嘿伙计们我的pthreads遇到了一些麻烦。我不断得到一个段错误，我相信当我让我的线程等待时。我希望有人可以看看，看看我哪里出错了。
快速概述应该发生的事情。我正在将文件一次读入缓冲区1000个字符，我应该使用POSIX线程计算其中的行数。我必须通过锁定，解锁，等待和信令来实现它。
#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <unistd.h>
#include <pthread.h>
/**Structs**/
typedef struct BufferElement {
int blockLength;
char block[1050];
} BufferElement;
//Method declarations
void *produce( void* inputFile );
void *consume();
//Global Variables
FILE *inFile;
BufferElement *PCbuffer;
const int BLOCK_SIZE_MAX = 1000;
int lineNum = 0;
pthread_t producer;
pthread_t consumer;
pthread_mutex_t mu = PTHREAD_MUTEX_INITIALIZER;
pthread_cond_t cvFull = PTHREAD_COND_INITIALIZER;
pthread_cond_t cvEmpty = PTHREAD_COND_INITIALIZER;
int main( int argc, char** argv ) {
//Check for correct number of arguements
if ( argc != 2 ) {
fprintf( stderr, "Usage: ./lab7 file\n" );
exit( -1 );
}
//Check to make sure you can open the file for reading
inFile = fopen( argv[1], "r" );
if ( inFile == NULL ) {
printf( "Cannot open %s\n", argv[1] );
exit( -1 );
}
//Initialize the mutex lock
if ( pthread_mutex_init( &mu, NULL ) != 0 ) {
fprintf( stderr, "Can't initialize mutex\n" );
exit( -1 );
}
//Initialize the condition variable for producer
if ( pthread_cond_init( &cvFull, NULL ) != 0 ) {
fprintf( stderr, "Can't initialize condition variable\n" );
exit( -1 );
}
//Initialize the condition variable for consumer
if ( pthread_cond_init( &cvEmpty, NULL ) != 0 ) {
fprintf( stderr, "Can't initialize condition variable\n" );
exit( -1 );
}
//Create the producer thread
if ( pthread_create( &producer, NULL, produce, ( void* ) argv[1] ) != 0 ) {
fprintf( stderr, "Error in creating producer thread\n" );
exit( -1 );
}
//Create the consumer thread
if ( pthread_create( &consumer, NULL, consume, ( void* ) NULL ) != 0 ) {
fprintf( stderr, "Error in creating consumer thread\n" );
exit( -1 );
}
//Join the producer thread
if ( pthread_join( producer, NULL ) != 0 ) {
fprintf( stderr, "Error in thread join" );
exit( -1 );
}
//Join the consumer thread
if ( pthread_join( consumer, NULL ) != 0 ) {
fprintf( stderr, "Error in thread join" );
exit( -1 );
}
//Print out the total number of lines
printf( "\nNumber of lines in file: %d\n", lineNum );
//Close the input file
fclose( inFile );
return 0;
}
/**
* Producer function for the producer-consumer cycle. Takes characters
* and puts them in the buffer
* @return void* nothing
*/
void* produce( void* inputFile ) {
printf("bigmoney\n");
//Declare helper variables
int temp;
char fileChar;
PCbuffer = malloc( sizeof( BufferElement ) ); //Malloc buffer
fileChar = getc( inFile ); //Get first char
//Begin the feeding of the buffer
for( temp = 0; temp != BLOCK_SIZE_MAX; temp++ ) {
//Take the lock and perform tasks
if ( pthread_mutex_lock( &mu ) != 0 ) {
fprintf( stderr, "Error in mutex_lock\n" );
exit( -1 );
}
//Wait for thread
while ( PCbuffer->blockLength == 0 ) {
printf("phil");
if ( pthread_cond_wait( &cvFull, &mu ) != 0 ) {
fprintf( stderr, "Error in cond_wait" );
exit( -1 );
}
}
PCbuffer->block[ temp ] = fileChar;//Adjust block values
fileChar = getc( inFile ); //Get next char
//Now take lock away
if ( pthread_mutex_unlock( &mu ) != 0 ) {
fprintf( stderr, "Error in mutex_unlock\n" );
exit( -1 );
}
//Signal the other thread
if ( pthread_cond_signal( &cvEmpty ) != 0 ) {
fprintf( stderr, "Error in cond_signal" );
exit( -1 );
}
//Break off if we reach the end of the file
if( fileChar == EOF ) break;
}
printf("moms\n");
PCbuffer->blockLength = temp; //Update block length
printf("%d\n", BLOCK_SIZE_MAX);
printf("%d\n", PCbuffer->blockLength);
return 0;
}
/**
* Consumer function for the producer-consumer cycle. Counts number of
* lines in the buffer and increments accordingly
* @return void* nothing
*/
void *consume() {
printf("jerryjackson\n");
//Declare helper variables
char fileChar;
printf( "%d\n", PCbuffer->blockLength );
//Count number of lines in buffer
for( int i = 0; i != PCbuffer->blockLength; i++ ) {
//Obtain the lock and finish tasks
if ( pthread_mutex_lock( &mu ) != 0 ) {
fprintf( stderr, "Error in mutex_lock\n" );
exit( -1 );
}
//Wait for thread
while ( PCbuffer->blockLength == BLOCK_SIZE_MAX ) {
printf("hatcher");
if ( pthread_cond_wait( &cvEmpty, &mu ) != 0 ) {
fprintf( stderr, "Error in cond_wait" );
exit( -1 );
}
}
fileChar = PCbuffer->block[ i ];
//If we are at the end of a line then we know there's another
//line to increment up
if( fileChar == '\n' ) lineNum++;
//Now take lock away
if ( pthread_mutex_unlock( &mu ) != 0 ) {
fprintf( stderr, "Error in mutex_unlock\n" );
exit( -1 );
}
//Signal the other thread
if ( pthread_cond_signal( &cvFull ) != 0 ) {
fprintf( stderr, "Error in cond_signal" );
exit( -1 );
}
}
//Free the malloced memory
//free( PCbuffer );
PCbuffer = NULL;
return 0;
}