 instances), and C (6 instances)
• Snapshot at time T0:
Allocation Request Available
A B C A B C A B C
P0 0 1 0 0 0 0 0 0 0
P1 2 0 0 2 0 2
P2 3 0 3 0 0 0
P3 2 1 1 1 0 0
P4 0 0 2 0 0 2
• Sequence <P0, P2, P3, P1, P4> will result in Finish[i] = true for all i
41. Example (Cont.)
• P2 requests an additional instance of type C
Request
A B C
P0 0 0 0
P1 2 0 2
P2 0 0 1
P3 1 0 0
P4 0 0 2
• State of system?
– Can reclaim resources held by process P0, but insufficient
resources to fulfill other processes; requests
– Deadlock exists, consisting of processes P1, P2, P3, and P4
42. Detection-Algorithm Usage
• When, and how often, to invoke depends on:
– How often a deadlock is likely to occur?
– How many processes will need to be rolled back?
• one for each disjoint cycle
• If detection algorithm is invoked arbitrarily,
there may be many cycles in the resource
graph and so we would not be able to tell
which of the many deadlocked processes
“caused” the deadlock.