RfidResearchGroup/proxmark3
1
1
Fork 0
mirror of https://github.com/RfidResearchGroup/proxmark3.git synced 2025-01-18 22:20:45 +08:00
Code Issues Projects Releases Packages Wiki Activity

Fixed so storeCommand/getCommand are multithread-safe (at least dual-thread). Hopefully. http://www.proxmark.org/forum/viewtopic.php?pid=7400#p7400

Browse source
This commit is contained in:
martin.holst@gmail.com 2013-06-06 18:30:00 +00:00
parent c338502409
commit 1bad971361
1 changed files with 4 additions and 17 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

21
client/cmdmain.c
View file

@ -39,7 +39,7 @@ static UsbCommand cmdBuffer[CMD_BUFFER_SIZE];
//Points to the next empty position to write to
static int cmd_head;//Starts as 0
//Points to the position of the last unread command
static int cmd_tail = -1;//Starts as -1
static int cmd_tail;//Starts as 0
static command_t CommandTable[] =
{
@ -211,7 +211,7 @@ void UsbCommandReceived(UsbCommand *UC)
*/
void storeCommand(UsbCommand *command)
{
if(cmd_head == cmd_tail)
if( ( cmd_head+1) % CMD_BUFFER_SIZE == cmd_tail)
{
//If these two are equal, we're about to overwrite in the
// circular buffer.
@ -221,14 +221,7 @@ void storeCommand(UsbCommand *command)
UsbCommand* destination = &cmdBuffer[cmd_head];
memcpy(destination, command, sizeof(UsbCommand));
//Also, if cmd_tail is still -1 because the buffer was
// previously empty, set it to head
if(cmd_tail < 0) {
cmd_tail = cmd_head;
}
cmd_head++; //increment head
cmd_head %= CMD_BUFFER_SIZE;//wrap around
cmd_head = (cmd_head +1) % CMD_BUFFER_SIZE; //increment head and wrap
}
/**
@ -239,7 +232,7 @@ void storeCommand(UsbCommand *command)
int getCommand(UsbCommand* response)
{
//If head == tail, there's nothing to read, or if we just got initialized
if(cmd_head == cmd_tail || cmd_tail == -1){
if(cmd_head == cmd_tail){
return 0;
}
//Pick out the next unread command
@ -247,12 +240,6 @@ int getCommand(UsbCommand* response)
memcpy(response, last_unread, sizeof(UsbCommand));
//Increment tail - this is a circular buffer, so modulo buffer size
cmd_tail = (cmd_tail +1 ) % CMD_BUFFER_SIZE;
//In order to detect when the buffer overwrites itself, we set the
// tail to -1 whenever it 'catches up' with head : this means the buffer is empty.
// Otherwise, head==tail could mean both: either empty or full.
if(cmd_tail == cmd_head){
cmd_tail = -1 ;
}
return 1;