Database System Concepts
Database System Concepts
7th Edition
ISBN: 9780078022159
Author: Abraham Silberschatz Professor, Henry F. Korth, S. Sudarshan
Publisher: McGraw-Hill Education
Bartleby Related Questions Icon

Related questions

bartleby

Concept explainers

Question

Write a program that uses UNIX system calls to “ping-pong” a byte between two processes over
a pair of pipes, one for each direction. Measure the program’s performance, in exchanges per
second. 

Transcription for Educational Website:

---

**2. Answer Memory Allocation Question**

```c
void func() {
    int x; // declares an integer on the stack
    ...
}

void func() {
    int *x = (int *) malloc(sizeof(int));
    ...
}

#include <stdlib.h>
...
void *malloc(size_t size);

double *d = (double *) malloc(sizeof(double));

int *x = malloc(10 * sizeof(int));
printf("%d\n", sizeof(x));

int x[10];
printf("%d\n", sizeof(x));
```

*Note: Allocating and freeing memory is fraught with possible errors.*

**Can you explain?**

See text section 14.4 for important caveats.

---

In this example, the focus is on understanding memory allocation in C programming, specifically comparing stack and heap allocation and their implications:

- The first code block shows an integer variable `x` declared on the stack.
- The second block demonstrates dynamic memory allocation using `malloc`, which allocates memory on the heap.
- The importance of including the `<stdlib.h>` library, which provides the `malloc` function, is highlighted.
- An example of allocating memory for a `double` variable using `malloc` is provided.
- The size of dynamically and statically allocated integer arrays is printed, illustrating the difference between stack and heap memory sizes.
- The note highlights that correctly handling memory allocation and deallocation is critical to prevent errors.

For a detailed explanation, refer to text section 14.4.
expand button
Transcribed Image Text:Transcription for Educational Website: --- **2. Answer Memory Allocation Question** ```c void func() { int x; // declares an integer on the stack ... } void func() { int *x = (int *) malloc(sizeof(int)); ... } #include <stdlib.h> ... void *malloc(size_t size); double *d = (double *) malloc(sizeof(double)); int *x = malloc(10 * sizeof(int)); printf("%d\n", sizeof(x)); int x[10]; printf("%d\n", sizeof(x)); ``` *Note: Allocating and freeing memory is fraught with possible errors.* **Can you explain?** See text section 14.4 for important caveats. --- In this example, the focus is on understanding memory allocation in C programming, specifically comparing stack and heap allocation and their implications: - The first code block shows an integer variable `x` declared on the stack. - The second block demonstrates dynamic memory allocation using `malloc`, which allocates memory on the heap. - The importance of including the `<stdlib.h>` library, which provides the `malloc` function, is highlighted. - An example of allocating memory for a `double` variable using `malloc` is provided. - The size of dynamically and statically allocated integer arrays is printed, illustrating the difference between stack and heap memory sizes. - The note highlights that correctly handling memory allocation and deallocation is critical to prevent errors. For a detailed explanation, refer to text section 14.4.
Expert Solution
Check Mark
Knowledge Booster
Background pattern image
Computer Science
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, computer-science and related others by exploring similar questions and additional content below.
Similar questions
Recommended textbooks for you
Text book image
Database System Concepts
Computer Science
ISBN:9780078022159
Author:Abraham Silberschatz Professor, Henry F. Korth, S. Sudarshan
Publisher:McGraw-Hill Education
Text book image
Starting Out with Python (4th Edition)
Computer Science
ISBN:9780134444321
Author:Tony Gaddis
Publisher:PEARSON
Text book image
Digital Fundamentals (11th Edition)
Computer Science
ISBN:9780132737968
Author:Thomas L. Floyd
Publisher:PEARSON
Text book image
C How to Program (8th Edition)
Computer Science
ISBN:9780133976892
Author:Paul J. Deitel, Harvey Deitel
Publisher:PEARSON
Text book image
Database Systems: Design, Implementation, & Manag...
Computer Science
ISBN:9781337627900
Author:Carlos Coronel, Steven Morris
Publisher:Cengage Learning
Text book image
Programmable Logic Controllers
Computer Science
ISBN:9780073373843
Author:Frank D. Petruzella
Publisher:McGraw-Hill Education